How Foods Cure Cancer

~ January 1998 No.31 ~

Headlines that announce another study in which a common fruit or vegetable reduces the incidence of cancer are becoming more and more common. This is happening as scientists are able to detect, isolate and concentrate minor constituents of foods that have anti-cancer properties. At the same time our understanding of how cancer develops and spreads is expanding. The development of cancer can be divided into several related but distinct stages. At each stage it appears that consumption of certain foods or food ingredients can slow or reverse the cancer.

common fruit or vegetable reduces the incidence of cancer

Food or food ingredients can act to suppress, block or to transform agents that can cause cancer. In the normal course of digestion and metabolism, compounds that start out as being safe and nutritious can be converted to procarcinogens or compounds that have been shown to be capable of causing cancer. A food or food ingredient that prevents this conversion is called a suppressor. Antioxidents such as vitamin C and vitamin E would be examples of suppressors as they prevent the formation of free radicals that have been shown to cause cell damage that can lead to many cancers.

When procarcinogens are formed, they have to be transported to the organ or tissue where they then attack healthy cells and start the growth of the cancer. Some compounds, termed blockers, have been shown to be able to prevent the procarcinogens from locating where they can do their damage. The blocker reacts with the procarcinogen forming a product that can be quickly excreted from the body before it can become established.

Agents that act as transformers act in a similar way to blockers. Transformers are able to react with or metabolize the procarcinogen into nontoxic products. Some blockers are enzymes systems that occur naturally in the body and are capable of metabolizing a wide range of compounds. The activity of these enzymes can be increased by changes in the diet, and this can provide protection when the body is exposed to procarcinogen or carcinogens.

Once a cancer has become established the cells that it has invaded lose their ability to stick together. The infected cells are then able to break away and circulate throughout the body via the blood and lymph systems. The appearance of cancer in organs and tissues distant from the initial site of disease results. Some food ingredients such as the flavones in orange,tangerine and grapefruit have been shown to be able to restore the adhesion between cells that would prevent the spread of cancer cells in the body.

The many factors that cause cancer and allow it to grow and spread in the body are not all well understood. But it is becoming more and more evident that many foods contain components that can act against cancer cells at very particular stages of cancer initiation, growth, development and spread.

New research shows that healthy people with high levels of anger, hostility or depression also have high blood levels of C-reactive protein, an indicator of inflammation of the arteries. More and more, heart experts are recognizing that this arterial inflammation is key to the cardiovascular disease process, and this latest study suggests reductions in anger might help reduce heart woes.

"Anger seems to predict an increased risk of heart disease in initially healthy individuals, and several studies have shown that," said study author Edward Suarez, an associate professor of psychiatry and behavioral sciences at Duke University. However, until now, no one had studied links between anger and inflammation. "This is the first step to link the behavior to this [heart disease] mechanism - one that's garnering a lot of attention" among cardiologists, he said.

The findings appear in the September issue of Psychosomatic Medicine.

In the study, Suarez tested C-reactive protein (CRP) blood levels in 121 healthy, nonsmoking men and women between 18 and 65 years of age. On the same day, he also measured each participant's level of anger, hostility and depression using a series of standard psychological tests. He found that - in the absence of heart disease risk factors such as smoking, obesity and high blood pressure - high levels of these negative emotional states "significantly predicted the blood level of CRP." Those who were prone to anger, hostility or depression had two to three times higher CRP levels than their more mellow peers, the researchers said.

It's not yet clear why this association exists, but studies are under way to shed light on pathways by which anger or depression might encourage inflammation. In one study, Suarez plans to track patients for two years, to see if hotheaded individuals are any more likely to develop elevated CRP levels over time.

Other studies are planned that focus on anger's effect on stress hormones such as noradrenaline and norepinephrine. The latter hormone, in particular, works on a second chemical, nuclear factor-kappa B, "as a kind of 'off/on' switch" for inflammation," Suarez said. "When that switch is turned on, it begins a cascade of events that leads to the promotion or release of inflammatory proteins."

In the meantime, people concerned about their heart health might want to just "cool it" when tempers flare. "It's very important to pay attention to how we can change these behaviours," Suarez said. "I know it isn't easy, though."
"It's difficult to change patterns of behaviour that are intrinsic to who we are as individuals, so it's not going to be an overnight thing," he added. "But we can start by saying, 'What gets me angry?' and 'If I get angry, do I start to feel depressed and withdrawn from my social network?' " Also, take a stress break. "If a walk around the park can calm you down, do it," Suarez said.