http://www.drkellyturner.com/2014/04/using-herbs-and-supplements-to-help-fight-cancer/
The main difference between chemotherapy and vitamin or herbal supplements is that most chemotherapy is designed to kill cancer cells, while most supplements are designed to strengthen the immune system so that it can then remove cancer cells. The hope is that, by creating an internal environment that is incredibly strong and healthy, cancer cells will not be able to thrive.
Today’s fruits and vegetables contain much smaller amounts of vitamins than they did a hundred years ago. This is due to pesticide use, a lack of trace minerals in the soil, and the harvesting of fruits and vegetables long before they are ripe in order to transport them across the country. Consider this staggering fact: today’s fruits and vegetables have up to 40% fewer vitamins and minerals than they did just 50 years ago. Given this widespread lack of minerals and nutrients in the food supply, you can see why supplements may be necessary for maintaining health in today’s world.
However, when it comes to the science, the jury’s still out. Sadly, this is because many herbal supplements can not be patented, and therefore large pharmaceutical companies have very little incentive to conduct research on them—because they would not be able to make money off them. Nevertheless, smaller studies have shown that various supplements do indeed have cancer-fighting properties. For example, numerous studies done on epigallocatechin (ECGC)—a compound found in green tea—have found that it actively kills cancer cells, while other studies have found that mushroom supplements such as “turkey tail” increase the number of natural killer cells in cancer patients. Additional studies have shown that high doses of vitamin C, high doses of turmeric spice, and daily doses of probiotics all help to boost the immune system’s cancer-fighting capabilities.