Vitamin B supplementation did not slow cognitive decline in patients with Alzheimer disease

Oct 14, 2008

High-dose vitamin B supplementation for patients with mild to moderate Alzheimer disease did not slow the rate of cognitive decline, according to a study in the October 15 issue of JAMA.

Evidence of homocysteine (an amino acid produced by the body) elevation in Alzheimer disease (AD) and the involvement of homocysteine in neuropathological mechanisms suggest that reduction of homocysteine may offer an approach to altering the disease. B vitamins that influence homocysteine metabolism have been considered as a therapeutic option to reduce risk of AD or slow its progression, according to background information in the article. According to the authors, prior studies of B vitamins to reduce homocysteine in AD have not had sufficient size or duration to assess their effect on cognitive decline.

Paul S. Aisen, M.D., of the University of California, San Diego, and colleagues conducted a clinical trial to determine if reduction of homocysteine levels with high-dose supplementation with folic acid and vitamins B6 and B12 for 18 months would slow the rate of cognitive decline in 409 individuals with mild to moderate AD. Participants were randomly assigned to two groups of unequal size to increase enrollment (60 percent treated with high-dose supplements [5 mg/d of folate, 25 mg/d of vitamin B6, 1 mg/d of vitamin B12] and 40 percent treated with identical placebo). A total of 340 participants (202 in active treatment group and 138 in placebo group) completed the trial while taking study medication. Cognitive abilities were measured via testing with the Alzheimer Disease Assessment Scale (ADAS-cog).

The researchers found that even though the vitamin supplement regimen was effective in reducing homocysteine levels, it had no beneficial effect on the primary cognitive measure: the rate of change in ADAS-cog score did not differ significantly between treatment groups. The authors did find that symptoms of depression were more common in the high-dose supplement group.

"Many studies suggest that relative elevation of homocysteine is characteristic of AD, and laboratory research implicates homocysteine in neurodegenerative mechanisms. High-dose B vitamin supplementation in individuals with normal levels of B vitamins was effective in reducing homocysteine levels. However, our study does not support the treatment of individuals with mild to moderate AD and normal vitamin levels with B vitamin supplements," the authors conclude.

Citation: JAMA. 2008;300[15]:1774-1783.

Source: JAMA

Explore further: Biomedical engineer looks at new applications for novel lupus drug

add to favorites email to friend print save as pdf

Related Stories

Nike krypton laser achieves spot in Guinness World Records

23 minutes ago

A set of experiments conducted on the Nike krypton fluoride (KrF) laser at the U.S. Naval Research Laboratory (NRL) nearly five years ago has, at long last, earned the coveted Guinness World Records title for achieving "Highest ...

Narcissistic CEOs and financial performance

23 minutes ago

Narcissism, considered by some as the "dark side of the executive personality," may actually be a good thing when it comes to certain financial measures, with companies led by narcissistic CEOs outperforming those helmed ...

Election surprises tend to erode trust in government

27 minutes ago

When asked who is going to win an election, people tend to predict their own candidate will come out on top. When that doesn't happen, according to a new study from the University of Georgia, these "surprised losers" often ...

Fires in Central Africa During July 2014

33 minutes ago

Hundreds of fires covered central Africa in mid-July 2014, as the annual fire season continues across the region. Multiple red hotspots, which indicate areas of increased temperatures, are heavily sprinkled ...

Atomic structure of key muscle component revealed

3 minutes ago

Actin is the most abundant protein in the body, and when you look more closely at its fundamental role in life, it's easy to see why. It is the basis of most movement in the body, and all cells and components ...

Recommended for you

Monitoring the rise and fall of the microbiome

5 hours ago

Trillions of bacteria live in each person's digestive tract. Scientists believe that some of these bacteria help digest food and stave off harmful infections, but their role in human health is not well understood.

Antioxidant biomaterial promotes healing

13 hours ago

When a foreign material like a medical device or surgical implant is put inside the human body, the body always responds. According to Northwestern University's Guillermo Ameer, most of the time, that response can be negative ...

Immune response may cause harm in brain injuries, disorders

15 hours ago

Could the body's own immune system play a role in memory impairment and cognitive dysfunction associated with conditions like chronic epilepsy, Alzheimer's dementia and concussions? Cleveland Clinic researchers believe so, ...

User comments : 0