Switch to Diet-Colas (or Water) to Avoid Diabetes

Summarized by Robert W. Griffith, MD
November 26, 2004

Introduction

Type 2 diabetes is being diagnosed more and more frequently these days - about 17 million people in the USA are affected. And the obesity epidemic goes hand-in-hand with this trend. Nutritionists have noticed that the consumption of soft drinks has increased by 60% in adults from 1977 to 1997, and more than doubled in children and adolescents. Is there a connection? What do you think! To prove the connection, however, scientists at Harvard examined data from the Nurses Health Study, and published their findings in the Journal of the American Medical Association. Here's a summary of their report.

What was done

Over 90,000 women in the Nurses Health Study II were enrolled in 1991. For the next 8 years, questionnaires were sent twice a year, asking about dietary intake, weight change, and information on smoking habits, contraceptive use, hormone replacement therapy (HRT), and pregnancies.

Specific questions about dietary beverage consumption were sent at baseline, in 1995, and in 1999. After excluding those women with diabetes or other chronic diseases, as well as those who didn't complete the questionnaires adequately, there were over 51,000 subjects left for analysis.

Sugar-sweetened soft drinks, diet soft drinks, and fruit juice consumption was classified into 4 groups: less than 1 drink per month, 1-4 drinks per month, 2-6 drinks per week, and one or more drinks per day.

If any woman reported diabetes, they were asked to give sufficient details to see whether it was type1 or type 2 diabetes. The analyses paid particular attention to changes in energy intake from beverages between 1991 and 1995 and from 1995 to 1999.

What was found

There were 741 cases of type 2 diabetes reported in the 51,603 women in the study. In those women who kept a stable, or regular, energy intake derived from beverages, there was no difference between groups in weight gain. However, in those who increased their sugar-sweetened drink intake from low (one or less a month) to high (one or more a day), there were weight increases of 4.5 kg (10 pounds) over the 4 year periods. Women who decreased their sugary drink intake from high to low had only small increases in weight - 0.15 and 1.3 kg ( 1/3 and 3 pounds) for the first and second 4-year period, respectively.

Increased consumption of fruit punch (not fruit juice) was also associated with a greater increase in weight compared with decreased consumption.

After adjustments to allow for the effects of physical activity, smoking, family history of diabetes, HRT, contraceptive use, and dietary differences, it was found that women drinking one or more sugar-sweetened drinks a day were almost twice as likely to develop type 2 diabetes, compared to those who drank less than one a month. A similar result was found for fruit punch consumption.

What does this mean?

This study is another strong indictment of sweetened soft drinks, such as Coke, Pepsi, or other colas with sugar. We have already reported on a recent study showing that they are associated with features of the metabolic syndrome, which in turn has been linked to a shortened life span (see first link below).

Why are these drinks harmful? It seems that they provide 'empty calories' without giving a sense of fullness or satiety. In animal experiments, drinking sugar-laced water is not compensated for by a reduction in solid food intake.

It's noteworthy that fruit punches carried the same sort of risk in this study. Punches contain only a small proportion of fruit juice but large amounts of high-fructose corn-syrup. They should be avoided, too.

By now sufficient evidence has accumulated to show that diet sodas are safe and also effective in reducing calorie intake when substituted for regular colas. Anyone concerned with their long-tem health should give up sugar-containing sodas and fruit punch, and switch to diet drinks or water (bottled or tap water).

Source

• Sugar-sweetened beverages, weight gain, and incidence of type 2 diabetes in young and middle-aged women. MB. Schultze, JA. Manson, DS. Ludwig,  et al., JAMA, 2004, vol. 292, pp. 927--934

Related Links
Diet and the Metabolic Syndrome
Sugar Substitutes
Fast Food

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