Patients have simple, adaptable options to fight dementia decline
Herbs, supplements, and hormones show promise
There may be no worse times in a medical practitioner’s professional life than those agonizing months — and possibly years — watching patients with dementia slowly decline.
While science has not yet found a cure for Alzheimer’s disease (AD) or the numerous other forms of dementia, some natural therapies are showing promise in slowing the progression of the disease. AD and dementia rob people of brain function while leaving their bodies essentially healthy, condemning them to a life essentially as a shell.
And some lifestyle changes also may help prevent or delay the onset of AD and other forms of dementia.
Probably, the most promising new research comes from the University of Hawaii in Honolulu. Researchers following a group of elderly men for 35 years found that those who took high doses of vitamins E and C had higher mental ability late in life and were protected against vascular dementia that sometimes occurs after a stroke.1
Other researchers worldwide have sung the praises of Ginkgo biloba, commonly known as "the memory booster," for its ability to delay the progression of AD at least as well as the most commonly used prescription medications.2
Others say estrogen provides a protective effect in women using hormone replacement therapy (HRT).3 (See related article on natural HRT, p. 41.)
Still others say lifestyle changes, including stress reduction, exercise, a low-fat diet rich in omega-3 fatty acids, and B vitamins, offer even more protection. (See box, p. 40.)
Another vote for antioxidants
"We believe antioxidants like vitamins C and E may protect against vascular dementia by limiting the amount of brain damage that persists after a stroke," says lead author Kamal Masaki, MD, associate professor of geriatric medicine at the University of Hawaii.
"These supplements may also play a role in providing protection against brain cell and membrane injury involved in many aging-related diseases, thus resulting in significantly higher scores on mental performance tests later in life," she says.
Masaki’s team is following 3,385 Japanese-American men between ages 71 to 93, who have been participants in the Honolulu Heart Program, a prospective study of heart disease and stroke initiated in 1965.
The men were assessed for dementia and mental abilities during exams from 1991 to 1993. Of the participants, 47 were diagnosed with AD, 35 with vascular dementia, and 50 with other or mixed forms of dementia. In addition, 254 had low cognitive test scores without diagnosed dementia, and the remaining 2,999 showed no cognitive impairment.
Participants taking both vitamin C and E supplements regularly (at least once a week) in 1988 were 88% less likely to have vascular dementia four years later and 69% less likely to have other forms of dementia other than vascular or Alzheimer’s.
Previous studies have shown that antioxidants may slow the progression of AD, but "surprisingly, there was no reduction in the occurrence of AD," says Masaki. "We are not exactly sure why."
Participants without dementia were divided into four groups based on mental performance:
- low;
- low-normal;
- mid-normal;
- high-normal.
Those taking vitamin supplements in 1988 had an approximately 20% greater chance of better cognitive function than those who took no vitamin E or C. However, those who reported taking vitamin E and C supplements in 1982 and 1988 had an approximately 75% greater chance of better mental performance during the 1991-93 examinations.
"This suggests that long-term use could significantly improve cognitive function in late life," says Masaki. "We originally thought that the beneficial impact antioxidant vitamin supplements has against vascular dementia was due to the prevention of stroke. However, to our surprise, we found that there was not a significant association between vitamin supplementation and clinically recognized stroke.
"It is critically important for patients to practice preventive efforts shown to lower stroke risk and to have broad-ranging beneficial effects," she continues. "More effective strategies for prevention must also be found. Therefore, a prevention trial of both vitamin E and vitamin C is needed to further examine the potential protective effects on both vascular dementia and AD."
Vascular dementia is the second most common cause of dementia in the United States (following AD), and the most common cause of dementia in Japan. Those with vascular dementia face physical impairments related to stroke, such as paralysis and loss of speech, language and visual disturbance, in addition to mental impairment.
Vitamin E is enthusiastically embraced as a matter of course in many major clinical settings.
"It is our common practice to give 2,000 IU of vitamin E for patients with Alzheimer’s," says Alan Jacobs, MD, assistant director of the memory disorders program at Cornell University’s Weill School of Medicine in New York City.
He says the effects of the vitamin E haven’t been startling, but "we see a modest, but statistically relevant benefit." Jacobs says it is important for patients to use vitamin E supplements containing alpha-tocopherol (the natural form as opposed to dl-alpha-tocopherol, which is the synthetic form).
"Vitamin E is a powerful antioxidant, and its free radical containment properties probably stop the buildup of plaque, which contributes to heart disease and dementia," says Jacobs.
Results in clinical practice are less apparent with vitamin C, but he says, "It would not cause any harm to take 1,000 mg a day."
Vitamin E gets the go-ahead
Jacobs also advocates prophylactic doses of C and E and levels of 500 mg to 1,000 mg and 400 IU to 800 IU respectively for patients not diagnosed with any form of dementia.
"Vitamin E supplementation is pretty well accepted in most Alzheimer’s clinics," says Barry S. Oken, MD, professor of neurology at Oregon Health Sciences University in Portland, OR.
Oken’s clinic recommends up to 2,000 IU of vitamin E for patients with AD because "its antioxidant and anti-inflammatory properties seem to slow the progression of AD," he says. Such dosage levels may lead to spontaneous bleeding in some patients, he warns, so the usage of high doses of vitamin E should be monitored.
However, Oken argues, there is evidence that vitamin E does not reach the brain in doses lower than 1,000 IU, which is the rationale for the high dosages. "There are four neurologists at our clinic, and there is no consistent pattern of dosage, although all of us recommend vitamin E."
Oken says his most commonly prescribed dosage is 1,000 IU — at which level he hasn’t seen any serious side effects.
Ginkgo biloba, an extract from the leaves, fruit, and seeds of the ancient ginkgo tree, has been extensively employed in Europe, particularly in Germany, for all forms of dementia. While there have been many positive results reported, the poor nature of most of the studies make most of these results suspect, writes Oken in a review study published in the Archives of Neurology in 1988.
"Of more than 50 articles identified, only four studies met all the inclusion criteria," says Oken. Yet those results warrant additional study — and certainly don’t rule out ginkgo as a treatment for AD, he says.
There is a small but significant effect of about 3% on a three-to-six month treatment with 120 mg to 240 mg of ginkgo biloba extract on objective measures of cognitive function in AD, Oken writes.
It is a mild and short-term improvement, Oken emphasizes. "It’s not very dramatic, but it’s at least as good as cholinomimetics being used for the same purpose."
Most ginkgo extracts now sold in the United States are standardized to contain at least 24% ginkgo flavone glycosides and 6% terpene lactones for an effective dosage, he says.
There have been case reports of increased bleeding in ginkgo users, especially when combined with the daily use of aspirin, says Oken. Clinicians should ask patients if they are taking ginkgo and be particularly vigilant if they are using blood thinners. Since ginkgo is one of the most commonly used herbs in the United States, he says, physicians should always ask patients if they are using it.
Opinions rosy on use of ginkgo
Jacobs says he is waiting for more evidence before he recommends his patients use ginkgo, but he doesn’t discourage its use if a patient inquires. "I don’t think it is bad in any way; I’d just like to see more research being done on it."
The National Institutes of Health’s National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute on Aging currently are conducting a $15 million multicenter study to test the efficacy of Ginkgo biloba on older people at risk for dementia.
Test sites are at the University of Pittsburgh, Johns Hopkins University in Baltimore, the University of California-Davis, and Wake Forest University School of Medicine in Winston-Salem, NC.
Researchers are in the process of recruiting 2,000 participants at four centers. Participants will be randomized into two groups: one on placebo and the other on 240 mg of ginkgo. The primary outcome of the study will be pinpointing the onset of any type of dementia, and the secondary outcome will be measuring changes in cognitive function.
A recent Columbia University review found significant and remarkable protection against dementia among women who were using HRT. The risk was reduced by 30% in one study and 50% in another. Some studies also have associated estrogen use with better performance on verbal and visual memory testing later in life.3
However, studies show the effects of estrogen replacement are less significant for patients with AD or who later develop AD.
Researchers theorize the biological mechanism, which could be responsible for these effects, to include activation of the cholinergic system, antioxidant action, neurotropic stimulation, and anti-amyloidogenic properties.
In addition, a Harvard review found that women without dementia who took postmenopausal estrogen replacement therapy had significantly higher scores on verbal memory tests and 30% higher scores on verbal fluency tests. However, the reviewers concluded that hormone users did not have better overall cognitive function than nonusers.4
Oken says he is not terribly impressed with the quality of the available research on estrogen and dementia, but says ongoing research may be more persuasive. There is currently no research being done in this field with natural hormone replacement. (See story at right.)
Lifestyle changes for the better
Finally, experts on aging have long advocated proper diet, stress reduction, and mental stimulation as means of warding off dementia and memory loss in old age.
A study published in May in the British Journal of Psychiatry brings up some interesting food for thought: the possibility that as people begin to lose function in one part of the brain, they may gain it in another region.4
One study participant was an inventor with numerous patents to her credit. Though her dementia caused serious degeneration of language-related skills, her ability to refine her inventions continued virtually undisturbed.
In another case, a patient who once had been linguistically talented began to lose his ability, while a new musical ability began to emerge. Yet another patient who had mastered languages as diverse as Chinese, Italian, and Russian suffered a deterioration in his ability to manipulate words, but gained an exceptional ability to compose classical music, although he had little training in the field.
Of the 12 patients in the study, "seven developed new skills (five visual and two musical) in the setting of dementia, while five maintained visual and/or musical abilities despite progression of dementia."
This led researchers to conclude that the creative process may become a secondary outlet for expression when other faculties fail.
References
- Masaki KH, Losonozy KG, Izmirlian G, et al. Association of vitamin E and C supplement use with cognitive function and dementia in elderly men. Neurology 2000; 54:1,265-1,272.
- Oken BS, Storzbach DM, Kaye JA. The efficacy of Ginkgo biloba on cognitive function in Alzheimer’s disease. Arch Neurol 1998; 55:1,409-1,415.
- Grodstein F, Chen J, Pollen DA. Postmenopausal hormone therapy and cognitive function in healthy older women. J Am Geriatr Soc 2000; 48:746-752
- Miller BL, Boone K, Cummings JL. Functional correlates of musical and visual ability in frontotemporal dementia. Br J Psychiatry 2000; 176:458-463.
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