According to a new study published in the Journal of Medicinal Food, researchers at University of California, Davis, in Davis, California, have found that consuming a diet rich in whole walnuts or walnut oil decreased the rate of prostate cancer growth, reduced cholesterol, and increased insulin sensitivity in mice.
In addition, the walnut-rich diet reduced insulin-like growth factor 1 (IGF-1), which has been shown to cause prostate and breast cancer. For the study, researchers sought to investigate which part of walnuts cause the health benefits that have been identified in previous studies. Researchers fed mice either whole walnuts, walnut oil, or a mixture of walnut-like fat for 18 weeks.
They found that the walnuts and walnut oil, but not the fatty acid mixture, caused health benefits like decreased prostate cancer growth and decreased cholesterol. The findings suggest that the meat and oil of walnuts cause health benefits, but not the omega-3 fatty acids of the walnut; however, it could also be a combination of the three components. The study also found that the health benefits of walnuts are not magnesium, selenium, or zinc.
The researchers note that although this study does not prove that the benefits of walnuts will translate from mice to humans, it may be beneficial to incorporate walnuts into a diet.
Researchers at UC Davis and other institutions have found that diets rich in whole walnuts or walnut oil slowed prostate cancer growth in mice. In addition, both walnuts and walnut oil reduced cholesterol and increased insulin sensitivity.