Ninety per cent of strokes, which cost our healthcare system $450m a year and challenge survivors and their families, are avoidable if we actively reduce risk in these 10 key areas, says new research.

This year about 9000 Kiwis will have a stroke - 2500 of them will die and three-quarters of the survivors will be moderately to severely disabled.

Almost half of the survivors will require long-term help in their everyday activities - deeply challenging for the survivors and their families, and a significant cost for our healthcare system.

In New Zealand, stroke is the third leading cause of death after cancer and heart disease, and the greatest cause of disability in older people.

Most people believe that strokes are unavoidable or are determined by genetics. New research published in The Lancet this week, however, suggests that 90 per cent of strokes could be prevented if people take action to reduce risk in 10 key areas.


The study looked at 27,000 participants in 32 countries and compared the lifestyles of stroke victims to people who were in good health. Although New Zealand data wasn't included in this study, it included men and women of all ages from diverse ethnic groups and different socioeconomic backgrounds.

Previous research has found that Maori and Pacific Island New Zealanders are more likely to suffer a stroke than European New Zealanders, and men are more likely to suffer a stroke than women.

A stroke is caused by a sudden interruption of the blood supply to the brain, which can lead to permanent brain damage or death.

There are two basic types of stroke, ischaemic and haemorrhagic. Ischaemic strokes, the most common, occur when a blood clot completely blocks an artery inside or supplying the brain. Ischaemic strokes make up the majority of strokes in older people. Less common, but more likely to affect those under 65, are haemorrhagic strokes, which occur when an artery in the brain bursts, leaking blood into the brain - this causes pressure to build, which can lead to brain tissue damage in the local area.

Common symptoms of stroke include sudden weakness or numbness of the face, arm or leg, especially on one side of the body, sudden blurred or lost vision, sudden difficulty speaking or understanding what others are saying, and sudden loss of balance.

The research found hypertension - high blood pressure - to be the greatest contributing factor, with the research predicting that almost half of all strokes could be prevented just by reducing blood pressure.

Lack of exercise and physical inactivity were the next biggest risk factors, with a sedentary lifestyle increasing the risk of having a stroke by 23 per cent. Diet came in third, with an 18.6 per cent increased risk of stroke associated with a poor diet (the quality of a person's diet was assessed against a measure called the Alternative Healthy Eating Index, which compares diet quality against US guidelines.)

In fourth place, smoking raised the chance of a stroke by 12.4 per cent. Drinking alcohol and suffering from stress each increased stroke risk by 5.8 per cent. Other factors that were found to increase stroke risk included being overweight, suffering from diabetes, having high cholesterol, and failing to take preventative medication for any heart arrhythmia.

Suffering a stroke can have a profoundly debilitating impact on the lives that it affects.

Costing New Zealand $450 million a year in direct costs at present, strokes are also responsible for other costs including lost productivity, payment for medications and private rehabilitation.

By proactively addressing these 10 factors, we have the potential to reduce the long term medical costs associated with strokes, and have a positive impact for the health of up to 8100 New Zealanders every year.