Pecan consumption linked to improved cardiovascular and diabetic biomarkers

Researchers have conducted a study to see if eating pecans had an impact on cardiovascular disease and diabetes biomarkers. This study was funded by National Pecan Shellers Association and findings are published in journal Nutrition.

Researchers conducted a placebo-controlled crossover trial of 26 subjects. All subjects were provided with meals to carefully control their food intake. For 4 weeks one group had a diet with 15% of daily calorie intake provided with pecans. Both the control diet and the pecan-rich diet were low in fruits, vegetables, and fiber. Calorie levels, as well as protein, carbohydrate, and total fat, were kept the same. Results of the study showed improvements in serum insulin, insulin resistance, pancreatic beta cell function and cardiovascular disease biomarkers.

“Pecans are naturally high in monounsaturated and polyunsaturated fats, so replacing a portion of the saturated fat in the diet with these healthier fats can explain some of the cardioprotective effects we observed,” said lead researcher, Diane McKay, Ph.D. “But pecans also contain a number of bioactive plant compounds as well as vitamins and essential minerals that all likely contributed to this benefit. What’s really interesting is that just one small change – eating a handful of pecans daily – may have a large impact on the health of these at-risk adults.”

Reference: Mckay, Diane, Misha Eliasziw, C. Chen, and Jeffrey Blumberg. “A Pecan-Rich Diet Improves Cardiometabolic Risk Factors in Overweight and Obese Adults: A Randomized Controlled Trial.” Nutrients 10, no. 3 (2018): 339. doi:10.3390/nu10030339.

Research funding: National Pecan Shellers Association

Adapted from press release by Kellen Communications.

Nutraceuticals, what are they? how we should regulate them?

A new review published in the British Journal of Clinical Pharmacology looks at the potential of nutraceuticals, stressing the need for a proper definition of nutraceuticals and clear regulations to ensure their safety.

In the review article, a team led by Ettore Novellino, PhD and Antonello Santini, PhD, of the University of Napoli Federico II in Italy, states that nutraceuticals with proven efficacy and health benefits substantiated by clinical data could be used as powerful tools to prevent and treat medical conditions, especially in individuals who may not yet be eligible for conventional pharmaceutical drugs.

The authors propose the following definition for nutraceuticals: the phytocomplex of a vegetable or the pool of secondary metabolites from an animal. Both are concentrated and administered in a pharmaceutical form and are capable of providing beneficial health effects, including the prevention and/or treatment of a disease.

“Nutraceuticals, in the collective imagination of the consumer, tend to be confused and wrongly identified with many other products available on the market on the basis of potential health benefits,” said Dr. Novellino. “An evaluation of the safety, the mechanism of action, and the effectiveness of nutraceuticals and substantiating this with clinical data is the central point that differentiates nutraceuticals from food supplements.”

Dr. Santini added that the growing demand and interest in nutraceuticals justifies the need for a restructuring of the entire regulatory framework that differentiates nutraceuticals from food supplements. “We propose a regulatory system that is similar to the one used for drugs, which is more rigorous and more complex than the one commonly accepted for food supplements,” he said. “It is important for consumer protection that national authorities and regulatory agencies require manufacturers to provide data to support any claim in the labels of products when the term nutraceutical is used.”

Citation: Santini, Antonello, Silvia Miriam Cammarata, Giacomo Capone, Angela Ianaro, Giancarlo Tenore, Luca Pani, and Ettore Novellino. “Nutraceuticals: opening the debate for a regulatory framework.” British Journal of Clinical Pharmacology, 2018. doi:10.1111/bcp.13496.

Adapted from press release by Wiley publications.

Vitamin E requirements increased in people suffering from metabolic syndrome

New research has shown that people with metabolic syndrome need significantly more vitamin E – which could be a serious public health concern, in light of the millions of people who have this condition that’s often related to obesity. A study published in the American Journal of Clinical Nutrition also made it clear that conventional tests to measure vitamin E levels in the blood may have limited accuracy compared to tests made in research laboratories, to the point that conventional tests can actually mask an underlying problem.

Vitamin E supplements. Credit: John Liu / Oregon State University.

Vitamin E – one of the more difficult micronutrients to obtain by dietary means – is an antioxidant important for cell protection. It also affects gene expression, immune function, aids in the repair of wounds and the damage of atherosclerosis, is important for vision and neurologic function, and largely prevents fat from going rancid.

Nutrition surveys have estimated that 92 percent of men and 96 percent of women in the United States fail to get an adequate daily intake of vitamin E in their diet. It is found at high levels in almonds, wheat germ, various seeds and oils, and at much lower levels in some vegetables and salad greens, such as spinach and kale.

This study was done by researchers at the Linus Pauling Institute at Oregon State University and the Human Nutrition Program at The Ohio State University, as a double-blind, crossover clinical trial focusing on vitamin E levels in people with metabolic syndrome. “The research showed that people with metabolic syndrome need about 30-50 percent more vitamin E than those who are generally healthy,” said Maret Traber, a professor in the OSU College of Public Health and Human Sciences, and Ava Helen Pauling Professor in the Linus Pauling Institute.

“In previous work, we showed that people with metabolic syndrome had a lower bioavailability of vitamin E. Our current work uses a novel approach to measure how much vitamin E the body needs. This study clearly demonstrates that people with metabolic syndrome need a higher intake of this vitamin.”

More than 30 percent of the American public are obese, and more than 25 percent of the adults in the United States meet the criteria for metabolic syndrome, putting them at significantly increased the risk for cardiovascular disease and type-2 diabetes primary causes of death in the developed world.

That syndrome is defined by diagnosis of three or more of several conditions, including abdominal obesity, elevated lipids, high blood pressure, pro-inflammatory state, a pro-thrombotic state and insulin resistance or impaired glucose tolerance. This research, for the first time, also clearly outlined a flaw with conventional approaches to measuring vitamin E.

By “labeling” vitamin E with deuterium, a stable isotope of hydrogen, scientists were able to measure the amount of the micronutrient that was eliminated by the body, compared to the intake. The advanced research laboratory tests, which are not available to the general public, showed that people with metabolic syndrome retained 30-50 percent more vitamin E than healthy people – showing that they needed it. When the body doesn’t need vitamin E, the excess is excreted.

But in the group with metabolic syndrome, even as their tissues were taking up and retaining the needed vitamin E, their blood levels by conventional measurement appeared about the same as those of a normal, healthy person.

“We’ve discovered that vitamin E levels often look normal in the blood, because this micronutrient is attracted to high cholesterol and fat,” Traber said. “So vitamin E can stay at higher levels in the circulatory system and give the illusion of adequate levels, even as tissues are deficient.

“This basically means that conventional vitamin E blood tests as they are now being done are useless.”

The findings support the conclusion that people with metabolic syndrome have higher levels of oxidative and inflammatory stress, scientists said in their conclusion, and require more antioxidants such as vitamins E as a result.

Citation: Maret G Traber, Eunice Mah, Scott W Leonard, Gerd Bobe, and Richard S Bruno. “Metabolic syndrome increases dietary α-tocopherol requirements as assessed using urinary and plasma vitamin E catabolites: a double-blind, crossover clinical trial.” The American Journal of Clinical Nutrition 2017 pp: ajcn138495
DOI: 10.3945/ajcn.116.138495
Research funding: National Institutes of Health, National Dairy Council, and DSM Nutrition.
Adapted from press release by Oregon State University.

Decreased mortality associated with eating red hot chili peppers

Researchers at the Larner College of Medicine at the University of Vermont, who found that consumption of hot red chili peppers is associated with a 13 percent reduction in total mortality primarily in deaths due to heart disease or stroke in a large prospective study. The study was published recently in PLoS ONE.

Chili Peppers. Wikipedia

Going back for centuries, peppers and spices have been thought to be beneficial in the treatment of diseases, but only one other study — conducted in China and published in 2015 – has previously examined chili pepper consumption and its association with mortality. This new study corroborates the earlier study’s findings.

Using National Health and Nutritional Examination Survey (NHANES) III data collected from more than 16,000 Americans who were followed for up to 23 years, medical student Mustafa Chopan ’17 and Professor of Medicine Benjamin Littenberg, M.D., examined the baseline characteristics of the participants according to hot red chili pepper consumption. They found that consumers of hot red chili peppers tended to be “younger, male, white, Mexican-American, married, and to smoke cigarettes, drink alcohol, and consume more vegetables and meats had lower HDL-cholesterol, lower income, and less education,” in comparison to participants who did not consume red chili peppers. They examined data from a median follow-up of 18.9 years and observed the number of deaths and then analyzed specific causes of death.

“Although the mechanism by which peppers could delay mortality is far from certain, Transient Receptor Potential (TRP) channels, which are primary receptors for pungent agents such as capsaicin (the principal component in chili peppers), may in part be responsible for the observed relationship,” say the study authors.

There are some possible explanations for red chili peppers’ health benefits, state Chopan and Littenberg in the study. Among them are the fact that capsaicin – the principal component in chili peppers is believed to play a role in cellular and molecular mechanisms that prevent obesity and modulate coronary blood flow, and also possesses antimicrobial properties that “may indirectly affect the host by altering the gut microbiota.”

“Because our study adds to the generalizability of previous findings, chili pepper — or even spicy food – consumption may become a dietary recommendation and/or fuel further research in the form of clinical trials,” says Chopan.

Citation: Chopan, Mustafa, and Benjamin Littenberg. “The Association of Hot Red Chili Pepper Consumption and Mortality: A Large Population-Based Cohort Study.” PloS one 12, no. 1 (2017): e0169876.
DOI: 10.1371/journal.pone.0169876
Adapted from press release by the University of Vermont.

Research in mice show antioxidants in blue maize have protective effect against metabolic syndrome

A new study shows that a rat model of metabolic syndrome fed a high-sugar and high-cholesterol diet and given blue maize extract showed significant improvement in systolic blood pressure, high density lipoprotein (HDL) cholesterol, and triglyceride levels compared to those not given the extract. The natural antioxidants present in blue maize may help protect against metabolic syndrome, cardiovascular disease, diabetes, and cancer, raising interest in using blue maize as a component of functional foods and nutraceuticals, according to an article published in Journal of Medicinal Food.

Credit: Pexels /Pixabay

In the article Rosa Isela Guzman-Geronimoa and coauthors from Universidad Veracruzana, Instituto Tecnologico de Veracruz, and Unidad Oaxaca/Calle Hornos, Mexico, report that the animals fed a high-sugar and high-cholesterol diet that received blue maize extract had a significantly smaller increase in abdominal fat compared to the abdominal fat gain in rats that did not receive the extract.

“Anti-obesity food materials are always in demand, and this study brings out not only the importance of blue maize in controlling adipocity, but also the potential role of cholesterol in the development of obesity,” says Journal of Medicinal Food Editor-in-Chief Sampath Parthasarathy, MBA, PhD, Florida Hospital Chair in Cardiovascular Sciences and Interim Associate Dean, College of Medicine, University of Central Florida.

Citation: Guzmán-Gerónimo Rosa Isela, Alarcón-Zavaleta Tania Margarita, Oliart-Ros Rosa María, Meza-Alvarado José Enrique, Herrera-Meza Socorro, and Chávez-Servia José Luis. “Blue Maize Extract Improves Blood Pressure, Lipid Profiles, and Adipose Tissue in High-Sucrose Diet-Induced Metabolic Syndrome in Rats.” Journal of Medicinal Food. December 2016, ahead of print. DOI:10.1089/jmf.2016.0087

Role of Vitamin C in cancer treatment

Vitamin C has a patchy history as a cancer therapy, but researchers at the University of Iowa believe that is because it has often been used in a way that guarantees failure. Most vitamin C therapies involve taking the substance orally. However, the UI scientists have shown that giving vitamin C intravenously and bypassing normal gut metabolism and excretion pathways create blood levels that are 100 – 500 times higher than levels seen with oral ingestion. It is this super-high concentration in the blood that is crucial to vitamin C’s ability to attack cancer cells.

Citrus fruits, a rich source of Vitamin C. Credit: LoggaWiggler/pixabay

Earlier work by UI redox biology expert Garry Buettner found that at these extremely high levels (in the millimolar range), vitamin C selectively kills cancer cells but not normal cells in the test tube and in mice. Physicians at UI Hospitals and Clinics are now testing the approach in clinical trials for pancreatic cancer and lung cancer that combine high-dose, intravenous vitamin C with standard chemotherapy or radiation. Earlier phase 1 trials indicated this treatment is safe and well-tolerated and hinted that the therapy improves patient outcomes. The current, larger trials aim to determine if the treatment improves survival.

In a study, published in journal Redox Biology, Buettner and his colleagues have homed in on the biological details of how high-dose vitamin C (also known as ascorbate) kills cancer cells. The study shows that vitamin C breaks down easily, generating hydrogen peroxide, a so-called reactive oxygen species that can damage tissue and DNA. The study also shows that tumor cells are much less capable of removing the damaging hydrogen peroxide than normal cells.

“In this paper we demonstrate that cancer cells are much less efficient in removing hydrogen peroxide than normal cells. Thus, cancer cells are much more prone to damage and death from a high amount of hydrogen peroxide,” says Buettner, a professor of radiation oncology and a member of Holden Comprehensive Cancer Center at the University of Iowa. “This explains how the very, very high levels of vitamin C used in our clinical trials do not affect normal tissue, but can be damaging to tumor tissue.”

Normal cells have several ways to remove hydrogen peroxide, keeping it at very low levels so it does not cause damage. The new study shows that an enzyme called catalase is the central route for removing hydrogen peroxide generated by decomposing vitamin C. The researchers discovered that cells with lower amounts of catalase activity were more susceptible to damage and death when they were exposed to high amounts of vitamin C.

Buettner says this fundamental information might help determine which cancers and which therapies could be improved by inclusion of high-dose ascorbate in the treatment. “Our results suggest that cancers with low levels of catalase are likely to be the most responsive to high-dose vitamin C therapy, whereas cancers with relatively high levels of catalase may be the least responsive,” he explains. A future goal of the research is to develop methods to measure catalase levels in tumors.

Citation: Doskey, Claire M., Visarut Buranasudja, Brett A. Wagner, Justin G. Wilkes, Juan Du, Joseph J. Cullen, and Garry R. Buettner. “Tumor cells have decreased ability to metabolize H 2 O 2: Implications for pharmacological ascorbate in cancer therapy.” Redox Biology 10 (2016): 274-284.
DOI: 10.1016/j.redox.2016.10.010
Research Funding: National Institutes of Health, Gateway for Cancer Research.
Adapted from press release by the University of Iowa.

Chronic headache and Vitamin D deficiency

Vitamin D deficiency may increase the risk of a chronic headache, according to a new study from the University of Eastern Finland. The findings were published in Scientific Reports.

The Kuopio Ischaemic Heart Disease Risk Factor Study, KIHD, analyzed the serum vitamin D levels and occurrence of a headache in approximately 2,600 men aged between 42 and 60 years in 1984-1989. In 68% of these men, the serum vitamin D level was below 50 nmol/l, which is generally considered the threshold for vitamin D deficiency. A chronic headache occurring at least on a weekly basis was reported by 250 men, and men reporting chronic headache had lower serum vitamin D levels than others.

When the study population was divided into four groups based on their serum vitamin D levels, the group with the lowest levels had over a twofold risk of a chronic headache in comparison to the group with the highest levels. A chronic headache was also more frequently reported by men who were examined outside the summer months of June through September. Thanks to UVB radiation from the sun, the average serum vitamin D levels are higher during the summer months.

The study adds to the accumulating body of evidence linking a low intake of vitamin D to an increased risk of chronic diseases. Low vitamin D levels have been associated with the risk of a headache also by some earlier, mainly considerably smaller studies.

In Finland and in other countries far from the Equator, UVB radiation from the sun is a sufficient source of vitamin D during the summer months, but outside the summer season, people need to make sure that they get sufficient vitamin D from food or from vitamin D supplements.

No scientific evidence relating to the benefits and possible adverse effects of long-term use in higher doses yet exists. The Finnish Vitamin D Trial, FIND, currently ongoing at the University of Eastern Finland will shed light on the question, as the five-year trial analyses the effects of high daily doses of vitamin D on the risk factors and development of diseases. The trial participants are taking a vitamin D supplement of 40 or 80 micrograms per day. The trial also investigates the effects of vitamin D supplementation on various pain conditions.

Citation: Virtanen, Jyrki K.,  Rashid Giniatullin, Pekka Mäntyselkä, Sari Voutilainen, Tarja Nurmi, Jaakko Mursu, Jussi Kauhanen & Tomi-Pekka Tuomainen. “Low serum 25-hydroxyvitamin D is associated with higher risk of frequent headache in middle-aged and older men.” Scientific Reports 2017 vol: 7 pp: 39697.
DOI: 10.1038/srep39697
Adapted from press release by the University of Eastern Finland.

Research shows red cabbage microgreens reduce weight gain and lower cholesterol in mice fed on high-fat diet

Microgreens are sprouting up everywhere from upscale restaurants to home gardens. They help spruce up old recipes with intense flavors and colors and are packed with nutrients. Now research has shown that for mice on a high-fat diet, red cabbage microgreens helped lower their risk factors for developing cardiovascular disease and reduce their weight gain. The report appears in ACS’ Journal of Agricultural and Food Chemistry.

In an animal study, red cabbage microgreens helped lower “bad” cholesterol. Credit: American Chemical Society

Microgreens are tender, immature plants and herbs that take only a week or two to grow before they’re ready for harvesting. A growing body of research suggests that microgreens could offer more health benefits than their mature counterparts. And since previous studies have shown that full-grown red cabbage can help guard against excessive cholesterol, Thomas T.Y. Wang and colleagues wanted to see if red cabbage microgreens might have a similar or even greater effect than their larger counterparts.

To test their hypothesis, the researchers used mice that were a modelled for obesity. These animals also tend to develop high cholesterol and other risk factors for cardiovascular disease. The team divided 60 of these mice into different diet groups. They received food low in fat or high in fat, and with or without either red cabbage microgreens or mature red cabbage. Both the microgreens and mature cabbage diets reduced weight gain and levels of liver cholesterol in the mice on high-fat diets. The study showed that microgreens intake lowered LDL cholesterol, liver triglyceride, and inflammatory cytokine levels in the animals. 

Citation: Huang, Haiqiu, Xiaojing Jiang, Zhenlei Xiao, Lu Yu, Quynhchi Pham, Jianghao Sun, Pei Chen, Wallace Yokoyama, Liangli Lucy Yu, Yaguang Sunny Luo, and Thomas T. Y. Wang. “Red cabbage microgreen lower circulating LDL, liver cholesterol and inflammatory cytokines in mice fed a high fat diet.” Journal of Agricultural and Food Chemistry (2016).
DOI: 10.1021/acs.jafc.6b03805
Research funding: U.S. Department of Agriculture.
Adapted from press release by The American Chemical Society.

Research on Zebrafish show that probiotic bacteria help reduce stress and anxiety

Researchers at the University of Missouri, using a zebrafish model, determined that a common probiotic sold in supplements and yogurt can decrease stress-related behavior and anxiety. Studying how gut bacteria affect behavior in zebrafish could lead to a better understanding of how probiotics may affect the central nervous system in humans. Their results recently were published in Scientific Reports a journal of Nature.

“Zebrafish are an emerging model species for neurobehavioral studies and their use is well-established in drug-screening,” said Aaron Ericsson, director of the MU Metagenomics Center and a research assistant professor in the Department of Veterinary Pathobiology. “Our study has shown that simple probiotics that we normally use to keep our digestive tract in sync, could be beneficial to reducing our stress levels as well.”

In a series of studies, researchers tested how zebrafish behaved after doses of Lactobacillus plantarum, a common bacteria found in yogurt and probiotic supplements. In the first study, scientists added the bacteria to certain tanks housing zebrafish; other tanks of zebrafish received no probiotics. Then, the researchers introduced environmental stressors to both groups, such as draining small amounts of water from the tank and overcrowding.

“Each day we introduced a different stressor — tests that are validated by other researchers and cause higher anxiety among zebrafish,” said Elizabeth Bryda, professor of veterinary pathobiology in the MU College of Veterinary Medicine. “These are common environmental stress patterns, such as isolation stress and temperature change, so it made the tests relevant to humans as well.”

By analyzing the gene pathways of both groups of fish, the research team found that zebrafish that were given the probiotic supplements showed a reduction in the metabolic pathways associated with stress. “By measuring the genes associated with stress and anxiety, our tests were able to predict how this common probiotic is able to benefit behavioral responses in these fish,” said Daniel Davis, assistant director of the MU Animal Modeling Core.

To test their theory further, the researchers measured the movements of fish in their tanks using sophisticated computer measuring and imaging tools. Previous studies of fish behavior have found that fish that are stressed tend to spend more time at the bottom of their tanks. Once the fish were administered probiotics, they tended to spend more time toward the top of the tanks — the change in behavior indicating they were less stressed or less anxious.

Citation: Davis, Daniel J., Holly M. Doerr, Agata K. Grzelak, Susheel B. Busi, Eldin Jasarevic, Aaron C. Ericsson, and Elizabeth C. Bryda. “Lactobacillus plantarum attenuates anxiety-related behavior and protects against stress-induced dysbiosis in adult zebrafish.” Scientific Reports 6 (2016).
DOI: http://dx.doi.org/10.1038/srep33726
Research funding: Missouri-Columbia College of Veterinary Medicine
Adapted from press release by the University of Missouri-Columbia.

Research discovers beneficial role of omega-3 fatty acids on brown fat

Omega-3 fatty acids are able to stimulate the activation of brown and beige adipose tissues, a discovery that would promote the development of new therapies for obesity and other metabolism diseases, according to a research study published in the journal Nature Communications under the supervision of Professor Francesc Villarroya, from the Department of Biochemistry and Molecular Biomedicine and the Biomedical Research Center Red-Fisiopatología de la Obesidad y Nutrición (CIBEROBN) of the Institute of Health Carlos III.

In the new study, carried out in laboratory animal models, the research team noticed that Omega-3 fatty acids (n-3 PUFAS) stimulate the activation of brown and beige adipose tissue through a specific receptor (GPR120), which enables the release of the hormone FGF21 (21 fibroblast growth factor). This hormone, built by the adipocyte, is a molecule that regulates lipid glucose and metabolism and therefore, it is an effective target for the action mechanism of Omega-3.

“This discovery has implications in the understanding of the positive effects of n-3 PUFAS on the control of metabolic diseases and other aspects regarding the treatment for obesity and type 2 diabetes”, says Professor Francesc Villarroya, member of the Institute of Biomedicine of the University of Barcelona (IBUB) and head of the Research Group in Genetics and Molecular Biology of Mitochondrial Proteins and Associated Diseases.

The study shows that Omega-3 fatty acids enable the adaptive thermogenesis in mammals’ brown adipose tissue, an essential mechanism for the adaptation of the organism to cold environments. With rodents, it has been proved that the brown adipose tissue is able to create warmth and protect from obesity through the activation of energy expenditure.

The main function of brown adipose tissue is to burn calories and to make physical warmth out of fat (thermogenesis). However, a recent study by this research team has defined that brown adipose tissue also acts as an endocrine organ and can secrete factors that activate fat and carbohydrates metabolism. The most known factors up to now are FGF21, neuregulin 4 and interleukin-6, among other molecules of biological interest.

According to Francesc Villarroya, “these molecules, released by the adipose tissue (brown adipocytes or batokines) have positive metabolic effects. For this reason, they could be used in new therapies for obesity and related metabolic diseases”.

Citation: “The lipid sensor GPR120 promotes brown fat activation and FGF21 release from adipocytes” Tania Quesada-López, Rubén Cereijo, Jean-Valery Turatsinze, Anna Planavila, Montserrat Cairó, Aleix Gavaldà-Navarro, Marion Peyrou, Ricardo Moure, Roser Iglesias, Marta Giralt, Decio L. Eizirik & Francesc Villarroya. Nature Communications 2016 vol: 7 pp: 13479
DOI: http://dx.doi.org/10.1038/ncomms13479
Adapted from press release by Universitat de Barcelona