Diet and regular soft drinks linked to increase in risk factors for heart disease

Drinking more than one soft drink daily — whether it’s regular or diet — may be associated with an increase in the risk factors for heart disease, Framingham researchers reported in Circulation: Journal of the American Heart Association.

“We were struck by the fact that it didn’t matter whether it was a diet or regular soda that participants consumed, the association with increased risk was present,” said Ramachandran Vasan, M.D., senior author of the Framingham Heart Study and professor of medicine at Boston University School of Medicine.

“In those who drink one or more soft drinks daily, there was an association of an increased risk of developing the metabolic syndrome.” Metabolic syndrome is a cluster of cardiovascular disease and diabetes risk factors including excess waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL “good” cholesterol) and high fasting glucose levels. The presence of three or more of the factors increases a person’s risk of developing diabetes and cardiovascular disease.

Prior studies linked soft drink consumption to multiple risk factors for heart disease. However, this study showed that association not only included drinking regular calorie-laden soft drinks, but artificially sweetened diet sodas as well, researchers said.

“Moderation in anything is the key,” said Ravi Dhingra, M.D., lead author of the study and an instructor in medicine at Harvard Medical School. “If you are drinking one or more soft drinks a day, you may be increasing your risk of developing metabolic risk factors for heart disease.”

The Framingham study included nearly 9,000 person observations made in middle-aged men and women over four years at three different times.

In a “snapshot in time” at baseline, the researchers found that individuals consuming one or more soft drinks a day had a 48 percent increased prevalence of the metabolic syndrome compared to those consuming less than one soft drink daily.

In a longitudinal study of participants who were free of metabolic syndrome at baseline (6,039 person observations), consumption of one or more soft drinks a day was associated with a 44 percent higher risk of developing new-onset metabolic syndrome during a follow-up period of four years.

The researchers also observed that compared to participants who drank less than one soft drink daily, those who drank one or more soft drinks a day had a:

* 31 percent greater risk of developing new-onset obesity (defined as a body mass index [BMI] of 30 kilograms/meter2 or more);
* 30 percent increased risk of developing increased waist circumference;
* 25 percent increased risk of developing high blood triglycerides or high fasting blood glucose;
* 32 percent higher risk of having low HDL levels.
* A trend towards an increased risk of developing high blood pressure that was not statistically significant.