Eating your five-a-day could help prevent Alzheimer's, a new study suggests, after scientists found people who were deficient in vitamin A were more likely to develop the disease.
Scientists monitored more than 300 elderly people in China and discovered that those with higher levels of the vitamin were 60pc less likely to have developed dementia.
Researchers found that 75pc of those with either mild or significant vitamin A deficiency had cognitive impairment, compared to 47pc of those with normal vitamin A levels.
Vitamin A is naturally found in fruits and vegetables such as carrots, broccoli, peaches and avocados as well as fish and liver.
A second part of the research found that mice with low levels of vitamin A from birth developed more amyloid, the sticky substance that builds up in the brains of Alzheimer's patients and prevents brain cells from communicating.
"Our study clearly shows that marginal deficiency of vitamin A, even as early as in pregnancy, has a detrimental effect on brain development and has long-lasting effect that may facilitate Alzheimer's disease in later life," said Dr Weihong Song, a professor of psychiatry and Canada Research Chair in Alzheimer's Disease at the University of British Columbia.
The researchers found that mice with a mild vitamin A deficiency performed worse on tests of learning and memory in adulthood.
Even when the mice deprived of vitamin A in the womb were given a normal diet as pups, they performed worse than mice which got a normal amount of the nutrient in the womb but were deprived after birth. It suggests that the damage had already been done in the womb.
"In some cases, providing supplements to the newborn Alzheimer's disease model mice could reduce the amyloid beta level and improve learning and memory deficits," added Prof Song. "It's a matter of the earlier, the better."
The researchers concluded that a healthy, balanced diet was the best way to ensure adequate levels of the nutrient to ward off Alzheimer's disease.
The study, was published today in the journal 'Acta Neuropathologica'.