A new animal study, published in the Journal of Clinical Biochemistry and Nutrition, suggests regular walnut consumption may be a promising intervention for reducing negative outcomes associated with Helicobacter pylori (H. pylori) infection, a widespread bacterial infection that affects more than half of the world's population.
Using mice models, researchers from the CHA Cancer Prevention Research Center in Korea found preliminary evidence that eating a diet rich in walnuts may help protect against negative outcomes associated with H. pylori infection. Specifically, the research found that walnut extracts, formed from whole walnuts, may help create protective proteins and anti-inflammatory actions in the gut that may safeguard against H. pylori infection and resulting cancer in mice. The study was supported by the California Walnut Commission.
Prevalence of H. pylori is most common in developing countries as it is generally related to socioeconomic status and hygienic conditions and is thought to be spread through person to person contact or even through food and water. H. pylori infection is a major cause of ulcers in the stomach and small intestine as well as stomach cancer and peptic ulcer disease. While treatments are currently available, there are concerns about the bacteria's growing resistance to antibiotics.
Due to increasing challenges associated with antibiotic resistance, researchers have been investigating dietary and other non-bacterial approaches to improve impact from H. pylori infection, such as in this new study.
This is not the first time walnuts have been linked to a lower risk of gastrointestinal cancer development in mice. Two other animal studies published in Cancer Prevention Research and Nutrients found that walnuts in the diet may suppress colon tumor development by modifying gut bacteria as well as inhibit the progression of colorectal cancer by suppressing angiogenesis - the development of new blood vessels which facilitates the growth of cancer cells.
Animal studies are valuable for providing background information and can be used as a basis for future research in humans. Based on the existing body of evidence, including this study on walnuts, dietary approaches to reduce symptoms of H. pylori infection, such as inflammation, seem worthwhile to pursue in a well-designed clinical trial to confirm the findings.
Park, J.M., et al. (2021) Dietary intake of walnut prevented Helicobacter pylori-associated gastric cancer through rejuvenation of chronic atrophic gastritis. Journal of Clinical Biochemistry and Nutrition. doi.org/10.3164/jcbn.20-103.