Research suggests the following foods maintain what researchers call “healthy brain aging.”
Thanks to their high polyphenol content, berries protect brain cells by fighting free radical damage, reducing inflammation and increasing the clearance of toxic proteins that accumulate with age.
When berries are out of season, add frozen and dried berries to your diet. One serving is equivalent to ½ cup of fresh or frozen berries or ¼ cup of dried ones.
To get the full range of hundreds of phytochemicals found in these foods, consume whole fruit more often than juice.
Adding a handful of walnuts to your diet is another way to keep your brain healthy. A previous study found that a walnut-rich diet – equivalent to one ounce or 14 walnut halves in humans – was able to reverse age-related motor and cognitive deficits in rats.
Polyphenols in walnuts are thought to protect the brain by fending off free radicals and promoting communication between brain cells and the growth of new brain cells. Like berries, walnuts also activate the brain’s house-cleaning process.
A study of 3,718 Chicago residents aged 65 and older found that people who ate more than two vegetable servings each day had a 40 per cent slower rate of cognitive decline compared with their peers who ate less than one serving. Leafy green vegetables such as kale, arugula, Swiss chard, collard greens, rapini, romaine lettuce and spinach offered the most protection. (Age-related cognitive decline – the subtle decrease in memory and thinking processes – is considered to be a normal consequence of getting older.)
Scientists attribute their protective effect of leafy greens to vitamin E, an antioxidant that protects brain cells from oxidative damage and inflammation.
One serving is equivalent to ½ cup of cooked greens or one cup of salad greens.
Eating oily fish on a weekly basis may also keep your brain healthy as you age. A four-year study of older adults revealed that those who ate fish at least once a week – compared with rarely or never – were 60 per cent less likely to develop Alzheimer’s disease.
Another study linked regular fish consumption to a 60 per cent lower risk of dementia, in particular Alzheimer’s dementia.
Omega-3 fatty acids in fish, especially DHA (docosahexaenoic acid), make up 60 per cent of the communicating membranes of the brain where they keep the lining of brain cells flexible so memory messages can pass easily between cells.
DHA also reduces inflammation and may prevent the build-up of a protein called beta amyloid, which can interfere with communication between brain cells.
The best sources of DHA include salmon, trout, sardines, Arctic char, mackerel and herring. (These fish are also low in mercury.)
Limit your intake of foods high in saturated (animal) fats such as butter, cream, cheese and fatty meats. Saturated fat can damage arteries and a higher intake has been linked to a greater risk of Alzheimer’s disease.
Prepare foods with unsaturated fats such as olive oil, canola oil, flaxseed oil and non-hydrogenated margarine. Eat avocado and almonds more often, good sources of heart-healthy fat.
These fats help reduce inflammation, blood-clot formation and hardening of the arteries in the brain. The fat in salad dressing and cooking oils also helps the body absorb vitamin E in leafy greens.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV’s Canada AM every Wednesday.