July 1st, 2020

Stub out that cigarette: New study links smoking to higher risk of strokes in Blacks

Karen Miller

PHOTO: Thinkstock.com/Istock/Weerapatkiatdumrong

It is well known that smoking is the leading cause of preventable deaths world-wide. In the United States cigarette smoking is responsible for almost half a million deaths each year, including 41,000 resulting from secondhand smoke.

On average, smokers die 10 years earlier than nonsmokers, according to the Centers for Disease Control and Prevention.

The economic toll is significant. Nearly $170 billion is spent on medical care, while more than $156 billion accounts for lost productivity due to premature death.

Cigarette smoking is linked to a myriad of diseases, including cancer and respiratory and cardiovascular diseases. High on the list of cardiovascular diseases is stroke, the fourth leading cause of death in Blacks.

A stroke occurs when the flow of blood to the brain is blocked.

The impact of cigarette smoking on the incidence of stroke was assessed by the Framingham Heart Study, which was established in 1948 to determine the effect of various risk factors on heart health. The study concluded that even after controlling for other risk factors, cigarette smoking proved to be a significant independent contribution to the risk of stroke. And the more one smoked the greater the risk.

But the cohorts of the FHS were predominantly white. Researchers were unsure if these findings translated to Blacks.

In response, the Jackson Heart Study was developed to investigate the causes of cardiovascular diseases in African Americans. Participants were enrolled from the three counties that make up the Jackson, Mississippi metropolitan area.

A study based on some of the findings of the JHS was published in the most recent Journal of the American Heart Association. The research was funded by the National Heart, Lung, and Blood Institute and the National Institute for Minority Health and Health Disparities, both members of the National Institutes of Health.

The study included 4,410 Black men and women without a history of stroke who were classified into three groups: never smokers, current smokers and past smokers.

After controlling for other factors linked to stroke, such as high blood pressure, diabetes and high cholesterol, it was found that African Americans who smoke are more than twice as likely to have a stroke as never smokers. Intensity was a factor. More than 7 percent of those who smoked more than 20 cigarettes a day had experienced a stroke, compared to 3.4 percent of those who never smoked, and 6.6 percent who smoked fewer than 20 a day. “The bottom line is the more a person smokes, the greater their chance is of having a stroke,” said Dr. Adebamike A. Oshunbade, the lead author of the study.

The study also concluded that a higher level of plaque in the carotid arteries of smokers may have been a factor. Plaque is a waxy substance made up of fat and cholesterol. The carotid arteries are located on the sides of the neck and directly feed the brain. A stroke can occur if the plaque in these arteries obstructs the flow of blood to the brain.

The good news is that there was no significant difference in stroke development between past and never smokers. The results imply that kicking the habit can have favorable results.

The findings of the study are similar to those from the Framingham Heart Study, but, even after controlling for risk factors, suggest that smoking may have an even greater impact on Black smokers. Studies conducted by the National Institutes of Health have found that black people between the ages of 45 and 54 die of strokes at a rate that’s three times greater than their white counterparts.

The key message is that it’s best not to smoke. But if you do, it’s best to stop. Help is available.