While resveratrol (the component in red wine that is hyped to be so good for you) has been shown to inhibit cancer replication and help induce cancer cells to commit suicide, it turns out that it can also mess up the immune system by inhibiting cells that kill infections and cancer (macrophages, T-cells and B-cells). So red wine may not be the beverage of choice during cold and flu season, or if you have chronic infections like UTI’s, yeast infections, prostate infections, sinus infections, etc. because resveratrol may inhibit your body’s ability to fight them off. Of course if you have certain autoimmune conditions where you are trying to suppress the immune system, resveratrol may be useful (though I wouldn’t recommend it in the form of red wine due to the negative effects of alcohol and histamine). But in general immune suppression should be a last resort in my opinion.
 
It’s also worthy to note the difference between slowing the growth of cancer cells by interfering with their cell cycle, and the cancer cells being destroyed by a targeted attack of the immune system. When people truly beat cancer, meaning a real cure and not just temporary remission or management, it’s usually because the immune system recognizes it and kills the tumors. That’s why researchers are working frantically on cancer vaccines … they know the most powerful weapon against cancer is your immune system. So in this study they showed that resveratrol inhibits two immune components that result in reduced numbers of natural killer cells (NKs) and tumor necrosis factor (TNF). NKs and TNF are two very powerful weapons our immune systems have to kill cancer, so we should think carefully before we inhibit them. Combining resveratrol with other herbs that upregulate NKs and TNF can also counteract these negative effects while still utilizing resveratrols ability to induce cell death in cancer cells, but you really need to know what you’re doing. So once again, we need to eye nutritional supplement hype with caution. Resveratrol can be useful, but it is not a panacea and should be used judiciously. By the way, curcumin was found to have the same immunosuppressive properties that resveratrol has.
 
Clin Exp Immunol. 2007 Jan;147(1):155-63