It is amazing how many seemingly obscure causes and effects there are in this world, and all it takes is a little creativity and perseverance to find them. Recently, scientists from the University of California (UC) in Davis found out that, at least in mice, eating walnuts can actually slow down the growth of tumors. In fact, after 18 weeks of being on a walnut-rich diet, the mice had tumors half the size as mice on a similar diet. Further research will be upcoming to explore more beneficial effects of walnuts. Some believe that walnuts can be even used to prevent tumors from ever forming. The unlucky subject mice in the experiment were genetically programmed to develop prostate cancer. UC Davis researchers assessed the size of their tumors at 9,18 and 24 weeks. Some mice were on the walnut diet, consuming the human equivalent of 2.4 ounces of walnut per day. The other subject group ate a soybean oil diet which was formulated to match the walnut diet in terms of nutrients, fat levels, and fatty acid profiles. Amazingly, at 18 weeks, the tumors were half the size in the walnut group than the other group. Overall, the rate of tumor growth was 28 percent less for the walnut group. Walnuts are high in fat as well as omega-3 polyunsaturated fats and antioxidants. Previous research has suggested that a low fat diet is recommended for reducing the risk of and slowing the growth of prostate cancer. However, going on a low fat diet may exclude walnuts and their powerful tumor-fighting qualities. \"If additional research determines that walnuts have the same effect in men as they do in mice, adhering to a diet that excludes walnuts to lower fat would mean that prostate cancer patients could miss out on the beneficial effects of walnuts,\" said lead author Paul Davis, a research nutritionist in the Department of Nutrition at UC Davis and researcher with the UC Davis Cancer Center. The UC Davis research was not able to pinpoint any single chemical within the walnut responsible for slowing tumors. However, they found significant correlations in their study. For example, the researchers learned that the walnut-fed mice had lower LDL cholesterol (bad cholesterol). They also noticed a difference with how the liver, a major source of cholesterol and insulin-like growth factor (IGF-1), metabolized the walnuts compared with the soybean oil diet. The study was conducted with colleagues from the USDA Western Regional Research Center and was funded by the California Walnut Board. The study was published in the British Journal of Nutrition.