Diet drinks and metabolic syndrome
Thu Feb 07, 2008 at 01:42:18 PM PDT
A new study came out linking diet soft drinks to the development of metabolic syndrome, a set of symptoms that indicates a high risk for cardiovascular disease and diabetes. This is a prospective study that assessed the dietary intake of over 9000 metabolically normal middle-aged participants, then followed them for 9 years watching for the development of metabolic syndrome.
Unsurprisingly, high intakes of meat and fried food were positively correlated with metabolic syndrome while dairy appeared to be weakly protective. But the strong correlation with diet soft drinks was not predicted.
One study never proves anything, especially in nutrition, a notoriously difficult science. But this study appears well designed with no obvious (to me) methodological flaws, and there is some precedent from another very highly regarded study:
Diet soda also was positively associated with incident MetSyn, with those in the highest tertile of intake at 34% greater risk than those in the lowest tertile. The strength of this association was surprising. However, it is consistent with recent data from the Framingham Heart Study, which found a 56% increased risk of MetSyn among those consuming (greater than or equal to) 1 serving of diet soda per day.
A weak association with sweetened drinks was not statistically significant in this study. The authors draw no positive or negative conclusion from this but they are careful to point out that other studies have shown that sweetened drinks also have negative consequences.
I've been watching for a result like this ever since laboratory studies indicated that artificial sweeteners can fool the body into releasing insulin. The body tries hard to keep blood sugar chemistry within a certain range; misregulation of insulin levels can't possibly be good for us. I have this image in my head of gangs of rogue insulin molecules, unemployed due to lack of sufficient sugar, wandering the bloodstream and looking for trouble.
