Research Finds Consumption of Soda, Including Diet, Related to Metabolic Syndrome
Individuals who consume at least one soft drink per day are more likely to have metabolic syndrome, compared with those who do not consume soda, according to collaborative research by investigators from the University of South Australia, University of Maine and the Luxembourg Institute of Health.
More than a third of American adults are affected by metabolic syndrome — factors that increase risk for heart disease, diabetes and stroke, according to the American Heart Association.
The connection between soft drink consumption and metabolic syndrome held for both diet and regular soda, according to the researchers. The study is one of the first to find similar patterns of results from two diverse geographic areas — central New York state and Luxembourg.
The research team was led by University of South Australia nutritionist and psychologist Georgina Crichton, who did graduate research at UMaine; UMaine psychologist and epidemiologist Merrill “Pete” Elias; and cardiovascular researcher Ala’a Alkerwi from the Luxembourg Institute of Health.
The study involved cross-sectional data from 803 adults who participated in the Maine-Syracuse Longitudinal Study (MSLS) and 1,323 adults from the Observation of Cardiovascular Risk Factors in Luxembourg Study (ORISCAV-LUX).
Individuals in both MSLS and ORISCAV-LUX who consumed at least one soft drink per day —regular or diet — had a two-fold higher risk for metabolic syndrome compared with those who did not consume soft drinks, when adjusted for dietary factors, total energy intake and cardiovascular risk factors. Diet soda drinkers were not exempted from being at higher risk. Metabolic syndrome was higher in those who consumed at least one diet soft drink per day than in nonconsumers, in both study locations.
In both studies, lower intakes of fruit and vegetables were observed in regular soft drink consumers compared to nonconsumer. Diet soft drink consumers also had higher waist circumference and body mass index in both study sites. In Luxembourg, higher diet soft drink consumption was associated with higher systolic BP and with higher fasting plasma glucose (blood sugar levels).
Diet modification to reduce soft drink consumption, including diet drinks, is one lifestyle change that may help optimize metabolic health, according to the researchers, who reported their findings in the journal “Nutrients.” (2015).
Metabolic syndrome or MetS is a clustering of cardio-metabolic risk factors in an individual, namely abdominal obesity, high blood pressure, high triglyceride levels and low HDL cholesterol (the “good” cholesterol). Having MetS increases ones risk for cardiovascular disease, coronary heart disease, stroke and type 2 diabetes mellitus. MetS was defined as present if three out of five risk factors were present: waist circumference ≥ 88 cm for women or 102 cm for men; fasting glucose ≥ 100 mg/dL (or drug treatment); blood pressure ≥135/85 mmHg or treatment for hypertension; serum triglycerides ≥150 mg/dL (or drug treatment); and high density lipoprotein (HDL)-cholesterol ≤ 40 mg/dL in men or 50 mg/dL in women.
Prevalence of MetS was considerably higher in the U.S. (44 percent) than in the Luxembourg sample (26 percent). A greater proportion of participants in ORICAV-LUX study consumed non-diet soft drinks (60 percent of participants), compared with the MSLS study (43 percent of participants), but consumption of diet soft drinks was higher in the MSLS (24 percent of participants), compared with 11percent in ORISCAV-LUX. However, of those who consumed soft drinks, average number of drinks consumed per day was higher at the U.S. site (two servings/day for diet and regular drinks) than in the Luxembourg participants (one serving/day for both drink types).
The UMaine study initiated in 1975 by Elias, principal investigator and professor Michael A. Robbins (co-investigator) is based on 35 years of study of arterial blood pressure, cardiovascular disease risk factors and neuropsychological functioning sponsored, in part by the National Institute on Aging and National Heart Lung, and Blood Institute of the National Institutes of Health. The Luxembourg study represents a major national population-based study of relations among nutrition and risk factors for cardiovascular disease. The conclusions are the authors and not those of NIH.