High blood pressure (BP) is an important risk factor for cardiovascular disease (CVD) worldwide.1,2Current guidelines classify adults with an average systolic blood pressure (SBP) of 130 to 139 mmHg and/or diastolic blood pressure (DBP) of 80 to 89 mmHg as having stage 1 hypertension (previously, these numbers would have qualified as only prehypertension).3 Adults with stage 1 hypertension have about a 2-fold increase in CVD risk compared with their counterparts with a normal BP (SBP < 120 mm Hg and DBP < 80 mm Hg).3 Furthermore, evidence suggests that lowering SPB to below 130 mmHg further reduces CVD risk.4
Sodium is undoubtedly the dietary constituent that is most linked with BP. Warnings about the hypertensive effects of salt actually date back centuries, although in 1904 Ambard and Beaujard are credited with first suggesting salt increases blood pressure.5Close behind in recognition, is potassium, which in contrast to sodium, is hypotensive.6 Besides these two minerals, there are almost certainly many other dietary factors, including alcohol and fiber, that affect BP as well. Although soy has received relatively little attention in this regard, there is intriguing evidence that one or more soy components lower blood pressure.
Not surprisingly, health authorities emphasize the benefit of adopting an overall dietary pattern that lowers disease risk rather than focusing on making single dietary changes. That sentiment certainly applies to elevated BP because there is ample evidence that overall dietary pattern impacts this condition. For example, clinical and population studies show that vegetarian diets can have BP-lowering effects,7 likely as a result of multiple dietary factors common to these diets.8 Vegetarians do typically consume greater amounts of soyfoods than their nonvegetarian counterparts, but even vegetarian diets lacking in soy are associated with lower BP.9