Adding walnuts to your everyday diet could boost specific bacteria that can improve cardiovascular health.
Walnuts are an excellent source of alpha-linolenic acid (ALA) which is an omega-3 essential fatty acid.
Walnut is not only a tasty snack, but a new study suggests that it may be heart- and gut-healthy as well.
Dr Kristina Petersen, the study’s co-author, said:
“Replacing your usual snack — especially if it’s an unhealthy snack — with walnuts is a small change you can make to improve your diet.
Substantial evidence shows that small improvements in diet greatly benefit health.
Eating two to three ounces of walnuts a day as part of a healthy diet could be a good way to improve gut health and reduce the risk of heart disease.”
Past studies have found that a diet consisting of less saturated fats in combination with walnuts benefits the heart by lowering risk factors, such as high blood pressure and bad cholesterol.
The cardiovascular health benefits of walnuts may be related to changes to the bacteria that live in the gastrointestinal tract.
Professor Penny Kris-Etherton, study co-author, said:
“There’s a lot of work being done on gut health and how it affects overall health.
So, in addition to looking at factors like lipids and lipoproteins, we wanted to look at gut health.
We also wanted to see if changes in gut health with walnut consumption were related to improvements in risk factors for heart disease.”
The study found that a six-week diet containing 57 to 99 grams of whole walnuts per day boosted beneficial bacteria such as Roseburia, Eubacterium eligens, Lachnospiraceae, and Butyricicoccus.
Dr Petersen said:
“The walnut diet enriched a number of gut bacteria that have been associated with health benefits in the past.
One of those is Roseburia, which has been associated with protection of the gut lining.
We also saw enrichment in Eubacteria eligens and Butyricicoccus.”
The research team saw an association between high levels of Eubacterium eligens and a reduction in blood pressure and heart disease risk factors.
They also saw that Lachnospiraceae and another bacteria were effective in lowering blood pressure and total cholesterol.
Dr Regina Lamendella said:
“Foods like whole walnuts provide a diverse array of substrates — like fatty acids, fiber and bioactive compounds — for our gut microbiomes to feed on.
In turn, this can help generate beneficial metabolites and other products for our bodies.”
About the author
Mina Dean is a Nutritionist and Food Scientist. She holds a BSc in Human Nutrition and an MSc in Food Science.
The study was published in The Journal of Nutrition (Tindall et al., 2019).