The Diet Cancer Story

My wife was been “free of cancer” for well over 5 years, but at her last mammogram checkup they discovered a growth they could not otherwise account for and want to do another byopsy-type lump removal. This inevitably raises the heady and frightening spectre of “cancer” once again. As I write, this “ectomy” is still in our future, so the results and reactions are also “still in our future. We’ve been there, several times, but that won’t make a diagnosis of malignancy any easier, any less emotionally traumatic, even though the “period of adjustment” is eased somewhat.

So after 8-9 years cancer free she was diagnosed in January, 2005 with another lump and it was removed in early April, 2005. Yes, it was malignant, but, in the doctor’s words, it was a ‘friendly” tumor. Our “period of adjustment” has been much easier this time around.

Cancer is the second leading cause of death in North America (after heart and other cardiovascular diseases) with lung cancer heading the list, followed by bowel, breast, prostate, pancreas and other malignancies. Cancer prevention is therefore a top for health authorities. Of known cancer causes, smoking tobacco accounts for about a third of the cases and diet is blamed for another 30-70 per cent, although the relationship between food and cancer is hazier than for tobacco, and there are no pat answers.

In general, cancer risks can be diminished by avoiding tobacco use, protecting skin from ultraviolet rays, limiting alcohol intake and - according to the latest evidence - by eating enough fruit and vegetables. Recent results from many studies link low intakes of fresh fruit and vegetables to high cancer rates. Some researchers claim that inadequate intakes of fruit and vegetables double the risks of cancer at many sites - as well as markedly increasing risks of heart disease and cataracts. Since only about 10 per cent of North Americans eat the recommended amount of fruit and vegetables, there's ample room for improvement in fighting cancer. (Very recent studies suggest that anti-inflammatories, such as ASA/Aspirin and other nonsteroidals may help to prevent some cancers.)

Diet-cancer links are complex to unravel

As foods are complex mixtures and people make wide and varied choices, it is hard to prove definite relationships between food and cancer. Much of what is known about the dietary causes of cancer comes from epidemiological studies (that examine the distribution and risks for disease). Epidemiological comparisons of cancer rates in different countries and how they change offer clues. When people migrate to a new country and mimic its lifestyle, they soon acquire the same cancer rates as those in the adopted country. For example, if Japanese people (who have low rates of breast and colon cancer but high rate so stomach cancer) move to the U.S., they acquire typical American cancer rates - high colon and breast cancer rates, low risks of stomach cancer.

Studies reveal a picture of the diet-cancer link in which some dietary constituents may promote certain cancers - such as fat (mainly from meat), excess energy (calorie) intake and heavy alcohol consumption - while other components, especially antioxidants in fruit and vegetables, may help to prevent cancer. Other dietary constituents that may protect against certain cancers include fatty acids in fish (the N-3 or omega-3 fatty acids) and folic acid (a B vitamin). Large studies now underway should tell us in a few years which dietary components promote or combat tumour formation.

The protective anti-cancer effects of fruit and veggies

Low intakes of fruit and vegetables have been consistently linked to high cancer rates in many countries around the world. Yet, less than 10 per cent of North Americans eat the recommended 5-10 daily servings. The fruit and vegetables that appear most protective against cancer are raw, dark green leafy vegetables (such as spinach, kale and lettuce), cruciferous or cabbage-family types (such as brussel sprouts, cabbage, cauliflower, broccoli), and orange forms such as carrots, squash, citrus and other fruits. Different plant foods may protect against different cancers, for example:

* dark green vegetables may protect against lung cancer;

* cruciferous (cabbage family) vegetables and carrots appear protective against colon cancer;

* citrus and other fruits rich in vitamin C may lower risks of mouth, larynx, stomach and esophageal tumours.

The constituents in plant foods thought to ward off cancer include antioxidants - such as vitamins C, E and carotenes (vitamin A precursors) - and starches (which may protect against colon cancer). Other plant compounds such as indoles, flavones, phenols, coumarins, isothiocyanates, sterols and limonene may also play an anti-cancer role. Together, the plant components or phytochemicals that fight cancer have been dubbed "chemopreventive agents."

The possible "chemopreventive" role of antioxidants

The cancer-combatting or chemopreventive effects of fruit and vegetables are attributed by some experts to antioxidants such as the carotenoids or vitamin-A precursors. Their action in inhibiting cancer is ascribed mainly to the ability to combat the oxidative hits that damage DNA and cell membranes. The carotenoids are red, orange and yellow pigments found in fruit and vegetables such as cantaloupe, tomatoes, corn, carrots and peppers, as well as in green leafy vegetables such as spinach, brussel sprouts and broccoli (where their orange/yellow colour is masked by the green pigment, chlorophyll). Some carotenoids are converted into active vitamin A (retinal) inside the body, others not.

How about dietary supplements?

Since certain constituents in fruit and vegetables seem to reduce cancer risks, it is reasonable to wonder whether one should take supplements. While opinions vary, most nutritional scientists do not encourage use of vitamin or other supplements for cancer prevention. People can obtain all the necessary vitamins, minerals and other essential nutrients from a well balanced diet. There are no scientific grounds at present to support the anti-cancer benefits of taking vitamin or antioxidant supplements. "Besides the risk of toxicity from vitamin megadoses, there is the added danger," notes one University of Toronto expert, "that people who take supplements may falsely believe they are eating well, yet fail to achieve the health benefits of a balanced diet."

In addition to the expense, those who take supplements may neglect to eat the recommended quota of fruit and vegetables, miss out on other valuable components and get less effective health protection. The evidence for a cancer-protective effect of individual supplements is far less convincing than that for fresh fruit and vegetables as a whole. There is also concern about the safety of antioxidant supplements. Although vitamins C, E and beta-carotene have low toxicity, even when consumed in doses above recommended daily amounts, a few studies suggest that consuming large doses might not be safe.

Large studies now underway will clarify the action of individual dietary components. The joint effect of the many varied compounds in whole fruit and vegetables gives far greater protection against cancer than any individual nutrient or supplement. Finally, remember that diet is basically worthless if you are not getting the proper nutrition from your diet. If the basic nutrients from your diet are not being used to help heal your body and maintain overall health, you are wasting your time, effort, money and life. A healthy diet begins with proper and full nutrition.

The place to begin with your nutrition, the method to get the most benefit out of the foods you eat, especially in our modern world with foods rampant with antibiotics, poisoning of our lakes, rivers and oceans (not to mention the land and air), is to make liberal use of both herbal dietary supplements and especially dietary aids such as organic greens.