KEY POINTS

  • Walnuts are rich in healthy fats, fiber, minerals and vitamins
  • Walnut consumption improves gut health and reduces heart disease risk
  • Walnuts increased the beneficial gut bacteria: Roseburia, Eubacteria eligens, and Butyricicoccus

Walnuts are not just a tasty snack option, but being enriched with healthy fats, fiber, minerals, and vitamins makes them a healthy one. A new study has reported that walnuts promote good bacteria, which are beneficial for both the gut and the heart.

The researchers from Penn State University have demonstrated that consuming walnuts every day as a part of a healthy diet was linked to increases in health-promoting bacteria. Such changes in the gut microbiome were also linked to improvements in heart disease risk.

Study: Walnuts can be a heart- and gut-healthy snack

"Replacing your usual snack -- especially if it's an unhealthy snack -- with walnuts is a small change you can make to improve your diet," Science Daily quoted Kristina Petersen assistant research professor at Penn State. "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."

Previous studies have shown that walnuts, when consumed alongside a diet low in saturated fats, might provide heart-healthy benefits. Consuming whole walnuts have also been linked to low blood pressure and blood cholesterol levels.

The research included 42 overweight/obese individuals in the 30-65 age group. Prior to the study, they were asked to follow an average American diet for a couple of weeks. Post this run-in-diet, the study participants were randomly assigned to one of three different diets, which included less saturated fat. While one of them incorporated walnuts, one included the same amount of alpha-linolenic acid (ALA) and polyunsaturated fatty acids, and the third diet included partially substituted oleic acid for the same amount of ALA.  The participants were asked to follow these diets for six weeks with a break between the diet period.

The researchers collected the fecal samples 72 hours before the study ended in order to analyze the bacteria in the gastrointestinal tract.

The findings of the study reported that the walnut diet enriched the gut bacteria associated with health benefits, especially Roseburia, Eubacteria eligens, and Butyricicoccus. They also noted changes in gut bacteria and risk factors for heart diseases. The study demonstrated how individuals can feed their gut microbiome in a positive way.