Nutrition and Alzheimer's: How
Strong Is the Link?
For: Does Turmeric Keep Your Brain Healthy? April 2002
The risk of Alzheimer's disease rises with age.
At age 70 about 3% of all people are affected by it. At 85 the percentage
rises to 20 to 30%. This devastating disorder, a progressive decline
in mental functions that is ultimately fatal, remains a mystery
in spite of years of research. There is no cure, and the drug treatments
that exist are not very effective. And the experts have only hunches
about how to prevent it. But one of these hunches is growing stronger:
good nutrition over a lifetime and, in particular, during later
life may help ward off Alzheimer's.
It's known that many nutrients play a role in
healthy brain function—for example, B vitamins such as thiamin,
B6, B12, and folic acid. Vitamin B12 and folic acid help form certain
proteins essential for memory, and thiamin, too, is needed for a
key brain chemical. Lack of these vitamins could increase the risk
of Alzheimer's. For instance, studies conducted at Tufts University
and other centers have found that low blood levels of folic acid
are associated with memory problems and Alzheimer's. Essential
as folic acid is, though, it's not certain that a deficiency
in it is the cause of Alzheimer's in these people, or even
that people with Alzheimer's fail to consume enough folic acid;
the problem may be that their bodies are less able to absorb or
utilize it.
Vitamins C and E—friends of memory, maybe
Antioxidants—notably vitamins C and E and beta
carotene—are also essential to optimal brain function. The
theory is that anti-oxidants prevent free radicals from damaging
brain cells—damage that inevitably increases as people age.
High blood levels of antioxidants are associated with high mental
function, including memory. One study of healthy men showed that
those taking vitamin C and E pills at least once a week did better
on memory tests, over a long period, than those who took no supplements.
Another study showed that patients with Alzheimer's who were
treated for two years with vitamin E were able to live independently
longer. But not all research supports the idea that antioxidants
improve or protect brain function in older people.
In a study of healthy older adults recently published
in Nutrition, Dr. R. K. Chandra of Memorial University of
Newfoundland found that healthy people over 65 improved their mental
capabilities when they took nutritional supplements. These included
vitamins C, B6, E, and D, folic acid, and minerals such as iron,
zinc, and selenium. Megadoses weren't necessary—all that
was needed was what any good multivitamin/mineral supplement would
supply. Dr. Chandra concluded that such supplements could improve
mental functioning and thus quality of life for older people. The
right nutrients, he believes, might even delay the onset of Alzheimer's
disease.
Bottom line: It is too
early to blame Alzheimer's on nutritional deficiencies. Certainly
no one should conclude or claim that any vitamin or mineral will
prevent or cure Alzheimer's. Nevertheless, there's hope
in this research—and no downside risk. A plant-centered diet
with low-fat or nonfat dairy products, fish, and small amounts of
lean meats will supply the nutrients older people need, and a basic
daily multivitamin/mineral supplement should cover any shortfalls.
If you don't get enough calcium from food, a calcium pills
are also a good idea. And we recommend a daily supplement of vitamin
E (200 to 400 IU of natural E), plus vitamin C (250 to 500 milligrams,
which is easy to get from food instead of a supplement). This way
you can't lose—and you might indeed help prevent the memory
loss associated with aging, or even delay or prevent Alzheimer's.
UC Berkeley Wellness Letter, February 2002
