Lifestyle factors drive global stroke cost – Expert reaction

Over 90 percent of the death and disability caused by stroke is linked to modifiable risk factors, finds a new global study lead by a Kiwi.

The authors of the new research, published in The Lancet Neurology, say that taxation could be the key to lowering these risk factors and decreasing the global burden of stroke. 

The researchers used data from the Global Burden of Disease Study to estimate the disease burden of stroke associated with 17 risk factors in 188 countries, covering the years 1990-2013.  Globally, the ten leading risk factors for stroke were high blood pressure, diet low in fruit, high body mass index (BMI), diet high in sodium, smoking, diet low in vegetables, environmental air pollution, household pollution from solid fuels, diet low in whole grains, and high blood sugar.

“Smoking, poor diet and low physical activity are some of the major risk factors for stroke worldwide, suggesting that stroke is largely a disease caused by lifestyle risk factors,” said lead author Professor Valery L Feigin, of Auckland University of Technology,  in a Lancet Neurology media release.

“Controlling these risk factors could prevent about three-quarters of strokes worldwide.

“Our findings are important for helping national governments and international agencies to develop and prioritise public health programmes and policies. Governments have the power and responsibility to influence these risk factors through legislation and taxation of tobacco, alcohol, salt, sugar or saturated fat content, while health service providers have the responsibility to check and treat risk factors such as high blood pressure.”

“Taxation has been proven to be the most effective strategy in reducing exposure to smoking and excessive intake of salt, sugar and alcohol. If these risks take a toll on our health, and taxation is the best way to reduce exposure to these risks, it logically follows that governments should introduce such taxation and reinvest the resulting revenue back into the health of the population by funding much needed preventative programmes and research in primary prevention and health. All it takes is recognition of the urgent need to improve primary prevention, and the good will of the governments to act,” says Professor Feigin.

Our colleagues at the UK SMC collected the following expert commentary.

Dr Tim Chico, Reader in Cardiovascular Medicine & consultant cardiologist, University of Sheffield, said:

“This study combines information from a huge array of sources to try to provide an informed estimate of the relative contribution of different influences on the risk of stroke. Although there is always some uncertainty about such estimates, this study represents probably the most comprehensive attempt at understanding the extent to which multiple risk factors promotes stroke and other diseases.

“Although the press release and editorial highlight the impact of air pollution on stroke risk, this relative importance of this was much lower in Western Europe (and the UK) compared with less developed countries, in part because a lot of such air pollution comes from cooking over open fires using coal, wood, or dung.

“For me, the most relevant finding to the UK is that around 70% of strokes are associated with things that an individual can definitely address; smoking, low levels of physical activity, and poor diet (low in vegetables fruit, and whole grains), and this is entirely consistent with lots of other studies.”

Dr Patrick McSharry, Head of Catastrophe Risk Financing & statistician, University of Oxford, said:

“This extensive study across 188 countries between 1900 and 2013 employs robust statistical analyses to determine the most significant stroke risk factors.  Environmental and household air pollution is responsible for almost one third of the global disability linked to stroke. While also responsible for global warming, air pollution has increased the stroke burden by 33% over the last quarter of a century.

“Although air pollution is generally a greater risk factor in developing countries (33.7% compared to 10.2% for developed countries), environmental pollution (10.2%) was strikingly higher than previously established risk factors such as alcohol (6.8%) and high cholesterol (5.4%) in the UK.

“The top five risk factors in the UK are high blood pressure (47.7%), high body mass index (27.1%), diet low in fruit (25.1%), diet low in vegetables (23.1%) and smoking (14.7%). Low physical activity is another prominent risk factor (11.6%) that increases for adults over 70. A positive finding for policymakers is that 90% of the stroke burden is attributed to modifiable risk factors. This suggests that behaviour change strategies using taxation and education to promote a healthy diet and regular exercise could dramatically decrease the stroke burden in the UK.”