Daily Nut Consumption Linked to Significantly Lower Risk of High Blood Pressure, Study Finds

Consuming a daily serving of nuts, roughly the amount that fits in the palm of one's hand, may significantly decrease the risk of developing high blood pressure, according to a comprehensive review of existing research. The study, which analyzed data from nearly 150,000 individuals across eight long-term studies, found that individuals who ate about 30 grams (approximately 1 ounce) of nuts per day had a 26% lower risk of being diagnosed with hypertension compared to those who did not consume nuts.

Further analysis revealed that for every additional 28 grams of nuts consumed daily, the risk of developing high blood pressure decreased by 20%. The findings were published in the British Journal of Nutrition.

The meta-analysis included eight studies involving 143,380 participants, aged 18 to 87, of whom 20,665 were diagnosed with high blood pressure. The studies originated from the US, France, Spain, South Korea, China, and Iran, with most including both men and women.

Researchers observed that the highest levels of nut consumption were associated with a 16% lower risk of high blood pressure when compared to the lowest intake levels. The study suggested that the blood pressure-lowering benefits plateaued, with no additional significant advantage from consuming more than 35 grams per day, and diminishing returns below 25 grams daily.

While the review did not specifically examine whether nuts can lower blood pressure in individuals already diagnosed with hypertension, experts suggest that a healthy diet, regular exercise, and maintaining a healthy weight are crucial for managing the condition. Nuts are recognized components of heart-healthy diets such as the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet, both of which have been linked to improved blood pressure and cholesterol levels.

The specific types of nuts consumed were not detailed in the reviewed studies, but prior research has indicated that almonds, cashews, walnuts, and peanuts are among those associated with a reduced risk of hypertension. The study also did not specify whether the nuts were salted, a factor known to increase the risk of high blood pressure.

Potential mechanisms for these benefits include L-arginine, an amino acid found in nuts that the body uses to produce nitric oxide, a compound that helps relax and widen blood vessels. Additionally, the fiber in nuts can be metabolized by gut bacteria into byproducts linked to lower blood pressure, and antioxidants present in nuts may help reduce inflammation that can elevate blood pressure. Nuts are also a good source of protein, magnesium, and potassium, which contribute to vascular health.

High blood pressure affects nearly half of adults in the United States, equating to approximately 37 million people. The study's observational nature means it cannot definitively establish a cause-and-effect relationship, but it provides substantial evidence for the association between nut consumption and a reduced risk of hypertension. The researchers recommended opting for unsalted mixed nuts and considering them as a substitute for processed snacks.