Older adults who eat diets high in antioxidants may not have
a lower risk of dementia or stroke, a new study suggests.
Researchers found that people who ate or drank lots of
coffee, tea, oranges and red wine were just as likely to develop neurological
problems over the next 14 years as those who skimped on antioxidant-rich foods.
"The literature on antioxidants and dementia has been
mixed," said Elizabeth Devore, who led the new research at Brigham and
Women's Hospital in Boston.
Although there's some evidence that specific vitamins have a
protective effect in the brain, she said it's unclear whether that's the case
for all antioxidants - which include vitamin C, vitamin E, selenium and
"There is the thought that overall antioxidants might
be helpful, but it's also true that if you actually look at the individual
antioxidants, there's not necessarily a reason to think that one would behave
exactly the same way in the body as the next."
How the study was
The Netherlands-based study included 5 395 people aged 55
years and older, who reported their usual consumption of 170 different foods in
Devore and her colleagues tracked those participants over
the next 14 years, during which 599 were diagnosed with dementia - including
484 with Alzheimer's disease - and 601 had a first stroke.
People who consumed the most antioxidants, according to an
analysis of their diets, were just as likely to end up having either of those
neurological disorders as study participants who hardly got any antioxidants.
That pattern held after the researchers took into account
people's ages, how much they ate in general and whether they smoked, according
to the findings published. There was also no link between total dietary
antioxidants and white or gray matter volume in the brain, according to scans done
on 462 of the participants.
Since the study looked only at foods consumed, it can't
address whether antioxidant supplements may impact dementia or stroke risk,
according to Devore. Her team concludes that it's still likely certain
individual antioxidants have positive effects on the brain.
"There have been a number of studies that have shown
that higher intake of dietary vitamin E is associated with lower risk of
dementia," Devore said. The same goes for vitamin C and stroke risk, she
That suggests people should continue eating plenty of fruits
and vegetables, including berries, and seek out specific antioxidants, she
"For dementia specifically and stroke specifically, if
you're worried about those you should try to take in vitamin E for dementia and
vitamin C for stroke."