Posts Tagged “gut health”
Two new research studies show that daily almond consumption may help support gut health.
Among the key findings, the papers show almonds may act as prebiotics, promoting the growth of beneficial gut bacteria and supporting a healthy gut microbiome, as well as play an essential role in the gut-heart axis.
Research also showed almond consumption boosts the production of butyrate, benefiting both gut and heart health.
The research, funded by the Almond Board of California, reviewed the evidence for almonds acting as prebiotics and explained how they might benefit gut health.
Prebiotics are substances that nourish or feed beneficial gut bacteria in the large intestine, helping them grow and thrive. This results in a diverse and balanced gut microbiota, promoting healthy digestion, strengthening the immune system, and, according to emerging research, potentially benefiting brain function and protecting against disease.
The comprehensive review showed that almonds have significant potential as a functional food with a prebiotic effect.
The study found almonds benefit gut health by enhancing the balance and diversity of gut bacteria, as well as boosting the production of beneficial compounds such as short-chain fatty acids (SCFAs). These compounds help protect the gut lining, aid in mitigating inflammation, and support metabolic health.
“Almonds contain dietary fiber, polyphenols, and non-digestible carbohydrates like oligosaccharides, which provide their prebiotic effects,” said Professor Jack Gilbert, University of California, San Diego, project lead for the National Institutes of Health (NIH)’s Nutrition for Precision Health initiative and co-author of the paper.
The research evaluated the body of evidence on almonds and gut health, including laboratory experiments (in vitro studies), clinical trials, and systematic reviews, which collate the findings of many studies on a specific topic.
Although the study authors concluded that there is sufficient evidence to show that almonds have a prebiotic effect, they emphasized that further studies are required, particularly those using standardized methods.
Also funded by the Almond Board of California, another study examined the benefits of almonds on cardiovascular and gut health, and explored the links between the two areas.
The researchers reviewed numerous studies and presented their findings in a discussion paper, focusing on the impact of almond consumption on cardiovascular health, related risk factors, and the gut microbiome.
The data concluded that almonds promote the growth of beneficial gut bacteria and boost the production of SCFAs, particularly butyrate. The review also confirmed that eating almonds can support heart health, for example, by lowering “bad” LDL-cholesterol and blood pressure.
The researchers also speculated that the impact of almonds on gut health may influence heart health.
“The gut-heart axis is an emerging and exciting area of interest in cardiovascular research, and our literature review suggests almonds may positively affect this,” said Ravinder Nagpal, co-author of the paper and Director of The Gut Biome Lab at Florida State University.
The microbiologist explained that collectively, almonds’ microbiome benefits help alleviate inflammation and support metabolic function, which could result in cardioprotective effects.
The researchers noted a lack of studies examining how substances produced by gut microbes after consuming almonds specifically affect cardiometabolic health, so more data is needed.
Both papers echo the findings in a recently published consensus paper, which confirmed that eating almonds stimulates the growth of beneficial bacteria and the production of SCFAs and other substances that may influence metabolic health.
How do almonds show prebiotic potential?
Almonds contain several substances that function as prebiotics. These include:
- Fiber: Almonds are a good source of dietary fiber with 4g per one-ounce serving.
- Polyphenols: Almonds contain polyphenols that, according to the research team, “exhibit prebiotic-like effects by selectively promoting the growth of beneficial gut bacteria and modulating the microbiome through their antioxidant (vitamin E) and antimicrobial activity.”
- Oligosaccharides (Non-Digestible Carbohydrates): These carbohydrates help feed beneficial bacteria in the gut.
One ounce (28 g) of almonds provides 6g of protein, 4g of fiber, 13g of unsaturated fat, only 1g of saturated fat, and 15 essential nutrients, including 77mg magnesium (18.3% DV), 210mg potassium (4%DV), and 7.27mg vitamin E (50% DV). They make a great snack, are perfect for topping cereal or yogurt, and are a delicious addition to stir fries, curries, and salads.
A recent study has revealed that incorporating avocados into the diet can positively influence the microbiota of adults living with abdominal obesity, without requiring any caloric restrictions, and thus improving gut health.
Conducted as part of the Habitual Diet and Avocado Trial (HAT), the 26-week randomized controlled trial involved 1,008 participants who were split into two groups: one that consumed one avocado daily and another that maintained their usual dietary habits.
Fecal samples from a subset of 230 participants were collected at the start of the study, after four weeks, and after the 26-week period. Researchers at the University of California, Los Angeles, utilized advanced shotgun metagenomics sequencing to assess the gut microbiota composition and diversity.
The findings indicated that participants in the avocado-consuming group experienced a notable increase in gut microbiota diversity by the four-week mark, a change that persisted throughout the study. Particularly, individuals with lower scores on the Healthy Eating Index (HEI-2015), reflecting less nutritious dietary habits at the outset, showed a more significant increase in microbiota diversity when consuming avocados compared to those in the control group.
At the end of the study, the avocado group demonstrated significant changes in beta diversity, suggesting shifts in the overall composition of gut bacteria. At the species level, notable increases were observed in beneficial gut bacteria, including Faecalibacterium prausnitzii and Bacterium AF16_15. However, functional analysis indicated no significant differences in metabolic pathways between the two groups.
The study, which highlights the potential prebiotic benefits of avocados, suggests that incorporating this nutrient-rich fruit could be particularly advantageous for individuals with lower diet quality scores. These findings open new avenues for dietary interventions aimed at improving gut health in people with abdominal obesity.
By the California Walnut Commission
FOLSOM, Calif. — Multiple new research abstracts suggest walnuts may have the potential to positively affect several important health factors. From their impact on colon cancer and certain aspects of cognitive aging, to their positive effect on both gut health and vascular health, the research findings presented at Experimental Biology 2015 (EB) detail our latest understanding of walnuts’ inner workings. Running March 28 through April 1 in Boston, this annual meeting attracted an international audience of over 14,000 leading research scientists and exhibitors.
“These findings help advance the understanding of the many advantages of eating walnuts as part of a healthy diet, and add to the more than 159 published papers over 20 years that have shown how walnuts affect heart health, diabetes, cancer, cognition, fertility and weight management,” said Dennis A. Balint, CEO, California Walnut Commission.
There are numerous possible active ingredients in walnuts that may be contributing factors in providing these health benefits. One component that differentiates walnuts is alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid. Walnuts are the only nut that contain a significant amount of alpha-linolenic acid (ALA) with 2.5 grams per one ounce serving.
While scientific conclusions cannot yet be drawn from the abstracts presented at EB 2015, the following summaries share the latest findings:
- Colon Cancer: For the first time, researchers looked at whether components of walnuts have an effect on colon cancer cells. This cell study1 was conducted by the Department of Nutritional Science and Food Management at the Ewha Womans University in Korea, and showed that walnut extract significantly slowed the survival of the cancer stem cells as well as reduced the stemness of colon cancer stem cells. Given the results, researchers state there is reason to further explore the role of walnut consumption in colon cancer therapies targeting cancer stem cells.
- Gut Health: The gut microbiome is an ecosystem of bacteria that helps our bodies digest and use the food we eat; changes in the gut microbiome are linked to chronic diseases. A recent animal study2 conducted by the Department of Physiology School of Medicine at Louisiana State University Health Sciences Center looked at the effect of walnuts on two major gut bacteria communities. A diet with walnuts (approximately 2 ounce human diet equivalent) significantly altered the ratio of the two communities, therefore suggesting “a new mechanism, changing the gut microbial environment, by which walnuts may exert their beneficial health effects.” As this study was performed on animals, however, findings cannot yet be implied for humans.
- Aging, Brain Health: This animal study3 from the Human Nutrition Research Center on Aging at Tufts University looked at healthy rats, both young and old, and the impact of walnuts – a source of polyunsaturated fatty acids and nutrients such as folate, selenium, magnesium and polyphenols – on mechanisms in critical regions of the brain. Animals were segmented into three groups – one, the control group, who ate no walnuts at all (0%); a second that had 6% of their diet comprised of walnuts; and a third that had 9% of their diet comprised of walnuts (equivalent to one ounce and 1.5 ounces respectively in a human diet). The groups were monitored for ten weeks. According to the researchers, incorporating walnuts into one’s diet may have protective effects on the aging brain. As this study was performed on animals, however, findings cannot yet be implied for humans.
- Vascular Health: Microvascular function refers to the health of our smallest blood vessels, such as capillaries. A study4 from the Departments of Nutrition and Internal Medicine at the University of California, Davis of postmenopausal women with high cholesterol looked at the short-term impact of walnut consumption. The group that ate 40 grams, or 1.5 ounces, of walnuts per day saw improved vascular function. The study concludes this improvement is due to the effects from the walnut-derived fatty acids, alpha-linolenic acid (ALA) and linoleic acid (LA).
Findings like these pave the way for additional research aimed at understanding walnuts’ role in disease prevention and management.