In the first study of its kind to examine a link between the consumption of added sugars and lipid measures, scientists from Emory University in Atlanta report that dietary sugars may also be boosting triglyceride levels, which have been linked to increased heart disease risk.
Their findings, published in the Journal of the American Medical Association (JAMA), were based on analysis of data from 6,113 adults participating in the National Health and Nutrition Examination Survey (NHANES) 1999-2006.
The data also shows that the daily consumption of added sugars has increased by about 6 per cent since the late 1970s, with 15.8 per cent of calories now coming from added sugars – in 1977-1978 it was only 10.6 per cent.
“Added sugars are food additives that can be recognized by consumers and have been proposed for specific labeling on food and beverage packaging,” wrote the researchers, led by Jean Welsh.
“The results of our study demonstrate that increased added sugars are associated with important cardiovascular disease risk factors, including lower HDL-C levels, higher triglyceride levels, and higher ratios of triglycerides to HDL-C,” they added.
Only last month the UK’s Food Standards Agency unveiled its final recommendations to industry for cutting sugar and saturated fat in soft drinks, confectionery and bakery products, which includes trimming back portion sizes of some products.
Reformulation of products along healthier lines is billed as part of the struggle against obesity, along with increased physical activity and education efforts. The FSA’s strategy has been to engage with the food industry over the efforts it can make, and try to take into consideration factors that can limit the scope of reformulation and impacts.
Welsh and her co-workers investigated if consumption of added sugars could affect blood lipid levels; and in particular levels of HDL-cholesterol, LDL-cholesterol, and triglycerides.
Using NHANES data, the researchers grouped the participants according to their intakes of added sugars: The reference group consumed less than 5 per cent of total calories as added sugar, while the other groups consumed 5 to less than 10 per cent, 10 to less than 17.5 per cent, 17.5 to less than 25 per cent, and 25 per cent or over.
Results showed that HDL levels were lower among people who consumed increasing levels of added sugars. The reference group has HDL levels of about 59 mg/dL, while people with the highest intakes of added sugars had HDL levels of about 48 mg/dL.
Furthermore, higher consumption of added sugars was associated with higher triglyceride levels and higher ratios of triglycerides to HDL-C, said the researchers.
Pointing the finger at fructose
Commenting on the potential mechanism, Welsh and her co-workers noted that, while the actual mechanism is “not completely understood”, studies have indicated a role for fructose – “a monosaccharide found in large quantities in nearly all added sugars”. The sugar has been reported to increase fat production in the liver and the production of both triglycerides and very low density lipoproteins
"Although long-term trials to study the effect of reducing added sugars and other carbohydrates on lipid profiles are needed, our data support dietary guidelines that target a reduction in consumption of added sugar,” added the researchers.
2010, Volume 303, Issue 15, Pages 1490-1497
“Caloric Sweetener Consumption and Dyslipidemia Among US Adults”
Authors: J.A. Welsh, A. Sharma, J.L. Abramson, V. Vaccarino, C. Gillespie, M.B. Vos