Stroke patient Navid Rahayi, 52, has limited mobility in his right arm and trouble speaking. (CBC)

A Canadian-led study suggests about 90 per cent of the risk of having a stroke is preventable through lifestyle changes.

In Friday's issue of the Lancet medical journal, the international study suggests high blood pressure and nine other risk factors are associated with most of the risk of stroke.

Dr. Martin J. O'Donnell and Dr. Salim Yusuf of McMaster University in Hamilton and colleagues analyzed data from 3,000 stroke patients and 3,000 controls without stroke of the same age and gender in 22 developed and developing countries from March 2007 to April 2010.

"Our findings suggest that 10 risk factors are associated with 90 per cent of the risk of stroke," the study's authors concluded.

"Targeted interventions that reduce blood pressure and smoking, and promote physical activity and a healthy diet, could substantially reduce the burden of stroke," the study added.

High blood pressure was the most important for stroke, increasing the risk by 2.64 times, compared with having no history of hypertension.

The burden of stroke is not only a physical one, said Dr. Antoine Hakim, CEO and scientific director of the Canadian Stroke Network in Ottawa, which helped fund the research.

"When your brain is hit — let me be blunt — you're not the same person anymore. Perhaps what is obvious is you're not walking, you're not talking, but what is often not obvious is also you're not thinking and you're not able to function intellectually at the same level."

Hakim would like to see blood-pressure cuffs available in more places so more people would be aware of the silent killer that has many treatment options.

Stroke fears

Stroke patient Navid Rahayi, 52, of Toronto was taking drugs for high blood pressure, high cholesterol and clinical depression, medication that he mistakenly thought would protect him.

"I was very scared, I was thinking I was going to die," Rahayi recalled of his stroke in January. "I couldn't move, I couldn't do anything at the hospital, I was emotional all the time. I couldn't believe what happened to me."

During rehab, Rahayi worked on socializing and managing his medications. He has adopted a dog for companionship and exercise, and he now cycles and is making progress in his recovery.

Hypertension is also increasingly hitting people at a younger age. In the last 10 years in Canada, there has been a three-fold increase in hypertension among people aged 34 and younger, Hakim noted.

In the study, prevention steps like quitting smoking and eating more fish and fruit were linked to the greatest risk reductions for stroke.

The study also offered important information for doctors and medical researchers, such as the relative importance of many of these risk factors for stroke and heart attack. For example, blood pressure was the most important risk factor for stroke, while blood lipids or fats were the most important risk factors for heart attack.

The research was also funded by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Pfizer Cardiovascular Award, Merck, AstraZeneca and Boehringer Ingelheim.