CHICAGO—Teenagers who reduce their daily salt intake by a seemingly small amount can markedly reduce their likelihood of hypertension in young adulthood, according to data reported at the American Heart Association Scientific Sessions.
Additionally, the decreased risk of hypertension can be expected to extend into middle age provided that teenagers maintain their dietary salt reduction as they age.
Kirsten Bibbins-Domingo, MD, associate professor of medicine, epidemiology and biostatistics at the University of California in San Francisco, and colleagues used computer modeling analysis to quantify the benefits of a daily 3-gram decrease (approximately half a teaspoon) in dietary salt consumed by American teenagers.
The data showed that decreased dietary salt among teens also leads to lower rates of cardiovascular disease (CVD) and death as teens reach young adulthood and middle age.
In the United States, teenagers consume 9.2 grams per day of salt (or 3,800 mg per day of sodium), more than any other age group. The American Heart Association recommends that Americans consume less than 5.8 grams per day of salt, or fewer than 2,300 mg sodium. Not surprisingly, the major source of dietary salt in teens is processed and prepared foods.
Reducing daily salt intake by 3 grams would reduce the number of hypertensive adolescents and young adults by 44%-63%, said Dr. Bibbins-Domingo, Co-Director of the UCSF Center for Vulnerable Populations. In absolute numbers, the reduction would translate into 380,000 to 550,000 fewer hypertensives among individuals aged 12-24 years.
If the teenagers continue to ingest no more than 3 grams of salt a day, this would lead to 30%-43% (2.7 million to 3.9 million) fewer hypertensive adults aged 35-50 years of age.
In an earlier study, Dr. Bibbins-Domingo and her team projected that a 3-gram decrease in salt reduction in adults would result in a population-wide decrease in the yearly number of new cases of coronary heart disease by 120,000 and deaths from CVD by 100,000. The cardiovascular benefits of dietary salt reduction were similar to those achieved with reductions in cigarette smoking, obesity, and cholesterol levels.
The investigators wanted to extend their research to include teenagers given the excess amount of salt consumed by U.S. teenagers coupled with the fact that the teenage years are the time in which health behaviors are established for life. Moreover, 3%-5% of American teenagers already have hypertension, and hypertension in young adult years is highly correlated with hypertension later in life, she added.
The researchers projected that a 3-gram decrease in daily salt intake among teenagers would result in:
- 7%-12%, or 120,000 to 210,000, fewer coronary heart disease events
- 8%-14%, or 36,000 to 64,000, fewer myocardial infarctions
- 5%-8%, or 16,000 to 28,000, fewer strokes
- 5%-9%, or 69,000 to 120,000, fewer deaths from any cause.
Reducing salt intake by 3 grams per day reduced systolic blood pressure by only 1 mm, Dr. Bibbins-Domingo observed. However, small effects over a teenager’s lifetime and over the entire population “end up having a major impact on cardiovascular health,” she said.
“The message to doctors is to remember that cardiovascular risk can start early and that excess salt can be a major contributor, and that means that doctors need to discuss with their patients the importance of limiting salt intake in the diet,” she said.