Women, Soft Drinks, and Stroke

Long-time readers are probably well aware that we think that you should avoid soft drinks in favor of water, tea, or coffee. Earlier this year we reported on the link between soda and the risk of stroke (Bite, 5/16/12), and there's research linking soda to weight gain (Bite, 4/17/07), diabetes (Bite, 5/23/07), and heart disease (Bite, 5/12/06).

In a study recently published in the American Journal of Clinical Nutrition (2012;96(6):1390-7), researchers in Japan noted that those studies that looked at the association between heart disease and soft drinks were mostly done on women. That said, the effects of soft drinks on cholesterol levels and other metabolic markers seem to be stronger in women than in men. The researchers designed a study that looked at the effects of drinking soft drinks on the risk of heart disease and stroke and analyzed the results according to sex.

This was a prospective study of nearly 40,000 Japanese men and women with no history of stroke or cancer who were between 40 and 59 years of age at the start of the study, in 1990. At the start of the study the participants responded to demographic, lifestyle, and health questionnaires, then filled out a dietary questionnaire that included questions about soft drinks. (For the purposes of the study, "soft drinks" were defined as those beverages with added sucrose or high-fructose corn syrup, and included cola-type drinks, flavored juices, and fruit juices that were not 100% juice.) Similar questionnaires followed in 1995 and 2000.

At the close of the study at the end of 2007, the researchers compared the soft drink intake of those who experienced heart disease or stroke with those who had not. The results for men and women were analyzed separately.

After taking into accounts such variables as high blood pressure, diabetes, smoking status, and Body Mass Index, the researchers found that women who drank the most soft drinks were 93% more likely more likely to have an ischemic stroke than those women who drank soft drinks only rarely or not at all. Those men who drank the most soft drinks, on the other hand were actually less likely to experience an ischemic stroke, although the reduction in risk is not something considered clinically significant.

What this means for you

Two things jumped out from this article. First, note that the soft drinks were defined as sweetened soft drinks and not non-caloric beverages. Second, this study from Japan defined one serving as equal to 250g (almost 9 ounces), while the studies done in the United States define a serving as 355 milliliters (about 12 ounces). That means that the same number of servings in Japan is about 25% less in total ounces than we would expect here in the United States, and that is something to be concerned about. Best to avoid soft drinks altogether in favor of water, coffee, or tea, but if you must have a soft drink, choose those with no calories.

First posted December 12, 2012