For children, lower consumption of sugary beverages was linked with an increase of "good cholesterol" over a 12 month period in a Boston study.

In adults, substantial evidence ties high sugar intake to increased triglycerides and decreased good cholesterol. But the link had not been investigated in a racially diverse sample of U.S. school children, according to Maria I. Van Rompay of Tufts University in Boston.

Rompay and colleagues analyzed food frequency questionnaires filled out by 690 Boston children, ages eight to 15. The questionnaires, filled out at the start of the study and six and 12 months later, assessed the kids' intake of sugar-sweetened beverages like regular sodas, fruit juices with less than 100 percent fruit, and sweetened teas.

Only 380 kids provided usable questionnaire responses by month 12.

They also provided blood samples at the start and at the 12-month point to be measured for high-density lipoprotein (HDL) or "good" cholesterol and triglycerides, which can increase the risk of coronary artery disease.

At the start of the study, about 85 percent of the kids said they had consumed sugary beverages over the previous week, drinking an average of almost three servings per week. Almost 20 percent reported having at least one sugary beverage per day.

Older kids and those from a lower socioeconomic status tended to drink more sugary beverages. Those who drank more sugary beverages also tended to consume more total calories, fewer fruits or vegetables per day, and to spend more time sedentary.

Over time, average sugary beverage consumption was not linked to changes in HDL or triglycerides. Both HDL and triglyceride levels increased over the study period for the whole group, on average.

But kids who decreased their sugary beverage intake by at least one serving per week had greater increases in HDL, the good cholesterol, compared with those who did not change their intake or increased it.

Changing beverage intake was not tied to triglyceride levels, the researchers reported in the Journal of Nutrition.

The study was limited by the fact that children's self-reporting of dietary intake isn't necessarily reliable.

And the study did not include hard endpoints, like stroke or heart disease.

Studies of adults have linked higher consumption of sugary beverages with higher risk of high blood pressure, coronary heart disease, and stroke, so reducing consumption in adults may be beneficial, Van Rompay told Reuters Health by email.

"In children and adolescents, however, fewer longitudinal studies have been done, and these studies have investigated relationships between (sugary beverage) consumption and risk factors for heart disease and diabetes, including overweight/obesity, dyslipidemia, and insulin resistance," she said. "To our knowledge, research results linking reduced (sugary beverage) consumption to better endpoints in kids such as stroke or heart attack have not been reported."

About 20 percent of youth aged eight to 17 years have a risky blood lipid concentration, or dyslipidemia, she said.

"Dyslipidemia among children/adolescents is concerning because blood lipid concentrations from childhood track into adulthood, and having dyslipidemia as a child or adolescent may be evidence of early development of heart disease," Van Rompay said.

Many parents may not know their child has this risk factor, she said.

"Lower diet quality is a modifiable risk factor for disease, which means that dietary intake is something parents could help their children (or adolescent) change for the better," she said. "Thus, it seems important for parents to help children minimize, or replace, (sugary beverages) with more healthful, nutrient-dense beverages, as well as aim for improved diet quality overall, to help set children and adolescents on a track for a healthier life overall."