Programs designed to prevent obesity in children may help lower kids' blood pressure, according to a new review of past studies.
Researchers found that programs targeting both diet and physical activity were more effective than programs that focused on one or the other.
Although it's generally thought of as a disease of middle-aged and older adults, children can also develop high blood pressure, or hypertension. The American Heart Association recommends that children have yearly blood pressure checks, saying that detecting high blood pressure early will improve a child's health.
Blood pressure during childhood can track into adulthood, and when kids have elevated blood pressure they are more likely to have hypertension when they become adults.
High blood pressure is more common among children who are overweight and obese, so the authors of the review wanted to see if obesity-prevention programs also improved blood pressure in kids.
The research team analyzed data from 23 studies of obesity interventions, including almost 19,000 kids in total. The interventions targeted diet, physical activity or both and lasted at least one year, or six months for school-based programs.
Studies compared children who received a particular intervention with those who did not. In the majority of studies, children were randomly assigned to go through the obesity-prevention program or to be in a comparison group.
Four of the interventions showed positive effects on both body fat and blood pressure. Eleven suggested a beneficial effect on blood pressure, but no effect on body fat.
They found that obesity prevention programs reduced blood pressure among children, by an average of 1.64 millimeters of mercury (mm Hg) in systolic blood pressure and 1.44 mm Hg in diastolic blood pressure.
The reduction was more pronounced in the studies that used a combined approach with both diet and physical activity interventions.
Measuring blood pressure has become a standard part of children's medical care, just like measuring height and weight. But deciding what's normal and what's high blood pressure is more complicated than it is in adults.
In adults there is an accepted standard of 140/90 (mm Hg), which is the cut-off point. For kids, on the other hand, assessments are based on how their blood pressure compares to other children of their age, height and gender. Treatment depends on how high the blood pressure is.
There are things parents can do that are beneficial for kids' blood pressure, such as helping them lose weight if they're overweight or obese.
Dietary changes such as reducing sodium or following the DASH diet can also help (DASH stands for Dietary Approaches to Stop Hypertension). The DASH diet is rich in fruits and vegetables, fibre and low-fat dairy, foods that provide nutrients that benefit blood pressure and cardiovascular health including calcium, magnesium and potassium.
Source: Circulation, online February 19, 2014.