Alzheimer’s disease is a brain disorder that occurs in the later years of life. Individuals with Alzheimer’s disease develop progressive loss of memory and gradually lose the ability to function and to take care of themselves. The cause of this disorder is not known. Some studies suggest that it may be related to an accumulation of aluminum in the brain.[1] Despite this, aluminum toxicity has been studied in humans, and it is quite distinct from Alzheimer’s disease.[2] Therefore, the importance of aluminum in causing Alzheimer’s disease remains an unresolved issue.
Whether aluminum in the diet can cause Alzheimer’s disease remains controversial.[3][4] Until this issue is resolved, it seems prudent for healthy people to take steps to minimize exposure to this unnecessary and potentially toxic metal. This can be done by reducing intake of foods cooked in aluminum pots, foods that come into direct contact with aluminum foil, and beverages stored in aluminum cans. Some water authorities add aluminum to the water supply to prevent the accumulation of particulate matter in the water. In such areas, bottled water may be preferable. It appears most unlikely, however, that avoidance of aluminum exposure after the diagnosis of Alzheimer’s disease could significantly affect the course of the disease.
Preliminary evidence has linked populations at high risk for Alzheimer’s disease with higher levels of dietary fat and calories; similarly, fish intake has been linked with low-risk populations.[5][6][7] Whether these foods can actually increase or reduce the risk of Alzheimer’s disease, however, remains unknown.
Phosphatidylserine, which is related to lecithin, is a naturally occurring compound present in the brain. Though it is clearly not a cure, phosphatidylserine (100 mg three times per day) has been shown to improve mental function (such as ability to remember names and ability to recall the location of frequently misplaced objects) in individuals with Alzheimer’s disease.[8] However, the phosphatidylserine used in these studies was obtained from the brain of cows, which at least in England has been found to sometimes be infected with a virus that could cause Creutzfeldt-Jakob syndrome, a rare and fatal disease in humans. A totally safe plant source of phosphatidylserine is also available—however, this is a different form of phosphatidylserine, and its effectiveness has not yet been documented.[9]
Large amounts of vitamin E may slow the progression of Alzheimer’s disease, according to researchers from the Alzheimer’s Disease Cooperative Study. A two-year double blind study of 341 individuals with Alzheimer’s disease of moderate severity found that 2,000 IU per day of vitamin E extended the time patients were able to care for themselves (such as bathing, dressing, and other necessary daily functions), compared with patients taking a placebo.[10] Preliminary evidence has linked people who use antioxidant supplements (vitamins E or C) to a lower risk of Alzheimer’s disease compared with people not taking supplements.[11] Other preliminary research shows that higher blood levels of vitamin E correlate with better brain functioning in middle-aged and older adults.[12] The link between antioxidants and protection might make sense because in conditions related to Alzheimer’s disease, oxidative damage appears to be part of the disease process.[13]
DMAE (2-dimethylaminoethanol), like choline, may increase levels of the brain neurotransmitter acetylcholine. One uncontrolled four-week trial of fourteen senile patients given DMAE supplements of 600 mg three times per day did not show any changes in memory (based on ability to recall faces, numbers, or names) but did produce positive behavior changes in some of the patients.[14] However, subsequent research of a double blind, placebo-controlled design did not find a significant benefit from the use of DMAE in people with Alzheimer’s disease.[15]
The acetyl group that is part of acetyl-L-carnitine contributes to the production of the neurotransmitter acetylcholine. Several clinical trials suggest that acetyl-L-carnitine delays the progression of Alzheimer’s disease,[16] improves memory,[17] and enhances overall performance in some individuals with Alzheimer’s disease.[18] One double blind study found that acetyl-L-carnitine slowed progression of the disease in people under the age of sixty-five but paradoxically appeared to have the opposite effect in older patients.[19] Overall, however, most research indicates improvement in short-term studies and reduction in the rate of deterioration in longer studies (lasting one year).[20] A typical supplemental amount is 1 gram taken three times per day (total amount equaling 3 grams per day). Alzheimer’s research has been done with the acetyl-L-carnitine, rather than the L-carnitine form of this nutrient.
Huperzine A is a substance first found in Huperzia serrata, a Chinese medicinal herb. In a well-designed, placebo-controlled trial, 58% of people with Alzheimer’s disease had significant improvement in memory and cognitive and behavioral functions after taking 200 mcg of huperzine A twice per day for eight weeks—a statistically significant improvement over the 36% who responded to placebo.[21] Another double blind report using injected huperzine A confirmed a positive effect in people with dementia, including, but not limited to, Alzheimer’s disease.[22]
Mitochondrial function appears to be impaired in people with Alzheimer’s disease. Due to its effects on mitochondrial functioning, one group of researchers has given coenzyme Q10 (along with iron and vitamin B6) to several people with Alzheimer’s disease and reported that the progression of the disease was prevented for one and a half to two years.[23]
Preliminary research had suggested that people with Alzheimer’s disease should avoid zinc supplements.[24] More recently, preliminary evidence in four patients actually showed improved mental function with zinc supplementation.[25] In a convincing review of the zinc/Alzheimer’s disease research, perhaps the most respected zinc researcher in the world concluded that zinc does not cause or exacerbate Alzheimer’s disease symptoms.[26]
A small uncontrolled study showed that oral NADH improved mental function in people with Alzheimer’s disease.[27]
Some researchers have found links between Alzheimer’s disease and evidence of vitamin B12 and folic acid deficiencies,[28] while others consider the problem to be of only minor significance.[29] Little is known about whether supplementation with either vitamin would significantly help people with this disease. Nonetheless, it makes sense for people with Alzheimer’s disease to be medically tested for vitamin B12 and folate deficiencies and to be treated if they are deficient.
Are there any side effects or interactions? Research the individual supplement for information about any side effects or interactions.
An extract made from the leaves of the Ginkgo biloba tree is a leading treatment for early-stage Alzheimer’s disease in Europe. While not a cure for this serious condition, Ginkgo biloba extract (GBE) may improve memory and quality of life and slow progression in the early stages of the disease. In addition, three double blind studies have shown that GBE is helpful for people in early stages of Alzheimer’s disease, as well as the closely related multi-infarct dementia.[30][31][32] Patients with other types of dementia, including problems due to poor blood flow to the brain, also respond to GBE.
The tonic, or adaptogenic, class of herb is often used traditionally for elderly persons experiencing mental decline, although this use does not have scientific studies to support it. Examples include Asian ginseng (100–200 mg per day of the standardized herbal extract), eleuthero (Siberian ginseng) (2–3 grams per day of the dried root or 300–400 mg per day of the concentrated solid extract standardized on eleutherosides B and E), astragalus (two to three 500 mg capsules three times per day), and ashwagandha.
Ashwagandha has been shown to improve memory, although it has not been studied in Alzheimer’s patients.[33]
Asian ginseng has the longest history of use in traditional Chinese medicine and is commonly used for older individuals showing signs of memory loss. Asian ginseng improves and sharpens mental concentration and performance, including attention and memory.[34][35] While not as thoroughly researched as GBE for this condition, studies show that ginseng is effective at improving memory and also countering depression in the elderly. Some herbal supplements combine GBE with Asian ginseng.
It's always prudent to read about any herb in advance of taking it especially if you are consuming prescription or non-prescription drugs also. If, for example, you are taking an antidepressant medication the use of a herb that seems to have a similar effect is probably not a good idea since the effects would tend to add together. If you have any doubts at all see your medical advisor and obtain his/her opinion first.
