Gut bacteria and flavonoid-rich foods are linked and improve blood pressure levels

Queens University Belfast (Ireland), August 23, 2021

Flavonoid-rich foods, including berries, apples, pears and wine, appear to have a positive effect on blood pressure levels, an association that is partially explained by characteristics of the gut microbiome, according to new research published today in Hypertension, an American Heart Association journal.

“Our gut microbiome plays a key role in metabolizing flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood pressure-lowering effects are achievable with simple changes to the daily diet,” said lead investigator of the study Aedín Cassidy, Ph.D., chair and professor in nutrition and preventive medicine at the Institute for Global Food Security at Queen’s University in Belfast, Northern Ireland.

Flavonoids are compounds found naturally in fruits, vegetables and plant-based foods such as tea, chocolate and wine, and have been shown in previous research to offer a variety of health benefits to the body. Flavonoids are broken down by the body’s gut microbiome—the bacteria found in the digestive tract. Recent studies found a link between gut microbiota, the microorganisms in the human digestive tract, and cardiovascular disease (CVD), which is the leading cause of death worldwide. Gut microbiota is highly variable between individuals, and there are reported differences in gut microbial compositions among people with and without CVD.

With increased research suggesting flavonoids may reduce heart disease risk, this study assessed the role of the gut microbiome on the process. Researchers examined the association between eating flavonoid-rich foods with blood pressure and gut microbiome diversity. The study also investigated how much variance within the gut microbiome could explain the association between intake of flavonoid-rich foods and blood pressure.

A group of 904 adults between the ages of 25 and 82, 57% men from Germany’s PopGen biobank were recruited for this study. (The PopGen biobank includes participants from a network of seven biobanks in Northern Germany.) Researchers evaluated the participants’ food intake, gut microbiome and blood pressure levels together with other clinical and molecular phenotyping at regular follow-up examinations.

Participants’ intake of flavonoid-rich foods during the previous year was calculated from a self-reported food questionnaire detailing the frequency and quantity eaten of 112 foods. Flavonoid values were assigned to foods according to United States Department of Agriculture data on flavonoid content in food.

Gut microbiome for participants was assessed by fecal bacterial DNA extracted from stool samples. After an overnight fast, participants’ blood pressure levels were measured three times in three-minute intervals after an initial five-minute rest period. Researchers also collected participants’ lifestyle information, including sex, age, smoking status, medication use and physical activity, as well as family history of coronary artery disease, the number of daily calories and fiber consumed, and each participant’s height and weight was measured to calculate BMI (body mass index).

The analysis of regular flavonoid intake with gut microbiome and blood pressure levels found:

• Study participants who had the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears, had lower systolic blood pressure levels, as well as greater diversity in their gut microbiome than the participants who consumed the lowest levels of flavonoid-rich foods.
• Up to 15.2% of the association between flavonoid-rich foods and systolic blood pressure could be explained by the diversity found in participants’ gut microbiome.
• Eating 1.6 servings of berries per day (one serving equals 80 grams, or 1 cup) was associated with an average reduction in systolic blood pressure levels of 4.1 mm Hg, and about 12% of the association was explained by gut microbiome factors.

• Drinking 2.8 glasses (125 ml of wine per glass) of red wine a week was associated with an average of 3.7 mm Hg lower systolic blood pressure level, of which 15% could be explained by the gut microbiome.

“Our findings indicate future trials should look at participants according to metabolic profile in order to more accurately study the roles of metabolism and the gut microbiome in regulating the effects of flavonoids on blood pressure,” said Cassidy. “A better understanding of the highly individual variability of flavonoid metabolism could very well explain why some people have greater cardiovascular protection benefits from flavonoid-rich foods than others.”

While this study suggests potential benefits to consuming red wine, the American Heart Association suggests that if you don’t drink alcohol already, you shouldn’t start. If you do drink, talk with your doctor about the benefits and risks of consuming alcohol in moderation. According to a statement on dietary health by the American Heart Association, alcohol intake can be a component of a healthy diet if consumed in moderation (no more than one alcoholic drink per day for women and 2 alcohol drinks per day for men) and only by nonpregnant women and adults when there is no risk to existing health conditions, medication-alcohol interaction, or personal safety and work situations.

The authors note that participants for the study were from the general population, and the participants were unaware of the hypothesis. However, residual or unmeasured confounding factors (such as other health conditions or genetics) can lead to bias, thus these findings cannot prove a direct cause and effect, although the researchers did conduct a detailed adjustment in their analyses for a wide range of diet and lifestyle factors. The authors noted the focus of this study was on specific foods rich in flavonoids, not all food and beverages with flavonoids.

Physical activity associated with better cognition in breast cancer patients

Moderate to vigorous exercise may be important in addressing ‘chemo brain’

Washington University School of Medicine, August 19, 2021

A new study from Washington University School of Medicine in St. Louis has found a strong association between high levels of physical activity and the ability to maintain cognitive function among breast cancer patients treated with chemotherapy. The research lays the groundwork for future clinical trials aimed at investigating whether moderate to vigorous exercise can ward off what is commonly referred to as “chemo brain,” a decline in cognitive function many breast cancer patients experience.

The study appears online Aug. 18 in the Journal of Clinical Oncology. Collaborators include researchers at the University of Rochester Medical Center in Rochester, N.Y., and the National Cancer Institute of the National Institutes of Health (NIH).

“Cognitive decline related to cancer treatment is a growing clinical concern,” said first author Elizabeth A. Salerno, PhD, an assistant professor of surgery in the Division of Public Health Sciences at Washington University. “Some patients with cancer experience memory lapses, difficulty concentrating or trouble finding the right word to finish a sentence. Knowing the detrimental effects of chemotherapy on cognitive function, we wanted to understand the dynamic relationships between physical activity and cognition before, during and after chemotherapy to hopefully inform early, cost-effective prevention strategies to promote health in these patients. Our findings suggest that maintaining higher levels of physical activity may indeed be important for protecting cognition in patients with breast cancer undergoing chemotherapy.”

The researchers emphasized that their observational study can’t demonstrate that physical activity definitively protects against chemotherapy-related cognitive decline; it’s possible that physically active people have other characteristics, independent of exercise, that may protect cognition. But the study sets the stage for clinical trials investigating whether physical activity interventions before and during chemotherapy can indeed ward off treatment-related cognitive decline.

“Physical activity is a complex behavior,” Salerno said. “So, it will be important to test whether we can intervene with physical activity during a specific time window, such as during chemotherapy, and protect cognitive function in patients of all activity levels.”

The researchers analyzed data from a national sample of 580 breast cancer patients and 363 cancer-free participants, who acted as controls. The scientists measured physical activity as reported by patients on a questionnaire taken before, immediately after and six months after chemotherapy. At the same three times, the researchers also assessed four different measures of cognitive function.

At the beginning of the study, about 33% of the cancer patients met physical activity guidelines set by the U.S. Department of Health and Human Services. The guidelines recommend at least 150 minutes of moderate to vigorous physical activity per week. During chemotherapy, the percentage of patients meeting the guidelines dropped to 21% and then rebounded to 37% six months after treatment ended. The proportion of cancer-free participants meeting the weekly minimum of 150 minutes of moderate to vigorous physical activity hovered around 40% at all three time points.

“Despite this recovery to pre-chemotherapy physical activity levels, a majority of patients remained insufficiently active,” said Salerno. “As we consider the design of future physical activity interventions during chemotherapy, it will be important to understand what may be driving this rebound, whether it be improved health status now that chemotherapy is over or renewed motivation toward healthy aging during survivorship.”

The four assessments of cognition included two measures of how individuals perceive their own cognition; a test of visual memory; and a test of sustained attention. Inactive patients showed what is classified as a moderate reduction in perceived cognitive function, which is considered clinically meaningful. On all of the assessments, patients who had met the physical activity guidelines before and after chemotherapy consistently outperformed patients who had never met the guidelines. The cancer-free study participants performed similarly on all of the assessments, regardless of whether they had met the physical activity guidelines.

Importantly, breast cancer patients who had met the physical activity guidelines before chemotherapy ended up performing similarly to active and inactive healthy participants on the memory and attention tests. While objective measures of memory and attention indicated that physically active cancer patients had performed about as well as cancer-free participants, the physically active patients still perceived a significant decline in cognition, especially during chemotherapy. However, their perceived decline was not as great as that of the inactive patients. The researchers speculate that the self-reported measures of cognition may be capturing other common problems associated with chemotherapy, such as anxiety, fatigue or depression.

“Patients who were consistently meeting physical activity guidelines during chemotherapy not only had better cognitive recovery after chemotherapy completion, they also did not demonstrate clinically meaningful perceived cognitive decline, meaning that they did not report a large perceived cognitive change,” said senior author Michelle C. Janelsins, PhD, an associate professor at the University of Rochester Medical Center and Wilmot Cancer Institute. “By assessment with our objective cognitive measures, patients who were meeting physical activity guidelines prior to chemotherapy had better cognitive function scores following chemotherapy and looked cognitively similar to people who didn’t have cancer.”

Added Salerno: “These findings contribute to the growing body of evidence highlighting the importance of promoting physical activity as early as possible across the continuum of cancer care.”

Increasing omega 3, lowering linoleic acid decreases migraine duration, frequency in trial

National Institutes on Aging, August 19, 2021

According to news originating from Baltimore, Maryland, research stated, “To determine whether dietary interventions that increase n-3 fatty acids with and without reduction in n-6 linoleic acid can alter circulating lipid mediators implicated in headache pathogenesis, and decrease headache in adults with migraine. Three arm, parallel group, randomized, modified double blind, controlled trial.”

Our news journalists obtained a quote from the research from National Institutes on Aging, “Ambulatory, academic medical center in the United States over 16 weeks. 182 participants (88% women, mean age 38 years) with migraines on 5-20 days per month (67% met criteria for chronic migraine). Three diets designed with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and linoleic acid altered as controlled variables: H3 diet (n=61)- increase EPA+DHA to 1.5 g/day and maintain linoleic acid at around 7% of energy; H3-L6 diet (n=61)- increase n-3 EPA+DHA to 1.5 g/day and decrease linoleic acid to <= 1.8% of energy; control diet (n=60)- maintain EPA+DHA at <150 mg/day and linoleic acid at around 7% of energy. All participants received foods accounting for two thirds of daily food energy and continued usual care. The primary endpoints (week 16) were the antinociceptive mediator 17-hydroxydocosahexaenoic acid (17-HDHA) in blood and the headache impact test (HIT-6), a six item questionnaire assessing headache impact on quality of life. Headache frequency was assessed daily with an electronic diary. In intention-to-treat analyses (n=182), the H3-L6 and H3 diets increased circulating 17-HDHA (log ng/mL) compared with the control diet (baseline adjusted mean difference 0.6, 95% confidence interval 0.2 to 0.9; 0.7, 0.4 to 1.1, respectively). The observed improvement in HIT-6 scores in the H3-L6 and H3 groups was not statistically significant (-1.6, – 4.2 to 1.0, and -1.5, -4.2 to 1.2, respectively). Compared with the control diet, the H3-L6 and H3 diets decreased total headache hours per day (-1.7, – 2.5 to -0.9, and -1.3, -2.1 to -0.5, respectively), moderate to severe headache hours per day (-0.8, – 1.2 to -0.4, and -0.7, -1.1 to -0.3, respectively), and headache days per month (-4.0, -5.2 to -2.7, and -2.0, -3.3 to -0.7, respectively). The H3-L6 diet decreased headache days per month more than the H3 diet (-2.0, -3.2 to -0.8), suggesting additional benefit from lowering dietary linoleic acid. The H3 L6 and H3 diets altered n-3 and n-6 fatty acids and several of their nociceptive oxylipin derivatives in plasma, serum, erythrocytes or immune cells, but did not alter classic headache mediators calcitonin gene related peptide and prostaglandin E2.”

According to the news editors, the research concluded: “The H3-L6 and H3 interventions altered bioactive mediators implicated in headache pathogenesis and decreased frequency and severity of headaches, but did not significantly improve quality of life.”

This research has been peer-reviewed.

Small changes in diet could help you live healthier, more sustainably

University of Michigan, August 19, 2021

Eating a hot dog could cost you 36 minutes of healthy life, while choosing to eat a serving of nuts instead could help you gain 26 minutes of extra healthy life, according to a University of Michigan study.

The study, published in the journal Nature Food, evaluated more than 5,800 foods, ranking them by their nutritional disease burden to humans and their impact on the environment. It found that substituting 10% of daily caloric intake from beef and processed meats for a mix of fruits, vegetables, nuts, legumes and select seafood could reduce your dietary carbon footprint by one-third and allow people to gain 48 minutes of healthy minutes per day.

“Generally, dietary recommendations lack specific and actionable direction to motivate people to change their behavior, and rarely do dietary recommendations address environmental impacts,” said Katerina Stylianou, who did the research as a doctoral candidate and postdoctoral fellow in the the Department of Environmental Health Sciences at U-M’s School of Public Health. She currently works as the Director of Public Health Information and Data Strategy at the Detroit Health Department.

This work is based on a new epidemiology-based nutritional index, the Health Nutritional Index, which the investigators developed in collaboration with nutritionist Victor Fulgoni III from Nutrition Impact LLC. HENI calculates the net beneficial or detrimental health burden in minutes of healthy life associated with a serving of foodconsumed.

Calculating impact on human health

The index is an adaptation of the Global Burden of Disease in which disease mortality and morbidity are associated with a single food choice of an individual. For HENI, researchers used 15 dietary risk factors and disease burden estimates from the GBD and combined them with the nutrition profiles of foods consumed in the United States, based on the What We Eat in America database of the National Health and Nutrition Examination Survey. Foods with positive scores add healthy minutes of life, while foods with negative scores are associated with health outcomes that can be detrimental for human health.

Adding environmental impact to the mix

To evaluate the environmental impact of foods, the researchers utilized IMPACT World+, a method to assess the life cycle impact of foods (production, processing, manufacturing, preparation/cooking, consumption, waste), and added improved assessments for water use and human health damages from fine particulate matter formation. They developed scores for 18 environmental indicators taking into account detailed food recipes as well as anticipated food waste.

Finally, researchers classified foods into three color zones: green, yellow and red, based on their combined nutritional and environmental performances, much like a traffic light.

The green zone represents foods that are recommended to increase in one’s diet and contains foods that are both nutritionally beneficial and have low environmental impacts. Foods in this zone are predominantly nuts, fruits, field-grown vegetables, legumes, whole grains and some seafood.

The red zone includes foods that have either considerable nutritional or environmental impacts and should be reduced or avoided in one’s diet. Nutritional impacts were primarily driven by processed meats, and climate and most other environmental impacts driven by beef and pork, lamb and processed meats.

The researchers acknowledge that the range of all indicators varies substantially and also point out that nutritionally beneficial foods might not always generate the lowest environmental impacts and vice versa.

“Previous studies have often reduced their findings to a plant vs. animal-based foods discussion,” Stylianou said. “Although we find that plant-based foods generally perform better, there are considerable variations within both plant-based and animal-based foods.”

Based on their findings, the researchers suggest:

• Decreasing foods with the most negative health and environmental impacts including high processed meat, beef, shrimp, followed by pork, lamb and greenhouse-grown vegetables.
• Increasing the most nutritionally beneficial foods, including field-grown fruits and vegetables, legumes, nuts and low-environmental impact seafood.

“The urgency of dietary changes to improve human health and the environment is clear,” said Olivier Jolliet, U-M professor of environmental health science and senior author of the paper. “Our findings demonstrate that small targeted substitutions offer a feasible and powerful strategy to achieve significant health and environmental benefits without requiring dramatic dietary shifts.”

Study finds Ginkgo biloba extract comparable with donepezil in improving functional recovery in Alzheimer disease

Nanjing Medical University (China) August 18, 2021

According to news reporting from Nanjing, People’s Republic of China, research stated, “Ginkgo biloba extract (GBE) and donepezil have been reported to be effective in patients with Alzheimer’s disease (AD). Nonetheless, how these drugs impact spontaneous brain activities and how they consequently improve functional recovery are currently unclear.”

The news correspondents obtained a quote from the research from First Affiliated Hospital of Nanjing Medical University: “This study was to explore the efficacy of GBE vs. donepezil and their add-on efficacy on functional recovery and the adaption of spontaneous brain activities following pharmacologic treatment in patients with AD. Patients with AD were enrolled and assigned to the GBE group (n = 50), the donepezil group (n = 50), or the combined group (n = 50). Neuropsychological assessments, including minimum mental state examination (MMSE), Alzheimer’s disease assessment scale-cognition (ADAS-Cog), instrumental activity of daily living (IADL), geriatric depression scale (GDS), neuropsychiatric inventory (NPI), and quality of life in Alzheimer’s disease (QOL-AD), were conducted at baseline, 1 month, 3 months, and 6 months. Resting-state functional magnetic resonance imaging (rs-fMRI) was collected to compare the amplitude of low-frequency fluctuation (ALFF), percent amplitude of fluctuation (PerAF), regional homogeneity (ReHo), and degree centrality (DC) at baseline and 6 months. No major significant differences were detected in all comparisons between groups across all follow-up time points. For intragroup comparison, MMSE and ADAS-Cog scores differed significantly across all follow-ups in three groups. The combined group showed significant improvement of GDS scores between baseline and 6 months (p = 0.007). The GBE group (p = 0.044) and donepezil group (p = 0.012) demonstrated significant improvement of NPI scores between baseline and 6 months. Significant correlations were observed between IADL and ALFF in the right gyrus rectus (p = 0.03) and in the left superior cerebellum gyrus (p = 0.01), between GDS and ALFF in the right middle temporal gyrus (p = 0.01), between NPI and PerAF in the left fusiform gyrus (p = 0.03), and between MMSE and ReHo in right superior frontal gyrus (p = 0.04). GBE was comparable with donepezil in the improvement of functional recovery in patients with AD while the combined application of GBE and donepezil seems unnecessary.”

According to the news reporters, the research concluded: “GBE-mediated improvement of functional recovery was characterized by decreased ALFF values in the right gyrus rectus and decreased PerAF values in the left fusiform gyrus. These featured variations of imaging metrics in specific brain regions may serve as biomarkers in the monitoring of the therapeutic efficacy of GBE.”

Why do people sacrifice short-term happiness for long-term welfare?

Imperial College London, August 16, 2021

 

According to the hedonic principle, people are motivated by the pursuit of pleasure and, conversely, the avoidance of pain. Although there is a great deal of evidence to support this theory of motivation, both from psychological studies and everyday life, the theory does not explain why people often engage in activities that are unpleasant yet critical for their long-term welfare.

In other words, why do most people spend so much time working and doing housework when they could be engaging in leisure activities? And, perhaps more importantly, why do other people struggle to maintain steady employment and clean living conditions? The answers have a profound impact on the mental and physical health of individuals, as well as our survival as a species.

Working in the emerging field of computational social science, Maxime Taquet et al., an interdisciplinary team of data scientists, physicians, and psychologists from the US, the UK, Belgium, and Spain, has gathered large amounts of data to help explain how humans sacrifice short-term happiness to maximize long-term welfare. By monitoring the moods and activities of 30,000 people for about a month using a smartphone application, the researchers discovered that a person’s mood has a significant impact on what kinds of activities they decide to do.

Specifically, the data showed that when a person is in a good mood, they are more likely to do housework and other unpleasant yet useful activities over the next few hours than when they are in a bad mood. When feeling bad, people tend to choose activities later that day that are more pleasurable, such as playing sports and spending time with friends, apparently in an effort to feel better.

The researchers explain that the results are interesting because they show that people do not always seek pleasure-enhancing activities, only at times when they’re in a bad mood. This finding supports the “hedonic flexibility hypothesis” first proposed by Herbert Simon in the 1960s, which suggests that people have multiple goals, some short-term and some long-term, and a person’s mood helps them prioritize among these goals in the same way that the current study has found. People who are in a bad mood tend to focus on improving their mood at that moment, whereas people in a good mood tend to think more about the future.

“Using this data, we showed that people are a lot more long-term-oriented than previously thought, truly ‘managing’ their mood through their choice of activities,” coauthor Yves-Alexandre de Montjoye at the Imperial College London Data Science Institute told Phys.org. “This shows, using big data, how we humans routinely sacrifice our short-term happiness for our long-term welfare.”

In future studies, the researchers want to examine the underlying mechanisms that explain exactly how mood influences a person’s choice of activities. For example, a bad mood may be associated with people being tired or having difficulty concentrating, which indirectly affects people’s decisions.

The research is published in the journal Proceedings of the National Academy of Sciences.

 

Physical exercise modulates iron in Alzheimer’s disease

University of Eastern Finland, August 23, 2021

A recent experimental study shows how regular physical exercise modulates iron metabolism in both the brain and the muscles. The findings also help to better understand the benefits of exercise in Alzheimer’s disease. The study was published in a special issue of the International Journal of Molecular Sciencesentitled Redox Active Metals in Neurodegenerative Diseases: Therapeutic Implications.

Dysregulation of brain iron metabolism and iron accumulation is known to be associated with ageing and AD, although underlying mechanisms remain unclear. It is known that iron load and inflammation regulate the synthesis of hepcidin, the main iron regulatory protein. In particular, the inflammation-modulating cytokine interleukin-6 (IL-6), also known to modulate brain-muscle crosstalk, is involved in the activation of hepcidin synthesis in the brain. Although regular physical exercise is known to have a beneficial effect on total body iron metabolism and anti-inflammatory action, the role of regular exercise on iron homeostasis in the brain and in the context of AD remains unclear.

The researchers utilised wildtype mice and 5xFAD transgenic mice, modelling AD to explore the effect of regular physical exercise on the modulation of iron homeostasis. Half of the mice had unlimited use of a running wheel during the six-month experiment.  The levels of iron and iron-related proteins were analysed in the brain and skeletal muscle. The researchers also investigated the potential involvement of iron in the crosstalk between the brain and periphery upon regular exercise.

The current study demonstrates that regular physical exercise modulates iron storage and trafficking in both the brain and skeletal muscle. Moreover, this study is the first to report a reduction of cortical hepcidin in response to regular physical exercise. The results suggest that IL-6 is a key modulator of hepcidin in exercise-induced brain iron modulation. These findings help to better understand why regular exercise is beneficial in AD, and may provide new insight for disease prevention or effective treatment approaches.