Salt and Blood Pressure Tie May Not Be Completely Clear

Sodium intake and blood pressure connection not certain, but BMI may be tied to hypertension

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Limiting salt to save the heart is an idea that has long been stressed. But a new study suggests that the relationship between sodium and high blood pressure might be more complicated.

The study, led by French researchers, looked at the relationship between a number of factors — including diet and weight — and blood pressure.

The study found a stronger relationship between weight and blood pressure than sodium intake and blood pressure.

"When possible, try to swap fresh veggies for processed snack foods."

The term "blood pressure" describes the force of blood against artery walls. When the pressure is high (also called hypertension) it can contribute to a number of health issues, such as heart disease.

The new study, which was led by Helene Lelong, MD, of Paris-Descartes University in France, looked at how a number of lifestyle and nutritional factors affected blood pressure.

To do so, Dr. Lelong and team used data from the ongoing, Web-based NutriNet-Santé study. A total of 8,670 adults provided three 24-hour dietary recall records, as well as three blood pressure measurements and information on lifestyle factors.

The study authors found that the clearest connection was not between sodium and blood pressure, but body mass index (BMI) and blood pressure.

BMI is a ratio of height to weight that measures body fat. In the study, blood pressure was higher in both men and women with higher BMIs.

High salt intake, however, was tied to higher blood pressure in men only. The authors also found that both men and women who ate more fruits and vegetables had lower blood pressure. However, this relationship was not as strong as the relationship between BMI and blood pressure.

"There are definitely genetic components to having high blood pressure, and medications can treat it to some degree, but we're always trying to additionally focus on things that we can do to help patients in addition to medications," said Jeffrey M. Schussler, MD, an interventional cardiologist at Baylor Heart and Vascular Hospital and Baylor University Medical Center at Dallas.

"Salt has been suggested as one of the contributors to having high blood pressure, and to some degree it does," Dr. Schussler said. "Being overweight or obese (which is a significant problem in the US and worldwide) seems to be even more of a contributor. I typically do recommend that patients who have high blood pressure limit their salt intake. Even though it may not be the biggest contributor, it makes sense to do whatever we can to help control high blood pressure."

Dr. Lelong and team studied only French patients, and dietary data like sodium intake levels were self-reported. Further research is needed to confirm these findings among a more diverse group, the authors noted.

The study was published online Sept. 3 in the American Journal of Hypertension.

A number of organizations funded the study, including the French Ministry of Health and the Institute of Research in Public Health. The authors disclosed no conflicts of interest.

Review Date: 
September 10, 2014
Last Updated:
March 12, 2015