A successful combination
Fasting and vitamin C can help in the treatment of certain types of cancer
Anna Yudina, "Scientific Russia"
Scientists from Milan have found that a fasting-mimicking diet combined with vitamin C can be effective in the treatment of certain cancers, according to a press release A combo of fasting plus vitamin C is effective for hard-to-treat cancers, USC study shows.
Article by Maira Di Tano et al. The synergistic effect of fasting-mimicking diet and vitamin C against KRAS mutated cancers is published in the journal Nature Communications – VM.
In studies on mice, scientists found that the combination delayed tumor progression in multiple models of colorectal cancer in mice, and in some mice it caused regression of the disease.
"For the first time, we have demonstrated how a completely non–toxic intervention can effectively treat aggressive cancer," said Walter Longo, senior author of the study and director of the Longevity Institute at the University of Southern California. "We have taken two treatments that are widely studied as measures to slow aging – a diet that mimics fasting and vitamin C – and combined them as a powerful cancer treatment."
The researchers said that while fasting remains a problematic option for cancer patients, a safer and more feasible option is a low–calorie plant-based diet that causes cells to react as if the body were starving. Their results show that a low-toxicity treatment simulating fasting, plus vitamin C, can replace a more toxic treatment.
The results of previous studies on the potential of vitamin C in the fight against cancer have been mixed. Recent studies, however, are beginning to show some efficacy, especially in combination with chemotherapy. In this new study, the researchers wanted to find out whether a diet that mimics fasting can enhance the effect of high doses against vitamin C, fighting tumors, by creating an environment that would be unstable for cancer cells, but still safe for normal cells.
"Our first in vitro experiment showed remarkable effects," Longo said. – When using only a diet simulating starvation, or only vitamin C, there was a decrease in the growth of cancer cells and a slight increase in their death. But when used together, they had a dramatic effect, killing almost all cancer cells."
Longo and his colleagues found this strong effect only in cancer cells that had a mutation, which is considered one of the most difficult targets in cancer research. These mutations in the KRAS gene indicate that the body resists most anti-cancer treatments, and they reduce patient survival. KRAS mutations occur in about a quarter of all human cancers and are estimated to occur in about half of all colorectal cancers.
The study also provided clues as to why previous studies of vitamin C as a potential anticancer therapy have shown limited efficacy. The vitamin C treatment itself appears to trigger mutated KRAS cells to protect cancer cells by increasing levels of ferritin, an iron-binding protein. But thanks to a decrease in ferritin levels, scientists were able to increase the effect of vitamin C on cancer cells. Based on this discovery, scientists also found that patients with colorectal cancer with a high content of iron-binding protein have less chance of survival.
"In this study, we observed how fasting–mimicking diet cycles can enhance the effect of pharmacological doses of vitamin C on cancer with mutated KRAS," says Maira Di Tano, co-author of the IFOM study, FIRC Institute of Molecular Medicine. Oncology in Milan, Italy. – This happens through the regulation of iron levels and molecular mechanisms involved in oxidative stress. The results particularly point to a gene that regulates iron levels: heme-oxygenase-1."
Previous studies have shown that fasting slows down the progression of cancer and makes chemotherapy more effective in tumor cells, while protecting normal cells from the side effects associated with chemotherapy. The combination with vitamin C enhances the antitumor response of the immune system to the mouse model of breast cancer and melanoma.
Scientists believe that eventually cancer will be treated with low-toxic drugs in a way similar to how antibiotics are used to treat infections that kill certain bacteria, but which can be replaced with other drugs if the former is ineffective.
To move towards this goal, scientists needed to test two hypotheses: that their non-toxic combination interventions would work in mice, and that it would look promising for human clinical trials. In this new study, they demonstrated both. At least five clinical trials are underway, including one on patients with breast cancer and prostate cancer.
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