Going vegan may cut tumor-fed proteins, indicates a fresh research-but specialists warn that cancer prevention is not as easy as altering your diet. Mice experiments discovered amino acid methionine cutting out of their diets-found in poultry, red meat and fish-prevented the development of tumors. Moreover, it also increased the effectiveness of chemotherapy and radiation drugs. And when healthy people stopped eating the food, researchers saw indications of modifications in metabolism that could assist stave the tumors as well.
But experts warn that studies on diets to prevent cancer should be taken with a grain of salt. ‘Yet again this is a study in mice that has almost no implications for treatment of cancer in humans,’ said Dr Paul Pharoah, a professor of Cancer Epidemiology at the University of Cambridge. Cancers don’t have single causes or treatments – so it’s extremely unlikely that a single lifestyle change can stop tumor growth altogether.
But laboratory surveys assist researchers know how differences in diet, habits, gender, genetics, and much more can affect cancer growth and how aggressive the illness is, and what modifications can be helpful in slowing it down. Methionine limitation in Duke University laboratory trials on drug-resistant bowel cancers taken from real patients resulted them to respond to the drugs. Previous trials of Petri dish had shown that healthy cells can still flourish when the protein methionine is present, but cancer cells starve to death.
Dr Jason Locasale, a cancer biologist at Duke University, and his team tested this in mice with grafted tumor samples taken from people. When they saw the tumors stop growing in the mice, they decided to do a preliminary test in humans, by putting a small group on a restricted diet to limit their intake of methionine.
Said: ‘In people, a reduction in dietary methionine levels had a similar effect on metabolism to that seen in mice. ‘This may suggest a conserved response between humans and mice to dietary restriction of this amino acid. ‘These findings provide evidence that a targeted dietary manipulation can specifically affect tumor-cell metabolism to mediate broad aspects of cancer outcome.’
In the preliminary study, six middle-aged individuals received a low methionine diet for three weeks – equivalent to an 83 percent reduction in daily intake.The participants-five females and a person between 49 and 58-consumed a methionine-free drink and foods such as fruits, vegetables and refined grains.
At the end concentrations of their blood metabolites associated with those seen on the same nutritional limitation in mice. In the sequence of cancer models in mice that restrict methionine concentrations, tumor development was inhibited. Also spread was stopped when used in conjunction with the 5-fluorouracil chemotherapy drug, or radiation therapy. It offers new light on the cancer-poor metabolism connections. Fat acts almost like an organ– interacting with other body components.
It actually sends out signals that play a crucial role in regulating metabolism, the immune system and other functions. If we become overweight or obese, the normal running of the body can get knocked off balance by too many signals from fat. Methionine is an essential amino acid the body is unable to produce – and plays a critical role in metabolism. It is metabolized as part of a group of reactions called ‘one-carbon metabolism’ – which are also targeted by a number of cancer drugs.
But it was unclear whether specific dietary interventions could influence these, said Prof Locasale. He said: ‘Although cancer has a substantial metabolic component, the principles that define whether nutrition may be used to influence outcomes of cancer are unclear. ‘Nevertheless, it is established targeting metabolic pathways with pharmacological agents or radiation can sometimes lead to controlled therapeutic outcomes.
‘By contrast, whether specific dietary interventions can influence the metabolic pathways that are targeted in standard cancer therapies is not known.’ Forty years ago a landmark paper was published showing for the first time that cancer has ‘absolute methionine dependency.’
Normal cells flourish in a Petri dish -but cancerous cells die without the amino acid. Fresh patient tumors also depend on methionine. These include colon, breast, ovary, prostate, and skin. Pharmaceutical firms are working on drugs that reduce the level of methionine. However, since methionine is primarily derived from meat, a better approach is to eliminate it from diet. Lower methionine foods include fruits, nuts, vegetables, grains, and beans, a trendy vegan diet that is popular with celebrities.