Family doctor

More than three-quarters of the global stroke burden could potentially be reduced by changing lifestyle factors, a comprehensive study in The Lancet has suggested. The study found that 90% of the stroke burden worldwide is caused by modifiable risk factors such as smoking, blood pressure, diet and air pollution. The stroke burden is defined as the mortality and disability attributable to strokes around the world. The study takes into account the impaired quality of life associated with having a stroke as well as the direct mortality caused by them.

17 risk factors were analysed to find out their influence on the stroke burden. The top five modifiable risk factors contributing to strokes in Australia and New Zealand were:

1) Having a high systolic blood pressure

2) Having a high body mass index

3) Consuming a diet low in vegetables

4) Consuming a diet low in fruits

5) Smoking

One particularly significant finding of the study is that air pollution contributes very strongly to the burden of stroke in low and middle income countries, far more than was previously recognised. Another interesting finding is that the risk that has increased the most over the past 20 years is the sugar content in our diets. This trend has caused a 63.1% increase in stroke-related disability and mortality since 1990. Although the absolute rates of stroke attributable to a diet high in sugar remain low, the relationship between sugar and obesity and type 2 diabetes is worrying and suggests that this may have significant impacts on the stroke burden in the future.

The study has its limitations. Given the data available it was unable to take into account certain known and important risk factors for stroke such as atrial fibrillation and substance abuse.It was also unable to take into account different scales of risk such as how many cigarettes were smoked, or how high a blood pressure was. The study did not differentiate between the two main types of strokes, ischaemic and haemorrhagic which tend to have their own distinct risk profiles. Nonetheless, it is important to to reflect on the relationship between our environment and the current state of health worldwide. It is hopeful to think that there are risks within our control that we can manage to reduce the stroke burden around the world.

Reference:

1. Feigin, Valery L et al. "Global Burden Of Stroke And Risk Factors In 188 Countries, During 1990–2013: A Systematic Analysis For The Global Burden Of Disease Study 2013". The Lancet Neurology 15.9 (2016): 913-924. Web. 15 Aug. 2016.