QUINTAIS IMORTAIS

Ohio State University. "Low-carb diet may reduce diabetes risk independent of weight loss: Researchers report reversal of metabolic syndrome in some cases." ScienceDaily. ScienceDaily, 20 June 2019. <www.sciencedaily.com/releases/2019/06/190620100036.htm>.

Vanilla makes milk beverages seem sweeter

Date: June 20, 2019 Source: Penn State Summary: Adding vanilla to sweetened milk makes consumers think the beverage is sweeter, allowing the amount of added sugar to be reduced, according to new researchers, who will use the concept to develop a reduced-sugar chocolate milk for the National School Lunch Program.

Adding vanilla to sweetened milk makes consumers think the beverage is sweeter, allowing the amount of added sugar to be reduced, according to Penn State researchers, who will use the concept to develop a reduced-sugar chocolate milk for the National School Lunch Program.

"We are utilizing a learned association between an odor and a taste that will allow us to reduce the added sugar content," said Helene Hopfer, assistant professor of food science. "Reducing added sugar in products, just like reducing fat and salt, is the holy grail of food science."

The idea that congruent or harmonious odors enhance certain tastes is not new, explained Hopfer, whose research group in the College of Agricultural Sciences has been experimenting with these "cross-modal interactions" in food since she came to Penn State three years ago. Her goal is to see them actually incorporated into foods.

In a blind taste test that provided new insights into taste enhancement by an aroma, participants -- who did not know vanilla had been added to the milk -- consistently indicated that samples with vanilla were significantly sweeter than their added sugar concentrations could explain.

The subjects' responses indicate that with the addition of vanilla, the added sugar content in flavored milk could potentially be reduced by 20 to 50 percent, suggested lead researcher Gloria Wang, and people should not be able to perceive the beverage as less sweet.

"We maintain the sweetness perception by having this congruent odor -- this learned, associated odor -- basically trick the brain into thinking that there is still enough sweetness there," she said. "Based on our results, taste-aroma interaction is a robust effect."

Wang, now an associate scientist in product development with Leprino Foods Co. in Colorado, conducted the research at Penn State as part of her master's degree thesis in food science. She tested not only congruent taste-aroma combinations but incongruent combinations as well. It turned out that even a beef odor in milk slightly enhanced sweetness for study participants.

Given widespread concerns about sugar intake and health, manufacturers are reformulating their products to help address consumer demand, Wang noted. She believes the findings of the research, recently published in Food Quality and Preference, offer them a workable option to reduce added sugar in their products and retain the sweetness consumers demand.

The study was novel because it did not ask participants to rate individual attributes of the milk such as sweetness, intensity of vanilla odor or milk taste. Instead, participants took a more holistic approach and simply selected the best match for the vanilla milk from four differently sweetened milk choices.

Later this summer, Hopfer's lab in the Department of Food Science will start working on a two-year project, funded by the National Dairy Council, aimed at developing a reduced-sugar chocolate milk for the National School Lunch Program. The effort, based on the recent research using the synergistic actions between vanilla and sugar to reduce the added sugar content, will be a challenge because of the inherent bitterness of cocoa.

"The amount of sugar in chocolate milk is quite high because cocoa is very bitter, so you need some sugar to decrease the bitterness of the cocoa and then more to make it sweet," Hopfer said. "We are hoping to utilize what we found with odors to reduce the added sugar content by experimenting to find the sweet spot between cocoa powder, sugar content and vanilla flavor. We know that if it isn't sweet, children won't drink it."

Also involved in the research were Alyssa Bakke, staff sensory scientist in food science, and John Hayes, associate professor of food science and director of the Penn State Sensory Evaluation Center.

The U.S. Department of Agriculture's National Institute of Food and Agriculture supported this work.

Story Source:

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

Cite This Page:

Penn State. "Vanilla makes milk beverages seem sweeter." ScienceDaily. ScienceDaily, 20 June 2019. <www.sciencedaily.com/releases/2019/06/190620121410.htm>.

Omega-3 fatty acids fight inflammation via cannabinoids

Date: July 18, 2017 Source: University of Illinois at Urbana-Champaign Summary: Chemical compounds called cannabinoids are found in marijuana and also are produced naturally in the body from omega-3 fatty acids. A well-known cannabinoid in marijuana, tetrahydrocannabinol, is responsible for some of its euphoric effects, but it also has anti-inflammatory benefits. A new study in animal tissue reveals the cascade of chemical reactions that convert omega-3 fatty acids into cannabinoids that have anti-inflammatory benefits - but without the psychotropic high.

Chemical compounds called cannabinoids are found in marijuana and also are produced naturally in the body from omega-3 fatty acids. A well-known cannabinoid in marijuana, tetrahydrocannabinol, is responsible for some of its euphoric effects, but it also has anti-inflammatory benefits. A new study in animal tissue reveals the cascade of chemical reactions that convert omega-3 fatty acids into cannabinoids that have anti-inflammatory benefits -- but without the psychotropic high.

The findings are published in the Proceedings of the National Academy of Sciences.

Foods such as meat, eggs, fish and nuts contain omega-3 and omega-6 fatty acids, which the body converts into endocannabinoids -- cannabinoids that the body produces naturally, said Aditi Das, a University of Illinois professor of comparative biosciences and biochemistry, who led the study. Cannabinoids in marijuana and endocannabinoids produced in the body can support the body's immune system and therefore are attractive targets for the development of anti-inflammatory therapeutics, she said.

In 1964, the Israeli chemist Raphael Mechoulam was the first to discover and isolate THC from marijuana. To test whether he had found the compound that produces euphoria, he dosed cake slices with 10 milligrams of pure THC and gave them to willing friends at a party. Their reactions, from nonstop laughter, to lethargy, to talkativeness, confirmed that THC was a psychotropic cannabinoid.

It wasn't until 1992 that researchers discovered endocannabinoids produced naturally in the body. Since then, several other endocannabinoids have been identified, but not all have known functions.

Cannabinoids bind to two types of cannabinoid receptors in the body -- one that is found predominantly in the nervous system and one in the immune system, Das said.

"Some cannabinoids, such as THC in marijuana or endocannabinoids can bind to these receptors and elicit anti-inflammatory and anti-pain action," she said.

"Our team discovered an enzymatic pathway that converts omega-3-derived endocannabinoids into more potent anti-inflammatory molecules that predominantly bind to the receptors found in the immune system," Das said. "This finding demonstrates how omega-3 fatty acids can produce some of the same medicinal qualities as marijuana, but without a psychotropic effect."

Story Source:

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

Journal Reference:

Daniel R. McDougle, Josephine E. Watson, Amr A. Abdeen, Reheman Adili, Megan P. Caputo, John E. Krapf, Rodney W. Johnson, Kristopher A. Kilian, Michael Holinstat, Aditi Das. Anti-inflammatory ω-3 endocannabinoid epoxides. Proceedings of the National Academy of Sciences, 2017; 201610325 DOI: 10.1073/pnas.1610325114

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University of Illinois at Urbana-Champaign. "Omega-3 fatty acids fight inflammation via cannabinoids." ScienceDaily. ScienceDaily, 18 July 2017. <www.sciencedaily.com/releases/2017/07/170718142909.htm>.

Using omega 3 fatty acids to treat Alzheimer's and other diseases?

Date: July 18, 2017 Source: Louisiana State University Health Sciences Center Summary: Understanding how dietary essential fatty acids work may lead to effective treatments for diseases and conditions such as stroke, Alzheimer's disease, age-related macular degeneration, Parkinson's disease and other retinal and neurodegenerative diseases. The key is to be able to intervene during the early stages of the disease.

Understanding how dietary essential fatty acids work may lead to effective treatments for diseases and conditions such as stroke, Alzheimer's disease, age-related macular degeneration, Parkinson's disease and other retinal and neurodegenerative diseases. The key is to be able to intervene during the early stages of the disease. That is the conclusion of a Minireview by Nicolas Bazan, MD, PhD, Boyd Professor and Director, and Aram Asatryan, PhD, postdoctoral researcher, at the Neuroscience Center of Excellence at LSU Health New Orleans School of Medicine published in the Journal of Biological Chemistry's Thematic Minireview Series: Inflammatory transcription confronts homeostatic disruptions.

Docosahexaenoic acid (DHA), a key essential Omega-3 fatty acid, produces signaling molecules called docosanoids in response to disruptions in the state of equilibrium within cells caused by injury or disease. Neuroprotectin D1 (NDP1) is a docosanoid that the Bazan lab discovered and found protects neurons by controlling which and how certain genes in the retina and brain respond.

Research shows that the preclinical events in Alzheimer's disease including neuroinflammation, damage to dendritic spines -- small doorknob-shaped protrusions that help transmit electrical signals to the cell -- and problems with cell-to-cell communication coincide with decreased DHA content in the brain. The neuroprotective bioactivity of NPD1 includes inflammatory modulating properties as well as features that promote cell survival, both of which contribute to restoring a stable state of equilibrium, or homeostasis, within the cell.

In experimental models of stroke, researchers at LSU Health New Orleans Neuroscience Center led by Bazan have shown that the administration of NPD1 reduces the size of stroke damage and also saves tissue in the rim surrounding the stroke core, which remains viable for a short time.

Research has demonstrated that DHA from the liver is also retained and concentrated in photoreceptor cells and that retinal degeneration occurs when photoreceptor cells fail to capture DHA. When a gene that regulates the uptake of DHA is turned off, photoreceptor cells die and a single amino acid mutation in this receptor can cause retinitis pigmentosa.

Cells die through a variety of mechanisms. Contributors include a family of reactive oxygen species -- compounds formed continuously as by-products of aerobic metabolism such as from reactions to drugs and environmental toxins, or when the levels of antioxidants are diminished creating oxidative stress, as well as inflammation and the disease process. Cell death is considered to be reversible until a first "point of no return" checkpoint is passed. The authors describe how NPD1 acts to stop cells from passing that checkpoint in cell death activation pathways including apoptosis, necrosis, necroptosis, pyroptosis, and pyronecrosis, among others.

The Minireview summarizes the effects of the essential fatty acid family member DHA and its bioactive derivative NPD1 in the context of a specific target of gene regulation. The authors also describe the mechanism of a pathway of regulation by a bioactive lipid that has a significant impact on cellular homeostasis -- how NPD1 activates pro-survival genes and suppresses pro-death genes.

"The organizational and functional complexity of the brain raises new questions regarding how the cellular events described here operate in response to disrupted homeostasis to attain neuroprotection in pathological conditions," notes Bazan. "It is our hope that this knowledge will contribute to managing early stages of such devastating diseases as Alzheimer's, stroke, traumatic brain injury, age-related macular degeneration, Parkinson's and others."

Story Source:

Materials provided by Louisiana State University Health Sciences Center. Note: Content may be edited for style and length.

Journal Reference:

Aram Asatryan, Nicolas G. Bazan. Molecular mechanisms of signaling via the docosanoid neuroprotectin D1 for cellular homeostasis and neuroprotection. Journal of Biological Chemistry, 2017; jbc.R117.783076 DOI: 10.1074/jbc.R117.783076

Cite This Page:

Louisiana State University Health Sciences Center. "Using omega 3 fatty acids to treat Alzheimer's and other diseases?." ScienceDaily. ScienceDaily, 18 July 2017. <www.sciencedaily.com/releases/2017/07/170718124732.htm>.

sexta-feira, 15 de novembro de 2019

Health benefits of the Mediterranean diet are confirmed, but just for the upper class

Only the most advantaged people actually benefit from the Mediterranean diet, Italian study says

Date: August 1, 2017 Source: Istituto Neurologico Mediterraneo Neuromed I.R.C.C.S. Summary: The Mediterranean diet reduces the risk of cardiovascular disease but only if you are rich or highly educated. This is the surprising finding by researchers who performed a study on over 18,000 subjects.

The Mediterranean diet reduces the risk of cardiovascular disease but only if you are rich or highly educated. This is the surprising finding by researchers from the Italian I.R.C.C.S. Neuromed, who performed a study on over 18,000 subjects recruited within the Moli-sani study and published in the International Journal of Epidemiology.

Cardiovascular advantages associated with the Mediterranean diet are well-known but now the Italian study, conducted by a team of researchers at the Department of Epidemiology and Prevention led by Giovanni de Gaetano, reveals that such benefits are strongly influenced by the socioeconomic position of people. Basically, given a comparable adherence to this eating pattern, the study has shown that the reduction in cardiovascular risk is observed only in people with higher educational level and/or greater household income. No actual benefits were observed for the less advantaged groups.

"The cardiovascular benefits associated with the Mediterranean diet in a general population are well known -- says Marialaura Bonaccio, researcher at the Department of Epidemiology and Prevention and first author of the study -- Yet for the first time our study has revealed that the socioeconomic position is able to modulate the health advantages linked to Mediterranean diet. In other words, a person from low socioeconomic status who struggles to follow a Mediterranean model, is unlikely to get the same advantages of a person with higher income, despite the fact that they both similarly adhere to the same healthy diet."

Neuromed researchers went further and tried to unravel the possible mechanisms underlying such disparities.

"Given a comparable adherence to the Mediterranean diet, the most advantaged groups were more likely to report a larger number of indices of high quality diet as opposed to people with low socioeconomic status -- explains Licia Iacoviello, head of the Laboratory of nutritional and molecular Epidemiology at the Department -- For example, within those reporting an optimal adherence to the Mediterranean diet (as measured by a score comprising fruits and nuts, vegetables, legumes, cereals, fish, fats, meat, dairy products and alcohol intake) people with high income or higher educational level consumed products richer in antioxidants and polyphenols, and had a greater diversity in fruit and vegetables choice. We have also found a socioeconomic gradient in the consumption of whole-grain products and in the preferred cooking methods. These substantial differences in consuming products belonging to Mediterranean diet lead us to think that quality of foods may be as important for health as quantity and frequency of intake."

"Our results should promote a serious consideration of socioeconomic scenario of health -- comments Giovanni de Gaetano, director of the Department -- Socioeconomic disparities in health are growing also in access to healthy diets. During the very last years, we documented a rapid shifting from the Mediterranean diet in the whole population, but it might also be that the weakest citizens tend to buy 'Mediterranean' food with lower nutritional value. We cannot be keeping on say that the Mediterranean diet is good for health -- de Gaetano concludes -- if we are not able to guarantee an equal access to it."

The Moli-sani Project

Started in March 2005, it involves about 25,000 citizens living in the Molise region. The aim is to learn about environmental and genetic factors underlying cardiovascular disease, cancer and degenerative pathologies. Moli-sani study, now based in I.R.C.C.S. Neuromed, has transformed an entire Italian region in a large research lab.

Story Source:

Materials provided by Istituto Neurologico Mediterraneo Neuromed I.R.C.C.S.. Note: Content may be edited for style and length.

Journal Reference:

Marialaura Bonaccio, Augusto Di Castelnuovo, George Pounis, Simona Costanzo, Mariarosaria Persichillo, Chiara Cerletti, Maria Benedetta Donati, Giovanni de Gaetano, Licia Iacoviello on behalf of the Moli-sani Study Investigators. High adherence to the Mediterranean diet is associated with cardiovascular protection in higher but not in lower socioeconomic groups: prospective findings from the Moli-sani study. International Journal of Epidemiology, 2017 DOI: 10.1093/ije/dyx145

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Istituto Neurologico Mediterraneo Neuromed I.R.C.C.S.. "Health benefits of the Mediterranean diet are confirmed, but just for the upper class: Only the most advantaged people actually benefit from the Mediterranean diet, Italian study says." ScienceDaily. ScienceDaily, 1 August 2017. <www.sciencedaily.com/releases/2017/08/170801171047.htm>.

On the path to vitamin A in rice

Date: July 21, 2017 Source: Albert-Ludwigs-Universität Freiburg Summary: Biochemists have elucidated the structure of an enzyme that supplies carotenoid, investigators report. The lack of vitamin A in food is a major cause of health problems worldwide and can lead to blindness and even death. This is especially a problem in threshold or third-world countries, where children are likely to suffer from a lack of vitamin A or its precursor beta-carotene due to malnourishment.

The lack of vitamin A in food is a major cause of health problems worldwide and can lead to blindness and even death. This is especially a problem in threshold or third-world countries, where children are likely to suffer from a lack of vitamin A or its precursor beta-carotene due to malnourishment. Among their many functions, carotenoids are responsible for the bright orange color of sweet potatoes as well as their namesake, the carrot. Thanks to its intense color, beta-carotene is used in the food industry in soft drinks, yoghurts, and other food and is known as food coloring E160. Rice, which is the most important basic nutrient in Asia, has no beta-carotene in its kernel, but there are carotenoids in the leaves of the rice plant. These long, fat-soluble pigments are used by the plant not only in photosynthesis, during which the plant generates energy and oxygen, but in other processes as well.

One of the first precursors to beta-carotene is phytoene, which is colorless and not water-soluble and can be found in the lipid bilayer of plastid organelles -- in other words, in the outer layer of these closed cellular compartments, which is involved in many processes including photosynthesis. Here, the enzyme phytoene desaturase (PDS) transforms the phytoene into the next intermediate of synthesis, which already has a yellowish color. Researchers in the labs of Prof. Dr. Peter Beyer at the Faculty of Biology and Prof. Dr. Oliver Einsle at the Faculty of Chemistry and Pharmacy of the University of Freiburg have successfully elucidated the three-dimensional structure of phytoene desaturase in rice, along with the mechanism of phytoene transformation. In order to achieve this, Dr. Sandra Gemmecker and Anton Brausemann had to isolate the highly pure enzyme and crystalize it, so they could obtain a three-dimensional structural image through diffraction experiments with X-rays. They then discovered that the PDS becomes partially immersed in the lipid bilayer of the plastid organelles and contains a hydrophobic tunnel that leads into its interior. Catalysis begins when the phytoene molecule enters this tunnel and reaches the reaction center of the enzyme, where one half of the phytoene molecule is transformed into the next intermediary carotenoid stage. After this intermediary product leaves the tunnel the same way it came, it enters another PDS enzyme right next to the first, where it is completely transformed. A helper molecule known as a quinone then regenerates the enzyme. The quinone accesses the enzyme through the same tunnel and takes up excess electrons, thereby preparing the enzyme for the next reaction cycle.

If the PDS enzyme in a plant does not function properly, for example due to a reaction to a herbicide, then the plant's seedlings become pale and whitish instead of green and the plant dies within a few days. Since the early twentieth century, scientists worldwide have been working to reveal the exact mechanisms of carotene synthesis. This has proven difficult, however, due to the complicated composition of various enzyme complexes and because of their relatively low numbers in plant cells. The researchers from the University of Freiburg were able to elucidate the structure of the PDS enzyme using a specialty: They added a molecule of norflurazon, an herbicide developed in the 1970s, during the isolation of PDS. Due to the presence of norflurazon, PDS is deactivated and thus no longer available to the growing plant, causing it to bleach and die. Knowledge about the position and orientation of this bleaching herbicide within the enzyme can therefore be useful to researchers when developing new agents in the future. It is now also possible to induce specific changes in the sequence of the enzyme and use biotechnological procedures to give crops an advantage over weeds.

Story Source:

Materials provided by Albert-Ludwigs-Universität Freiburg. Note: Content may be edited for style and length.

Journal Reference:

Anton Brausemann, Sandra Gemmecker, Julian Koschmieder, Sandro Ghisla, Peter Beyer, Oliver Einsle. Structure of Phytoene Desaturase Provides Insights into Herbicide Binding and Reaction Mechanisms Involved in Carotene Desaturation. Structure, 2017; DOI: 10.1016/j.str.2017.06.002

Cite This Page:

Albert-Ludwigs-Universität Freiburg. "On the path to vitamin A in rice." ScienceDaily. ScienceDaily, 21 July 2017. <www.sciencedaily.com/releases/2017/07/170721090111.htm>.

quinta-feira, 14 de novembro de 2019

Too much vitamin A may increase risk of bone fractures

Date: October 9, 2018 Source: Society for Endocrinology Summary: Consuming too much vitamin A may decrease bone thickness, leading to weak and fracture prone bones, according to a new study in mice.

Consuming too much vitamin A may decrease bone thickness, leading to weak and fracture prone bones, according to a study published in the Journal of Endocrinology. The study, undertaken in mice, found that sustained intake of vitamin A, at levels equivalent to 4.5-13 times the human recommended daily allowance (RDA), caused significant weakening of the bones, and suggests that people should be cautious of over-supplementing vitamin A in their diets.

Vitamin A is an essential vitamin that is important for numerous biological processes including growth, vision, immunity and organ function. Our bodies are unable to make vitamin A but a healthy diet including meat, dairy products and vegetables should be sufficient to maintain the body's nutritional needs. Some evidence has suggested that people who take vitamin A supplements may be increasing their risk of bone damage. Previous studies in mice have shown that short-term overdosing of vitamin A, at the equivalent of 13-142 times the recommended daily allowance in people, results in decreased bone thickness and an increased fracture risk after just 1-2 weeks. This study is the first to examine the effects of lower vitamin A doses that are more equivalent to those consumed by people taking supplements, over longer time-periods.

In this study, Dr Ulf Lerner and colleagues from Sahlgrenska Academy at the University of Gothenburg, report that mice given lower doses of vitamin A, equivalent to 4.5-13 times the RDA in humans, over a longer time period, also showed thinning of their bones after just 8 days, which progressed over the ten week study period.

Dr Ulf Lerner commented, "Previous studies in rodents have shown that vitamin A decreases bone thickness but these studies were performed with very high doses of vitamin A, over a short period of time. In our study we have shown that much lower concentrations of vitamin A, a range more relevant for humans, still decreases rodent bone thickness and strength."

Next, Dr Ulf Lerner intends to investigate if human-relevant doses of vitamin A affect bone growth induced by exercise, which was not addressed in this study. Additionally, his team will study the effects of vitamin A supplementation in older mice, where growth of the skeleton has ceased, as is seen in the elderly.

Dr Ulf Lerner cautions: "Overconsumption of vitamin A may be an increasing problem as many more people now take vitamin supplements. Overdose of vitamin A could be increasing the risk of bone weakening disorders in humans but more studies are needed to investigate this. In the majority of cases, a balanced diet is perfectly sufficient to maintain the body's nutritional needs for vitamin A."

Story Source:

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

Journal Reference:

Vikte Lionikaite, Karin L Gustafsson, Anna Westerlund, Sara H Windahl, Antti Koskela, Juha Tuukkanen, Helena Johansson, Claes Ohlsson, Herschel H Conaway, Petra Henning, Ulf H Lerner. Clinically relevant doses of vitamin A decrease cortical bone mass in mice. Journal of Endocrinology, 2018; DOI: 10.1530/JOE-18-0316

Cite This Page:

Society for Endocrinology. "Too much vitamin A may increase risk of bone fractures." ScienceDaily. ScienceDaily, 9 October 2018. <www.sciencedaily.com/releases/2018/10/181009102538.htm>.

domingo, 10 de novembro de 2019

Wheat that pumps iron, naturally

Research shows possibility of increasing nutrition without sacrificing yield

Date: October 3, 2018 Source: American Society of Agronomy Summary: Crop breeders are developing a biofortified wheat that could make proper nutrition

Is biofortification the best thing since sliced bread? Well, biofortified wheat could certainly make it easier to help some humans get proper nutrition.

Biofortification is the process of naturally increasing the nutritional value of a crop. Unlike fortification, which might add a mineral like iron directly to something like bread dough, the goal of biofortification is to have the wheat in the dough naturally contain more iron in the first place.

Robert Graybosch of the USDA Agricultural Research Service explains that about 60% of the world's population doesn't get enough iron. This happens because the food people eat doesn't contain enough minerals or contains what are called 'antinutrients.' These are molecules that prevent the body from absorbing good nutrients.

"Fortification is potentially useful as people in many parts of the world do not consume a balanced diet and their main foods lack minerals," he says. "This can be addressed by fortification, the process of adding minerals back to food products. This is done with flours used for bread baking."

However, some people are hesitant to eat products with what they think might be weird ingredients, he adds. Graybosch is trying to naturally enhance the minerals of wheat flours to help people around the world get more iron.

"Biofortification can be done via traditional plant breeding using natural genetic variation or natural mutations, or via genetic engineering," he says. "If one found a mutation that resulted in more grain iron, and then bred this trait into wheat that was produced and consumed, then we could say the crop has been biofortified."

Graybosch and his team developed experimental breeding lines of winter wheat. Breeding lines are the first step in the long process of creating a new type of wheat that farmers can grow. The team tried to combine two properties -- low phytate and high grain protein -- without lowering grain yield. Phytate is an antinutrient that prevents the body from taking in some minerals.

Biofortification is a delicate balance. Often, increasing the nutrition causes the overall grain yield to drop. This can lead to the wheat being overall less nutritious and can also hurt farmers' profits.

Their results show that combining the two traits without any bad effects on grain yield is possible. It increased the amount of zinc, calcium, and manganese humans could get from it. Although more work needs to be done to get it in wheat that can be planted by farmers, the genes can be used to develop more nutritious wheat without sacrificing yield.

The next steps in their research, some of which they have already undertaken, are to then breed these beneficial genes into plants adapted for areas where wheat is grown, such as the Great Plains of the U.S.

"It is important to note that all wheat grown in a specific area is adapted to that area," Graybosch explains. "Great Plains wheats do well in the Great Plains, but not elsewhere. If the trait is of interest in other locations, additional breeders need to start introducing it to their own backgrounds. And they are interested in doing so."

Graybosch says his journey to this research began as he walked home from work one day. He wanted to devise a project to investigate "the most important nutritional problem facing mankind," which he learned was likely that people weren't getting enough iron. He and then-graduate student Jorge Venegas started to look for genes that would improve the nutrition of wheat.

"I think anything that can improve food mineral nutrition at low or no cost to the consumer is of value," Graybosch says. "Anything we can do to improve nutrition worldwide will go a long way toward improving the lives of our fellow earthlings."

Story Source:

Materials provided by American Society of Agronomy. Original written by Kaine Korzekwa. Note: Content may be edited for style and length.

Journal Reference:

Jorge P. Venegas, Robert A. Graybosch, Brian Wienhold, Devin J. Rose, Brian M. Waters, P. Stephen Baenziger, Kent Eskridge, Guihua Bai, Paul St. Amand. Biofortification of Hard Red Winter Wheat by Genes Conditioning Low Phytate and High Grain Protein Concentration. Crop Science, 2018; 58 (5): 1942 DOI: 10.2135/cropsci2018.03.0175

Cite This Page:

American Society of Agronomy. "Wheat that pumps iron, naturally: Research shows possibility of increasing nutrition without sacrificing yield." ScienceDaily. ScienceDaily, 3 October 2018. <www.sciencedaily.com/releases/2018/10/181003090336.htm>.

quarta-feira, 6 de novembro de 2019

Avocados, as a substitution for carbohydrates, can suppress hunger without adding calories

Meals that include fresh avocado can significantly suppress hunger and increase meal satisfaction

Date: May 8, 2019 Source: Illinois Institute of Technology Summary: A new study suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.

A new study released by the Center for Nutrition Research at Illinois Institute of Technology suggests that meals that include fresh avocado as a substitute for refined carbohydrates can significantly suppress hunger and increase meal satisfaction in overweight and obese adults.

As rates of obesity in the United States continue to rise, the findings from Illinois Tech suggest that simple dietary changes can have an important impact on managing hunger and aiding metabolic control.

The new research, published in the peer-reviewed journal Nutrients, assessed the underlying physiological effects of including whole and half fresh Hass avocados on hunger, fullness, and how satisfied subjects felt over a six-hour period. Researchers evaluated these effects in 31 overweight and obese adults in a randomized three-arm crossover clinical trial. These dietary changes were also shown to limit insulin and blood glucose excursions, further reducing the risk of diabetes and cardiovascular disease by adding healthy fats and fibers into a regular daily diet.

"For years, fats have been targeted as the main cause of obesity, and now carbohydrates have come under scrutiny for their role in appetite regulation and weight control," said Britt Burton-Freeman, Ph.D., director of the Center for Nutrition Research at Illinois Tech. "There is no 'one size fits all' solution when it comes to optimal meal composition for managing appetite. However, understanding the relationship between food chemistry and its physiological effects in different populations can reveal opportunities for addressing appetite control and reducing rates of obesity, putting us a step closer to personalized dietary recommendations."

The research found that meals including avocado not only resulted in a significant reduction in hunger and an increase in how satisfied participants felt, but also found that an intestinal hormone called PYY was an important messenger of the physiological response.

Story Source:

Materials provided by Illinois Institute of Technology. Note: Content may be edited for style and length.

Journal Reference:

Lanjun Zhu, Yancui Huang, Indika Edirisinghe, Eunyoung Park, Britt Burton-Freeman. Using the Avocado to Test the Satiety Effects of a Fat-Fiber Combination in Place of Carbohydrate Energy in a Breakfast Meal in Overweight and Obese Men and Women: A Randomized Clinical Trial. Nutrients, 2019; 11 (5): 952 DOI: 10.3390/nu11050952

Cite This Page:

Illinois Institute of Technology. "Avocados, as a substitution for carbohydrates, can suppress hunger without adding calories: Meals that include fresh avocado can significantly suppress hunger and increase meal satisfaction." ScienceDaily. ScienceDaily, 8 May 2019. <www.sciencedaily.com/releases/2019/05/190508134529.htm>.

sábado, 14 de setembro de 2019

Diet's effect on gut bacteria could play role in reducing Alzheimer's risk

Date: September 3, 2019 Source: Wake Forest Baptist Medical Center Summary: Could following a certain type of diet affect the gut microbiome -- the good and bad bacteria that live in the gastrointestinal tract -- in ways that decrease the risk of Alzheimer's disease? According to researchers, that is a fair possibility.

Could following a certain type of diet affect the gut microbiome -- the good and bad bacteria that live in the gastrointestinal tract -- in ways that decrease the risk of Alzheimer's disease?

According to researchers at Wake Forest School of Medicine, that is a fair possibility.

In a small pilot study, the researchers identified several distinct gut microbiome signatures -- the chemicals produced by bacteria -- in study participants with mild cognitive impairment (MCI) but not in their counterparts with normal cognition, and found that these bacterial signatures correlated with higher levels of markers of Alzheimer's disease in the cerebrospinal fluid of the participants with MCI.

Through cross-group dietary intervention, the study also showed that a modified Mediterranean-ketogenic diet produced changes in the gut microbiome and its metabolites that correlated with reduced levels of Alzheimer's markers in the members of both study groups.

The study appears in the current issue of EBioMedicine, a journal published by The Lancet.

"The relationship of the gut microbiome and diet to neurodegenerative diseases has recently received considerable attention, and this study suggests that Alzheimer's disease is associated with specific changes in gut bacteria and that a type of ketogenic Mediterranean diet can affect the microbiome in ways that could impact the development od dementia," said Hariom Yadav, Ph.D., assistant professor of molecular medicine at Wake Forest School of Medicine, who co-authored the study with Suzanne Craft, Ph.D., professor gerontology and geriatric medicine at the medical school and director of Wake Forest Baptist Health's Alzheimer's Disease Research Center.

The randomized, double-blind, single-site study involved 17 older adults, 11 with diagnosed MCI and six with normal cognition. These participants were randomly assigned to follow either the low-carbohydrate modified Mediterranean-ketogenic diet or a low-fat, higher carbohydrate diet for six weeks then, after a six-week "washout" period, to switch to the other diet. Gut microbiome, fecal short-chain fatty acids and markers of Alzheimer's, including amyloid and tau proteins, in cerebrospinal fluid were measured before and after each dieting period.

The study's limitations include the subject group's size, which also accounts for the lack of diversity in terms of gender, ethnicity and age.

"Our findings provide important information that future interventional and clinical studies can be based on," Yadav said. "Determining the specific role these gut microbiome signatures have in the progression of Alzheimer's disease could lead to novel nutritional and therapeutic approaches that would be effective against the disease."

The research was supported by grant P30 AG049638 and award R01 AG055122 from the National Institute on Aging, Department of Defense grant W81XWH-18-1-0118, National Center for Advancing Translational Sciences grant UL1 TR001420 and a grant from the Hartman Family Foundation.

Story Source:

Materials provided by Wake Forest Baptist Medical Center. Note: Content may be edited for style and length.

Journal Reference:

Ravinder Nagpal, Bryan J. Neth, Shaohua Wang, Suzanne Craft, Hariom Yadav. Modified Mediterranean-ketogenic diet modulates gut microbiome and short-chain fatty acids in association with Alzheimer's disease markers in subjects with mild cognitive impairment. EBioMedicine, 2019; DOI: 10.1016/j.ebiom.2019.08.032

Cite This Page:

Wake Forest Baptist Medical Center. "Diet's effect on gut bacteria could play role in reducing Alzheimer's risk." ScienceDaily. ScienceDaily, 3 September 2019. <www.sciencedaily.com/releases/2019/09/190903120514.htm>.

Vitamin D: How much is too much of a good thing?

High doses of vitamin D may result in a decrease in bone density

Date: September 3, 2019 Source: University of Calgary Summary: A three-year study has shown that there is no benefit in taking high doses of vitamin D. More research is required to determine if high doses may actually compromise bone health.

When bare skin is exposed to sunlight, it makes Vitamin D, which is needed by our bodies to absorb calcium and ensure strong, healthy bones. With bathing suit skin exposure, it only takes about 10-15 minutes of sun exposure during the summer to generate all the vitamin D your body needs for the day. Unfortunately, for Canadians, exposure to sunlight is diminished during the long winter months. This results in many turning to supplements to get the required vitamin D.

For normal, healthy adults, Health Canada recommends a total daily intake of 600 international units (IU) up to age 70, and 800 IU after age 70. Other sources, like Osteoporosis Canada, suggest adults at risk of osteoporosis, a condition characterized by bone loss, should take 400 -- 2,000 IU of Vitamin D. However, some people may be taking up to 20 times the recommended daily dose to prevent or treat a variety of medical conditions that might be related to having not enough vitamin D. So, what is the correct dose? And, how much is too much?

"Although vitamin D may be involved in regulating many of the body's systems, it is the skeleton that is most clearly affected by vitamin D deficiency," says Dr. David Hanley, MD, an endocrinologist in the Cumming School of Medicine (CSM), and one of the principal investigators of the study. "Current Health Canada recommendations were set to prevent the bone diseases caused by vitamin D deficiency for the vast majority of healthy Canadians. But it has been more difficult to clearly establish the optimal dose of vitamin D. When we designed this study, there remained a question whether there's more benefit in taking a higher dose."

A three-year study by researchers at the Cumming School of Medicine's McCaig Institute for Bone and Joint Health published in the Journal of the American Medical Association (JAMA), showed there is no benefit in taking high doses of vitamin D. The study followed 300 volunteers between the ages of 55 and 70 in a double-blind, randomized clinical trial to test the hypothesis that with increasing doses of vitamin D, there would be a dose-related increase in bone density and bone strength. A third of the study participants received 400 IU of vitamin D per day, a third received 4,000 IU per day, and a third received 10,000 IU per day.

Volunteers had both their bone density and bone strength measured using a new, high-resolution computed tomography (CT) scan of bone at the wrist and ankle, called an XtremeCT, used only for research. The XtremeCT, located in the McCaig Institute's new Centre for Mobility and Joint Health, is the first of its kind in the world, and allows researchers to look at bone microarchitecture in detail never seen before. Standard dual-X-ray absorptiometry (DXA) bone density was also obtained. Participants received scans at the start of the study and at 6, 12, 24 and 36 months. To assess vitamin D and calcium levels, researchers also collected fasting blood samples at the beginning of the study and at 3, 6, 12, 18, 24, 30 and 36 months as well as urine collections annually.

Bone mineral density (BMD) is determined by measuring the amount of calcium and other minerals in a defined segment of bone. The lower the bone density, the greater the risk for bone fracture.

Adults slowly lose BMD as they age, and the DXA results showed a modest decrease in BMD over the duration of the study, with no differences detected between the three groups. However, the more sensitive measurement of BMD with high resolution XtremeCT showed significant differences in bone loss among the three dose levels.

Total BMD decreased over the three-year period by 1.4 per cent in the 400 IU group, 2.6 in the 4,000 IU group and 3.6 in the 10,000 IU group. The conclusion was that, contrary to what was predicted, vitamin D supplementation at doses higher than those recommended by Health Canada or Osteoporosis Canada were not associated with an increase in bone density or bone strength. Instead, the XtremeCT detected a dose-related decrease in bone density, with the largest decrease occurring in the 10,000 IU per day group. More research is required to determine if high doses may actually compromise bone health.

"We weren't surprised that using DXA we found no difference among the treatment arms, whereas with XtremeCT, the latest in bone imaging technology, we were able to find dose-dependent changes over the three years. However, we were surprised to find that instead of bone gain with higher doses, the group with the highest dose lost bone the fastest," says Steve Boyd, a professor in the CSM and one of the principal investigators of the study. "That amount of bone loss with 10,000 IU daily is not enough to risk a fracture over a three-year period, but our findings suggest that for healthy adults, vitamin D doses at levels recommended by Osteoporosis Canada (400-2000 IU daily) are adequate for bone health."

A secondary outcome of the study indicated a potential safety concern with taking high levels of vitamin D. Although there were incidents in all three arms of the study, the investigators found that participants assigned to receive higher doses of daily vitamin D supplementation (4000 IU and 10,000 IU) over the three years were more likely to develop hypercalciuria (elevated levels of calcium in the urine), compared to those receiving a lower daily dose. Hypercalciuria is not uncommon in the general population, but is associated with increased risk of kidney stones and may contribute to impaired kidney function.

Hyperalciuria occurred in 87 participants. Incidence varied significantly between the 400 IU (17%) 4000 IU (22%) and 10,000 IU (31%) study groups. If hypercalciuria was detected in study participants, calcium intake was reduced. After repeat testing, the hypercalciuria usually resolved.

"What we can see in this study is that large doses of vitamin D don't come with a benefit to the skeleton," says Dr. Emma Billington, MD, one of the authors of the study. "For healthy adults, 400 IU daily is a reasonable dose. Doses of 4,000 IU or higher are not recommended for the majority of individuals."

Story Source:

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

Journal Reference:

Lauren A. Burt, Emma O. Billington, Marianne S. Rose, Duncan A. Raymond, David A. Hanley, Steven K. Boyd. Effect of High-Dose Vitamin D Supplementation on Volumetric Bone Density and Bone Strength. JAMA, 2019; 322 (8): 736 DOI: 10.1001/jama.2019.11889

Cite This Page:

https://www.sciencedaily.com/releases/2019/09/190906172413.htm

University of Calgary. "Vitamin D: How much is too much of a good thing? High doses of vitamin D may result in a decrease in bone density." ScienceDaily. ScienceDaily, 3 September 2019. <www.sciencedaily.com/releases/2019/09/190903134738.htm>.

Disrupting the gut microbiome may affect some immune responses to flu vaccination

Date: September 6, 2019

Source: NIH/National Institute of Allergy and Infectious Diseases

Summary:

The normal human gut microbiome is a flourishing community of microorganisms, some of which can affect the human immune system. Researchers have now found that oral antibiotics, which can kill gut microorganisms, can alter the human immune response to seasonal influenza vaccination.

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Offering children a variety of vegetables increases acceptance

Date: September 9, 2019 Source: Elsevier Summary: Although food preferences are largely learned, dislike is the main reason parents stop offering or serving their children foods like vegetables. A new study has demonstrated that repeatedly offering a variety of vegetables increased acceptance and consumption by children.

Child with fresh vegetables (stock image).

Although food preferences are largely learned, dislike is the main reason parents stop offering or serving their children foods like vegetables. A new study in the Journal of Nutrition Education and Behavior, published by Elsevier, demonstrated that repeatedly offering a variety of vegetables increased acceptance and consumption by children.

"In Australia, dietary guidelines for vegetable consumption by young children have increased although actual consumption is low," said lead author Astrid A.M. Poelman, PhD, CSIRO Agriculture & Food, Sensory, Flavour and Consumer Science, North Ryde, Australia. "This study introduces an effective strategy for parents wanting to address this deficiency."

This study recruited 32 families with children between the ages of four and six where low consumption of vegetables was reported. Parents completed an online survey and attended an information meeting prior to participating. Three groups were created: children introduced to a single vegetable; children to receive multiple vegetables; and a group where eating habits were not changed.

Study data were collected in several ways: two dinner meals served at the research facility during which children could eat as much of the broccoli, cauliflower and green beans as they wished; changes to actual vegetables consumed at home, childcare or school recorded through food diaries; and parents reporting on usual vegetable consumption.

Strategies of offering vegetables were parent led and home based. Families introducing one vegetable served broccoli and families trying multiple vegetables served broccoli, zucchini and peas. Parents were provided with a voucher to purchase the vegetables and given instructions on portion size and cooking instructions along with tips on how to offer the vegetables. Children were served a small piece of vegetable three times a week for five weeks. A sticker was given as a reward to children trying a vegetable.

There was no difference between groups at the start of the study for any of the methods measured. The dinner meal, during which the children ate without parents present, did not increase consumption perhaps due to an unfamiliar setting. Vegetable acceptance increased for both the single and multiple vegetable groups during the intervention. Families that offered multiple vegetables recorded an increase in consumption from .6 to 1.2 servings, while no change in consumption was observed in families serving a single vegetable or families that did not change their eating habits. Increased acceptance for multiple vegetables was noted during the five weeks of the study and sustained at three-month followup. Following the study parents reported that offering the vegetables was "very easy" or "quite easy" with the majority following the instructions provided by the study.

Dr. Poelman recommended, "While the amount of vegetables eaten increased during the study, the amount did not meet dietary guidelines. Nonetheless, the study showed the strategy of offering a variety of vegetables was more successful in increasing consumption than offering a single vegetable."

Story Source:

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

Journal Reference:

Astrid A.M. Poelman, Conor M. Delahunty, Maeva Broch, Cees de Graaf. Multiple vs Single Target Vegetable Exposure to Increase Young Children's Vegetable Intake. Journal of Nutrition Education and Behavior, 2019; 51 (8): 985 DOI: 10.1016/j.jneb.2019.06.009

Cite This Page:

Elsevier. "Offering children a variety of vegetables increases acceptance." ScienceDaily. ScienceDaily, 9 September 2019. <www.sciencedaily.com/releases/2019/09/190909123713.htm>.

Dietary supplement may help with schizophrenia

Date: September 9, 2019 Source: University College London Summary: A dietary supplement, sarcosine, may help with schizophrenia as part of a holistic approach complementing antipsychotic medication, according to a researcher.

A dietary supplement, sarcosine, may help with schizophrenia as part of a holistic approach complementing antipsychotic medication, according to a UCL researcher.

In an editorial published in the British Journal of Psychiatry, Professor David Curtis (UCL Genetics, Evolution & Environment and QMUL Centre for Psychiatry) suggests the readily available product could easily be incorporated into treatment plans, while calling for clinical trials to clarify the benefit and inform guidelines.

"Sarcosine represents a very logical treatment and the small number of clinical trials so far do seem to show that it can be helpful. It certainly seems to be safe and some patients report feeling better on it," he said.

"Sarcosine may be a helpful treatment for schizophrenia but we should be carrying out further studies in order to find out for sure."

Sarcosine naturally occurs in foods such as egg yolks, turkey and legumes, and can be bought as a dietary supplement, sometimes promoted as a 'brain health supplement', with various claims being made that are not all backed up by adequate evidence.

Professor Curtis writes that there is now good evidence from multiple lines of study that some patients with schizophrenia may have defects in the functioning of receptors for glutamate, a common neurotransmitter in the brain, and that sarcosine can help glutamate receptors to work better.

Researchers have been accumulating evidence that if these glutamate receptors did not function properly then people could develop psychosis and other symptoms of schizophrenia.

Professor Curtis and colleagues have recently added to the evidence, showing that genetic variants which damage this receptor increase the risk of schizophrenia.

The only risk identified so far seems to be that some people taking sarcosine to treat schizophrenia who are also on antidepressants may experience hypomania (disinhibition and euphoria), which Professor Curtis says highlights the importance of consulting with health professionals before taking sarcosine.

"Some studies have used it on its own as a treatment but I think the obvious thing to try first would be for patients to take it alongside their regular antipsychotic medication, in order to produce further improvement," said Professor Curtis.

He says that health professionals need to be aware of sarcosine so that they know how to respond if a patient asks them about it, given that it's increasingly being used as an alternative therapy.

"I would encourage psychiatrists to review the evidence, and while they may reach different conclusions, it seems reasonable to conclude that suggesting sarcosine to a patient with schizophrenia would be defensible and evidence-based.

"Because it is freely available and fairly cheap, there is nothing to stop somebody with schizophrenia from buying it and trying it themselves, which underscores the need for health professionals to get our heads around it. I would certainly warn them not to stop their regular medication and to continue following the advice of their psychiatrist," he said.

Story Source:

Materials provided by University College London. Note: Content may be edited for style and length.

Journal Reference:

David Curtis. A possible role for sarcosine in the management of schizophrenia. The British Journal of Psychiatry, 2019; 1 DOI: 10.1192/bjp.2019.194

Cite This Page:

University College London. "Dietary supplement may help with schizophrenia." ScienceDaily. ScienceDaily, 9 September 2019. <www.sciencedaily.com/releases/2019/09/190909193217.htm>.

sábado, 7 de setembro de 2019

Presentes nas frutas, proteínas similares às do látex podem causar alergia

05.09.2019

Entre as frutas que contêm essas proteínas estão mamão, figo, banana, abacate, kiwi e melão. Alérgicos ao látex devem ficar atentos

Editorias: Ciências da Saúde - URL Curta: jornal.usp.br/?p=270083

Mamão papaia – Foto: Sebástian Freire / Flickr

O fenômeno se chama “síndrome látex-fruta” e acontece porque algumas frutas, como mamão, figo, banana, abacate, kiwi e melão, têm em sua composição proteínas semelhantes àquelas presentes no látex da Hevea brasiliensis – a famosa seringueira. “A quimopapaína, por exemplo, encontrada no látex do mamão, pode provocar essa síndrome. A esse fenômeno chamamos reatividade cruzada. Tem gente que é alérgica à borracha [látex] e que também tem ou pode desenvolver alergia ao mamão, ao figo, à banana”, explica Gabriela Justamante Händel Schmitz, que estudou a reatividade cruzada em seu trabalho de doutorado na Faculdade de Ciências Farmacêuticas (FCF) da USP.

De acordo com ela, uma proteína do látex da seringueira, denominada cisteína protease, tem a sequência de aminoácidos muito similar à da quimopapaína. “Como elas são similares, em alguns indivíduos o organismo pode responder com essa reatividade cruzada. Se sou alérgica à borracha, usada para fazer uma luva, por exemplo, posso ser ou vir a ser alérgica a mamão – e também ao figo, à banana, ao abacate, ao kiwi, ao melão. Todos esses frutos têm proteínas similares às encontradas no látex da Hevea brasiliensis.”

A pesquisadora afirma que as pessoas alérgicas à proteína do látex da Hevea têm imunoglobulinas E (IgEs) específicas para essa proteína. “Se comem um mamão, que tem uma proteína similar à proteína da seringueira, a proteína do mamão consegue se encaixar nas IgEs sintetizadas para a proteína do látex da Hevea, e então o paciente tem todas as reações alérgicas que teria a artefatos feitos do látex da seringueira.”

Extração do látex na Hevea brasiliensis – Foto: https://pt.depositphotos.com/80829696/stock-photo-milky-latex-extracted-from-natural.html

Segundo ela, cada vez se descobrem mais proteínas similares às da seringueira em frutos. “Muitas crianças têm esse tipo de alergia, e o diagnóstico é difícil. Por isso, estamos indo atrás de novos alérgenos. Só do mamão há cinco alérgenos descobertos. E não fazemos ideia de quantos mais podem existir.”

A cientista conta que muitos pacientes brasileiros têm alergia à mandioca e ao látex, há inclusive um estudo de um grupo do Hospital das Clínicas sobre isso.

O látex encontrado no mamão (principalmente na casca) contém uma enzima proteolítica chamada papaína, que tem funções bactericidas, anti-inflamatórias e bacteriostáticas, além de ser usada em medicamentos para auxiliar a digestão. “A papaína presente no látex do mamão é um alérgeno bem descrito dessa fruta, chamado Cari p papain. Porém, quem tem alergia a mamão pode ser alérgico a outras proteínas dele que ainda não foram descobertas”, afirma a pesquisadora.

Ela explica que a produção de látex é um mecanismo de defesa da planta contra predadores e situações de estresse. “O látex do mamão, assim como outras substâncias produzidas por diversas plantas, tem ação biológica. E, em quase todos os casos, essas substâncias são sintetizadas pela planta para a sua defesa, o que significa que são tóxicas para os predadores. Assim, em grandes quantidades, podem ser tóxicas para nós”, resume.

Sobre o FoRC

Criado em 2013, o FoRC é um dos Centros de Pesquisa, Inovação e Difusão (Cepids) apoiados pela Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp). Reúne equipes multidisciplinares de diferentes instituições de pesquisa do Estado de São Paulo: USP, Unicamp, Unesp, Instituto de Tecnologia de Alimentos (Ital) e Instituto Mauá de Tecnologia (IMT). Suas linhas de pesquisa estão estruturadas em quatro pilares: Sistemas Biológicos em Alimentos; Alimentos, Nutrição e Saúde; Qualidade e Segurança de Alimentos e Novas Tecnologias e Inovação. Além de realizar pesquisas e promover a transferência de tecnologias e novos conhecimentos para a sociedade, o FoRC também realiza atividades de difusão do conhecimento científico.

Da Assessoria de Comunicação do FoRC

segunda-feira, 17 de junho de 2019

Red and white meats are equally bad for cholesterol

Date: June 4, 2019 Source: University of California - San Francisco Summary: Contrary to popular belief, consuming red meat and white meat such as poultry, have equal effects on blood cholesterol levels, according to a new study.

Contrary to popular belief, consuming red meat and white meat such as poultry, have equal effects on blood cholesterol levels, according to a study published today in the American Journal of Clinical Nutrition.

The study, led by scientists at Children's Hospital Oakland Research Institute (CHORI) -- the research arm of UCSF Benioff Children's Hospital Oakland -- surprised the researchers with the discovery that consuming high levels of red meat or white poultry resulted in higher blood cholesterol levels than consuming a comparable amount of plant proteins. Moreover, this effect was observed whether or not the diet contained high levels of saturated fat, which increased blood cholesterol to the same extent with all three protein sources.

"When we planned this study, we expected red meat to have a more adverse effect on blood cholesterol levels than white meat, but we were surprised that this was not the case -- their effects on cholesterol are identical when saturated fat levels are equivalent," said the study senior author Ronald Krauss, M.D., senior scientist and director of Atherosclerosis Research at CHORI.

Krauss, who is also a UCSF professor of medicine, noted that the meats studied did not include grass-fed beef or processed products such as bacon or sausage; nor did it include fish.

But the results were notable, as they indicated that restricting meat altogether, whether red or white, is more advisable for lowering blood cholesterol levels than previously thought. The study found that plant proteins are the healthiest for blood cholesterol.

This study, dubbed the APPROACH (Animal and Plant Protein and Cardiovascular Health) trial, also found that consuming high amounts of saturated fat increased concentrations of large cholesterol-enriched LDL particles, which have a weaker connection to cardiovascular disease than smaller LDL particles.

Similarly, red and white meat increased amounts of large LDL in comparison to nonmeat diets. Therefore, using standard LDL cholesterol levels as the measure of cardiovascular risk may lead to overestimating that risk for both higher meat and saturated fat intakes, as standard LDL cholesterol tests may primarily reflect levels of larger LDL particles.

Consumption of red meat has become unpopular during the last few decades over concerns about its association with increased heart disease. Government dietary guidelines have encouraged the consumption of poultry as a healthier alternative to red meat.

But there had been no comprehensive comparison of the effects of red meat, white meat and nonmeat proteins on blood cholesterol until now, Krauss said. Nonmeat proteins such as vegetables, dairy, and legumes, such as beans, show the best cholesterol benefit, he said.

"Our results indicate that current advice to restrict red meat and not white meat should not be based only on their effects on blood cholesterol," Krauss said. "Indeed, other effects of red meat consumption could contribute to heart disease, and these effects should be explored in more detail in an effort to improve health."

Story Source:

Materials provided by University of California - San Francisco. Original written by Lorna Fernandes. Note: Content may be edited for style and length.

Journal Reference:

Nathalie Bergeron, Sally Chiu, Paul T Williams, Sarah M King, Ronald M Krauss. Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial. The American Journal of Clinical Nutrition, 2019; DOI: 10.1093/ajcn/nqz035

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