February 9, 2011 – At the American Stroke Association’s International Stroke Conference 2011today, two different research studies were presented that connects the intake of diet soda and increased salt intake to an increase in heart and vascular risk, as well as an increase in stroke occurrences.
The study was a large, multi-ethnic Northern Manhattan Study (NOMAS) and is a collaboration of investigators at Columbia University in New York and Miami’s Miller School of Medicine. It began in 1993 to examine the stroke incidence and risk factors throughout a multi-ethnic population. According to the study, there were a total of 3,298 participants over 40 years of age, with the average age being 69. The breakdown included 63% women, 21% Caucasian, 24% black, and 53% Hispanic.
In the first study presented by lead author and epidemiologist at the University Of Miami Miller School Of Medicine, Hannah Gardener, they found that those who consumed a diet soda every day had a 61% higher risk of a vascular or heart event than those who did not consume any soda.
The 2,564 participants in the soda study were divided into 7 groups based on their drinking habits and were broken down as follows: no soda (less than one soda a month), moderate regular soda (one per month to six per week), daily regular soda, moderate diet soda, daily diet soda, and then there were two groups that include those who drank both diet and regular sodas in the moderate and daily categories.
The average follow-up for the study was 9.3 years and within that time frame, there were 559 vascular events. Researchers then took into account such things as family history of vascular disease, smoking status, age, sex, ethnicity, whether they regularly exercised, and their alcohol consumption and daily caloric intake, the study still presented with an increased risk at 48% higher for those that consumed daily diet soda.
Gardener stated, “If our results are confirmed with future studies, then it would suggest that diet soda may not be the optimal substitute for sugar-sweetened beverages for protection against vascular outcomes”.
In the study involving sodium, 2,657 from the Manhattan participants were followed through 9.7 years, and with the same background accounted for as in the soda study, as well as adjusting for diabetes, high cholesterol, high blood pressure and any previous heart disease, they had 187 occurrences of ischemic strokes. Risks were shown to increase 16% for every 500mg of sodium additionally consumed each day.
The U.S. Dietary Guidelines for Americans daily sodium intake is less than 2,300 mg. One-third of the study participants fell below those guidelines. The American Heart Association recommends an intake of less than 1,500 mg per day, and there were only 12% of participants whose intake fell below that. The average daily sodium intake for participants was 3,031 mg.
With this study, Gardener states, “The take-home message is that high sodium intake is a risk factor for ischemic stroke among people with hypertension as well as among those without hypertension, underscoring the importance of limiting consumption of high sodium foods for stroke prevention”.
While there are still limitations in both studies, and more studies will need to be conducted in order to draw a conclusive correlation between diet sodas and sodium intake with the increased risk of vascular issues, this does raise the question. As with any part of one’s diet, moderation is always the key. However, it does make one wonder if reaching for that diet soda to save a few calories is really worth the possible risk.
Diet Soda may raise odds of vascular events; salt linked to stroke risk, American Heart Association