A combination of a low-calorie, plant-based diet and high levels of Vitamin C might offer a new and less-toxic way to combat malignant mesothelioma.
A report published in the journal Nature Communications says the combination delayed tumor progression in mouse models of colorectal cancer. In some mice, it even caused their tumors to shrink.
The most-affected tumors had a genetic mutation found in about a quarter of human cancers, including some cases of mesothelioma. Mutations in the KRAS gene help mesothelioma resist standard cancer treatments.
The study indicates that adding Vitamin C to a diet that mimics fasting might help doctors get around this mesothelioma defence mechanism.
The Anti-Cancer Effects of Ascorbic Acid
Vitamin C is also known as ascorbic acid. Some studies suggest that it has cancer-fighting potential. Ascorbic acid fights inflammation and oxidation that play a role in some cancers. Previous studies show high levels of this vitamin can have a modest anti-tumor effect. The effect is more pronounced in combination with chemotherapy.
But for mesothelioma patients and others with the KRAS mutation, high-dose Vitamin C is less effective. It seems to signal KRAS-mutated cells to protect themselves by producing more ferritin. Ferritin is a protein that binds to iron.
Fortunately, there is a natural way to reduce ferritin. The method involves convincing the body that it is fasting. Like Vitamin C, fasting may slow age-related decline and help fight cancer.
Researchers at the University of Southern California and the IFOM Cancer Institute in Milan reasoned that there might be a synergistic effect to using these two approaches together.
Vitamin C Enhances Power of Fast-Like Diet
The scientists gave high doses of Vitamin C to fasting mice with colorectal cancer. The combination had a powerful effect.
“Our first in vitro experiment showed remarkable effects,” said Valter Longo, the senior author and the director of the USC Longevity Institute. “When used alone, fasting-mimicking diet or vitamin C alone reduced cancer cell growth and caused a minor increase in cancer cell death. But when used together, they had a dramatic effect, killing almost all cancerous cells.”
Even though fasting may slow the growth of cancer cells, doctors do not recommend it for people with malignant mesothelioma. True fasting can deplete the body and make it harder to manage mesothelioma treatments.
USC and IFON researchers say cancer patients can achieve a similar effect with a low-calorie, plant-based diet. This kind of diet causes cells to act as if they are fasting. This includes reducing their production of ferritin.
“Fasting-mimicking diet cycles are able to increase the effect of pharmacological doses of vitamin C against KRAS-mutated cancers,” said Maria Di Tano, a study co-author at the IFOM, FIRC Institute of Molecular Oncology in Milan, Italy. “This occurs through the regulation of the levels of iron and of the molecular mechanisms involved in oxidative stress.”
The authors say they hope their research can help lead to less toxic cancer treatments.
In the meantime, mesothelioma patients should never make changes to their diet or use supplements without consulting their doctor. Certain foods and supplements can hinder the effects of cancer treatment.
Di Tano, M, et al, “Synergistic effect of fasting-mimicking diet and vitamin C against KRAS mutated cancers”, May 11, 2020, Nature Communications, Upen Access online article, https://www.nature.com/articles/s41467-020-16243-3
“A combo of fasting plus vitamin C is effective for hard-to-treat cancers, study shows”, News Release, University of Southern California, May 12, 2020, https://www.sciencedaily.com/releases/2020/05/200512151941.htm