New research suggests walnuts may be good for the gut and help promote heart health

A new study discloses there may be a link between heart and gut health boosted by eating walnuts. Findings from this new study, published in the Journal of Nutrition, show that consuming walnuts enriches certain gut bacteria in the digestive system associated with improvements in blood pressure and cholesterol. Researchers believe this could be due to the unique combination of bioactive compounds, fatty acids and dietary fiber found in walnuts.¹

Increasingly, the public look for foods that reduce risk factors and contribute to health, with gut and heart health being the top benefits that are sought after. This is with good reason considering that cardiovascular mortality in the MENA has been estimated to triple from 1990 to 2020. While the survival rate from a heart attack in the Western hemisphere (countries such as Copenhagen) is on average 60-64%, Middle Eastern countries fall drastically short of this average, especially in light of the statistics that show this rate goes no higher than a mean 5-10% in Dubai. Doctors state that 2 out of 10 people in the UAE suffer from poor gut health, which makes them equally grave as heart diseases, and that poor eating habits might have an effect on the aggravation of the problem².

In this new trial conducted at The Pennsylvania State University and Juniata College, study participants included 42 overweight or obese (BMI: 25.0 – 39.9kg/m²) individuals aged 30-65 and at risk for heart disease. Participants first followed an average American diet (48% carbohydrate, 17% protein, 35% fat, 7% saturated fat) for two weeks to be sure that everyone started at the same baseline. They were then randomly assigned to a diet that replaced some saturated fat with either walnuts, a vegetable oil blend that included the same fatty acids as walnuts (including omega-3 ALA, a type of polyunsaturated fat), or a vegetable oil blend that was higher in omega-9 oleic acid (a type of monounsatured fat). These diets were designed to understand if the good, unsaturated fats in walnuts are responsible for benefits or if other nutrients found in whole walnuts, such as bioactive compounds and fiber, may be playing an additional role. All participants followed each diet for six weeks with a break (average of 22.8 days) in between each intervention. Microorganisms living in the digestive sections of the individuals, and health markers such as blood pressure and cholesterol were analysed before and after each of the diets.

Individuals who consumed walnuts and the vegetable oil with the same fatty acid profile as walnuts showed positive shifts in gut bacteria compared to the average American diet, suggesting a positive impact of omega-3 ALA. Those following the walnut diet only, had a unique enrichment of a particular species of bacteria – one that plays an important role in metabolizing ellagitannins, a bioactive component of walnuts that may be associated with cardiovascular benefits.