Your diet and your brain
What you eat every day does a lot more than just fuel your body, it plays an important part in your cognitive health.
“There is a direct physical connection between the brain and your gut,” says Kien Vuu, MD, assistant professor of Health Sciences at UCLA and founder of VuuMD Performance and Longevity. “It’s called the vagus nerve and it links down from the brain to the gut and surrounding nervous system, sending messages back and forth between the two. When you eat poorly or eat foods that irritate the gut, it will send that signal to your brain, which can cause memory issues and brain fog.”
There’s been lots of research focusing on what to eat to feed your brain. In general, foods that are good for your heart—fruit, vegetables, healthy fats, and more—are also good for your brain. (And exercise is known to be particularly good for brain health, too.)
But a study published in a September 2020 issue of the Journal of Alzheimer’s Disease, suggests there may be some lesser-known types of food that are associated with cognitive function.
(Plus, make sure to skip these foods that can zap your brain power.)
For the Journal of Alzheimer’s Disease study, researchers monitored a large sample of subjects over a 10-year period to collect both dietary and cognitive data. The study included 1,787 adults in the UK aged 46 to 77 who took a touchscreen questionnaire and a test of their ability to “think on the fly.”
The test measured fluid intelligence, or the ability to problem-solve without prior knowledge. The participants took the test two more times at two to three-year intervals.
“By doing an observational study we could model the 10-year trajectory of cognitive change as the outcome (rather than just one point in time values), as well as get a sense of the entire diet participants were eating during that time,” says Brandon Klinedinst, a PhD student in neuroscience at Iowa State University and one of the study’s lead researchers.
After examining the data, the researchers discovered daily consumption of cheese was associated with better performance on the cognitive test. This type of flexible thinking—the ability to take information you already know and use it in other ways, such as doing a crossword puzzle—becomes progressively more difficult as we get older, particularly for those at high risk for Alzheimer’s. (Here are 15 things that can slow down Alzheimer’s.
“Cheese is often synonymous with indulgent eating because of its saturated fat content,” says Auriel Willette, PhD, assistant professor of food science and human nutrition at Iowa State University and a lead researcher of the study.
“But cheese has healthy nutrients like conjugated linoleic acid (CLA), which is especially high in grass-fed cows or in cheeses with longer aging times or that are more oxygenated—like blue, Swiss, sharp cheddar, and brie,” he says. “Higher levels of CLA have been linked to anti-inflammation, weight loss, and better regulation of fats, in part through omega-3 fatty acids.”
These types of studies can’t prove cause and effect—some other factor might be associated with both cheese-eating and mental performance, like having a higher income. However, the researchers took into account other factors, like socioeconomic status, when looking at the results.
“Our findings suggested that eating lamb weekly seemed to be related to better fluid thinking, which is in line with the Mediterranean diet and others that suggest eating meat in moderation,” says Willette. “It’s very lean while also being protein dense.”
Another reason this meat might be better than the rest may be in how it’s raised before it gets to your plate. “Lamb tends not to be an industrial meat,” says Dr. Vuu. “Pasture-bred meats [like lamb] don’t have antibiotics pumped into them and are also a lower inflammatory meat compared to other red meats.”
Alcohol, in moderation
In the same study, alcohol intake of any kind seemed beneficial, with red wine sometimes showing an added benefit. Participants in the study who drank alcohol had higher flexible thinking scores than those who abstained.
“Wine comes from fermented fruit, so it’s rich in antioxidants,” says Willette. Polyphenols, one variety of antioxidants, “are naturally produced in the pulp, seeds, and skin of the grape. Polyphenols like resveratrol, quercetin, and others have been related to factors that increase blood flow.”
Although it’s speculation at this point, he adds, “more blood flow might mean more blood sugar and nutrients that are absorbed and used by parts of the brain responsible for flexible thinking.”
The brain is very susceptible to antioxidant stress, says Dr. Vuu. Things like obesity or a diet high in fat or sugar can impact the mind, making antioxidants a great source of protection against these stressors.
Keep in mind that most experts say that the health benefits of alcohol (including this study) aren’t enough to recommend that non-drinkers start drinking. And they note that the benefits turn into risks if you exceed a moderate intake, which is considered to be two drinks a day for men and one for women.
“Omega-3s are important nutrients for every cell membrane, but particularly ones in our brain,” says Dr. Vuu.
You probably already know salmon is a top source of omega-3s, but what about other types of fish? There’s an easy acronym to help with this called SMASH, says Dr. Vuu. It stands for sardines, mackerel, anchovies, salmon, and herring—all oily fish sources with big brain benefits.
Research published in Neurology suggests that eating seafood with omega-3 fatty acids at least once a week may protect against memory loss. This association was even stronger in those who had the APOE4 gene variant, which is known to increase a person’s risk of developing Alzheimer’s.
(It’s not just fish. Learn some surprising food sources that have omega-3s to add to your diet.)
You have to be mindful of what kind of chocolate you’re buying (sorry, a Snickers bar won’t do much here), but pure dark chocolate can help improve cognitive health. “The cacao in dark chocolate has flavonols, which act as an antioxidant and can help protect the brain,” says Dr. Vuu.
And apparently every little bit helps. A review of studies published in Frontiers in Nutrition showed a link between flavonol consumption and better memory, higher test scores, and improved blood flow in the brain, which may indirectly improve memory and cognitive thinking.
Green tea has a moderate amount of caffeine in it, which is a brain stimulant that can boost brain and memory function. (This means you can use your coffee habit as a means to strengthen your brain, as well.)
“Green tea has a few properties that coffee doesn’t have, the biggest one being theanine,” says Dr. Vuu. “This is an amino acid that can cross into the brain and make you feel more relaxed and less anxious, improving your mental function.”
Green tea also has similar polyphenols to red wine, meaning those who don’t drink alcohol can still get the brain benefits by steeping a cup of tea instead.
Find out eight more benefits of drinking green tea.