Curcumin (a component of turmeric) and DHA (an omega-3 fat in oily fish) protect against certain cancers by keeping cancer cells from multiplying. Combining the two may slow tumor growth and the spread of a type of breast cancer cells more so than when the compounds interact with the cancer cells separately, says a 2011 study in BMC Cancer. Researchers think DHA helps cells to utilize curcumin. Rub salmon or trout with turmeric or curry (a spice blend containing turmeric).