Walnuts may modestly lower elevated blood pressure, according to a clinical trial in the journal Hypertension. The Spanish study included 236 people (ages 63 to 79), with blood pressure ranging from normal to mild hypertension (less than 150/100). For two years, half supplemented their usual Mediterranean diet with walnuts (averaging 1½ ounces a day), while the other half continued with their normal diet but without any nuts (the control group).
The walnut group averaged a 4-point drop in systolic blood pressure (the first number) compared to the control group, with larger decreases seen in people with higher initial blood pressure. There was no decline in diastolic pressure (the second number). The researchers hypothesized that alpha-linolenic acid, an omega-3 fat in walnuts (but not in other nuts), may play a role in vascular health.
But they also noted that it’s not known if the results of the study can be extrapolated to other groups—for instance, people not eating a Mediterranean diet, younger adults, or those with moderate or severe hypertension. The research was part of the larger Walnuts and Healthy Aging study, funded by the California Walnut Commission.
This article first appeared in the UC Berkeley Wellness Letter.
Also see Walnuts Lower Blood Cholesterol.