Neuro-nutrition for the aging brain
Orsha Magyar, MSc, CHN
We’re learning that the foods we eat have a profound impact on how we feel, think, and behave. In fact, our diet is increasingly being recognized for its role in brain and mental health. Nutrition and neuroscience go hand in hand in keeping our brains healthy as we age. We can use nutritional neuroscience to focus our diet throughout our different life stages, targeting the evolving demands on our brains during our twenties, thirties, forties, fifties, and beyond.
When it’s hard to say no
Did you know that our brain is still maturing well into our twenties? Brain scans show that the last part of the brain to mature (the prefrontal cortex) isn’t fully hardwired until we reach about age 25. While the young brain is still maturing, it can be changed by external influences, including diet.
The young brain loves rewards, particularly sugary, fatty junk foods. These “non-foods” cause the release of dopamine in the brain’s reward centres. Excessive dopamine release causes the brain to recalibrate to expect this as the standard, and scientists think this might be a big driver of overeating and food addiction.
The prefrontal cortex regulates our decisions and, ultimately, our behaviours. Because it hasn’t reached full maturity yet, our diet choices in our twenties can often be suboptimal—like those late-night pizzas or entire tubs of ice cream.
The prefrontal cortex, not yet fully developed in our teens and early twenties, is the area of our brain that says “hey, stop that,” but it isn’t always the voice of reason in our youth. So, for optimal brain nutrition in our twenties, it’s best to lay off the junk food. Our prefrontal cortex will thank us.
When we might be eating for two
Many people start their families in their thirties, and nutrition has a massive impact on the brain health of the growing fetus.
But mom’s diet isn’t the only place to focus on nutrition. The genetic information carried by dad’s sperm can be modified by diet, too. Men who consume high-sugar diets may have lower sperm counts and slower swimming sperm. In the lab, the offspring of male mice who ate poor diets struggled at memory tests compared to those whose dads ate a healthy, balanced diet.
Friends with benefits
Our thirties are also the time to be working on maintaining a healthy gut microbiome. Alterations to the microbiota-gut-brain axis are linked to mental health issues including depression and anxiety. High-fibre foods rich in prebiotics feed the colonies of gut microbes that, in turn, nourish our brain and mental health.
When we’re trying to keep stress in check
Juggling multiple family, career, and compounding life commitments can take their toll in our forties. Stress is the body’s natural response to situations that threaten our well-being, priming the body and brain for action with the release of the hormones adrenalin and cortisol.
A stressed-out brain needs more energy, so cortisol acts to increase blood glucose, and adrenalin makes sure it gets to the brain. But the rebound effect of stress is low blood sugar, resulting in headaches, irritability, and poor judgement.
Stress has a big effect on our appetites too. Fluctuating blood glucose makes us crave carbohydrate-rich foods, such as chocolate, chips, and candy, to quickly replenish the glucose stores burned up following stressful experiences. The simple carbohydrates in these foods are bad for brain health, causing inflammation in the brain (neuroinflammation) that can increase risks of mood, anxiety, and memory disorders.
When we need to keep our brain well-oiled
With increasing lifespans, it’s vital that we keep our brains in good shape. Nutrition for brain health in our fifties and beyond should focus on preventing cognitive decline.
Brain-boosting antioxidant-rich foods such as blueberries contain plant compounds called flavonoids, which can help combat damage to neurons linked to age-related decline. The omega-3 fatty acids found in oily fish and nuts that are so good for overall health may also be helpful in keeping the aging brain healthy to reduce the risk of dementia.
Other “good fats” include monounsaturated fatty acids (MUFAs) found in olive oil, raw nuts and seeds, and avocados. Diets high in MUFAs, including the Mediterranean diet, are recognized to have positive benefits for the brain and mental health. Diets high in MUFAs also increase the levels of the brain chemical acetylcholine, which is essential for learning and memory (and which is reduced in the brains of people with Alzheimer’s disease).
Supplements for smart aging
Did you know?
Dementia, including Alzheimer’s disease, affects over half a million Canadians, with about 25,000 new cases diagnosed every year.
Important B vitamins
For moms-to-be, key dietary recommendations include folate (vitamin B9), a nutrient essential for fetal nerve cell growth that is found in dark green leafy vegetables, citrus fruits, legumes, and whole grains. Other brain-boosting B vitamins include B12 (cobalamin) and B1 (thiamine), which are also essential for nervous system development and preventing birth defects.
The brain science behind being ‘hangry’
Your brain is hungry, consuming about 20 percent of the body’s energy. And a stressed brain is like a sponge for sugar. That’s why you experience hypoglycemia with possible neuroglycopenia symptoms (low blood sugar) after a stressor. Always adding a healthy fat or protein to your carbs will help you push back against the “hangering” effects of stress on your blood sugar biology.