Anti‐Atherogenic Potential of Edible Mushrooms

For centuries, mushrooms have been used as medicinal plants, and, more recently, have been a growing component of a healthy diet. Mushrooms are low in sodium and are good sources of fiber, bioactive compounds, selenium, potassium and vitamin D, all which may contribute to a healthy heart through anti‐inflammatory and anti‐atherogenic activities. While several types of mushrooms have been studied for their effects on serum lipid profiles, few studies have demonstrated edible mushrooms' effects on atherogenesis. The specific objective of this study was to determine the effectiveness of two commonly consumed edible mushrooms, portobello mushroom (PBM) and shiitake mushroom (SHM), on the prevention of atherosclerosis and associated inflammation. Ldlr−/− mice were fed with one of 5 dietary compositions for 16 weeks: low‐fat (4% fat) control diet (LF‐C), high fat (8% fat) control (HF‐C) diet, 10% of HF‐C diet replaced with PBM powder (HF‐PBM), or with SHM powder, (HF‐SHM), or with a “control mixture”, best matched to the average nutrient levels of the mushroom powders (MIX‐C). Mice fed with HF‐PBM or HF‐SHM diet displayed lower body weight gains (p<0.05) compared to the other dietary groups. Among the two mushrooms fed mice, HF‐SHM fed mice had significantly lower average body weight gain compared to HF‐PBM group (p<0.01). Despite the low body weight gains, EchoMRI™ analysis of body composition revealed that the overall lean mass was not affected as significantly as fat mass, indicating a plausible positive effect of mushrooms on fat metabolism and lipid profiles. Mice fed HF‐SHM displayed the lowest fat mass (p<0.0001) and lean mass (p<0.01), relative to other groups, whereas mice fed HF‐PBM had a lower body fat mass (p<0.001) but not lean mass (p=0.24) compared to other groups. Ex‐vivo adhesion assay of monocytes to luminal surface of aorta showed that mice fed HF‐C exhibited a trend of a higher number of splenocyte attachment, whereas feeding mice with LF‐C and HF‐SHM exhibited a lower number of splenocyte adhesion. Further, quantitative en‐face analysis of aortic lesions using Oil Red O staining revealed that only mice fed HF‐SHM had significantly fewer aortic lesions compared to those of mice fed HF‐C (p<0.01) and MIX‐C (p<0.01). These results further support the potential role of high levels of bioactive compounds such as ergothioneine, a strong antioxidant in SHM, on suppression of dietary fat induced atherosclerosis, an inflammatory disease of arteries. Support or Funding Information Supported by USDA contract #58‐1950‐4‐003 and Mushroom Council.