Unhealthy Living Doubles Stroke Risk, Study

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Main Category: Stroke
Also Included In: Nutrition / Diet;  Sports Medicine / Fitness;  Smoking / Quit Smoking
Article Date: 20 Feb 2009 - 1:00 PDT

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Researchers who studied 20,000 middle aged and elderly UK residents for 10 years found that those who lived unhealthy lives characterized by smoking, lack of exercise, drinking too much alcohol and not eating enough fruit and vegetables, were twice as likely to have a stroke as counterparts with much healthier lifestyles.

The study was the work of first author Dr Phyo K Myint, clinical senior lecturer in the School of Medicine at the University of East Anglia in Norwich and in the Department of Public Health and Primary Care at the University of Cambridge, and colleagues and was published online in the BMJ on 19 February.

While there is clear evidence that individual lifestyle factors such as smoking and diet are linked with higher risk of heart attack and stroke, the impact of several factors combined has been less clear until now.

For the study, Myint and colleagues examined data from the Norfolk cohort of participants enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The whole of EPIC involves over half a million adults from all over Europe who enrolled in the 1990s.

The Norfolk contingent comprised 20,040 community-dwelling men and women aged 40 to 79 with no history of stroke or heart attack when they joined in 1993 to 1997 and were followed unto 2007.

The researchers gave one point for each of four health behaviours: being a current non-smoker, not being physically inactive, drinking only a moderate amount of alcohol (one to 14 units a week) and eating at least 5 portions of fruit and vegetables a day. The fruit and vegetable intake was assessed as blood levels of vitamin C (greater than or equal to 50 micromol per litre).

Thus a person who scored 4 had the "healthiest" lifestyle while a person who scored 0 had the "unhealthiest" lifestyle, based on these four health behaviours.

The results showed that:

• There were 599 incident strokes over an average follow up of 11.5 years (total of 229,993 person-years).


• After adjusting for other potential confounders such as age, sex, BMI, blood pressure, cholesterol, diabetes, use of aspirin, socioeconomic status, there was a significant trend (P<0.001) of increasing relative risk of stroke as health behaviour score went down point by point from 4 to 0.


• The relative risk of stroke for participants who scored 3 out of 4 on health behaviours was 1.15 compared to those who scored 4 out of 4.


• For participants who scored 2 out of 4 the relative risk was 1.58 and those who scored 1 out 4 it was 2.18.


• And the relative risk for participants who scored 0 out of 4 was 2.31.


• These patterns remained when the researchers looked at the figures in subgroups according to sex, age, BMI, socioeconomic status and after excluding deaths within two years.


• A significantly higher percentage of women scored 4 than men.


• About 260 participants (one per cent of the cohort) scored 0; this was linked to an absolute stroke rate of 5.8 per cent (15 of them had a stroke during the follow up).


• About 5,000 of the cohort (25 per cent) had a maximum score of 4; this was linked with an absolute stroke risk of 1.7 per cent.

The authors concluded that:

"Four health behaviours combined predict more than a twofold difference in incidence of stroke in men and women."

They said these findings support the idea that small changes to lifestyle can change one's chances of having a stroke.

BBC News reported that Myint told to the press:

"Over the study period we observed six people for every 100 participants who had no health behaviours suffered a stroke compared to about one to two people for every 100 participants who had four positive health behaviours."

"Together with the substantial existing body of evidence about modifiable behaviours and stroke risk, this may provide further encouragement to make entirely feasible changes which have the potential to have a major impact on stroke."

A stroke is when part of the brain stops working because of a lack of blood supply, for instance due to a blockage, or a hemhorrage. It is the leading cause of disability in adults in Europe and the US. In the UK it is the second leading cause of death, with heart attacks being the first and cancer the third.

"Combined effect of health behaviours and risk of first ever stroke in 20 040 men and women over 11 years' follow-up in Norfolk cohort of European Prospective Investigation of Cancer (EPIC Norfolk): prospective population study."
Phyo K Myint, Robert N Luben, Nicholas J Wareham, Sheila A Bingham, Kay-Tee Khaw.
BMJ 2009;338:b349.
Published online 19 February 2009, doi:10.1136/bmj.b349

Click here for Abstract.

Sources: Journal abstract, BBC News.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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