In the study, researchers fed mice with colorectal cancer a diet low in methionine, which is an amino acid found in meat, fish, eggs and dairy products that plays a significant role in metabolism and in many other functions in the human body.
The findings revealed that while administering a low dose of chemotherapy had no effect on tumor inhibition in mice, a low dose of chemotherapy in combination with a methionine-restricted diet led to “marked inhibition of tumor growth.” The researchers also tested the effect of a methionine-restricted diet on six healthy people and found that the diet’s effect on their metabolisms was similar to its effect on the mice’s metabolisms.
As cancer cells require dietary methionine to grow, limiting intake of the amino acid may quite literally starve cancer cells.
“What this study is showing is that there are many situations where a drug by itself doesn’t work, but if you combine the drug with the diet, it works. Or the radiation therapy doesn’t work well, but if you combine … with the diet, it works well,” Jason Locasale, an associate professor at Duke University’s School of Medicine, told AFP.
“You’re starving the cancer cells of certain nutrients, at a very basic level,” Locasale added.
However, he warned against the results being viewed as an “be-all, end-all” to cancer. “This is not some panacea,” he said.
Other experts who reviewed the study also warned readers to remain skeptical of the results for now.
Tom Sanders, professor emeritus of nutrition and dietetics at King's College London, also told AFP that "there is no evidence from this study to suggest following a vegan diet will help patients with cancer."
Locasale also told the outlet he eventually hopes to test the findings in humans, noting, however, that nutrition research often doesn’t get funded because it doesn’t lead to lucrative treatments from which the pharmaceutical industry can profit.
Nonetheless, Locasale noted that the link between health and diet is a “really exciting area right now,” and the goal is eventually to determine what diets cancer patients should follow to help them recover.
Previous studies have also linked methionine restriction to decreasing the rate of aging and increasing lifespan in yeast, fruit flies and rodents.