14 Jul 2014

How lifestyle choices can reduce the risk of Alzheimer’s

The recent history of Alzheimer’s research is quite a depressing one. A number of drugs that target the mechanisms underlying it have failed to work in human trials. The hope for a cure for the disease that will affect more than one on 10 of us before we die seems as remote as ever.

Yet this latest research published in the journal Lancet Neuroscience  gives some cause for a little optimism. And, unless you didn’t need reminding, another reason to give up the fags, cut down on the drinking and get off the sofa.

The research suggests our choice of lifestyle could reduce the risk of Alzheimer’s, or at least delay its onset sufficiently that we die of something else before dementia starts to set in.

The researchers looked at a number of large Alzheimer’s studies and UK population data and found that physical inactivity was strongly linked to whether someone went on to develop Alzheimer’s.

The risk was increased by about 80 per cent. While that sounds like a lot, remember that’s an 80 per cent increase in your lifetime risk of about 10 per cent, not an 80 per cent increase overall.

Lower, but significant associations were found for things like diabetes, high blood pressure, obesity, smoking and even educational achievement.

It’s important to note the research doesn’t show any of these factors “cause” Alzheimer’s. They are only associated with it. They haven’t shown that by exercising more or stopping smoking, Alzheimer’s is slowed or goes away – but there is evidence of a protective effect.

Many of the risks are also overlapping – diabetes, obesity and high blood pressure all go hand in hand. But by statistically teasing them apart, the researchers conclude nearly a third of all Alzheimer’s cases  could be prevented by improving lifestyle. By 2050 that could equate to 200,000 fewer cases in the UK.

Because the dominant risk factor for Alzheimer’s is how old we are, there is something of a paradox in the findings. The healthier the lifestyles we lead, the longer we are likely to live by reducing the risks of other diseases like heart disease and cancer. Then the risk we go on to get Alzheimer’s goes up.

However, other analyses suggest a healthy lifestyle helps slow the progression of Alzheimer’s, so if we are  going to get it eventually, at least we stand a better chance of having led a healthy active life up until that point. “It just reinforces the point that what applies to heart disease and diabetes applies to Alzheimer’s disease,” said study author Dr Sam Norton of Kings College London.

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