Walnuts show ability to protect against Ulcerative colitis
Walnuts contain a complex array of natural compounds and phytochemicals that exhibit a wide range of health benefits, including protection against inflammation and colon cancer.
Dietary supplementation with nuts has shown a variety of health benefits. Among the tree nuts, walnuts (Juglans regia) contain the highest levels of the omega-3 fatty acid, namely alpha-linoleic acid (ALA), with the most favorable ratio of omega-3:omega-6 fatty acids (1:4.2) .
Walnuts also contain a large number of phytochemicals, including phenolic antioxidants, and high levels of nutrients with beneficial properties to guard against a variety of diseases, including heart disease, diabetes, neurological disorders, inflammation and cancer [1,2,3]. Moreover, walnuts are a rich source of fiber (up to 6.4%), which has been shown to support the maintenance of disease remission in patients suffering from inflammatory bowel disease (IBD) .
The following study design is based upon the reported anti-inflammatory properties of walnuts [11,12,13]. Using a preclinical mouse model of UC, we have examined the potential health benefits of whole walnuts added to a Total Western Diet (TWD)  on the extent of intestinal injury following exposure of mice to the ulcerogenic agent, DSS. We have examined how walnut consumption, starting prior to DSS exposure and continuing throughout the entire disease course, may influence the extent of intestinal inflammation during both the acute and recovery phases of the experimentally-induced disease.
To gain further insight into how walnut consumption may ’condition’ the colonic mucosa towards a protective state, we have conducted a discovery-based metabolomic profiling analysis on both fecal samples and colonic mucosa obtained from mice maintained for two weeks on a walnut-supplemented diet. This analysis has identified significant increases in a number of lumenal and tissue metabolites, several of which may contribute to the observed protection from ulcerogenic injury observed in this study.
In summary, this study has shown that dietary supplementation of walnuts has the ability to protect mice against DSS-induced experimental colitis. The beneficial effects of dietary walnut consumption may be due in part to sustained alterations to the tissue microenvironment present within the colonic mucosa. A diet enriched in walnuts may shift the overall metabolic state of the colon towards one that is capable of resisting the ulcerogenic actions of DSS-induced injury. Our global discovery-based metabolite analyses have shown variability, possibly due to the relatively modest sample size (n = 3~10), and further analyses are warranted to validate these initial findings. However, significant changes in metabolites levels present in both fecal samples and colonic mucosa indicate that regular walnut consumption may improve lipid metabolism and enhance the production of antioxidants in the colon. It is reasonable to speculate that walnut consumption has provided the ’at-risk’ colonic mucosa with a more protective milieu which may better withstand subsequent environmental insults.
Read complete study at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566840/