REUTERS/Michael Kooren An unidentified man suffering from Alzheimer's disease and who refused to eat sleeps peacefully the day before passing away in a nursing home in the Netherlands. To match feature DUTCH-EUTHANASIA REUTERS/Michael Kooren (NETHERLANDS)

Senior moments are normal — scary, but normal. Forgetting a friend’s phone number, a celebrity’s name, or even what you came into a room to retrieve are all part of the typical aging process. It’s only when forgetfulness becomes a regular part of your day, or when the information lost is more immediate and necessary (your own address or a common word) that it becomes a concern.

More serious patterns of forgetting, along with language problems, are known as mild cognitive impairment (MCI), a step between standard cognitive decline and full-blown dementia — and as my colleague Belinda Luscombe recently pointed out, a condition that may be more common in men than women. Approximately 1 in 6 people over the age of 70 suffer from MCI, and fully 50% of people who develop MCI also develop Alzheimer’s within five years, according to background information in a new study by Oxford University researchers.

That study, published by PLoS ONE, suggests that a cocktail of B vitamins at high doses can decrease brain atrophy in patients with MCI. For the 24-month trial, researchers gave 168 people with MCI, ages 70 and older, either a daily placebo pill or a“TrioBe Plus” pill that contained high doses of vitamin B12, B6 and folic acid. All told, the intervention group was getting 300 times the recommended daily dosage of B12, 15 times the recommended dose of B6, and 4 times the recommended dose of folic acid.

The participants also underwent MRI brain scans at the beginning and end of their vitamin regimen. The 85 patients who took B vitamins showed an annual brain atrophy rate of 0.76%, compared with a rate of atrophy of 1.08% per year in the placebo group.

But before you start megadosing on B vitamins, consider that the current study did not actually measure the participants’ cognitive function. The researchers looked only at differences in brain atrophy, which may well be a marker of Alzheimer’s risk — but that isn’t clear from the new data.

The character of brain loss is also not clear. “Normal brain atrophy [is a loss of] nerve endings, without a loss of nerve cells – like the difference between losing a leaf and losing the whole tree,” says Dr. Caleb E Finch, a professor of gerontology and neurobiology at the University of Southern California, who did not participate in the study but called its findings significant. “Using the measurements from the study, there’s no way to tell which effect these people were having.”

What’s more, the study is small, with just 168 patients. The results need replication and further study. As one of the study’s authors, Helga Refsum, told journalists, “As a scientist, I would never be happy with the results of just one trial.”

It would be great if a cheap, over-the-counter vitamin pill could be used to treat Alzheimer’s — a disease that has been notoriously hard to address. In a recent high-profile setback, drugmaker Eli Lilly had to halt development of an experimental Alzheimer’s drug after late-stage clinical trials showed it did not halt progression of the disease, and actually worsened patients’ conditions.

But B vitamins have been tested before, with disappointing results. In a 2008 clinical trial, published in the Journal of the American Medical Association, researchers investigated the same cocktail of vitamins used in the new Oxford study, and found that B vitamins did not slow cognitive decline in patients with mild to moderate Alzheimer’s disease.

It’s worth noting also that a diagnosis of MCI is no guarantee that you’ll develop Alzheimer’s. “Everybody starts to lose some brain synapses by age 40, and obviously not everyone ends up demented,” says Finch, an expert on nutrition and the aging brain, adding that diagnoses of MCI include patients who are having a bad day or a bout of temporary depression, or are taking a medication that makes them groggy.

For now, there is little doctors can recommend to prevent or slow the onset of dementia. Stroke is a contributing factor to dementia, so maintaining heart health can help stave off the disease. Studies have associated a long list of lifestyle behaviors that may benefit the brain — exercise, mental stimulation, lowering blood pressure or cholesterol, eating well and staying socially active — but taken together the data aren’t strong enough to prescribe them as Alzheimer’s prevention.

More on Alzheimer’s

Study: Exercise Can Protect People at High Risk of Alzheimer’s

Why Do So Many Alzheimer’s Drugs Fail in Clinical Trials?

Study: Lifestyle May Not Prevent Alzheimer’s