Diet drinks linked to stroke, heart disease

We know that too much added sugars are bad for you - and in the Western diet these added sugars too often come from sugar-sweetened beverages like sodas and juice drinks. These have fairly convincingly been linked to increased risk of stroke and heart disease, so naturally people turn to sugar-free versions of the same drinks, thinking they're healthier. Unfortunately, a recent study in the American Heart Association journal, Stroke, suggests that artificially-sweetened (diet) beverages carry the same risks (doi:10.1161/STROKEAHA.118.023100).

An international team of researchers used data gathered from the Women's Health Initiative Observational Study, a large-scale, long-term study that includes over 90,000 postmenopausal women who were at least 50 years of age when the study was enrolling participants between 1993 and 1998.

Upon enrollment the participants responded to demographic and other questionnaires, received a physical exam that included blood tests, and brought in all of their medications to be added to their record. Three years after enrollment over 80,000 of the women returned to the clinic to repeat all of these procedures, and at that time the participants were also asked about their consumption of artificially-sweetened beverages, with the question specifically asking about "diet drinks such as Diet Coke or diet fruit drinks" and using the standard 12 ounce can as the serving unit.

For an average of almost 12 years, the authors tracked the participants' experiences of stroke, coronary heart disease, and death from all causes, using surveys of the participants as well as access to the National Death Index.

In their analysis, the authors took into account the participants' score on the Healthy Eating Index 2005, a measure of dietary quality, as well as Body Mass Index, history of diabetes or cardiovascular disease, high blood pressure, taking cholesterol-lowering medications, and health behaviors like drinking alcohol, exercising, and smoking.

Compared to those who "never or less than 1 time per week" consumed an artificially-sweetened beverage, those who consumed them at least 2 times per day were 23% more likely to have any type of stroke, 29% more likely to experience coronary heart disease (including a fatal or nonfatal heart attack), and 16% more likely to die of any cause. Almost 80% of these more-frequent consumers of diet drinks "never or rarely" drank regular soda (almost 9% did drank at least one regular soda per day).

It is important to note, however, that those who drank more artificially-sweetened beverages were more likely to be overweight or obese, exercised less, consumed more calories, and had a poorer quality diet overall than those who drank fewer diet drinks. They were also more likely to have diabetes and to have had a previous stroke or heart attack.

What this means for you

It's important to bear in mind that this is an observational study: it does not show that diet drinks cause stroke, heart attack or death. Not drinking diet sodas may be a marker for a healthier, more active lifestyle in general. We still urge you to keep sodas (whether sugared or artificially-sweetened) as occasional treats: your healthiest beverage options are still water, coffee, or tea.

First posted: February 27, 2018