Cutting calories by fasting every other day may make cells less prone to becoming cancerous, the results of a study in mice suggest.
Scientists at the University of California, Berkeley, found that when they put mice on a routine of alternate-day fasting, it reduced the rate at which the animals’ body cells divided and proliferated. Because cancer begins when abnormal cells are allowed to divide and spread unchecked, this slowed-down cell division could theoretically reduce the risk of tumor development according to Dr. Marc Hellerstein, who led the research.
“I think everyone would agree that if you reduce cell proliferation in cancer-prone tissue you’ve done a good thing” said Hellerstein.
The study adds to a growing body of evidence that links calorie cutting to both longer life and lower cancer risk in animals.
Whether fasting could help people lower their cancer risk or prolong their lives is not yet known. But the encouraging finding from this study, the authors say, is that it didn’t take substantial calorie deprivation to spur the potentially beneficial cellular changes.
The mice fasted four days a week and allowed to eat as much as they wanted on non-fasting days. The net effect was a five-percent lower-than-normal calorie intake, which in humans would amount to eliminating about 100 calories per day.
The impact of this modest calorie reduction on cell division was nearly as significant as what Hellerstein’s team saw in a group of mice whose calorie intake was slashed by one third.
Much research interest of late has gone toward the possible benefits of calorie restriction, in which calories are limited but not to the point of malnutrition. Calorie reduction has been shown to extend the lifespan, with studies demonstrating the phenomenon in species ranging from yeast to fish to some mammals.
There are a number of theories on why limiting food might make for a longer, healthier life. One idea is that slowing the rate of metabolism reduces the generation of oxygen free radicals, potentially cell-damaging molecules that are a normal byproduct of the metabolic process.
When it comes to cancer specifically, research has suggested that calorie cutting could be beneficial in a number of ways — with reduced cell proliferation being one.
Exactly why fasting or general calorie restriction might dampen cell proliferation is unclear, according to Hellerstein, but he said it is likely to be related to metabolic effects.
“I think that a tremendous signal kicks in” when the body is deprived of food, Hellerstein said. What the signal or signals are is unknown, but one possible player, according to the researcher, is insulin-like growth factor type 1 (IGF-1) — a protein that helps spur cells to multiply and has been implicated in the cancer process. Previous animal research has shown that calorie restriction reduces blood levels of IGF-1.
The new findings, according to Hellerstein, suggest the possibility of health benefits from moderate calorie restriction, whether through generally eating less or “intermittent” fasting.
– American Journal of Physiology, Endocrinology and Metabolism.
Dr. Keith & Laurie Nemec comments on Fasting Has an Anti-Cancer Effect:
This study showed another powerful truth—when less calories are taken in the body, the cells can fight cancer better. In tying this together with the previous study on living/raw vegan diets and health benefits the living/raw vegans had the benefits of:
1. Decreased CRP–decreased inflammation in the body which is the root cause of disease.
2. Decreased IGF-1—decreases cancer risk in rats.
3. Increased Vitamin D concentration which makes for strong bones.
In this study of fasting (decreasing total calories) the benefit was:
Decreased levels of IGF-1 which causes an anticancer effect on the cells. So this means the living/raw vegan diet did the same thing as the fasting diet and it decreased inflammation and had an anticancer effect on the cells.
What is a living/raw plant based vegan diet? It is fasting permanently from the SAD (Standard American Diet) of cooked food, processed food, meat, chicken, fish and dairy products which have all been shown to increase disease risk. For more information on the power of fasting: 7 Basic Steps to Total Health