In our last health column, we pointed out that countries where the consumption of animal protein and fat is low while the fiber content is high, the incidence rates of colon, breast, and prostate cancers are negligible. However, in countries, such as the United States, Canada, Australia and New Zealand, where diets are low in fiber but high in fat and animal protein, the rates of these kinds of adult cancers are much higher.
Could ethnic variations rather than diet account for these differences?
Researchers asked the same question. In a study published in 1979, they found, for example, that Japanese living in Japan had very few of these cancers. In Japan, fiber consumption then was high and fat and animal protein intake low (less than 15 percent of total calories). But when these Japanese migrated to Hawaii and adopted Western eating habits and lifestyles, their rates for these cancers increased dramatically and soon equaled those for other Americans.
What about carcinogens?
Not all the answers are in yet, but cancer is indeed associated with carcinogens—chemical irritants that can produce cancerous lesions over time. Bile acids are an example. And yet these carcinogens could be closely related to the overall diet. For instance, the amount of fat in the diet affects the amount of bile the body produces. In the intestinal tract some of these bile acids then can form irritating carcinogenic compounds. The longer these compounds stay in contact with the lining of the colon, the more irritation results. Nitrites are another example. Nitrites are used to preserve processed meat and to give cured meats their recognizable color. These can form N-nitroso compounds involved in carcinogenesis. And that’s where dietary fiber comes in—big time!
The important Role of Fiber
With a low-fiber diet, digested food moves slowly through the intestines, often taking from three to five days to complete the journey from entry to exit. Interestingly enough, most fibers absorb water like a sponge. This helps fill the intestines and stimulates them to increased activity. The high fiber content speeds up the transit time, and food now travels through the intestines in 24 to 36 hours.
This helps the colon in two ways: It shortens the exposure time to irritating substances, and it dilutes the concentration of the carcinogens as they pass through the colon thanks to fiber’s water-holding ability and insulating effect.
How does diet relate to breast and prostate cancers?
A high fat intake depresses the activity of important cells in the body’s immune system. This effect has been studied extensively in connection with breast cancer and may affect other types of cancer as well. Dairy products, while possibly being protective for colon cancer, have been clearly implicated in raising the risk for prostate cancer.
Are other lifestyle areas connected to cancer?
Alcohol consumption increases the risk for cancer of the esophagus, breast, liver, and colon, and does so dramatically for those who smoke as well. Excess weight raises the risk of cancer of the breast, colon, endometrium, kidney, pancreas and gallbladder. Then there are such things as exposure to asbestos, side-stream smoke, and toxic chemicals.
Summary
Surprisingly, just four lifestyle factors could prevent close to 80 percent of the adult cancers found in Industrialized society today:
1. no smoking
2. no alcohol,
3. a simpler, more natural plant based, whole food diet that’s very low in fat and high in fiber
4. normal weight.
Instead of one American in four dying of cancer, the risk could be reduced to one in 20. It’s not an impossible dream.