Your gut is filled with multiple strains of microbes—both good and bad. Research over many decades has shown that it’s vital they’re kept in balance to keep the brain and the body in good working order.
Since lifestyle factors influence the gut, researchers have examined if this gut microbiome could be targeted with specific exercises and dietary changes to sharpen memory and reduce the risk of dementia.
Let’s see what they found out in their latest studies…
The gut microbiome consists of bacteria, viruses, protozoa, and fungi. Imbalances, sometimes known as dysbiosis, within these different species are linked to impaired cognition. It’s no surprise that researchers theorize that rectifying any imbalance could potentially lower the risk of dementia.
The Gut-Brain Connection
The gut communicates dysbiosis to the brain via the vagus nerve. This is often referred to as the gut-brain axis. Transmitting this bad news can lead to chronic high cortisol and inflammatory factors that impair the blood–brain barrier which keeps pathogens and toxins out of the brain and promote inflammation and brain cell atrophy.
Researchers at Baycrest Health Sciences in Toronto, Canada, investigated the current state of research to see if diet and exercise can improve the gut and heal the brain.
All Diets Impact The Microbiome
In terms of diet the research team found articles on high fat, high sugar, and highly processed food diets as well as other research on specific components of the diet. However, these were all conducted in rodents.
There were also inconsistent findings on the impact of high fat diets, but diets high in sugar consistently and negatively affected the gut microbiome and, in turn, cognition. A highly processed diet reduced gut microbiome richness and diversity and reduced short-term memory.
Dietary components with the greatest benefit to the microbiome and brain were omega-3 fatty acids and sesamol, a polyphenol derived from sesame oil. But interventions with the most promising evidence came from high fiber diets.
A Mediterranean Diet Comes Out On Top
The only whole dietary intervention study in humans included 1,200 adults aged 65 to 79 who were randomly assigned to either a Mediterranean diet or a control diet for 12 months. The Mediterranean diet emphasizes increased intake of whole grains, fruits and vegetables, legumes, nuts, fish, and lower intake of red meat and processed foods.
Those eating the Mediterranean diet showed positive changes in the microbiome and significant improvements in cognition and memory compared to controls.
Little Data on Exercise
Compared to diet studies there were far fewer studies looking at the effects of exercise on both the gut and brain and there were none whatever in humans.
Mice on a running wheel exercise for 16 weeks saw positive changes in the microbiome and improved memory compared to controls. Two other rodent studies also suggested that starting exercise, specifically aerobic exercise, can lead to changes in the gut microbiome and brain health at the same time.
The limited amount of research led the authors of the study, published in The Journals of Gerontology: Series A in August, to write: “Little is known about how exercise intensity influences the gut–brain axis, and thus is an important endeavor for future research.”
Because of the lack of human data for both diet and exercise, the researchers are launching their own randomized controlled trial.
Senior author Dr. Nicole Anderson explained why this is needed, saying, “By better understanding how changes to the gut microbiome affect the relationship between lifestyle and brain health, we can strengthen existing lifestyle interventions and create new strategies to reduce dementia risk, helping older adults everywhere age fearlessly.”
While the research on diet and exercise’s impact on the gut microbiome continues, I think it’s important to stress that a healthy diet and regular exercise have already been proven to positively impact brain health in other ways. For instance, numerous studies point to improved blood flow and the effects of certain key nutrients such as B vitamins on memory. So, continue to make living a healthy lifestyle a daily habit and soldier on!