Researchers are reporting that the largest and longest independent clinical trial to assess ginkgo biloba’s ability to prevent memory loss has found that the supplement does not prevent or delay dementia or Alzheimer’s disease.

The study is the first trial large enough to accurately assess the plant extract’s effect on the incidence of dementia, experts said, and the results dashed hopes that it is an effective preventative. In fact, there were more cases of dementia among participants who were taking ginkgo biloba than among those who were taking a placebo, though the difference was not statistically significant.

For the trial, researchers from five academic medical centers in the United States recruited 3,069 community volunteers 75 and older. Most were cognitively normal, but 482 had mild cognitive impairment.

About half were given two doses of 120 milligrams of ginkgo biloba extract daily, while the other half were provided with placebo pills. Neither the participants nor the doctors knew who was receiving which pills. They were followed for a median of 6.1 years and assessed every six months for dementia.

During the study period, 523 cases of dementia were diagnosed. Of those, 246, or 16.1 percent, were in placebo users, and 277, or 17.9 percent, were in people taking ginkgo biloba.

 

 

Source:wallstreetjournal.com

A form of vitamin B3, Nicotinamide has been found to get rid of Alzheimer’s disease-related memory problems in lab mice, according to new research. Vitamin B3 is available over the counter at a low price.

The study showed that when mice that were bred to exhibit symptoms of Alzheimer’s received the human equivalent of two or three grams of B3, they acted as if they had never developed the disease, said one University of California researcher.

The vitamin acts in the brain to clear tau “tangles,” of Alzheimer’s disease. While the vitamins are available over the counter and are relatively safe, researchers warn that high doses such as the ones used in the study could potentially be dangerous. Researchers are currently enlisting people for human trials. Their research appears in the November 5 online version of the Journal of Neuroscience.

A new study found that vitamin B supplements don’t slow cognitive decline in patients with mild to moderate Alzheimer’s disease.

The theory was that vitamin B might slow the progression of Alzheimer’s symptoms because the nutrient lowers homocysteine levels, which are elevated in people with the disease. Homocysteine is an amino acid produced by the body and has also been linked to an increased risk of heart disease.

“The results of the study indicate that we were successful in lowering homocysteine levels, but this did not translate into cognitive or clinical benefits,” said lead researcher Dr. Paul S. Aisen, a professor at the University of California, San Diego, Department of Neurosciences. “The disappointing conclusion is that high-dose B vitamin treatment is not helpful in Alzheimer’s disease.”

Aisen thinks this study clearly demonstrates that people should not be taking vitamin B thinking it will combat the disease.

“This treatment is not useful and should not be recommended,” Aisen said. “Because Alzheimer’s disease is one of the major health-care problems in this country and worldwide, and because our current treatments are not adequately effective, many people are seeking alternatives, and one alternative has been to use vitamin therapy.”

The findings were published in the Oct. 15 issue of the Journal of the American Medical Association.

For the study, Aisen’s group randomly assigned 409 people with mild to moderate Alzheimer’s disease to high doses of folate, vitamin B6 and B12 or a placebo. The researchers then measured the rate of cognitive decline using the Alzheimer’s Disease Assessment Scale.

Over 18 months, they found that although vitamin B reduced homocysteine levels, there was no reduction in the rate of cognitive decline among patients taking the supplements. In fact, there was no significant difference in the scores on the Alzheimer’s Disease Assessment Scale among those taking supplements and those receiving a placebo.

Interestingly, the people taking high-dose vitamin B supplements had more symptoms of depression than those taking a placebo, the researchers noted.

Dr. Sam Gandy, chairman emeritus of the Alzheimer’s Association Medical and Scientific Advisory Council, said this study should put an end to the idea that lowering homocysteine levels helps Alzheimer’s patients.

“Since cerebrovascular disease pathogenesis and that of Alzheimer’s disease bear some relationship to each other, the hypothesis was put forward that if people were given B vitamin supplements to control their blood homocysteine, then this might lower the incidence of both stroke and Alzheimer’s disease,” he said. “Sadly, for the latter at least, the hypothesis has been rejected: Even among those with elevated homocysteine levels that were normalized with B vitamins, there was no obvious benefit in terms of lowering the risk for Alzheimer disease.”

Like similar studies with antioxidants, anti-inflammatory drugs and estrogen, this study suggests that treating the risk factors for Alzheimer’s after the patients have established disease is not useful and may even be harmful,” he said.

Pamela Mason, a spokeswoman for the Health Supplements Information Service, cautioned that vitamin B is a dietary supplement, not a drug, and shouldn’t be expected to perform like a drug.

“This is yet another study attempting to use high-dose vitamin supplements like drugs in the treatment and prevention of disease,” Mason said in a news release. “B vitamin supplements are not intended to be taken like drugs to prevent or treat Alzheimer’s disease. People should not be taking them for this purpose. They are health supplements, and their role is in helping to maintain good health, particularly in those large numbers of adults whose dietary intake is low. This study, like many other recent studies evaluating vitamins, does not address the issue of health maintenance.”