Little changes in our diet may bring amazing health benefits! For example, you just have to replace your daily snack, especially if it is an unhealthy snack, with about 10 walnuts and in a little more than one month you will be able to see some risk factors for heart disease decrease. This is the result of a very recent study published a few weeks ago in The Journal of Nutrition by a team of Pennsylvania State University (Tindall et al, J Nutr, Dec 2019).
Previous studies have already been able to show that walnuts are useful to lower LDL bad cholesterol and blood pressure with benefits for heart. However, the mechanism was not completely understood. In the research of today, the scientists recruited 42 adults aged between 30 and 65, all in overweight or obesity. For two weeks the participants to the study followed the typical Western diet. Then, they were divided into three groups. One group was asked to include in the diet walnuts, the second group was asked to take the same amount of alpha linolenic acid found in walnut through plant based oils and to exclude walnuts, the third group replaced the alpha linolenic acid of walnut with oleic acid through plant based oils, also in this case no walnuts were eaten. The purpose of this procedure was to verify if the beneficial effects of walnuts are determined by the fatty acids contained in the dry fruits or/and by the bioactive compounds and fibers. Well, after 6 weeks the microbiota, namely the bacteria of the gut, of those who included walnuts in their diet showed an increase of good bacteria, this was not observed in the other groups. Moreover, according to previous researches, the bacteria that increased after the walnut diet have also proven to be important for the health of the heart and linked to reduced cardiovascular risk factors. For example, scientists observed an increase of the bacteria Eubacterium eligens, linked to blood pressure. In particular, higher levels of these bacteria are associated to lower blood pressure values. In addition to this, walnuts diet has also been able to increase the values of Lachnospiraceae, connected to reduced values of LDL cholesterol and blood pressure.
For sure the study is limited since the analyzed sample is very small. Other researches will follow but this is a first step to understand how little changes in diet, such as including about ten walnuts per day, may affect the bacteria that live in the gut and that control several factors concerning the health of our body.