Very recent research has shown that walnuts protect the heart and combat cardiovascular diseases also through their beneficial action on the gut microbiota. The study was published in the journal Clinical Nutrition by an American team (Petersen et al, Clinical Nutrition, Sep 2023).
Walnuts and the heart, what we know
Regular intake of walnuts is cardioprotective. This fact is known. Based on previous studies, for example, walnuts are known to help reduce bad LDL cholesterol and triglycerides. But walnuts also protect the heart through other processes. In particular, it is believed that walnuts can support the gut microbiota and stimulate the production of short-chain fatty acids, which are anti-inflammatory substances. However, the action of walnuts on the intestinal microbiota has not yet been explored in depth. This is where the study we are talking about today comes into play.
Nuts and heart, a very important new piece is added
The scientists recruited 35 adults, average age 43 years and with a body mass index around 30, therefore overweight. All participants used to follow a Western-style diet. The volunteers were divided into three groups. The first group was asked to consume just over 50 grams of walnuts every day for 6 weeks. The second group had to follow a diet free of nuts but with the same intake of fatty acids and the third group a diet free of nuts but with the introduction of oleic acid. Well, at the end of the study it emerged that walnuts had acted at the level of the gut microbiota by stimulating the endogenous production of homoarginine, an amino acid which is considered the new promising candidate for assessing cardiovascular risk. In particular, low homoarginine values are associated with a higher risk of stroke, heart attack and heart failure. Thus, an increase in homoarginine, as observed only in the walnut group, indicates a reduction in cardiovascular risk.
The study is small and it will be necessary to verify the results by analyzing the effects of walnuts on much larger samples of the population and considering volunteers of normal weight and of different ages. However, what has been observed is certainly worthy of note because it adds a very important piece to our knowledge about the healthy properties of walnuts. Walnuts are good for the heart, this is a fact already known. However, the way in which this happens is less known. According to previous studies, walnuts improve cholesterol and triglyceride levels and from today we know that they also act on the gut microbiota and stimulate the production of substances associated with a reduction in cardiovascular risk. Here is another good reason to include walnuts in our daily diet, as a delicious snack for breakfast or mid-morning.