Food For Thought
by Richard S. Dargan...for the Albuquerque Journal
With baby boomers entering their retirement years, Alzheimer's disease looms as perhaps one of the most significant public helath issues of the future.
According to the Alzheimer's Association, the number of people with Alzheimer's disease will more than triple from the current 4.5 million to 16 million by the year 2050, when the last of the boomers will have reached their mid-80's. Those alarming statistics are helping to fuel research into the relationship between diet and Alzheimer's disease. While results so far are inconclusive, evidence suggests that people who adopt dietary practice recommended for a healthy heart will also reduce their risk of developing Alzheimer's disease.
"If it's good for the heart, it's good for the brain." says Betty Kuehne of the Albuquerque Alzheimer's Association. "There's no ironclad proof yet, but the preponderance of evidence shows that diet is important in preventing Alzheimer's," adds Willim Frey, director of the Alzheimer's Research Center at Regions Hospital in St. Paul Minn.
Alzheimer's disease is a progressive disorder characterized by damage to nerve cells in the brain. Early-stage symptoms include short-term memory loss. As the disease progresses, patients lose their abiltiy to function independently. The cause remaines unknown, and definitive diagnosis is possible only through post-mortem examination of brain tissue.
Eating habits: Much of the published research on Alzhimer's disease and diet has focused on specific foods and nutrients. But an ongoing study of elderly men a Columbia University Medical Center in New York City recently found that a healthful diet lowers the risk of the disease.
In the study, 2,258 elderly men adopted the Mediterreanean diet, named for the people in the Mediterranean Sea basin who eat lots of fish, grains, fruits and vetetables, and get much of their fat from olive oil and fish. Study subjects who followed the diet most strictly had the lowest risk of Alzheimer's disease.
"Researchers had been looking for elements in a diet in an isolated way, when in reality we eat foods in combinations," says study author Dr. Nikolaos Scarmeas, assistant professor of neurology at Columbia Univeristy Medical lCenter. "This is the first stage study that looked at a diet in general, rather than particular ingredients in isolation."
The principles of the Mediterranean diet...plenty of fruits, vegetables and whole graines, and little or no saturated and trans fats...are in line with those of leading health agencies in the United States. And existing research shows that adherence to those guidelines could keep your brain healthy.
A 2002 study of almost 1,500 people in Finland found that the risk of Alzheimer's disease was greatest for those with high cholestrerol and high blood pressure. In a Harvard University study, women who ate more green leafy vegetables like spinach and cruciferous vegetables such as broccoli and Brussels sprouts experienced a smaller decline in their cognitive skills than women who ate little of those vegetables.
The research also shows that a poor diet could hasten the course of the disease. A study at the Medical University of South Carolina found that mice fed a diet heavy in saturated fat and cholesterol had trouble completing memory tasks and also showed an increase in a toxic brain protein called beta amyloid, a common feature ofAlzheimer's.
Special compounds: While scientists have yet to pinpoint specific protective agents in food, several studies indicate that antioxidants may provide a natural defense against Alzheimer's disease. Antioxidants are compounds that neutralize free radicals, highly reactive molecules generated as part of our body's natural processes, as well as from environmental factors such as air pollution, infection and radiation. Free radicals can damage cells through a process known as oxidative stress. Because the brain is an area of high metabolic activity, it's thought that oxidative stress plays an important role in Alzheimer's disease, and a diet high in antioxidants might reduce that effect.
While some animal and laboratory studies support that theory, the available evidence from human studies is more limited and inconsistent. Several studies have found links between the antioxidant vitamin E and a reduced risk of Alzheimer's. Vitamin E is found with cell membraines and neutralizes free radicals as they are generated. Common food sources include vegetable oils, margarine, nuts and seeds. Moderate amounts of vitamin E are found in whole grains, egg yolks and vegetables and fruits.
Researchers at the Rush Institute for Healthy Aging in Chicago found that a diet rich in foods contining vitamin E might help protect some people from Alzheimer's disease. A study from Jons Hopkins University in Baltimore lent credence to those findings, concluding that vitamin E was strongle associated with a significant reduction of Alzheimer's risk. The Hopkins researchers also looked at vitamin C, another antioxidant, and found that it was somewhat useful in reducing disease risk.
The Rush Institute findings indicate that vitamin E and C are more effective against Alzheimer's disease if they are acquired through diet and not via supplementation. In fact, the Rush Institute researchers found no reduction in the risk of Alzheimer's disease among people who took vitamin E in supplement form.
That could be because food provides the body with different types of vitamin E, while supplements tend to contain only alpha-tocopherol, the most biologically active form of the vitamin. Another possibility is that food intake may be a better indicator of long-term exposure to the vitamin.
The next decade likely will bring more definitive findings, but in the meantime it appears that the same healthful diet practices advised for the heart could help the aging brain. And those practices should begin sooner rather than later.
"Alzheimer's disese starts years or even decades before manifestations in real life," says Scarmeas. "So the earlier you start a healthy diet, the better it would be."
Smart choices: Studies of Alzheimer's idsease and diet suggest the following foods and drinks might provide protection against the disease. Remember to discuss any changes in diet with your doctor.
Nuts: Nuts have omega 3 fatty acids, which research has linked with a lower risk of Alzheimer's. In addition, nuts like almonds are great source of the antioxidant vitamin E. However, the nuts you find in the snack food section of the store can have lots of added fat, calories and salt, so be sure to read the food labels.
Fish: Fish like salmon, cod and trout are rich in omega 3 fatty acids.
Coffee; Several studies have found a link between coffee consumption and a reduced risk of Alzheimer's disease. The caffeine in coffee appears to have an effect on the toxic beta amyloid proteins associated with Alzheimer's disease.
Sunflower seeds: Sunflower seeds provice an excellent source of vitamin E .
Red wine: A study on mice found that the equivalent of one glass of red wine a day had protective effects against Alzheimer's disease, possibly due to the presence of the antioxicant resveratrol.
Olive oil: A staple of the Mediterranean diet, olive oil contains vitamin E and antioxidants.
Beans: Kidney beans; lima beans; and other varieties are excellent sources of antioxidants and folic acid which has been linked to lower Alzheimer's disease risk.
Vegetables: Consumption of green leafy vegetables like spinach and cruciferous vegetables such as broccoli and Brussels sprouts could slow cognitive decline.
Fruits: Apples and citrus fruit appear to protect the brain against oxidative stress thanks to the presence of chemical substances know as polyhenols.