Antioxidants - which are found in foods like soy products, coffee and fruits - have been shown to be healthy substances for the body. Researchers wanted to see if they could also lower risk of dementia and stroke.
A recent study found older people who had higher amounts of antioxidants in their diet were not less likely to develop dementia or have a stroke.
But MRIs showed that the individuals who ate more antioxidants showed fewer signs of age-related brain damage.
These research authors concluded that antioxidants in the diet may protect brain cells, but may not lower the risk of stroke or dementia.
Some common antioxidants are vitamin E and flavonoids, which are found in some foods. They protect the body by acting like a housecleaning service to take out harmful substances that are created by the body.
Previous studies found that people who had a diet rich in flavonoids were at lower risk for dementia. So researchers led by Elizabeth E. Devore, ScD, from the Departments of Epidemiology at the Erasmus Medical Center in the Netherlands, wanted to know if a diet high in antioxidants could protect the brain.
There were 5,395 people in the study who were age 55 or older. None of the participants had dementia at the start of the study. Participants answered questions about which food items they ate regularly over the past year and how often they ate them.
The amount of antioxidants in common foods has been estimated. So the researchers used the amount of antioxidants in each type of food to add up each participant's total antioxidant intake.
Researchers followed the participants for about 14 years. During the study, about 600 participants developed dementia and about 600 had a stroke.
Participants whose diets were high in antioxidants were not less likely to develop dementia or have a stroke.
Five years into the study, about 500 participants agreed to have a magnetic resonance imaging (MRI) scan of the brain. The researchers looked for signs of brain damage associated with dementia. They wanted to see if antioxidants appeared to protect the brain.
The MRIs showed that people who had higher antioxidant intake had larger overall brain volume – meaning they did not show as much loss of brain cells.
However, antioxidants were not related to any of the specific brain changes that are associated with dementia.
This study did not measure exactly what people ate. So the results were estimated from participant's memory of their diet over the past year.
This study was published February 20 in Neurology. The study was funded by The Netherlands Organization for Scientific Research and the National Institutes of Health. The authors report no relevant conflicts of interest.