Diets high in plant food have been shown to possess beneficial health effects. In particular, data suggests that plant based diets are protective of cardiovascular disease. One aspect of cardiovascular disease that is particularly detrimental is the high blood pressure that occurs as one of the elements of disease progression. This is thought to occur through detrimental changes to the endothelial lining of the arteries that prevent the normal physiological dilation of the blood vessels following the systole. As a result diastolic pressure rises and this is one of the most important and useful risk factors for assessing cardiovascular disease. Lowering raised blood pressure is therefore highly important in disease management. A number of components of plants are thought to contribute to this effect, with essential fats, fiber, micronutrients and antioxidants being perhaps the most well studied. Nuts are a good source of all of these components and it is therefore no surprise that nuts confer protection against cardiovascular disease.
Nuts have been shown to lower blood pressure, although the exact reason for this effect is not known. A number of studies have investigated the effects of different nuts including tree tree nuts as well as legumes including peanuts. For example, in one study1, researchers reviewed the blood pressure lowering effects of consuming single or mixed nuts including walnuts, almonds, pistachios, cashews, hazelnuts, macadamia nuts, pecans as well as peanuts and soybeans, which are both legumes. This was done through a meta-analysis of existing studies carried out on nuts and blood pressure between 1958 and 2013. The results of the study showed that nut consumption did not significantly reduce blood pressure in the study populations as a whole, but when those with type 2 diabetes were excluded from the data, nut consumption significantly reduced systolic blood pressure in the otherwise healthy subjects. Therefore nuts may have mild blood pressure lowering effects in healthy humans.
When the type of nuts that were used was examined in a subgroup analysis, it was found that pistachio nuts, but not the other nut varieties, significantly lowered systolic blood pressure. Further, the pistachio nuts and mixed nut groups also experienced a lowering of diastolic blood pressure. Therefore in this review of 21 studies, a significant positive effect for nut consumption was found on blood pressure. Of the nuts analysed, pistachio nuts appeared to confer the greatest effects, and inclusion of pistachio nuts may explain the effects of mixed nuts also. These results therefore support the epidemiological evidence showing beneficial health outcomes for those that regularly consume tree nuts. One of these health benefits may result from a modest but significant lowering of blood pressure. Peanuts, soy bean nuts and other tree nuts have been shown to have other health effects and so should still be considered as worthy inclusions to a healthy diet. However, soy beans should be fermented properly prior to consumption.
RdB
