Previous studies have hinted at the link between diet and cancer treatment, according to the latest one published in the journal Nature Communications, a fasting-mimicking diet could be more effective at treating some types of cancer when combined with vitamin C. The study was conducted by the scientists from USC and the IFOM Cancer Institute in Milan.
The combination, according to the scientists help delayed tumour progression in multiple mouse models of colorectal cancer; whereas in some mice, it caused disease regression.
"For the first time, we have demonstrated how a completely non-toxic intervention can effectively treat an aggressive cancer," said Valter Longo, the study senior author and the director of the USC Longevity Institute at the USC Leonard Davis School of Gerontology and professor of biological sciences at the USC Dornsife College of Letters, Arts and Sciences.
"We have taken two treatments that are studied extensively as interventions to delay ageing-- a fasting-mimicking diet and vitamin C -- and combined them as a powerful treatment for cancer," added Longo.
While it is a challenge for many cancer patients to fast, a much safer option would be a low-calorie, plant-based diet that causes cells to respond as if the body were fasting, according to the researchers.
A low-toxicity treatment of fasting-mimicking diet plus vitamin C may have the potential to replace more toxic treatments, the findings suggested.
Recent studies have pointed at the efficacy of vitamin C in battling cancer, especially if it is combined with a potent treatment.
Through this new study, the research team tried to investigate whether a fasting-mimicking diet could enhance the high-dose vitamin C tumour-fighting action by creating an environment that would be unsustainable for cancer cells but still safe for normal cells.
"Our first in vitro experiment showed remarkable effects. 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," said Longo.
The study also provided clues about why previous studies of vitamin C as a potential anticancer therapy showed limited efficacy. By itself, a vitamin C treatment appears to trigger the KRAS-mutated cells to protect cancer cells by increasing levels of ferritin, a protein that binds iron.
During their investigation, scientists reduced levels of ferritin, which helped them increase vitamin C's toxicity for the cancer cells. And with this finding, they were also able discover that colorectal cancer patients with high levels of the iron-binding protein have a lower chance of survival.
"In this study, we observed how fasting-mimicking diet cycles are able to increase the effect of pharmacological doses of vitamin C against KRAS-mutated cancers," said Maira 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 results particularly pointed to a gene that regulates iron levels: heme-oxygenase-1," added Tano.
The research team's prior studies have shown slow progression rate due to fast mimicking diet, making chemotherapy more effective in tumour cells while protecting normal cells from chemotherapy-associated side effects.
However, they stressed upon the fact that the combination of the diet with vitamin C enhances the immune system's anti-tumour response in breast cancer and melanoma mouse models.
The team's goal was to study if the non-toxic combination interventions would work in mice, and that it would look promising for human clinical trials.The team is now investigating the effects of the fasting-mimicking diets in combination with different cancer-fighting drugs.
(This content including advice provides generic information only. It is in no way a substitute for qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.)