People who regularly consume sugary drinks are genetically more susceptible to becoming obese or overweight, researchers from the Harvard School of Public Health reported in NEJM (New England Journal of Medicine), September 21, 2012 issue.
The authors wrote that their study provides further evidence proving that genetic and environmental factors act together in driving up the risk of obesity.
Senior author, Lu Qi, assistant professor in the Department of Nutrition, said:
“Our study for the first time provides reproducible evidence from three prospective cohorts to show genetic and dietary factors – sugar-sweetened beverages – may mutually influence their effects on body weight and obesity risk. The findings may motivate further research on interactions between genomic variation and environmental factors regarding human health.”
Over the last thirty years, global consumption of sugar-sweetened beverages (SSBs) has risen considerably. Scientists from the The Yale Rudd Center for Food Policy and Obesity reported in October 2011 that sugary sodas are the number one source of calories in the diets of American teenagers.
Previous studies have pointed towards an association between sugary drinks, obesity and some chronic diseases, such as diabetes. A 2006 Harvard Health Letter linked the obesity explosion to the high consumption of sugary drinks. However, none have examined closely what the impact of environmental factors might be on genetic susceptibility to obesity. The consumption of SSBs is an environmental factor.
Lu Qi and team gathered and studied data on 198,229 people – 121,700 adults females in the BWH-based Nurses’ Health Study (NHS), 25,000 in the Women’s Genome Health Study (WGHS), and 51,529 in the Health Professionals Follow-up Study (HPFS). They had all been given and had completed various questionnaires which asked them about their consumption of food and drink over time.
They analyzed in more detail data from 6,934 adult females from NHS, 4,423 adult males from HPFS and 21,740 women from WGHS. They were all Caucasian, and “for whom genotype data based on genome-wide association studies were available”.
The researchers divided the participants into four groups, depending on sugary drink consumption:
- Very Low Consumption Group – participants drank a maximum of one sugary drink per month
- Low Consumption Group – participants drank between 1 and 4 servings per month
- Medium Consumption Group – from two to 6 servings per week
- High Consumption Group – at least one serving per day
In order to represent the overall genetic susceptibility/predisposition, a score was worked out on the basis of the 32 single-nucleotide polymorphisms known to be linked to body mass index (BMI).
The authors found that the participants in the High Consumption Group had twice the genetic predisposition to high BMIs compared to those in the Very Low Consumption Group.
The researchers explained that the “regular consumption of sugary beverages may amplify the genetic risk of obesity. In addition, individuals with greater genetic predisposition to obesity appear to be more susceptible to harmful effects of SSBs on BMI.”
Co-author, Frank Hu, professor of nutrition, wrote:
“SSBs are one of the driving forces behind the obesity epidemic,” says Frank Hu, professor of nutrition and epidemiology at HSPH and a co-author of this study. “The implication of our study is that the genetic effects of obesity can be offset by healthier food and beverage choices.”
Regular consumption of sugary drinks and food may also slow down the brain and memory functions, researchers from the David Geffen School of Medicine at UCLA reported in May 2012.
In December 2011, researchers from Johns Hopkins Bloomberg School of Public Health reported that children and adolescents drank fewer sugary drinks if calorie information was printed on the labels.
Written by Christian Nordqvist