5 minute read
March-April, 2023
HEALTHY NUTRITION, HAPPY BRAIN
THE ROLE OF NUTRITION ON BRAIN HEALTH
By Carol Harrison, RD
Recently, I asked a few fitness leaders what questions they have about nutrition and brain health. Here is what they wanted to know.
“I know physical activity is important for brain health, but does what you eat really matter for brain health?”
In a word, yes! Considerable research has shown the significant role that nutrition plays in brain and mental health. For example:
• Nutrition is one of the six pillars of brain health (the others being physical activity, mental exercise, social interaction, ample sleep and relaxation, and control of vascular risk factors). Food provides the nutrients necessary for proper brain function, including the building blocks to repair and maintain brain tissue.
• The brain is a hungry organ! Sending and processing signals all day long takes a lot of energy. That is why the brain uses about 20 percent of our body’s total daily energy.
• An undernourished brain could lead to poor cognitive function and mood instability—just think how “hangry” people can get if they go too long without eating.
• In the long term, poor nutrition can increase the risk for brain disorders such as Alzheimer’s disease and other forms of dementia. Eating a healthy diet can reduce your risk of diabetes, stroke, and heart disease, all of which are risk factors for dementia.
“What’s the single most important nutrition tip I can share with my fitness clients when it comes to nutrition and brain health?”
The brain is an active organ with substantial energy and nutrient needs—so we should feed it well!
The media often reports on single “brain superfoods” such as berries or walnuts but given the variety of nutrients required for optimal brain health it is our overall dietary patterns that matter most. Focus on eating a wide variety of highly nutritious foods. A straightforward way to do that is to follow the healthy plate approach: ½ veggies and/or fruit, ¼ quality protein, ¼ whole grains.
That may sound basic, but the reality is that most Canadians do not eat that way. Far too many of our calories (46 percent) come from ultra-processed foods that tend to be nutrient-poor and pro-inflammatory (soft drinks, chips, cookies, etc.), and we are not eating enough nutrient-rich foods containing the wide variety of nutrients needed for optimal brain health, like fatty fish, dark green and orange vegetables, fruit, beans, beef, fermented foods (kefir, kimchi, miso), eggs, nuts, seeds, whole grains, yogurt, lentils, and tofu.
“Would switching to a plantbased diet be beneficial?”
No doubt most people would benefit from eating more whole and minimally processed plantsourced foods.
Research on diets that have brain-health benefits, such as the Mediterranean diet, the DASH diet, and the MIND diet, are often misrepresented as being free of animal-based foods. In fact, they are plant-forward and include animal-based foods that are rich sources of bioavailable nutrients vital for brain health—for example, mineral-rich lean meats that offer vitamin B12, iron and zinc; fish high in omega-3 fats; and eggs rich in choline.
A better question might be: What should come off our plates to make room for more whole and minimally processed plant-based foods? And for better brain and overall good health, the obvious answer would be ultra-processed foods.
ULTRA-PROCESSED FOODS AND DEMENTIA RISK: WHAT DOES THE RESEARCH SAY?
Higher consumption of ultra-processed foods (UPF) is associated with a higher risk of dementia, according to a large study published in Neurology in 2022. Ultra-processed foods include soft drinks, candy, frozen pizza, protein bars, chips, hot dogs, and a wide range of other products that tend to be low in nutrients and high in calories, fat, sodium, sugar, and additives.
The researchers used the UK Biobank, a database of genetic and health information for half a million people in the United Kingdom, to find 72,083 participants aged 55-plus who did not have dementia. The study tracked this cohort for an average of 10 years, during which participants completed at least two 24-hour dietary questionnaires.
By March 2021, when follow-up ended, 518 people had developed dementia—287 were diagnosed with Alzheimer’s disease, and 119 with vascular dementia. The study does not prove that UPF causes dementia, only an association between the two, but researchers concluded that people who consumed the most UPF may be at higher risk for dementia than those who consumed the least. After adjusting for age, gender, family history, and other factors, they found that for every 10 percent increase in daily intake of UPF, the risk of dementia was 25 percent higher.
Here is the good news: Swapping out UPF for healthier foods can lower the risk of dementia, researchers found. Replacing 10 percent of UPF with an equivalent amount of unprocessed or minimally processed foods like fresh fruit, vegetables, legumes, milk, and meat “was estimated to be associated with a 19 percent lower risk of dementia.”
Carol Harrison is a registered dietician who loves her daily workouts! She has a food nutrition communications company in Toronto. For more recipes, healthy hacks or article suggestions, connect with Carol on IG @CarolHarrison.RD
