sábado, 2 de dezembro de 2017

Proteína de planta brasileira pode ajudar no combate ao HIV

Pesquisadores da USP encontram método de identificar e matar as células infectadas sem afetar as saudáveis



Um estudo da USP, em parceria com universidades norte-americanas, conseguiu demonstrar o uso da proteína Pulchellina no combate de células infectadas pelo HIV. O orientador da pesquisa e professor do Instituto de Física de São Carlos (IFSC) da USP, Francisco Eduardo Guimarães, explica que a proteína é tóxica e encontrada na planta trepadeira Abrus pulchellus, nativa do Brasil.
Flor de Abrus pulchellus – Foto: Vinayaraj via Wimedia Commons / CC BY-SA 3.0

Segundo o professor, a proteína não é danosa à saúde quando utilizada em pouca quantidade. No entanto, é possível conectar a Pulchellina a um anticorpo que tem a capacidade de identificar as células infectadas pelo vírus da Aids. Assim, ao entrar na célula infectada, a proteína se desprende do anticorpo e destrói a célula doente. A utilização desse método não afeta as células saudáveis. Para Guimarães, outro mérito da descoberta é conseguir ultrapassar a dificuldade de identificação e acesso das células doentes.

05.09.2017

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quinta-feira, 30 de novembro de 2017

Profa. San Marri Estudos das plantas medicinais

O que é uma flor? (p.01 de 02)

Restauro das nascentes do Rio Xingu

O potencial farmacológico dos produtos naturais

17 de novembro de 2017

José Tadeu Arantes | Agência FAPESP – Quase meio a meio: assim se dividem os medicamentos em relação às fontes de seus princípios ativos. Do total disponível no mercado, 49,6% são compostos sintéticos, geralmente fabricados a partir do petróleo, enquanto 50,4% originam-se de produtos naturais ou derivados. A expressão “produtos naturais ou derivados”, utilizada aqui em sentido lato, denomina moléculas produzidas por plantas, fungos, bactérias e outros organismos; ou moléculas artificialmente modificadas a partir dessas precursoras.

A informação foi dada por Alessandra Estáquio, professora da University of Illinois at Chicago (UIC), durante o 2º Workshop Recent Advances in the Chemistry of Natural Products, evento do programa BIOTA-FAPESP realizado no auditório da Fundação no dia 9 de novembro de 2017.

“É importante, para o desenvolvimento de medicamentos, recorrer às duas opções, ao sintético e ao natural. Os dois caminhos apresentam vantagens e desvantagens. A vantagem dos produtos naturais é que a atividade biológica que eles manifestam resulta de uma evolução de milhões de anos. Outra vantagem é que sua produção constitui um processo mais sustentável”, disse Eustáquio à Agência FAPESP. 

Como lembrou em sua apresentação outra participante do workshop, a professora Sarah O’Connor, do John Innes Centre, de Norwich, Reino Unido, o uso medicinal de plantas remonta ao Período Paleolítico. A possibilidade de modificar a estrutura química das moléculas, de modo a potencializar suas propriedades farmacodinâmicas, faz com que a pesquisa de produtos naturais ou derivados seja agora um campo altamente promissor.

Morfina (analgésica), eritromicina (antibiótica), ciclosporina (imunossupressora), artemisinina (antimalárica) são algumas substâncias com uso consolidado em medicina.

“Em alguns casos, a estrutura encontrada na natureza é utilizada diretamente como medicamento. Exemplo disso é o paclitaxel, um fármaco extraído da casca do teixo (Taxus brevifolia), empregado no tratamento do câncer. Mas a maioria dos compostos naturais necessita de alguma modificação para poder funcionar como medicamento. Alguns precisam ser estabilizados, porque se degradam muito rapidamente. Outros precisam de alterações que favoreçam sua absorção e distribuição no organismo humano. Outros ainda precisam que seu efeito seja potencializado. E assim por diante”, disse Eustáquio.

Mesmo no caso do paclitaxel, para se obter 1 quilo do produto são necessárias, em média, três mil árvores. Daí a necessidade de se recorrer à semissíntese ou à cultura de células vegetais para que o medicamento possa ser disponibilizado em escala comercial.

“Há várias formas de intervenção possíveis. Uma delas é a semissíntese, que consiste em isolar a molécula de interesse e modificá-la parcialmente por meio de processos químicos. Outra forma é reproduzir a estrutura completa por meio de síntese. Uma terceira maneira, mais recente, consiste em modificar os produtores dos compostos por meio de engenharia genética. Em alguns casos, a engenharia genética envolve transferir os genes responsáveis pelo composto de um organismo para outro – por exemplo, de uma planta para uma bactéria ou levedura. A vantagem, no caso, é que as bactérias ou leveduras são mais fáceis de cultivar e crescem mais rapidamente do que as plantas. Por exemplo, um grupo nos Estados Unidos, liderado por Jay Keasling, da University of California, Berkeley, conseguiu transferir os genes precursores da artemisinina para leveduras”, disse Eustáquio.

O grupo liderado pela pesquisadora na UIC trabalha com bactérias, tendo por horizonte o desenvolvimento de compostos antibióticos ou anticancerígenos.

“Nosso objetivo principal é entender como as bactérias sintetizam moléculas que podem ser usadas como antibióticos, quais são os genes envolvidos no processo. Com esse conhecimento, é possível fazer com que as bactérias produzam os compostos em maior quantidade, ou modificar as moléculas para que se tornem fármacos mais eficazes. É uma pesquisa básica, porém com a aplicação em mente”, disse a pesquisadora.

“Com o boom de sequenciamentos de genomas microbianos, ficou claro que o potencial biossintético dos microrganismos é muito maior do que se supunha. Uma bactéria típica, à qual são atribuídos alguns poucos compostos, pode produzir mais de 30, a partir de sua estrutura genômica. Ocorre que a maioria dos genes responsáveis pela biossíntese é silenciada ou não é bem expressa em condições laboratoriais de crescimento. Sabendo que genes são esses e qual é o seu potencial, torna-se possível ativar esses genes e obter os compostos correspondentes”, disse Eustáquio.

Segundo a pesquisadora, a capacidade de prever o potencial biossintético de microrganismos a partir dos sequenciamentos de seus genomas (“de genes a moléculas”) e de quais genes devem codificar para a biossíntese de um produto natural específico (“de moléculas a genes”) tem o potencial de promover grande inovação na fabricação de fármacos.

Falando sobre o workshop à Agência FAPESP, Roberto Berlinck, professor titular do Instituto de Química de São Carlos da Universidade de São Paulo (IQSC-USP), destacou que o evento trouxe pesquisadores dos Estados Unidos e do Reino Unido.

“São pesquisadores envolvidos em estudos na fronteira do conhecimento sobre o metabolismo de plantas e microrganismos, com o objetivo de entender como as moléculas de interesse são formadas e como se pode fazer uso delas para melhorar a qualidade de vida, já que esses compostos são utilizados para desenvolver medicamentos, tanto para humanos quanto para animais, e também em controle biológico na agricultura, substituindo herbicidas, pesticidas e outros”, disse.

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Unesp Notícias | Jornada de Plantas Medicinais

Vitamin D may be key for pregnant women with polycystic ovary syndrome

Study shows women with infertility due to PCOS have a significantly decreased likelihood of successful pregnancy if they are vitamin D deficient

Date: 6, 2017

Source: University of Pennsylvania School of Medicine

Summary:
Vitamin D may play a key role in helping some women seeking treatment for polycystic ovary syndrome (PCOS)-related infertility get pregnant. PCOS is a hormonal disorder affecting 5 to 10 percent of women of reproductive age. Results of the study show women who were Vitamin D deficient when starting fertility treatments were 40 percent less likely to achieve a pregnancy.

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Vitamin D may be simple treatment to enhance burn healing

Date: November 6, 2017

Source: Society for Endocrinology

Summary:
Patients with severe burns who have higher levels of vitamin D recover more successfully than those with lower levels, according to a new study. This study is the first to investigate the role of vitamin D in recovery from burn injury and suggests that vitamin D supplementation may be a simple and cost-effective treatment to enhance burn healing.


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Pimenta Carolina Reaper

Aplicativo Fitobula

Excelente aplicativo do Julino. #aplicativo #fitoterapia

Uma publicação compartilhada por Marcos Roberto Furlan (@quintaisimortais) em

Can cannabinoids be used to treat cancer?

Date: November 6, 2017

Source: Mary Ann Liebert, Inc./Genetic Engineering News

Summary:
When cannabinoids activate signaling pathways in cancer cells they can stimulate a cell death mechanism called apoptosis, unleashing a potent anti-tumor effect.

When cannabinoids activate signaling pathways in cancer cells they can stimulate a cell death mechanism called apoptosis, unleashing a potent anti-tumor effect. Yet cannabinoids, which have also shown strong activity against human tumor tissue grown in animal models, have undergone minimal testing in patients. Their potential use as antitumor drugs and/or to boost the effectiveness of conventional cancer therapies is examined in an article published in The Journal of Alternative and Complementary Medicine (JACM).

In "A Review of the Therapeutic Antitumor Potential of Cannabinoids," scientists present the results of a detailed survey of the medical and scientific literature focused on the effects of cannabinoids on signaling pathways involved in tumor cell proliferation and death. The researchers review the mechanisms of anticancer activity of cannabinoids, discuss the similarities and differences between exogenous (plant-derived) and endogenous cannabinoids, report on the clinical studies conducted to date to assess the anti-tumor effects of these compounds, and consider the possible adjuvant properties of cannabinoids in cancer treatment.

"Although medical cannabis is well-supported in the literature for symptom reduction from cancer treatment or the disease itself, there are many claims that cannabis can treat cancer itself," says Leslie Mendoza Temple, MD, ABOIM, University of Chicago Pritzker School of Medicine and Medical Director, Integrative Medicine Program. "So far, this is based on only a handful of small human studies, anecdote, or laboratory research. This article nicely summarizes some of the work done in the lab for an understanding of cannabis' potential anti-cancer mechanisms, while pointing to the paucity of human trials." Dr. Temple adds, "Federal rescheduling of cannabis is critical so we can study its effects in humans and determine cannabis' direct or indirect effects on cancer cells."

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Materials provided by Mary Ann Liebert, Inc./Genetic Engineering News. Note: Content may be edited for style and length.

Journal Reference:
Višnja Bogdanović, Jasminka Mrdjanović, Ivana Borišev. A Review of the Therapeutic Antitumor Potential of Cannabinoids. The Journal of Alternative and Complementary Medicine, 2017; DOI: 10.1089/acm.2017.0016

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Mary Ann Liebert, Inc./Genetic Engineering News. "Can cannabinoids be used to treat cancer?." ScienceDaily. ScienceDaily, 6 November 2017. <www.sciencedaily.com/releases/2017/11/171106121300.htm>.

Potential long-term negative impact of high protein diets

Research highlights need for better nutritional management in chronic kidney disease

Date: November 7, 2017

Source: University of California - Irvine

Summary:
High protein diets may lead to long-term kidney damage among those suffering from chronic kidney disease, according to new research.

High protein diets may lead to long-term kidney damage among those suffering from chronic chronic kidney disease, according to research led by nephrologist Kamyar Kalantar-Zadeh, MD, MPH, PhD, of the University of California, Irvine.

The review article, "Nutritional Management of Chronic Kidney Disease," was published in the New England Journal of Medicineand examines the role nutrition plays in managing chronic kidney disease, a condition that affects approximately 10 percent of the world's adult population. The article release coincides with the opening of the annual Kidney Week Congress, the world's premier nephrology meeting, in New Orleans, Louisiana.

"The high protein diet that has been used increasingly in recent years to control weight gain and obesity may have deleterious impacts on kidney health in the long term," said Kalantar-Zadeh, director of the Harold Simmons Center of Kidney Disease Research and Epidemiology, and chief of the Division of Nephrology and Hypertension, UC Irvine School of Medicine. Colleague Denis Fouque, MD, PhD of the University Claude Bernard Lyon, France, also contributed to this work.

Chronic kidney disease is defined as evidence of structural or functional renal impairment for three or more months and is generally progressive and irreversible. Applying the potential benefits of nutritional management of the condition have remained underutilized in the U.S. and many other countries, said Kalantar-Zadeh.

"There is an exceptionally high cost and burden of maintenance dialysis therapy and kidney transplantation," he said. "Thus, dietary interventions and nutritional therapy may be increasingly chosen as a management strategy for CKD, helping to increase longevity and delaying the need for the onset of dialysis for millions of people worldwide."

The research also indicates that a low protein, low salt diet may not only slows the progression of CKD as an effective adjunct therapy, but it can also be used for the management of uremia, or high levels of urea and other uremic toxins in the blood, in late-stage or advanced CKD and help patients defer the need to initiate dialysis.

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Materials provided by University of California - Irvine. Note: Content may be edited for style and length.

Journal Reference:
Kamyar Kalantar-Zadeh, Denis Fouque. Nutritional Management of Chronic Kidney Disease. New England Journal of Medicine, 2017; 377 (18): 1765 DOI: 10.1056/NEJMra1700312

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University of California - Irvine. "Potential long-term negative impact of high protein diets: Research highlights need for better nutritional management in chronic kidney disease." ScienceDaily. ScienceDaily, 7 November 2017. <www.sciencedaily.com/releases/2017/11/171107113225.htm>.

Traditional Amazonian drug linked to improved sense of wellbeing, study suggests

Date: November 9, 2017

Source: University of Exeter

Summary:
A psychedelic drug traditionally used in South America improves people's general sense of wellbeing and may offer a treatment for alcoholism and depression, new research suggests.
Ayahuasca is a blend of the Psychotria viridis bush and the stems of the Banisteriopsis Caapi vine.
Credit: Rafael Guimarães dos Santos

A psychedelic drug traditionally used in South America improves people's general sense of wellbeing and may offer a treatment for alcoholism and depression, new research suggests.

Ayahuasca, a psychedelic brew often used in the Amazon region, contains dimethyltryptamine (DMT) -- an illegal class A drug in the UK.

Previous research has suggested that psychedelic drugs such as LSD and magic mushrooms can help alcoholics tackle their addiction.

Using Global Drug Survey data from more than 96,000 people worldwide, researchers from the University of Exeter and University College London found that ayahuasca users reported lower problematic alcohol use than people who took LSD or magic mushrooms.

Ayahuasca users also reported higher general wellbeing over the previous 12 months than other respondents in the survey.

"These findings lend some support to the notion that ayahuasca could be an important and powerful tool in treating depression and alcohol use disorders," said lead author Dr Will Lawn, of University College London.

"Recent research has demonstrated ayahuasca's potential as a psychiatric medicine, and our current study provides further evidence that it may be a safe and promising treatment.

"It is important to note that these data are purely observational and do not demonstrate causality.

"Moreover, ayahuasca users in this survey still had an average drinking level which would be considered hazardous. Therefore, randomised controlled trials must be carried out to fully examine ayahuasca's ability to help treat mood and addiction disorders.

"However, this study is notable because it is, to the best of our knowledge, the largest survey of ayahuasca users completed to date."

Ayahuasca -- a blend of the Psychotria viridis bush and the stems of the Banisteriopsis caapi vine -- is used by indigenous tribes and religious groups in the Amazon region, as well as many visitors.

The online survey, which was promoted via social media, measured wellbeing using the Personal Wellbeing Index -- a tool used by researchers around the world which asks about things such as personal relationships, connection with the community and a sense of achievement.

Of the respondents, 527 were ayahuasca users, 18,138 used LSD or magic mushrooms and 78,236 did not take psychedelic drugs.

Senior author Professor Celia Morgan, of the University of Exeter, said: "If ayahuasca is to represent an important treatment, it is critical that its short and long-term effects are investigated, and safety established.

"Several observational studies have examined the long-term effects of regular ayahuasca use in the religious context.

"In this work, long-term ayahuasca use has not been found to impact on cognitive ability, produce addiction or worsen mental health problems.

"In fact, some of these observational studies suggest that ayahuasca use is associated with less problematic alcohol and drug use, and better mental health and cognitive functioning."

However, the survey data showed a higher incidence of lifetime mental illness diagnoses within the ayahuasca users. Subsequent analyses found that these were confined to users from countries without a tradition of ayahuasca use.

The researchers said future studies should examine the relationships between ayahuasca use, mental health, wellbeing and problematic alcohol and substance use among these people.

The survey also asked people about the experiences of ayahuasca, and most users said they took the drug with a healer or a shaman.

Ayahuasca was rated as less pleasant and with less of an urge to use more of it than LSD or magic mushrooms. Its acute effects usually lasted for six hours, and were most strongly felt one hour after consumption.

The paper, published in the Nature journal Scientific Reports, is entitled: "Well-being, problematic alcohol consumption and acute subjective drug effects in past-year ayahuasca users: a large, international, self-selecting online survey."

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Materials provided by University of Exeter. Note: Content may be edited for style and length.

Journal Reference:
Will Lawn, Jaime E. Hallak, Jose A. Crippa, Rafael Dos Santos, Lilla Porffy, Monica J. Barratt, Jason A. Ferris, Adam R. Winstock, Celia J. A. Morgan. Well-being, problematic alcohol consumption and acute subjective drug effects in past-year ayahuasca users: a large, international, self-selecting online survey. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-14700-6

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University of Exeter. "Traditional Amazonian drug linked to improved sense of wellbeing, study suggests." ScienceDaily. ScienceDaily, 9 November 2017. <www.sciencedaily.com/releases/2017/11/171109093134.htm>.

Mushrooms are full of antioxidants that may have antiaging potential

Date: November 9, 2017

Source: Penn State

Summary:
Mushrooms may contain unusually high amounts of two antioxidants that some scientists suggest could help fight aging and bolster health, according to a team of researchers.
Robert Beelman is Professor Emeritus of Food Science at Penn State and Director of the Center for Plant and Mushroom Foods for Health.
Credit: Patrick Mansell

Mushrooms may contain unusually high amounts of two antioxidants that some scientists suggest could help fight aging and bolster health, according to a team of Penn State researchers.

In a study, researchers found that mushrooms have high amounts of the ergothioneine and glutathione, both important antioxidants, said Robert Beelman, professor emeritus of food science and director of the Penn State Center for Plant and Mushroom Products for Health. He added that the researchers also found that the amounts the two compounds varied greatly between mushroom species.

"What we found is that, without a doubt, mushrooms are highest dietary source of these two antioxidants taken together, and that some types are really packed with both of them," said Beelman.

Beelman said that when the body uses food to produce energy, it also causes oxidative stress because some free radicals are produced. Free radicals are oxygen atoms with unpaired electrons that cause damage to cells, proteins and even DNA as these highly reactive atoms travel through the body seeking to pair up with other electrons.

Replenishing antioxidants in the body, then, may help protect against this oxidative stress.

"There's a theory -- the free radical theory of aging -- that's been around for a long time that says when we oxidize our food to produce energy there's a number of free radicals that are produced that are side products of that action and many of these are quite toxic," said Beelman. "The body has mechanisms to control most of them, including ergothioneine and glutathione, but eventually enough accrue to cause damage, which has been associated with many of the diseases of aging, like cancer, coronary heart disease and Alzheimer's."

According to the researchers, who report their findings in a recent issue of Food Chemistry, the amounts of ergothioneine and glutathione in mushrooms vary by species with the porcini species, a wild variety, containing the highest amount of the two compounds among the 13 species tested.

"We found that the porcini has the highest, by far, of any we tested," said Beelman. "This species is really popular in Italy where searching for it has become a national pastime."

The more common mushroom types, like the white button, had less of the antioxidants, but had higher amounts than most other foods, Beelman said.

The amount of ergothioneine and glutathione also appear to be correlated in mushrooms, the researchers said. Mushrooms that are high in glutathione are also high in ergothioneine, for example.

Cooking mushrooms does not seem to significantly affect the compounds, Beelman said.

"Ergothioneine are very heat stable," said Beelman.

Beelman said that future research may look at any role that ergothioneine and glutathione have in decreasing the likelihood of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease.

"It's preliminary, but you can see that countries that have more ergothioneine in their diets, countries like France and Italy, also have lower incidents of neurodegenerative diseases, while people in countries like the United States, which has low amounts of ergothioneine in the diet, have a higher probability of diseases like Parkinson's Disease and Alzheimer's," said Beelman. "Now, whether that's just a correlation or causative, we don't know. But, it's something to look into, especially because the difference between the countries with low rates of neurodegenerative diseases is about 3 milligrams per day, which is about five button mushrooms each day."

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Materials provided by Penn State. Note: Content may be edited for style and length.

Journal Reference:
Michael D. Kalaras, John P. Richie, Ana Calcagnotto, Robert B. Beelman. Mushrooms: A rich source of the antioxidants ergothioneine and glutathione. Food Chemistry, 2017; 233: 429 DOI: 10.1016/j.foodchem.2017.04.109

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Penn State. "Mushrooms are full of antioxidants that may have antiaging potential." ScienceDaily. ScienceDaily, 9 November 2017. <www.sciencedaily.com/releases/2017/11/171109100409.htm>.

Study reveals how a very low calorie diet can reverse type 2 diabetes

Date: November 9, 2017

Source: Yale University

Summary:
A research team has uncovered how a very low calorie diet can rapidly reverse type 2 diabetes in animal models. If confirmed in people, the insight provides potential new drug targets for treating this common chronic disease, said the researchers.
A very low calorie diet can rapidly reverse type 2 diabetes in animal models, report scientists.
Credit: © Denis Pepin / Fotolia

In a new study, a Yale-led research team uncovers how a very low calorie diet can rapidly reverse type 2 diabetes in animal models. If confirmed in people, the insight provides potential new drug targets for treating this common chronic disease, said the researchers.

The study is published in Cell Metabolism.

One in three Americans will develop type 2 diabetes by 2050, according to recent projections by the Center for Disease Control and Prevention. Reports indicate that the disease goes into remission in many patients who undergo bariatric weight-loss surgery, which significantly restricts caloric intake prior to clinically significant weight loss. The Yale-led team's study focused on understanding the mechanisms by which caloric restriction rapidly reverses type 2 diabetes.

The research team investigated the effects of a very low calorie diet (VLCD), consisting of one-quarter the normal intake, on a rodent model of type 2 diabetes. Using a novel stable (naturally occurring) isotope approach, which they developed, the researchers tracked and calculated a number of metabolic processes that contribute to the increased glucose production by the liver. The method, known as PINTA, allowed the investigators to perform a comprehensive set of analyses of key metabolic fluxes within the liver that might contribute to insulin resistance and increased rates of glucose production by the liver -- two key processes that cause increased blood-sugar concentrations in diabetes.

Using this approach the researchers pinpointed three major mechanisms responsible for the VLCD's dramatic effect of rapidly lowering blood glucose concentrations in the diabetic animals. In the liver, the VLCD lowers glucose production by: 1) decreasing the conversion of lactate and amino acids into glucose; 2) decreasing the rate of liver glycogen conversion to glucose; and 3) decreasing fat content, which in turn improves the liver's response to insulin. These positive effects of the VLCD were observed in just three days.

"Using this approach to comprehensively interrogate liver carbohydrate and fat metabolism, we showed that it is a combination of three mechanisms that is responsible for the rapid reversal of hyperglycemia following a very low calorie diet," said senior author Gerald I. Shulman, M.D., the George R. Cowgill Professor of Medicine and Cellular and Molecular Physiology and an investigator at the Howard Hughes Medical Institute.

The next step for the researchers will be to confirm whether the findings can be replicated in type 2 diabetic patients undergoing either bariatric surgery or consuming very low calorie diets. His team has already begun applying the PINTA methodology in humans.

"These results, if confirmed in humans, will provide us with novel drug targets to more effectively treat patients with type 2 diabetes," Shulman said.

Story Source:

Materialsprovided by Yale University. Original written by Ziba Kashef. Note: Content may be edited for style and length.

Journal Reference:
Rachel J. Perry, Liang Peng, Gary W. Cline, Yongliang Wang, Aviva Rabin-Court, Joongyu D. Song, Dongyan Zhang, Xian-Man Zhang, Yuichi Nozaki, Sylvie Dufour, Kitt Falk Petersen, Gerald I. Shulman. Mechanisms by which a Very-Low-Calorie Diet Reverses Hyperglycemia in a Rat Model of Type 2 Diabetes. Cell Metabolism, November 2017 DOI: 10.1016/j.cmet.2017.10.004

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Yale University. "Study reveals how a very low calorie diet can reverse type 2 diabetes." ScienceDaily. ScienceDaily, 9 November 2017. <www.sciencedaily.com/releases/2017/11/171109131240.htm>.

Consumption of antioxidant-rich foods is associated with a lower risk of type 2 diabetes, study shows

Date: November 9, 2017

Source: Diabetologia

Summary:
A lower risk of type 2 diabetes has been observed among individuals consuming food rich in antioxidants. This effect is largely contributed by fruit, vegetables, tea and other hot beverages, as well as moderate consumption of alcohol, as shown in a recent study.

A lower risk of type 2 diabetes has been observed among individuals consuming food rich in antioxidants. This effect is largely contributed by fruit, vegetables, tea and other hot beverages, as well as moderate consumption of alcohol, as shown in a recent study from an Inserm research group, published in Diabetologia, the journal of the European Association for the Study of Diabetes (EASD)

A diet rich in fruit and vegetables has previously been associated with a lower risk of certain cancers and cardiovascular conditions. An Inserm team (Health across generations, Center of Research in Epidemiology and Population Health, Villejuif, France) has now shown that such a diet is similarly associated with a reduced risk of type 2 diabetes.

The team already suspected there might be a link on the basis of previous studies showing that certain antioxidants, such as vitamins C and E, lycophenes or flavonoids, were associated with a reduction in type 2 diabetes risk. However, these studies looked only at isolated nutrients, not at the total antioxidant capacity of the diet. The researchers therefore wanted to verify whether overall diet, according to its antioxidant capacity, is associated with diabetes risk. Using data from the E3N cohort comprising French women recruited from 1990, then aged between 40 and 65 years, they followed 64,223 women from 1993 to 2008, all of whom were free from diabetes and cardiovascular disease at the time of inclusion in the study. Each participant completed a dietary questionnaire at the beginning of the study, including detailed information on more than 200 different food items. Using this information, together with an Italian database providing the antioxidant capacity of a large number of different foods, the Inserm researchers calculated a score for 'total dietary antioxidant capacity' for each participant. The group then analysed the associations between this score and the risk of diabetes occurrence during the follow-up period.

The results show that diabetes risk diminished with increased antioxidant consumption up to a level of 15 mmol/day, above which the effect reached a plateau. Increasing dietary antioxidants to this level could be achieved through eating antioxidant-rich foods such as dark chocolate, tea, walnuts, prunes, blueberries, strawberries or hazelnuts, to name just a few. Women with the highest antioxidant scores had a reduction in diabetes risk of 27% compared with those with the lowest scores. 'This link persists after taking into account all the other principal diabetes risk factors: smoking, education level, hypertension, high cholesterol levels, family history of diabetes and, above all, BMI, the most important factor', clarifies Francesca Romana Mancini, the first author of this study. The foods and drinks that contributed the most to a high dietary antioxidant score were fruits and vegetables, tea and red wine (consumed in moderate quantities). The authors excluded coffee from the analysis, despite its high antioxidant levels, because the antioxidants in coffee have already been shown to be associated with reduced type 2 diabetes risk, and might therefore mask the effects of antioxidants from other sources.

'This work complements our current knowledge of the effect of isolated foods and nutrients, and provides a more comprehensive view of the relationship between food and type 2 diabetes' explains Guy Fagherazzi, the lead researcher in charge of diabetes research in the E3N study. 'We have shown that an increased intake of antioxidants can contribute to a reduction in diabetes risk'. This now raises the question why: 'We know that these molecules counterbalance the effect of free radicals, which are damaging to cells, but there are likely to be more specific actions in addition to this, for example an effect on the sensitivity of cells to insulin. This will need to be confirmed in future studies', concludes Francesca Romana Mancini.

Story Source:

Materials provided by Diabetologia. Note: Content may be edited for style and length.

Journal Reference:
Francesca Romana Mancini, Aurélie Affret, Courtney Dow, Beverley Balkau, Fabrice Bonnet, Marie-Christine Boutron-Ruault, Guy Fagherazzi. Dietary antioxidant capacity and risk of type 2 diabetes in the large prospective E3N-EPIC cohort. Diabetologia, 2017; DOI: 10.1007/s00125-017-4489-7

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Diabetologia. "Consumption of antioxidant-rich foods is associated with a lower risk of type 2 diabetes, study shows." ScienceDaily. ScienceDaily, 9 November 2017. <www.sciencedaily.com/releases/2017/11/171109224048.htm>.

Omega-6 fatty acids do not promote low-grade inflammation

Date: November 13, 2017

Source: University of Eastern Finland

Summary:
The higher the serum linoleic acid level, the lower the CRP, according to a new study. Linoleic acid is the most common polyunsaturated omega-6 fatty acid.

The higher the serum linoleic acid level, the lower the CRP, according to a new study from the University of Eastern Finland. Linoleic acid is the most common polyunsaturated omega-6 fatty acid. The findings were published in the European Journal of Clinical Nutrition.

It has been speculated that a high intake of omega-6 polyunsaturated fatty acids may increase the risk of several chronic diseases by promoting low-grade inflammation, among other things. The reasoning behind this speculation is that in the human body, linoleic acid is converted into arachidonic acid (also an omega-6 fatty acid) which, in turn, is converted into various inflammation-promoting compounds.

C-reactive protein, or CRP, levels were measured from 1,287 healthy, 42-60 year-old men at the onset of the Kuopio Ischaemic Heart Disease Risk Factor Study in 1984-1989 at the University of Eastern Finland.

The study found that a low serum linoleic acid level was associated with higher serum CRP levels. When the study participants were divided into four groups based on their serum linoleic acid levels, the probability for an elevated CRP was 53% lower in the highest quarter compared to the lowest one. Other serum omega-6 fatty acids, such as arachidonic acid, gamma-linolenic acid or dihomo-y-linolenic acid, were not associated with CRP levels.

This research supports earlier findings. Clinical trials have shown that even a very high intake of linoleic acid does not increase inflammatory responses, nor has a significant impact on arachidonic acid levels. In the human body, linoleic acid is converted into various compounds that alleviate inflammation. It is worth noting that arachidonic acid, too, is converted into inflammation-alleviating compounds, and not just into inflammation-promoting ones. In the light of these facts, it can be concluded that the theory according to which linoleic acid promotes low-grade inflammation by increasing the body's arachidonic acid levels, is too simplified.

Linoleic acid, which is an essential omega-6 fatty acid, has been linked with a lower risk of chronic diseases in which low-grade inflammation is a significant risk factor. Examples of such diseases include cardiovascular diseases and type 2 diabetes. The serum linoleic acid level is mainly determined by a person's diet, and the main sources of linoleic acid are vegetable oils, plant-based spreads, nuts and seeds.

Story Source:

Materials provided by University of Eastern Finland. Note: Content may be edited for style and length.

Journal Reference:
Jyrki K. Virtanen, Jaakko Mursu, Sari Voutilainen, Tomi-Pekka Tuomainen. The associations of serum n-6 polyunsaturated fatty acids with serum C-reactive protein in men: the Kuopio Ischaemic Heart Disease Risk Factor Study. European Journal of Clinical Nutrition, 2017; DOI: 10.1038/s41430-017-0009-6

Cite This Page:
University of Eastern Finland. "Omega-6 fatty acids do not promote low-grade inflammation." ScienceDaily. ScienceDaily, 13 November 2017. <www.sciencedaily.com/releases/2017/11/171113095430.htm>.

Como o Suco de Pomelo ou Toranja pode Afetar os Medicamentos?

08.03.2017
Dr. Julino Soares

Uma das Interações Medicamentosas com alimentos mais conhecidas e grave é com o suco de pomelo ou grape fruit juice (Citrus paradisi [Rutaceae]). O pomelo pode aumentar ou diminuir a absorção de alguns medicamentos na corrente sanguínea, o que pode provocar mais reações adversas medicamentosas ou diminuição dos efeitos terapêuticos; por exemplo, alguns medicamentos para diminuir o colesterol (ex.: sinvastatina), anti-hipertensivos (ex.: nifedipina), ansiolíticos (ex.: buspirona), anti-histamínicos (ex.: fexofenadina) dentre outros.

O efeito do pomelo é de 24 horas e o consumo de um único copo de suco pode rapidamente modificar a biodisponibilidade de diversos medicamentos.

O mecanismo de ação do pomelo é por duas formas: i) inibição do citocromo P-450 (CYP3A4) no intestino delgado, o que possibilita um acúmulo de medicamento no corpo.

Porém, a intensidade desse efeito também vai depender da suscetibilidade de cada paciente, como a quantidade de CYP3A4 presente (baseline) ou; ii) inibição de algumas proteínas transportadoras de alguns fármacos, o que possibilita uma diminuição de fármaco absorvido, e consequentemente, dos efeitos terapêuticos esperados.

Referências

Bailey DG, Malcolm J, Arnold O, Spence JD. Grapefruit juice-drug interactions. Br J Clin Pharmacol. 1998 Aug;46(2):101-10.

FDA. Grapefruit Juice and Medicine May Not Mix. Food and Drug Administration Consumer Update, 2014. Disponível em: https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm292276.htm. Acesso em: 04.03.2017.

Frutas pouco conhecidas têm alto poder anti-inflamatório e antioxidante

02.10.2017
Pesquisa indica que cinco frutas típicas da Mata Atlântica possuem propriedades bioativas



EDIÇÃO DE IMAGEM LUIS PAULO SILVA

As frutas conhecidas como bacupari-mirim, araçá-piranga, cereja-do-rio-grande, grumixama e ubajaí ainda não ganharam fama, nem espaço nos supermercados. Se depender de suas propriedades bioativas, em questão de tempo elas poderão estar não só disputando espaço nas gôndolas como ganhando posição no ranking dos alimentos da moda.

Além dos valores nutricionais, as cinco frutas nativas da Mata Atlântica têm elevadas propriedades antioxidantes e anti-inflamatórias. Foi o que verificou uma pesquisa desenvolvida na Escola Superior de Agricultura Luiz de Queiroz (Esalq) da Universidade de São Paulo (USP) em parceria com a Faculdade de Odontologia de Piracicaba (FOP) da Universidade Estadual de Campinas (Unicamp) e a Universidade de La Frontera, no Chile.

“Não havia muito conhecimento científico sobre as propriedades dessas frutas nativas. Agora, com os resultados do nosso estudo, a ideia é fazer com que elas sejam produzidas por agricultura familiar, ganhem escala e cheguem aos supermercados. Quem sabe elas não se tornam um novo açaí?”, disse Severino Matias Alencar, do Departamento de Agroindústria, Alimentos e Nutrição da Esalq, se referindo ao sucesso comercial da fruta amazônica com grande quantidade de antioxidantes e que hoje tem a polpa exportada pelo Brasil para vários países.
Os professores Severino Matias de Alencar (à esq.), da Esalq, e Pedro Luiz Rosalen, da FOP-Unicamp

O trabalho, com apoio da FAPESP, teve resultados publicados na revista PLOS ONE.

No estudo foram avaliados os compostos fenólicos – estruturas químicas que podem ter efeitos preventivos ou curativos – e os mecanismos anti-inflamatórios e antioxidantes do extrato de folhas, sementes e polpa de quatro frutas do gênero Eugenia e uma do gênero Garcinia: araçá-piranga (E. leitonii), cereja-do-rio-grande (E. involucrata), grumixama (E. brasiliensis), ubajaí (E. myrcianthes) e bacupari-mirim (Garcinia brasiliensis), todas típicas da Mata Atlântica.

Como elas são espécies difíceis de serem encontradas e algumas estão em risco de extinção, as plantas foram fornecidas por dois sítios localizados no interior de São Paulo. As duas propriedades comercializam as plantas com o objetivo de preservação da coleção. Um dos produtores possui a maior coleção de frutas nativas do Brasil, somando mais de 1,3 mil espécies plantadas.

“Começamos nosso estudo prospectando as propriedades bioativas das frutas, pois sabíamos que elas poderiam ter boa quantidade de antioxidantes, assim como são as chamadas ‘berries’ americanas, como o mirtilo, a amora e o próprio morango, muito conhecidas pela ciência. Mas nossas frutas nativas se mostraram ainda melhores”, disse Alencar.

De acordo com o estudo, as espécies do gênero Eugenia têm um vasto potencial econômico e farmacológico evidenciado não só pelo número de publicações científicas, mas também pela exploração comercial de suas frutas comestíveis, madeira, óleos essenciais e uso como plantas ornamentais.

Elas são exemplos de alimentos funcionais, que, além das vitaminas e valores nutricionais, têm propriedades bioativas como o combate aos radicais livres – átomos instáveis e altamente reativos no organismo que se ligam a outros átomos, provocando danos como envelhecimento celular ou doenças.

“O organismo tem naturalmente antirradicais livres, que neutralizam e eliminam os radicais livres do corpo, sem causar dano. Porém, fatores como idade, estresse e alimentação podem promover um desequilíbrio nessa neutralização natural. Nesses casos, é preciso contar com elementos exógenos, ingerindo alimentos que tenham agentes antioxidantes como os flavonoides, as antocianinas do araçá-piranga e das outras frutas do gênero Eugenia”, disse Pedro Rosalen, da Faculdade de Odontologia da Unicamp em Piracicaba.

O pesquisador ressalta que há cerca de 400 espécies pertencentes ao gênero Eugenia distribuídas pelo Brasil, incluindo várias espécies endêmicas. “Temos uma imensidão de frutas nativas com compostos bioativos que trariam benefícios para a saúde da população. É preciso estudá-las”, disse.

Alencar é um dos pesquisadores do projeto “Bioprospecção de novas moléculas anti-inflamatórias de produtos naturais nativos brasileiros”, coordenado pelo professor Rosalen, também autor do artigo publicado na PLOS ONE.

Campeão contra inflamação

As frutas estudadas no projeto com elevada atividade antioxidante para serem usadas em indústrias de alimentos e farmacêuticas também tiveram pesquisadas as capacidades anti-inflamatórias. A grande estrela foi a araçá-piranga, como demonstraram em artigo publicado no Journal of Functional Foods.

“A araçá-piranga, espécie ameaçada de extinção, teve a melhor atividade anti-inflamatória em comparação com a de outras frutas do gênero Eugenia”, disse Rosalen. “O mecanismo de ação também é muito interessante, pois ocorre de forma espontânea e logo no começo da inflamação, impedindo uma via específica do processo inflamatório. Ela age também no endotélio dos vasos sanguíneos, evitando que os leucócitos transmigrem para o tecido agredido, reduzindo a exacerbação do processo inflamatório”

Rosalen destaca que os antioxidantes não têm como função única combater o envelhecimento ou a morte celular, mas a prevenção de doenças mediadas por processo inflamatório crônico. “A ação oxidante dos radicais livres também significa o surgimento de doenças inflamatórias dependentes, como diabetes, câncer, artrite, obesidade, doença de Alzheimer”, disse.

“Não percebemos muitas dessas lesões provocadas pelos radicais livres. São as inflamações silenciosas. Por isso, é importante a ação de sustâncias antioxidantes, que podem neutralizar os radicais livres”, disse Rosalen.

As pesquisas colaborativas, apoiadas pela Fapesp e pela Universidad de La Frontera, também permitiram ampliar o conhecimento sobre espécies nativas do Chile. Em um dos estudos, os autores demonstraram a atividade antioxidante e vasodilatadora da murtilla (Ugni molinae), uma fruta nativa do país.

No estudo publicado na Oxidative Medicine and Cellular Longevity, os pesquisadores destacam que o uso de preparações alimentares obtidas a partir de frutas e folhas da murtilla pode ter efeitos benéficos na prevenção e, possivelmente, no tratamento de sintomas de doenças cardiovasculares.

Alencar destaca que conhecer melhor as propriedades pode se mostrar uma boa alternativa para estimular a produção das frutas nativas.

“Antes do projeto com a Universidad de La Frontera, eu e o professor Pedro Rosalen já estudávamos as frutas nativas, pois acreditamos que elas podem revelar ótimas soluções alimentares para a sociedade”, disse.

O artigo Antioxidant and Anti-Inflammatory Activities of Unexplored Brazilian Native Fruits, de Juliana Infante, Pedro Luiz Rosalen, Josy Goldoni Lazarini, Marcelo Franchin e Severino Matias de Alencar, pode ser lido em http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152974.

Leia mais:

Vitamin D linked with better live birth rates in women undergoing assisted reproduction

Researchers call for a randomized controlled trial to investigate

Date: November 14, 2017

Source: European Society of Human Reproduction and Embryology

Summary:
Researchers are calling for a randomized clinical trial to be carried out to investigate the potential role of vitamin D supplementation in improving live birth rates following assisted reproduction treatment (ART). This follows a review and meta-analysis that shows a strong link between low vitamin D concentrations in women and lower live birth rates after ART compared to women who have the right amount of vitamin D in their bodies.

Researchers are calling for a randomised clinical trial to be carried out to investigate the potential role of vitamin D supplementation in improving live birth rates following assisted reproduction treatment (ART).

This follows a review and meta-analysis published today (Wednesday) in Human Reproduction one of the world's leading reproductive medicine journals, that shows a strong link between low vitamin D concentrations in women and lower live birth rates after ART compared to women who have the right amount of vitamin D in their bodies.

The researchers, led by Dr Justin Chu from the University of Birmingham (UK), caution that their findings do not mean that vitamin D supplementation necessarily improves women's chances of having a baby following ART as their research can only show an association and not that having sufficient concentrations of vitamin D actually cause the improved birth rate.

"Although an association has been identified, the beneficial effect of correction of vitamin D deficiency or insufficiency needs to be tested by performing a clinical trial. In the meantime, women who want to achieve a successful pregnancy should not rush off to their local pharmacy to buy vitamin D supplements until we know more about its effects. It is possible to overdose on vitamin D and this can lead to too much calcium building up in the body, which can weaken bones and damage the heart and kidneys," said Dr Chu, who is an academic clinical lecturer and specialist registrar in obstetrics and gynaecology at the University of Birmingham and Birmingham Women's and Children's NHS Foundation Trust, Tommy's National Centre for Miscarriage Research.

The researchers analysed data from 11 published studies that included 2,700 women who were undergoing ART (in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI) and/or frozen embryo transfer) and whose vitamin D status had been checked through blood tests.

They found that live births were a third more likely to occur in women who had the right amount of vitamin D when compared to women who did not. Vitamin D concentrations of more than 75 nanomoles per litre of blood (nmol/L) were considered sufficient, concentrations of less than 75 nmol/L were considered insufficient and less than 50 nmol/L were considered deficient.

A similar result was seen when the researchers looked at the results of pregnancy tests and clinical pregnancies (where a fetal heart beat could be detected). When compared with women who had deficient or insufficient concentrations of vitamin D, women who had sufficient vitamin D were 34% more likely to have a positive pregnancy test and 46% more likely to achieve a clinical pregnancy. No associations were found between miscarriage and vitamin D concentrations.

Co-author, Dr Ioannis Gallos, academic clinical lecturer and subspecialist trainee in reproductive medicine and surgery at the same institutions, said: "One startling finding was the high prevalence of vitamin D deficiency among these women. We found that only 26% of women in the studies had sufficient concentrations of vitamin D; 35% had deficient concentrations and 45% had insufficient concentrations."

The main source of vitamin D for people is sunlight. In the winter months it can be hard to get enough vitamin D and, in addition, some people are more at risk of vitamin D deficiency, for example those who don't get outdoors much, people with dark skin from African, African-Caribbean and south Asian backgrounds, and people who wear clothes that cover most of their skin when they are outdoors. Other studies have shown that there are higher conception rates in summer and autumn when women might be expected to have more vitamin D due to exposure to summer sunshine. Foods such as oily fish, red meat, liver and egg yolks also provide vitamin D, as well as vitamin D supplements.

The researchers say that possible mechanisms for the role played by vitamin D in pregnancy may be that it affects the success of embryo implantation in the womb in some way or that it is indication of the general well-being of the women.

"Testing for vitamin D concentrations is relatively cheap and widely available and its treatment is not costly," said Dr Chu. "It could be that correcting vitamin D deficiency could benefit women undergoing assisted reproduction treatment, but further research is needed to test this."

The study had some limitations. These included the fact that the studies analysed were often quite different and that vitamin D was assessed before ART was started in some studies and at the time that eggs were retrieved from the women in other studies.

Story Source:

Materials provided by European Society of Human Reproduction and Embryology. Note: Content may be edited for style and length.

Journal Reference:
Justin Chu, Ioannis Gallos, Aurelio Tobias, Bee Tan, Abey Eapen, Arri Coomarasamy. Vitamin D and assisted reproductive treatment outcome: a systematic review and meta-analysis. Human Reproduction, 2017; 1 DOI: 10.1093/humrep/dex326

Cite This Page:
European Society of Human Reproduction and Embryology. "Vitamin D linked with better live birth rates in women undergoing assisted reproduction: Researchers call for a randomized controlled trial to investigate." ScienceDaily. ScienceDaily, 14 November 2017. <www.sciencedaily.com/releases/2017/11/171114195047.htm>.

quarta-feira, 29 de novembro de 2017

Study in mice finds dietary levels of genistein may adversely affect female fertility

Date: November 14, 2017

Source: University of Illinois at Urbana-Champaign

Summary:
A new study of mice raises concerns about the potential impact that long-term exposure to genistein prior to conception may have on fertility and pregnancy.

Exposure to the phytoestrogen genistein prior to conception may adversely affect female fertility and pregnancy outcomes, depending on the dosage and duration of exposure, a new study in mice suggests.

Chronic preconception exposure to genistein affected pregnancy rates in mice and was associated with prolonged labor, smaller litters and pups, and higher rates of pup mortality, scientists at the University of Illinois report in a paper accepted for publication in the journal Reproductive Toxicology.

The findings add to a growing body of research that raises troubling questions about the potential health risks of long-term exposure to plant-based estrogens. Genistein is an isoflavone found in soy foods and dietary supplements, and, like other plant estrogens, may be consumed by women to relieve menopausal conditions such as hot flashes, weight gain and depression.

Genistein is among the chemicals that the National Institute of Environmental Health Sciences classifies as endocrine disruptors because they can interfere with bodily systems that are controlled by hormones.

"This is one of the first studies to look at long-term exposure to genistein in adult populations," said Jodi A. Flaws, a professor of comparative biosciences at Illinois and a co-author of the paper. "Many women are taking dietary supplements that contain genistein, and there is very little information on its potential effects on reproduction in adult women."

In a prior study, Flaws and her colleagues observed that treatment with another phytoestrogen found in licorice inhibited the ability of isolated ovarian follicles to grow and make sex steroid hormones. Food science and human nutrition professor William G. Helferich, the director of the Botanical Estrogen Research Center at the university, collaborated on that and the current study.

Extending that work, the researchers examined how chronic genistein exposure affected sex steroid hormone levels and pregnancy outcomes. Adult female mice in the current study were fed a diet containing 300, 500 or 1,000 parts per million of genistein, while their counterparts in the control group consumed food that was soy- and phytoestrogen-free.

The groups of mice that consumed the genistein were exposed to it for 30, 60, 150 or 240 days, which produced blood serum concentrations equivalent to those found in women who consume soy foods or supplements, said Illinois alumna Shreya Patel, who conducted the research as a doctoral student at the university.

"When we looked at animals exposed for 30 days, the gestation time -- the length of time they were pregnant -- was decreased, similar to premature births," Flaws said. "And after 60 days' exposure, they had fewer pups in their litters."

After 150 days, the mice that consumed 500 ppm or 1000 ppm of genistein were less likely to become pregnant after mating. Only 83 percent of the females in either of those groups were fertile, the researchers found.

After 240 treatment days, only 50 percent of mice in the 300-ppm group were fertile compared with 67 percent of those in the control group. However, genistein appeared to boost fertility rates among the two highest dose groups: 83 percent in the 500-ppm group and 100 percent in the 1,000-ppm group conceived.

"In order to say definitively that genistein was having a protective effect on fertility we would have had to continue the study longer," Patel said. "But that was a very interesting finding, which correlates with current knowledge and literature about genistein having a protective effect on certain health indicators."

While mice in the 240-day treatment group that gave birth bore normal-sized litters, they often killed their pups, and the pups were much smaller than peers of similar age.

Although the findings are preliminary, the researchers said that little is known about the potential effects of long-term phytoestrogen use, and women should be cautious about their exposure, especially if they plan to conceive in the near future.

"While women are consuming these dietary estrogenic supplements, this is an uncontrolled experiment in which the safety and efficacy are unknown," Helferich said.

"With endocrine disruptors, it's the dose that makes the poison," said Patel, who currently is in a postdoctoral program at Northwestern University. "People should be aware of what they're consuming, and some supplements may not be what they claim to be. It's probably best to consult a doctor or a dietitian."

Story Source:

Materials provided by University of Illinois at Urbana-Champaign. Note: Content may be edited for style and length.

Journal Reference:
Shreya Patel, James A. Hartman, William G. Helferich, Jodi A. Flaws. Preconception exposure to dietary levels of genistein affects female reproductive outcomes. Reproductive Toxicology, 2017; 74: 174 DOI: 10.1016/j.reprotox.2017.09.014

Cite This Page:
University of Illinois at Urbana-Champaign. "Study in mice finds dietary levels of genistein may adversely affect female fertility." ScienceDaily. ScienceDaily, 14 November 2017. <www.sciencedaily.com/releases/2017/11/171114123331.htm>.

Eating regular variety of nuts associated with lower risk of heart disease

Date: November 13, 2017

Source: American College of Cardiology

Summary:
People who regularly eat nuts, including peanuts, walnuts and tree nuts, have a lower risk of developing cardiovascular disease or coronary heart disease compared to people who never or almost never eat nuts, according to a new study. The study is the largest to date looking at frequency of nut consumption in relation to incident cardiovascular disease.
Eating nuts may reduce the risk of heart disease.
Credit: © rufar / Fotolia

People who regularly eat nuts, including peanuts, walnuts and tree nuts, have a lower risk of developing cardiovascular disease or coronary heart disease compared to people who never or almost never eat nuts, according to a study published today in the Journal of the American College of Cardiology. The study is the largest to date looking at frequency of nut consumption in relation to incident cardiovascular disease.

Recently, dietary recommendations have shifted toward diets including higher quantities of plant-based foods over animal-based foods, with most dietary patterns including nuts because of their association with reduced cardiovascular risk factors and unique nutritional composition.

While many past studies focused on nut consumption as a whole, researchers in this study also looked at the association between specific types of nuts -- peanut butter, peanuts, walnuts and tree nuts -- with major cardiovascular events. Peanuts were included even though they are actually a legume because they have a similar fatty acid and nutrient profile as other nuts.

The study looked at over 210,000 people, including women from the Nurses' Health Study and Nurses' Health Study II and men from the Health Professionals Follow-up Study, with up to 32 years of follow up. In all three groups, information about medical history, lifestyle and health conditions were collected via self-administered questionnaires every two years.

The primary endpoint of the study was major cardiovascular disease, defined as a combined endpoint of myocardial infarction, stroke or fatal cardiovascular disease. Secondary endpoints were total coronary heart disease, defined as fatal or non-fatal myocardial infarction, and total stroke, which included all fatal and non-fatal strokes. Researchers documented 14,136 cardiovascular disease cases, including 8,390 coronary heart disease cases and 5,910 stroke cases.

The study found a consistent inverse association between total nut consumption and total cardiovascular disease and coronary heart disease. Also, after looking at individual nut consumption, eating walnuts one or more times per week was associated with a 19 percent lower risk of cardiovascular disease and 21 percent lower risk of coronary heart disease. Participants who ate peanuts or tree nuts two or more times per week had a 13 percent and 15 percent lower risk of cardiovascular disease, respectively, and a 15 percent and 23 percent, lower risk of coronary heart disease, respectively, compared to those who never consumed nuts.

Participants who consumed five or more servings of nuts a week had a 14 percent lower risk of cardiovascular disease and a 20 percent lower risk of coronary heart disease than participants who never or almost never consumed nuts. The results were similar when accounting for consumption of tree nuts, peanuts and walnuts individually. Researchers found no evidence of an association between total nut consumption and risk of stroke, but eating peanuts and walnuts was inversely associated with the risk of stroke. Peanut butter and tree nuts were not associated with stroke risk.

"Our findings support recommendations of increasing the intake of a variety of nuts, as part of healthy dietary patterns, to reduce the risk of chronic disease in the general populations," said Marta Guasch-Ferre, PhD, lead author of the study and research fellow at the department of nutrition at Harvard T.H. Chan School of Public Health.

Several limitations were noted in the study, including that the sample size was limited to white health professionals. However, the researchers note that the results can be generalized to men and women of different ethnicities because there is no reason to expect the underlying mechanisms to be different. Also, because the nut intake was self-reported, errors are inevitable, and there was not data on how the nuts were prepared, so the influence of preparation methods was not able to be tested.

In an accompanying editorial comment, Emilio Ros, MD, PHD, of the Endocrinology and Nutrition service at the Hospital Clínic in Barcelona and investigator of CIBEROBN, a research network of Instituto de Salud Carlos III, Spain, confirmed that the consistency of the findings strongly suggests an association between nut consumption and heart disease protection, but there is more to research.

"Ideally, further investigations should test the effects of long-term consumption of nuts supplemented into the usual diet on hard cardiometabolic events," Ros said. "In the meantime, raw nuts, if possible unpeeled and otherwise unprocessed, may be considered as natural health capsules that can be easily incorporated into any heart-protective diet to further cardiovascular well-being and promote healthy aging."

Story Source:

Materials provided by American College of Cardiology. Note: Content may be edited for style and length.

Journal Reference:
Marta Guasch-Ferré, Xiaoran Liu, Vasanti S. Malik, Qi Sun, Walter C. Willett, JoAnn E. Manson, Kathryn M. Rexrode, Yanping Li, Frank B. Hu, Shilpa N. Bhupathiraju. Nut Consumption and Risk of Cardiovascular Disease. Journal of the American College of Cardiology, 2017; 70 (20): 2519 DOI: 10.1016/j.jacc.2017.09.035

Cite This Page:
American College of Cardiology. "Eating regular variety of nuts associated with lower risk of heart disease." ScienceDaily. ScienceDaily, 13 November 2017. <www.sciencedaily.com/releases/2017/11/171113195131.htm>.