| Extra B Vitamin May Keep
Mind Sharp in Old Age
NEW YORK (Reuters
Health) - Elderly people who get relatively
low amounts of the B vitamin niacin in their diets may be more
likely to develop Alzheimer's within the next few years than others,
according to preliminary research.
However, study author Dr. Martha
Clare Morris of Rush-Presbyterian-St. Luke's Medical Center in
Chicago, Illinois cautioned in an interview with Reuters Health
that this is a very early finding, which needs to be confirmed
by additional studies before the B vitamin can be linked to Alzheimer's.
"This is just something of interest
for further study," Morris said. "It's way too early in the research
to make recommendations."
In the current study, presented
during the Gerontological Society of America's 55th Annual Scientific
Meeting in Boston, Massachusetts, the researchers recorded how
much niacin a group of 815 dementia-free people at least 65 years
old ate in their diets, and tracked who developed Alzheimer's
over the next 4 years.
Food intake was recorded using
a questionnaire in which participants indicated how often they
ate certain foods during a previous period, often a year. Foods
that contain relatively high levels of niacin include meat such
as chicken, nuts, legumes and enriched grains and cereals. The
current recommended daily allowance (RDA) is 16 milligrams (mg)
per day for men and 14 mg per day for women.
The investigators divided people
into five groups based on their niacin intake. They discovered
that people who ate the most niacin--of whom half consumed more
than 22 mg each day--were 79% less likely to develop Alzheimer's
than were those who ate the least. Half of the lowest consumers
of the B vitamin took in less than 13 milligrams per day.
Morris explained that the benefits
of niacin appeared to kick in as soon as people increased their
intake only slightly, for the second-lowest niacin consumers were
also 70% less likely to develop Alzheimer's during the study period
than those who ate the least.
"So it really looked like it was
more of an increase in risk for people who had a low intake" of
the B vitamin, Morris said.
But why levels only slightly below
the niacin RDA were linked to an increased Alzheimer's risk remains
unclear, she added.
She noted that the previous analysis
did not factor in the effect of niacin, or vitamin B3, that participants
took in from supplements. Later, she and her colleagues combined
intake from supplements and diet, "and basically got pretty much
the same results," she said.
Although how low levels of niacin
in the body could lead to Alzheimer's remains unclear, Morris
said that people who eat relatively little of the nutrient may
develop a condition marked by confusion and psychosis, which niacin
supplements can correct. Animal studies also suggest that low
levels of niacin in the body could lead to brain cell damage.
Previous reports have shown that
some vitamin supplements contain much higher levels of niacin
than the RDA, and too much niacin may cause flushing, itching
and other symptoms. As a result, Morris recommended that people
who want to take in more niacin focus on getting it from foods.
"Supplemental forms of niacin should
be taken under the supervision of a physician," she said.
Reference Source 89