Regular readers of this blog will be aware of the detrimental effects that soft drink consumption has on health (here, here, here and here). Sugar sweetened soft drinks are damaging because of the presence of fructose either in the form of sucrose or high fructose corn syrup. Fructose is a metabolic poison and when consumed in products devoid of fibre, creates hepatic overload because of increased flux through the de novo lipogenesis pathway. Over time, this causes a deposition of lipids in tissues which causes insulin resistance and abdominal obesity. Artificially sweetened beverages fare no better because the sweetener aspartame may have deleterious effects on health, particularly regarding an increased risk of cancer (here) and modifications to normal serotonin uptake in the brain (here). Regular consumption of artificially sweetened soft drinks may also alter the satiety response causing further metabolic aberrations (here). As more studies are performed, the association between soft drink consumption and disease, particularly obesity, diabetes and cardiovascular disease, becomes statistically stronger.
In a recent prospective study, researchers1 investigated the association between soft drink consumption and cardiovascular disease in 39,786 Japanese men and women aged 40 to 59 years. The intake of soft drinks was assessed with a frequent food questionnaire and the incidence of cardiovascular disease was assessed through medical records. The results showed that for women, but not for men, soft drink consumption was associated with total stroke and ischaemic stroke. Comparisons of the highest intake of soft drinks (almost every day) with the lowest intake (never or rarely) showed a hazard ratio of 1.21 and 1.83, for total and ischaemic stroke, respectively. Adjustment for body mass index (BMI) and total energy intake had little effect on the statistical strength of the association. These result therefore support a growing body of evidence from epidemiological studies that show associations between soft drink consumption and disease. Animal experiments add weight to the contention that soft drinks are damaging to the health whether sugar sweetened or artificially sweetened.
The association between soft drink consumption and cardiovascular disease can be explained by the aberrations that consumption causes to normal metabolic regulation. In particular, glucose and appetite homeostasis become dysfunctional, and this leads to detrimental physiological changes that are disease forming. While mechanisms clearly exist by which soft drinks can cause these metabolic changes, consideration should also be given to the type of diet that includes such foods. In fact, soft drink consumption can be considered synonymous with a low quality diet containing nutrient poor overly processed energy dense foods. That such diets are likely necessary in order to drive Western lifestyle disease, does not exonerate soft drinks from blame, but places in context the part they play in the aetiology of such diseases. The actual size of this contribution is not known, but as more evidence accumulates it appears that their role as drivers of disease is significant. This is in part because of the sheer volume of soft drinks consumed by some individuals.
RdB
