Food for thought
Some old wives tales hold up better than others. There’s now proof chicken soup has antihistamine properties that work against colds. And carrots contain beta-carotene, which is good for your vision.
But is it true that eating fish is good for your brain?
According to Dr. Tiffany Chow, a neurologist and scientist at Baycrest’s Rotman Research Institute, current scientific evidence links brain health to the consumption of fish, as well as other foods.
“Fish that are high in omega-3 fatty acids, like salmon, mackerel, sardines and bluefin tuna, protect against inflammation and are good for the brain,” she says. “Fish is also a good source of protein instead of red meat, which is laced with the kind of fat that gets you into trouble in the long run in terms of stroke and brain maintenance.”
Both Drs. Chow and Greenwood also encourage people to eat more fruits and vegetables.
“There’s good epidemiological data out there to argue that people with a higher intake of fruits and vegetables have a lower risk of dementia,” says Dr. Greenwood. “We attribute this in part to the anti-oxidants.”
Research has shown that virtually any disease process will involve an “oxidating reaction” that causes cell damage. “If you want to look at how to minimize cell damage, you want to protect it from oxidative reactions,” she says. “That’s why anti-oxidants, commonly found in fruits and vegetables, are not only good for your brain they’re good for many other systems in your body, as well.”
Sometimes, it’s what you don’t eat that matters. That means trying to keep your sweet tooth in check! “Your brain is only two per cent of your body mass, but it consumes 20 per cent of your glucose intake, and doesn’t cope well with major fluctuations caused by foods with a high glycemic index,” says Dr. Chow. “That means watching your intake of sweets.”
Foods can be categorized by a ‘glycemic index,’ which groups foods according to their carbohydrate qualities. Foods with a high glycemic index include the usual suspects — ice cream, chocolate, croissants, but also bananas, carrots and dried fruit — and can result in large increases in blood glucose after they are ingested.
Dr. Chow describes a New York Mount Sinai School of Medicine study done with transgenic mice. “These mice were bred to develop the same types of plaques found in the brains of patients with Alzheimer’s disease. Although Alzheimer’s involves two important proteins, (plaques and tangles), these mice just developed plaques.”
When the mice had their caloric intake reduced by one-third, they developed fewer plaques in their brains. “But knowing that most people would not be willing to reduce their diet so drastically, the researchers decided to study the mice more carefully. What they found was that a substance called “resveratrol” was responsible for the decrease in plaque levels,” says Dr. Chow.
“Dr. Chow recommends smaller and more frequent portions spread throughout the day.”Resveratrol can be found in red wine, the skin of grapes, and pomegranate juice. “The next phase of the experiment was to take these mice and tank them up with wine,” says Dr. Chow. “The researchers actually made their own special Cabernet in the lab for the mice so they could carefully control the resveratrol. The mice that drank it did better.”
Although people who drink red wine became very excited by this news, Dr. Chow remains cautious. “You’d have to drink a lot of red wine in order for it to protect you against Alzheimer’s. People shouldn’t be drinking that much alcohol on a daily basis,” she says.
Dr. Chow strongly recommends a Mediterranean-style diet, based on fruits, vegetables, olive oil, legumes, grains and fish. She also recommends smaller and more frequent portions spread throughout the day to regulate glucose levels.
Our society has become accustomed to “supersized” portions, says Dr. Greenwood. “Historically, supersizing at restaurants has come out of competition, but we also supersize at home.”
She defines a serving of vegetables as about half a cup, while one piece of fruit is considered a serving of fruit.
Dr. Chow says one serving of protein is what you can fit onto the palm of your hand. “That’s one chicken breast, or three pecans, not half a can,” she says.
Dr. Chow insists that diet alone is not enough to protect your brain. “Exercise is important for your circulation, reducing stress and reducing body-mass index, which is a standard measure of a person’s weight in relation to his or her height.”
Brew for Your Brain
Every time you have a cup of tea, you may be helping your brain stay healthy.
That’s because new scientific research suggests that drinking tea may actually lower your risk of developing Alzheimer’s disease and other dementias.
“It’s possible that ingredients in tea help to maintain and improve brain health because of their effect on brain cells,” says Dr. Carol Greenwood, a Baycrest senior scientist and professor of nutritional sciences at the University of Toronto. Dr. Greenwood is also a long-standing scientific advisor to the Tea Association of Canada.
A recent animal study by Dr. Sylvia Mandel, of the Eve Topf Center for Neurodegenerative Diseases in Israel, shows the consumption of green tea flavonoids, a naturally occurring pigment in tea, helps keep brain cells healthy, and may even improve the brain’s ability to combat stressors. Furthermore, the flavonoids helped prevent brain cells from dying, and showed reductions in the number of compounds normally associated with Alzheimer’s disease
“This is one of several studies showing the beneficial effects of green tea on the brain,” says Dr. Greenwood. “In addition to supporting the repair of injured brain cells, tea flavonoids also have anti-oxidant properties that help protect against further damage.”
Although this specific study dealt with green tea, Dr. Greenwood says flavonoids in green tea are similar to those in other teas, with the exception of herbal varieties. “Herbal teas are made from infusions of many different plants,” she says. “Green and black teas are from the same plant. The main difference between them is the way the leaves are prepared.”