To avoid stroke later in life you should stay fit in your 40s, according to research carried out at the University of Texas.
The study, published in the journal Stroke, finds that people who stay fit in their mid to late 40s are a third less likely to have a stroke beyond the age of 65.
The researchers looked at data from 20,000 people who were given a fitness test between the ages of 45 and 53, who were then monitored until they were 65. The fittest 40 per cent were found to be 37 per cent less likely than the least fit to have had a stroke.
They say that this is because exercise increases blood flow to the brain, which slows down tissue decay.
The study’s lead author, Ambarish Pandey, said: ‘We all hear that exercise is good for you but many people still don’t do it.
‘Our hope is that this objective data on preventing fatal disease such as stroke will help motivate people to get moving and get fit.’
Study design was a prospective cohort of around 20,000 patients aged 45 to 53. Fitness was assessed via treadmill exercise test. Patients were followed in order to assess the relationship between exercise fitness and subsequent risk and occurrence of stroke.
Higher fitness levels were associated with a decreased risk of stroke of about 40 per cent. However, in fitter patients who subsequently developed risk factors such as hypertension, diabetes and atrial fibrillation prior to an event, fitness levels did not affect risk of stroke.
These findings are biologically plausible. In terms of the effect of exercise, namely decreasing blood pressure and heart rate, improving insulin sensitivity and the positive effect on blood vessels, it makes perfect sense that in the absence of other risk factors, exercise would be beneficial.
Hypertension and diabetes are diseases of the microvasculature (ie small blood vessels) and result in an inflammatory environment that causes vessel damage and predisposes to clot formation or haemorrhage, which cannot by itself be ameliorated by exercise alone. Indeed in some cases exercise itself may trigger the unwanted event.
Research score: 3/5