By keeping your heart healthy you could avoid Alzheimer's disease, say scientists.
They said that those who take simple steps from the age of 50 to reduce their risk of heart disease and stroke could hold off the crippling symptoms of dementia.
Eating a healthy diet, watching your weight, stopping smoking and keeping blood pressure normal have been shown to bolster the brain and help keep it alert. It means that every-one can play their part in protecting themselves by keeping fit and active.
Risk factors for heart disease in middle age, such as smoking and high blood pressure, accelerate the decline of brain function in older adults, according to scientists.
Researchers at King's College London found that people over 50 who smoked, had high blood pressure or were most at risk of suffering a stroke, performed poorly on a range of tasks designed to test memory recall, verbal fluency, attention span and learning ability.
"We all know smoking, high blood pressure, high cholesterol levels and a high BMI (body mass index) is bad for our heart. This research adds to the huge amount of evidence that suggests they can be bad for our head, too," the Daily Express quoted Jessica Smith, of the Alzheimer's Society, as saying.
"One in three people over 65 will develop dementia but there are things people can do to reduce their risk. Eating a balanced diet, maintaining a healthy weight, exercising regularly, getting your blood pressure and cholesterol checked regularly and not smoking can all make a difference," she suggested.
The study, published in the journal Age and Ageing, analysed data from more than 8,000 adults. It showed that smoking had the most impact on brain function, being linked with lower performance in all the tests.
Dr Simon Ridley, of the charity Alzheimer's Research UK, said: "Research has repeatedly linked smoking and high blood pressure to a greater risk of dementia and this study adds further weight to that evidence. These results underline the importance of looking after your cardiovascular health from mid-life onwards.
"With 820,000 people affected by dementia in the UK, and the numbers increasing, we urgently need to find ways to prevent the diseases that cause dementia. This can only come about through research, which is why it's vital to invest in research today," he noted.
Dementia is thought to be the result of long-term changes to the brain over 20 to 30 years. But a healthy heart is now seen as vital to help protect the brain.