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Anti-cancer and antidiabetic properties of maqui berry
Nova Southeastern University (US), April 2, 2021
Researchers at NOVA Southeastern University in Florida reviewed the potential use of Aristotelia chilensis, also known as maqui berry, as a nutritional supplement to combat hyperinsulinemia and related diseases. Their report was published in the journal Food Science and Human Wellness.
- The scientific community has long considered nutritional supplementation to be a possible alternative medicine or adjunct treatment to conventional therapies for common ailments and diseases.
- Recent studies show that A. chilensis can reduce postprandial insulin levels by as much as 50 percent and is just as effective as metformin at increasing insulin sensitivity and stabilizing blood glucose levels.
- The berry’s mechanism of action involves inhibiting sodium-dependent glucose transporters in the small intestine and slowing glucose’s rate of entry in the bloodstream, which effectively reduces the likelihood of blood sugar spikes and the corresponding rise in insulin levels.
- At the same time, the A. chilensis contributes to cancer prevention since chronically high blood glucose levels are linked to the development of cancers.
- Studies have shown that diabetics and prediabetics have an elevated risk of developing cancerous growths.
Based on the findings of previous studies, the researchers believe that consistent supplementation with A. chilensis could indirectly reduce the risk of cancer and other diseases that are promoted by hyperglycemia and hyperinsulinemia.
New research on vitamin D and respiratory infections important for risk groups
Karolinska Institutet (Sweden), April 1, 2021
Studies have shown that supplementary vitamin D seems to provide a certain degree of protection against respiratory infections. A new study involving researchers from Karolinska Institutet has now made the most comprehensive synthesis to date of this connection. The study, which is published in The Lancet Diabetes & Endocrinology, confirms that vitamin D protects against respiratory infections, a result that can have significance for the healthcare services.
Whether vitamin D can reduce the risk of infection is a still an open issue. Four years ago, a synthesis of current research was published that showed that vitamin D supplementation can provide a certain degree of protection against respiratory infections.
Now, the same researchers from, amongst other institutes, Karolinska Institutet, Harvard Medical School and Queen Mary University of London, have expanded the earlier material with an additional 18 studies and carried out new analyses.
Their results are based on 43 randomized and placebo-controlled studies on the possible relationship between vitamin D and respiratory infections involving almost 49,000 participants.
The material the researchers have drawn on comprised published as well as registered but as yet unpublished studies, and is the most comprehensive such compilation to date.
The new study adds further information about vitamin D as a protection against respiratory infections, but does not cover the question of whether vitamin D can protect against COVID-19.
Daily dose most effective
While the total protective effect against respiratory infections was 8%, the researchers found, for example, that a daily dose of vitamin D is much more effective than one given every week or month. There is no reason, either, to exceed the recommended dose.
“A particularly high dose doesn’t seem necessary,” says study co-author Peter Bergman, associate professor at the Department of Laboratory Medicine, Karolinska Institutet. “Those who received 400-1000 IU/day had the best response, as the group that received such a dose demonstrated a reduction in infection risk of 42%. I want to stress that there were no signals in the study that normal doses of vitamin D were dangerous or caused adverse reactions.”
Lower risk in vulnerable groups
One conclusion that Dr. Bergman says can be drawn from the study is that the healthcare services should be more alert to groups that have a known risk of vitamin D deficiency, such as people with dark skin, overweight people and the elderly.
“A daily dose of vitamin D can protect the bones and perhaps also reduce the risk of respiratory infections in vulnerable groups,” he continues. “The wider population will probably not benefit as much from the supplement, though. Vitamin D doesn’t make healthy people healthier.”
The researchers are now interrogating the mechanisms behind the protective effect of vitamin D against respiratory infections—for instance, what genetic factors determine why people respond differently to vitamin D supplements.
One weakness of the compilation procedure is the possible influence of “publication bias,” in that studies that do not demonstrate an effect are never published, which can create a false impression of how effective vitamin D is. To compensate for this, data from registered but as yet unpublished studies were also included.
The study received no external funding. Some of the co-authors have declared the receipt of grants from pharmaceutical companies and/or vitamin supplement manufacturers, although outside of this study. See the scientific paper for a full list of potential conflicts of interest.
Role of inflammatory diet and vitamin D in link between periodontitis and cognitive function
Instituto Universitario Egas Moniz (Portugal), March 25, 2021
According to news reporting originating from Almada, Portugal, research stated, “Patients suffering from periodontitis are at a higher risk of developing cognitive dysfunction. However, the mediation effect of an inflammatory diet and serum vitamin D levels in this link is unclear.”
The news reporters obtained a quote from the research from Periodontology Department: “In total, 2062 participants aged 60 years or older with complete periodontal diagnosis and cognitive tests from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 were enrolled. The Consortium to Establish a Registry for Alzheimer’s disease (CERAD) word learning subtest (WLT) and CERAD delayed recall test (DRT), the animal fluency test (AFT) and the digit symbol substitution test (DSST) was used. Dietary inflammatory index (DII) was computed via nutrition datasets. Mediation analysis tested the effects of DII and vitamin D levels in the association of mean probing depth (PD) and attachment loss (AL) in all four cognitive tests. Periodontitis patients obtained worse cognitive test scores than periodontally healthy individuals. DII was negatively associated with CERAD-WLT, CERAD-DRT, AFT and DSST, and was estimated to mediate between 9.2% and 36.4% of the total association between periodontitis with cognitive dysfunction (* * p* * < 0.05). Vitamin D showed a weak association between CERAD-DRT, AFT and DSST and was estimated to between 8.1% and 73.2% of the association between periodontitis and cognitive dysfunction (* * p* * < 0.05).”
According to the news editors, the research concluded: “The association between periodontitis and impaired cognitive function seems to be mediated both by a proinflammatory dietary load and vitamin D deficiency. Future studies should further explore these mediators in the periodontitis-cognitive decline link.”
More protein doesn’t mean more strength in resistance-trained middle-aged adults
University of Illinois at Urbana, March 25, 2021
A 10-week muscle-building and dietary program involving 50 middle-aged adults found no evidence that eating a high-protein diet increased strength or muscle mass more than consuming a moderate amount of protein while training. The intervention involved a standard strength-training protocol with sessions three times per week. None of the participants had previous weightlifting experience.
Published in the American Journal of Physiology: Endocrinology and Metabolism, the study is one of the most comprehensive investigations of the health effects of diet and resistance training in middle-aged adults, the researchers say. Participants were 40-64 years of age.
The team assessed participants’ strength, lean-body mass, blood pressure, glucose tolerance and several other health measures before and after the program. They randomized participants into moderate- and high-protein diet groups. To standardize protein intake, the researchers fed each person a freshly cooked, minced beef steak and carbohydrate beverage after every training session. They also sent participants home with an isolated-protein drink to be consumed every evening throughout the 10 weeks of the study.
“The moderate-protein group consumed about 1.2 grams of protein per kilogram of body weight per day, and the high-protein group consumed roughly 1.6 grams per kilogram per day,” said Colleen McKenna, a graduate student in the division of nutritional sciences and registered dietician at the University of Illinois Urbana-Champaign who led the study with U. of I. kinesiology and community health professor Nicholas Burd. The team kept calories equivalent in the meals provided to the two groups with additions of beef tallow and dextrose.
The study subjects kept food diaries and McKenna counseled them every other week about their eating habits and protein intake.
In an effort led by U. of I. food science and human nutrition professor Hannah Holscher, the team also analyzed gut microbes in fecal samples collected at the beginning of the intervention, after the first week – during which participants adjusted to the new diet but did not engage in physical training – and at the end of the 10 weeks. Previous studies have found that diet alone or endurance exercise alone can alter the composition of microbes in the digestive tract.
“The public health messaging has been that Americans need more protein in their diet, and this extra protein is supposed to help our muscles grow bigger and stronger,” Burd said. “Middle age is a bit unique in that as we get older, we lose muscle and, by default, we lose strength. We want to learn how to maximize strength so that as we get older, we’re better protected and can ultimately remain active in family and community life.”
The American Food and Nutrition Board recommends that adults get 0.8 grams of protein per kilogram of body weight per day to avoid developing a protein deficiency. The team tried to limit protein consumption in the moderate-protein group to the Recommended Daily Allowance, but their food diaries revealed those participants were consuming, on average, 1.1 to 1.2 grams of protein per kilogram of body weight per day. Those in the high-protein group ate about 1.6 grams of protein per kilogram per day – twice the recommended amount.
Burd and his colleagues hypothesized that getting one’s protein from a high-quality source like beef and consuming significantly more protein than the RDA would aid in muscle growth and strength in middle-aged adults engaged in resistance training. But at the end of the 10 weeks, the team saw no significant differences between the groups. Their gains in strength, their body fat, lean body mass, glucose tolerance, kidney function, bone density and other “biomarkers” of health were roughly the same.
The only potentially negative change researchers recorded between the groups involved alterations to the population of microbes that inhabit the gut. After one week on the diet, those in the high-protein group saw changes in the abundance of some gut microbes that previous studies have linked to negative health outcomes. Burd and his colleagues found that their strength-training intervention reversed some of these changes, increasing beneficial microbes and reducing the abundance of potentially harmful ones.
“We found that high protein intake does not further increase gains in strength or affect body composition,” Burd said. “It didn’t increase lean mass more than eating a moderate amount of protein. We didn’t see more fat loss, and body composition was the same between the groups. They got the gain in weight, but that weight gain was namely from lean-body-mass gain.”
Burd said the finding makes him question the push to increase protein intake beyond 0.8-1.1 grams per kilogram of body weight, at least in middle-aged weightlifters consuming high-quality animal-based protein on a regular basis.
McKenna said the team’s multidisciplinary approach and in-depth tracking of participants’ dietary habits outside the laboratory makes it easier to understand the findings and apply them to daily life.
“We have recommendations for healthy eating and we have recommendations for how you should exercise, but very little research looks at how the two together impact our health,” she said. The study team included exercise physiologists, registered dietitians and experts on gut microbiology.
“This allowed us to address every aspect of the intervention in the way it should be addressed,” McKenna said. “We’re honoring the complexity of human health with the complexity of our research.”
Higher serum carotenoid levels linked with less visceral fat in women
Hirosaki University & Kagome Ltd (Japan), March 24 2021.
Visceral fat resides within the abdomen, where it surrounds the internal organs. Visceral fat is not only challenging to lose but is associated with an increase in inflammation and disorders such as type 2 diabetes and cardiovascular disease. In fact, high visceral fat area is a greater predictor of cardiovascular disease than waist circumference and body mass index (BMI).
A study reported on March 11, 2021 in Nutrients revealed an association between higher levels of carotenoids and a reduction in visceral fat area. The investigation included 310 men and 495 women who received an annual health examination as part of the Iwaki Health Promotion Project in Japan. Blood samples were analyzed for the carotenoids alpha carotene, beta carotene, beta cryptoxanthin, lycopene, lutein and zeaxanthin. Visceral fat area was measured using an abdominal bioimpedance method and BMI was calculated from anthropometric data. Diet history questionnaire responses provided information concerning food intake.
Total carotenoid levels were associated with the intake of leafy green vegetables, carrots and pumpkins, root vegetables and juice. Women’s carotenoid levels were significantly higher than those of men. Higher total carotenoid levels were associated with decreased visceral fat area and BMI in women, independent of fiber intake. Increased beta carotene, beta cryptoxanthin and lutein levels in women were also significantly associated with having a lower visceral fat area. The differences found between men and women in the study led the researchers to suggest that a threshold level of carotenoids might be necessary to influence visceral fat.
“This is the first study to evaluate the association between serum carotenoids levels and visceral fat area in healthy individuals,” Mai Matsumoto and associates announced. “Ingestion of carotenoid-rich vegetables (particularly lutein and beta carotene) may be associated with lower visceral fat area, a good predictor of cardiovascular disease, especially in women.”
Research suggests optimal time of day to consume longevity-supporting supplements
University of Waterloo (Ontario), March 24, 2021
Aging is a disease that can be fought with the appropriate combinations of supplements and behaviours, according to new research from the University of Waterloo.
Using a comprehensive mathematical model, the researchers also found that the best time of day for someone to take these supplements depends on their age. Some anti-aging supplements should be taken by young people at night, while older people should take it midday for the greatest effectiveness.
The two classes of drugs the researchers modelled are nicotinamide mononucleotide (NMN) and Resveratrol, which have been the subject of increased interest in recent years after reports emerged on their benefits on metabolism and increased lifespan of various organisms.
A debate over whether to classify aging as a disease has been ongoing for decades, with the vast majority in the field of aging research now classifying it as such. As recently as 2015, a team of international scientists authored a paper calling it “time to classify biological aging as a disease”–and the World Health Organization has made moves that bring it closer to that definition.
“It’s really important to try and change this wrong paradigm that aging is not treatable,” said Mehrshad Sadria, a PhD student in Waterloo’sDepartment of Applied Mathematics. “We shouldn’t think like 30 years ago when we thought that once a person gets into their 70s or 80s, they must be lethargic and ailing.
The clear association of aging with various serious diseases is a stronger motivator for better understanding aging, Sadria said. Recognizing aging as a disease can encourage investment and promote research efforts in identifying therapies that can delay the aging process.
“We can take these drugs that can extend our lifespan and improve our health. This study is the first step in understanding when is the best time for young people and older folks to take these supplements.”
Sadria and Anita Layton, professor of Applied Mathematics, Computer Science, Pharmacy and Biology at Waterloo, developed a mathematical model that simulates the circadian clock and metabolism in the mouse liver. The model is age-specific and can simulate liver function in a young mouse or an aged mouse.
They found that a young person, for example, should take NMN six hours after they wake up to achieve the highest efficiency. On the other hand, young individuals should take Resveratrol at night while older people should take it midday for the greatest effectiveness.
“The time you eat, what you eat, the time you sleep and the time you exercise are all factors that can affect your body, how you age and how you live,” Layton said. “People should be mindful of when they eat and ensure that it coincides with other things in their environment that impact their sleep/wake cycle or body clock, such as exposure to light because if not, it could cause conflict within the body.”
The study, Modeling the Effect of Ageing on the Circadian Clock and Metabolism: Implications on Timing of Medication, was recently published in the journal iScience.
Sugar not so nice for your child’s brain development
New research shows how high consumption affects learning, memory
University of Georgia, April 1, 2021
Sugar practically screams from the shelves of your grocery store, especially those products marketed to kids.
Children are the highest consumers of added sugar, even as high-sugar diets have been linked to health effects like obesity and heart disease and even impaired memory function.
However, less is known about how high sugar consumption during childhood affects the development of the brain, specifically a region known to be critically important for learning and memory called the hippocampus.
New research led by a University of Georgia faculty member in collaboration with a University of Southern California research group has shown in a rodent model that daily consumption of sugar-sweetened beverages during adolescence impairs performance on a learning and memory task during adulthood. The group further showed that changes in the bacteria in the gut may be the key to the sugar-induced memory impairment.
Supporting this possibility, they found that similar memory deficits were observed even when the bacteria, called Parabacteroides, were experimentally enriched in the guts of animals that had never consumed sugar.
“Early life sugar increased Parabacteroides levels, and the higher the levels of Parabacteroides, the worse the animals did in the task,” said Emily Noble, assistant professor in the UGA College of Family and Consumer Sciences who served as first author on the paper. “We found that the bacteria alone was sufficient to impair memory in the same way as sugar, but it also impaired other types of memory functions as well.”
Guidelines recommend limiting sugar
The Dietary Guidelines for Americans, a joint publication of the U.S. Departments of Agriculture and of Health and Human Services, recommends limiting added sugars to less than 10 percent of calories per day.
Data from the Centers for Disease Control and Prevention show Americans between the ages 9-18 exceed that recommendation, the bulk of the calories coming from sugar-sweetened beverages.
Considering the role the hippocampus plays in a variety of cognitive functions and the fact the area is still developing into late adolescence, researchers sought to understand more about its vulnerability to a high-sugar diet via gut microbiota.
Juvenile rats were given their normal chow and an 11% sugar solution, which is comparable to commercially available sugar-sweetened beverages.
Researchers then had the rats perform a hippocampus-dependent memory task designed to measure episodic contextual memory, or remembering the context where they had seen a familiar object before.
“We found that rats that consumed sugar in early life had an impaired capacity to discriminate that an object was novel to a specific context, a task the rats that were not given sugar were able to do,” Noble said.
A second memory task measured basic recognition memory, a hippocampal-independent memory function that involves the animals’ ability to recognize something they had seen previously.
In this task, sugar had no effect on the animals’ recognition memory.
“Early life sugar consumption seems to selectively impair their hippocampal learning and memory,” Noble said.
Additional analyses determined that high sugar consumption led to elevated levels of Parabacteroides in the gut microbiome, the more than 100 trillion microorganisms in the gastrointestinal tract that play a role in human health and disease.
To better identify the mechanism by which the bacteria impacted memory and learning, researchers experimentally increased levels of Parabacteroides in the microbiome of rats that had never consumed sugar. Those animals showed impairments in both hippocampal dependent and hippocampal-independent memory tasks.
“(The bacteria) induced some cognitive deficits on its own,” Noble said.
Noble said future research is needed to better identify specific pathways by which this gut-brain signaling operates.
“The question now is how do these populations of bacteria in the gut alter the development of the brain?” Noble said. “Identifying how the bacteria in the gut are impacting brain development will tell us about what sort of internal environment the brain needs in order to grow in a healthy way.”