Over the years there has been a huge increase in the amount of Sugar Sweetened Soft Beverages(SSSBs) and there is mounting evidence that this a critical factor contributing to the increasing incidence of Metabolic Syndrome. In the USA there has been a 5-fold increase in the volume of soft drinks between 1950 and 2000(1). In the UK information from the National Food Survey shows that there has been a 5-fold increase in the amount consumed between 1975 and 2000(2).
In a meta-analysis based on 88 selected studies it was found in 10 out of 12 studies there was a significant positive association between the amount consumed and the energy intake. It was concluded that these results provide clear and consistent evidence that people do not compensate for the added energy they consume in soft drinks by reducing their intake of other foods, resulting in increased total energy intakes. Not only do people fail to compensate for the energy consumed in soft drinks, but there is also some evidence that the increase in energy intake associated with soft drink consumption is even greater than can be accounted for by the beverages alone, suggesting that food energy intake is also higher(3).
In a recent study conducted at Aarhus University 60 healthy non-diabetic men and women aged between 20 and 50 years old agreed to consume one litre per day of a specified drink for a period of6 months(4). All of them were overweight or obese with BMIs ranging from 26 to 40. The 4 different drinks were:
- Sugar sweetened cola(Coca Cola)
- Aspartame sweetened diet cola(Coca Cola)
- Semi-skimmed milk
- Still mineral water
In addition to the experimental drink the participants also drank water, tea and coffee as well as their usual amount of alcohol.
The energy contents of the sugar-containing cola and of the milk were similar but it was somewhat lower in the other 2 drinks. There were 13 who dropped out leaving 47 who successfully completed the study. It was found that in the cola group there was an increase of 143% in the fat content of the liver compared with the baseline value. By contrast there was actually a decrease of about 10% in the liver fat with those who were consuming the semi-skimmed milk. There was little change in those consuming diet cola and water. An essentially similar pattern was observed for blood pressure. Those consuming the sugar-sweetened cola experienced a significant rise in blood pressure while there were small reductions in those consuming the milk and the diet cola while there was no change in the mineral water group. The sugar cola group was the only one to show an increase in the triglyceride(fat) content of the blood which is an indicator of increased risk of developing heart disease.
The fact that the sugar cola caused changes which are consistent with increasing risk in all 3 parameters is highly relevant. These results lend considerable support to growing body of evidence which identifies the increasing consumption of sugar and High Fructose Corn Syrup (HFCS) as the single key factor which is responsible for the increasing incidence of obesity, diabetes, high blood pressure and heart disease all of which are components of Metabolic Syndrome.
This study is particularly valuable because it was done over a relatively long period. With shorter studies there can be no confidence that any changes observed will be sustained permanently. It is highly relevant that the changes with semi-skimmed milk consumers seem to be beneficial to health. Therefore the reduction in the consumption of milk over the past 50 years is probably another factor contributing to the current deterioration in public health.
REFERENCES
- G Bray (2013) Advances in Nutrition 4 pp220-225
- National Food Survey which can be source at: http://webarchive.nationalarchives.gov.uk/20130103014432/http://www.defra.gov.uk/statistics/foodfarm/food/familyfood/nationalfoodsurvey/
- L MVartanian et al (2007) American Journal of Public Health 97 (4) pp667-675
- M Maersk et al (2012) American Journal of clinical Nutrition 95 (2) pp283-289