It's hard enough remembering to take your vitamins. But smart food choices could also help your brain. Certain nutrients—most notably antioxidants, B vitamins and omega-3 fatty acids—are showing the ability to fend off diseases such as stroke, Alzheimer's, Parkinson's and perhaps even brain tumors.
"The common thing you see in [each of those diseases] is aging," says James Joseph, Ph.D., a neuroscientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. "Oxidation and inflammation are present in each of these diseases. They're the Gemini twins of aging."
"The body tends not to deal with free radicals and inflammatory processes very well when you age," Joseph points out. "Nobody really knows why." So the trick, he says, is to eat foods rich in antioxidants and anti-inflammatories. "We've got to put enough stuff in our bodies to offset the changes that occur with aging."
Nearly 18 million people worldwide have some form of dementia, and Alzheimer's disease is the most common form of it. "We know for certain that Alzheimer's disease is a form of aging that is not normal," despite baby boomers' common fears that misplacing keys is an early sign of impending AD, says Maria Carrillo, Ph.D., director of medical and scientific relations for the Alzheimer's Association. "We know that there are these deposits—plaques and tangles—that are not present in the healthy brain."
The tangles involve neurofibers throughout the brain. The plaque is composed of beta-amyloid, a sticky protein that gets between and inside brain cells, effectively choking them. "It interrupts communication between the neurons and actually damages the neurons. The communications that have already been established start to fade away," Carrillo explains.
The Alzheimer's Association's Maintain Your Brain campaign educates consumers about lifestyle changes that lessen the likelihood of developing Alzheimer's. Exercise and mental stimulation are important components, but nutrition also plays a substantial role.
Anything that decreases inflammation plays a role in preventing Alzheimer's, Joseph says, because inflammation causes buildup of beta-amyloid. That means foods high in omega-3s—think salmon, trout and walnuts, or fortified eggs, bread and yogurt—could help stave off AD.
Folate, antioxidants, green tea, colostrum and foods low in cholesterol have also been shown in various studies to minimize the risk of AD. "I think right now there isn't any definitive proof that one [nutrient or food] works better than the others. It's very hard to say what the mechanism of action for any one of those is," Carrillo says.
But researchers are trying to find out. Consider the following:
Folate. Scientists induced memory impairment in elderly mice by feeding them a diet deficient in folate and vitamin E and high in pro-oxidant iron. Then they gave some of the mice apple juice concentrate; those who had the juice performed better in a maze test than a control group that did not receive it. "These data are consistent with normal, aged individuals being susceptible to neurodegeneration following dietary compromise such as folate deficiency," the study's authors wrote in the December 2005 Journal of Alzheimer's Disease. "These findings also support the efficacy of antioxidant supplementation, including consumption of antioxidant-rich foods such as apples, in preventing the decline in cognitive performance that accompanies normal aging."
That concurs with the results of an August 2005 study at the University of California, Irvine, which showed that people who had the most folic acid in their diet over a period of up to 14 years were the least likely to develop Alzheimer's. Foods rich in folic acid include spinach, kale and other leafy green vegetables, as well as lentils, quinoa and other legumes.
Antioxidants. Other studies have found that specific antioxidants present in certain foods—resveratrol in grapes and red wine, and anthocyanins in red cabbage, for example—prevent amyloid toxicity to cells.
Foods highest in antioxidants are the most effective. The antioxidant value of food is measured in ORAC (oxygen radical absorbing capacity) units. Blueberries are among the highest, with 3,000. Apples come in at only 300 but extract from their skins rates much higher.
Joseph says if consumers aren't armed with an ORAC chart, they can let color be their guide because fruits and vegetables with the deepest hues often have the greatest antioxidant effects. Enzyme inhibition. A September 2005 British study found that broccoli, potatoes, oranges, apples and radishes all contain compounds that inhibit an enzyme called acetylcholinesterase—the target of most Alzheimer's drugs.
Green tea. A Japanese study of more than 1,000 people over the age of 70 found that those who drank two or more cups of green tea daily were 50 percent less likely to show cognitive impairment than those who drank three or fewer cups a week. Researchers noted, however, that some other lifestyle factor associated with drinking green tea may have been responsible.
The three Cs. Joseph says curcumin—the active ingredient in turmeric, a spice used in curry—"actually removes plaques," at least in animal studies done so far. And a company that manufactures a product made from colostrum—found in mother's milk the first few days after delivery—found the product improved cognitive function in 40 percent of patients, with the results greatest in people in the early stages of Alzheimer's disease. British-based ReGen Therapeutics hopes to market the bovine-derived polypeptide as a nutraceutical soon.
Finally, new evidence hints that reducing cholesterol intake may prevent Alzheimer's as well as heart disease. Researchers in Germany found that cholesterol is linked to high amyloid levels.
Because foods low in saturated fat and cholesterol keep arteries clear, they are known for preventing heart attacks. But they can also prevent strokes, which are increasingly known as brain attacks in the medical community, due to the conditions' similarities.
A heart attack occurs when blood flow to the heart muscle is stopped or severely limited, according to the American Heart Association. A stroke occurs when blood flow to the brain is interrupted, by either a clot in an artery leading to the brain, or the rupture of a blood vessel, which causes blood to leak into the brain.
"Whatever's good for your heart is going to be good for your brain," says Carrillo of the Alzheimer's Association. "If you have a compromised vascular supply, you have compromised brain health." To prevent a stroke, then, and keep the brain's blood supply pumping, consumers can select low-fat, low-cholesterol foods that don't leave artery-clogging fatty deposits.
But science has found even more ways to prevent stroke through nutrition. Many use the same principles at work in preventing Alzheimer's disease. Foods rich in omega-3 fatty acids prevent inflammation and its contribution to stroke. Antioxidant-rich foods combat the oxidative stress that leads to stroke.
Foods high in vitamins B6, B12 and folate can thwart surges of homocysteine, an amino acid that can block the carotid arteries and prevent the brain from getting the nutrients it needs. In fact, a study published in the March 14 issue of Circulation reported that mortality from strokes declined by nearly 3 percent in the United States and more than 5 percent in Canada after folic acid fortification of some foods was mandated in 1998.
There's increasing scientific support for the role of produce in preventing stroke. Researchers from St. George's University of London found that people who ate five servings a day of fruits and vegetables lowered their stroke risk by 26 percent. Scientists did not pinpoint a specific mechanism, but suspected potassium, folate, fiber and antioxidants were responsible. Potassium is known to lower blood pressure, and high blood pressure is a common cause of stroke.
The natural form of vitamin E, known as alpha-tocotrienol or TCT, shows promise in preventing brain damage once stroke has occurred, according to a study in the October 2005 issue of Stroke. The richest food source of TCT is palm oil, according to the Ohio State University Medical Center.
Parkinson's disease, marked by tremors and difficulty walking and speaking, affects 1.5 million Americans. It normally strikes the elderly but has been known to affect younger people, including actor Michael J. Fox, who was 30 years old when diagnosed.
Mono- and polyunsaturated fatty acids may help prevent PD. Researchers in the Netherlands studied the diets of more than 5,200 people age 55 and older, all of whom were free of dementia and Parkinson's at the onset of the study. During the six years of the study, 51 people developed Parkinson's. Higher intakes of unsaturated fatty acids, as well as total fat intake, were "significantly associated" with a lower risk of developing the disease.
Preventing brain cancer
According to the Brain Tumor Society based in Watertown, Mass., phytonutrients in common foods have been shown in studies to kill brain tumor cells. Phytonutrients include catechins in green tea, genistein in soy, elemene in ginger, tangeretin and limonene in citrus peel, and anthocyanins in blueberries.
The BTS suggests eating antioxidant-rich foods, with a goal of consuming at least 5,000 ORAC units a day. It also recommends consuming omega-3s and limiting intake of sugar and carbohydrates to control inflammation.
When it comes to maintaining brain health, the common denominator is that mom was right: Eat your fruits and veggies—they're good for you. Pass that knowledge on, and your customers will remember to thank you.
Natural Foods Merchandiser volume XXVII/number 5/p. 22, 24