Why Coffee Lowers Stroke Risk and Soda Raises It


I’m a coffee drinker. I enjoy it in the morning and again around 5:00 pm, after my nap.

As a result, I was pleased to see the latest news that coffee actually reduces stroke risk. That particular issue has been a worry in recent months as I’ve struggled with occasional blood pressure spikes that have driven my systolic (upper) pressure above 200…and into stroke territory. On several occasions, those soaring numbers have also driven me right into the emergency room, at my local Sibley Hospital, for observation.

Conducted by researchers from Cleveland Clinic's Wellness Institute and Harvard University, this most recent study also showed that increased consumption of both sugar-sweetened and low-calorie sodas was associated with greater risk of stroke, the foundation of vascular dementia.

The news—published in the American Journal of Clinical Nutrition and reported in the article "In with the Coffee, Out with the Soda" in the November 25 issue of the online journal Alzheimer’s Weekly—is especially worrisome for regular soda drinkers. In the past, we’ve seen evidence that sugary drinks were linked to a variety of health problems, including weight gain, diabetes, high blood pressure, high cholesterol, gout and coronary artery disease. Now we can add stroke to that scary line-up.

On the other hand, drinking coffee—both high-test and decaf—was associated with lower stroke risk, in this latest study.

The report is compelling because the number of subjects studied was high. Researchers evaluated soda consumption among 43,371 men who participated in the Health Professionals Follow-Up Study between 1986 and 2008, and 84,085 women who participated in the Nurses' Health Study between 1980 and 2008. During that time, 2,938 strokes were documented in women, and 1,416 in the men.

How sugar increases stroke risk and coffee lowers it

Noticing the increased stroke risk among regular sweetened soda drinkers, researchers concluded that the heavy sugar load created regular spikes in blood glucose and insulin, eventually leading to glucose intolerance, insulin resistance and inflammation.

Those physiologic changes in turn can influence atherosclerosis, plaque stability and thrombosis—all risk factors for ischemic stroke and dementia. Interestingly, the research team noticed that the stroke risk was higher for women than it was for men.

What explained the stroke risk-lowering effect of coffee? It contains chlorogenic acids, lignans and magnesium—all antioxidants that appear to reduce stroke risk. When compared with one serving of sugar-sweetened soda, one serving of decaffeinated coffee was associated with a ten percent lower risk of stroke.

The story in Alzheimer’s Weekly included other conclusions:

“In addition, study findings show that men and women who consumed more than one serving of sugar-sweetened soda per day had higher rates of high blood pressure and high blood cholesterol and lower physical activity rates. Those who drank soda more frequently were also more likely to eat red meat and whole-fat dairy products. Men and women who consumed low-calorie soda had a higher incidence of chronic disease and a higher body mass index (BMI). The investigators controlled for these other factors in their analysis to determine the independent association of soda consumption on stroke risk.”

Adam Bernstein, M.D.—study author and Research Director at Cleveland Clinic's Wellness Institute—said: "What we're beginning to understand is that regular intake of these [soda] beverages sets off a chain reaction in the body that can potentially lead to many diseases—including stroke."

Bernstein also offered a warning:

“According to research from the USDA, sugar-sweetened beverage consumption has increased dramatically in the United States over the past three decades, and it's affecting our health. These [new study] findings reiterate the importance of encouraging individuals to substitute alternate beverages for soda.”

Washington, DC, resident John Schappi blogs about aging, exercise, diet, pills, supplements, and his life with Parkinson’s disease and prostate cancer. Once upon a time, he was addicted to nicotine, alcohol and sex. These days, his passions include gardening, playing bridge, meditating, going to the theater and traveling.

Aging, Parkinson’s, and Me

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As a chemist, I also worry about the effect of High Fructose Corn Syrup (HFCS) used as the sweetener rather than using sucrose. I understand that HFCS is easier to transport using tanker cars on the railroad instead of bags of sugar, but I try to avoid it whenever I can.
Was this study including coffee added to cream? :-) I tend to like cream on the heavy side and yes, I mean the flavored liquid kind. If the cream is not flavored I do add sugar to the coffee. I have noticed that the sugar in my coffee keeps me from getting that alertness spike actually look forward to from a good cup of coffee. I have tried black coffee but quickly vowed to myself to not make a habit of that ever! Great news for you John!!! -Susan
What about the effect of fake creamers with the coffee? I put a little milk, half-and-half or as a treat, real cream in my coffee, which cuts the irritation of the coffee. Reading labels on the commercial "creamers" scared me off of them--found that Splenda/sucralose affects my digestive system, and most of the other ingredients are not healthy. (No, I don't worry about the fat content of cream--a small amount isn't as big a deal as we were led to believe, not as bad as the artificial stuff.)