Vegetables ward off Alzheimer's
Eating a diet rich in vegetables may be one way to reduce the risk of developing Alzheimer's disease, research suggests.
US scientists found that a diet high in unsaturated, unhydrogenated fats - found in vegetables and some oils - may help lower risk.
However, a separate study found antioxidant vitamins - widely touted as good for general health - offer no such protective effect against Alzheimer's.
In the first study, scientists from Rush-Presbyterian-St. Luke's Medical Center in Chicago, examined 815 people aged 65 and older over a four year period.
At the start of the study none of the volunteers had Alzheimer's, but by its end 131 had developed symptoms.
The researchers found that the risk of developing the disease was highest among those who consumed the highest levels of saturated fat - found in meat and dairy products.
People who consumed a lot of saturated fat were 2.3 times more likely to develop symptoms than those whose diet was low in these fats.
Conversely, people whose diet contained high levels of unsaturated fat were up to 80% less likely to develop Alzheimer's disease than those who consumed low levels of unsaturated fats.
Lead researcher Dr Martha Clare Morris told BBC NewsOnline more research was needed to confirm the findings.
But she said: "There are studies to suggest that a diet high in unsaturated fat and low in saturated fat may raise levels of good cholesterol and lower levels of bad cholesterol in the blood."
It is thought that low-density lipoprotein, or bad, cholesterol may play a role in the formation of the amyloid plaques found in the brain of Alzheimer's patients.
Dr Morris said people should consider a switch to such a diet - if only because of abundant evidence that it helped to reduce the risk of heart disease.
In a second study researchers at Columbia University in New York concluded that carotenes and vitamins C and E obtained from diet or through supplements are not associated with a decreased risk of Alzheimer's.
It was suspected that these antioxidant vitamins may have a protective effect because they mimimise the damage to the body's tissues caused by charged particles known as free radicals.
Some suspect that Alzheimer's is caused in part by damage to brain cells caused by free radicals.
The Columbia researchers examined 980 people, of which 242 developed Alzheimer's symptoms during the four year study.
There was no evidence that those people who consumed carotenes or vitamins A and E were any less likely to develop the disease.
Both studies were published in the journal Archives of Neurology.
Source: BBC News