Most strokes are preventable, study finds

July 19, 2016

Providence Health Team

Ten risk factors that can be controlled to varying degrees are collectively responsible for nine of 10 cases of stroke worldwide, a new study has found. And hypertension – or high blood pressure – is the most significant.

Eliminating hypertension is “the key target in reducing the burden of stroke globally," said Martin O'Donnell, M.D., co-leader of the study, which was published in The Lancet. O’Donnell is a professor at the Population Health Research Institute at McMaster University in Hamilton, Canada.

About 800,000 people in the United States have a stroke each year, and about 130,000 are killed by stroke, according to the U.S. Centers for Disease Control and Prevention.

Risk factors include poor diet, high cholesterol

The study examined the cases of more than 26,900 stroke victims in 32 countries over eight years. It found the importance of key risk factors varied from region to region, but that collectively, 10 factors were responsible for more than 90 percent of the strokes:

Hypertension
Lack of regular physical activity
High cholesterol, or blood fats
Not eating a healthy diet
Smoking
Obesity
Heart conditions
Stress
Alcohol consumption
Diabetes

Investigators found that eliminating hypertension alone would cut the number of strokes almost by half, and if people were more active, the number of strokes would decline by more than a third.

Reducing stroke

Together, all of the risk factors accounted for 91.5 percent of ischemic stroke, or strokes caused by blood clots, and 87.1 percent of intracerebral hemorrhage, or bleeding in the brain.

The study “re-emphasizes the importance of these factors for cardiovascular health,” said Joseph Ho, M.D., medical director of neurointerventional surgery and co-medical director of neurological medical services at Providence St. Peter Hospital in Olympia, Wash.

“These are all things that are modifiable and can significantly reduce the incidence of and mortality from stroke,” he said.

The findings will help guide efforts to intervene to reduce stroke, said Salim Yusuf, M.D., also of McMaster University and another author of the study. Interventions will include “better health education, more affordable healthy food, avoidance of tobacco and more affordable medication for hypertension and dyslipidemia," or elevation of cholesterol or triglycerides.

Causes of hypertension

High blood pressure is a common, but dangerous condition in which the pressure of the blood is higher than it should be. About 70 million adults in the U.S. have high blood pressure, the CDC estimates.

The agency says a few lifestyle changes can help control your blood pressure:

Eat a diet that is low in salt and high in fruits and vegetables.
Be active, such as walking briskly for 10 minutes, three times a day, five days a week.
Don’t smoke, or quit if you do.