Are specific foods and spices missing from Western diets the key to prevention of cancers?
Sharyl Owen
November, 2004
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The countries with the world's lowest rates of cancers primarily reside within a narrow range of the earth's surface - between the Tropics of Capricorn & Cancer. These are all tropical and sub-tropical environments. They are also less developed nations, which arguably may have environmental factors which affect cancer rates positively. On the other hand, their medical problems are greater, their living conditions are often far worse than more industrialized countries, and their regulations on factors such as pollution, or chemical use for agriculture, are much more lax, allowing for more exposure of their populations to these types of conditions than what would be seen elsewhere in the world. The World Health Organization reports that the projected increase in cancer rates for the future in less developed nations is attributed partly to their adoption of unhealthy Western habits. It would be prudent to look at the foods in their diets which may be excluded in that shift to Western eating.
For data on world cancer rates, go to CANCERMondial, then click on Globocan 2002 (look towards the top right). Then, on the left navigation menu, there is a section called 'Graphs' and under that, an item called 'Cancer Map'. Click on Cancer Maps, and you will allow you to sort data by different criteria.
Lifestyle habits are at fault for much of the cancer occurrence in the industrialized world. Lung cancer for instance is linked quite strongly to smoking. An interesting piece of data however is the rate of smoking in one of these lesser developed nations, Thailand. An incredible 49% of the male population smokes cigarettes, and they almost all start smoking between the ages of 12 and 14. The smoking rate there has been high since WWII, so we have a long length of time for comparison to other cultures. The incidence of lung cancer in the United States for males is 61.9 per 100,000 persons in an age-standardized rate. For males in Thailand, the same age-standardized rate is only 25.5 per 100,000 of the population. The Thai people also have an average lifespan which is near that of the US, therefore they are living long enough for this type of cancer to predominate in their society. Source - Globocan 2002 data. It makes much sense to look at diet features in Thailand, and these other countries, which may be protective for cancers.
Graphs for combined cancer rates, world
I've taken three cultures with very low overall cancer rates, and made a comparison of foods between them. There are quite a few common foods and herbs or spices prevalent between them, and many of these are rarely used as food sources for Western industrialized nations. Where they are used, as in some of the spices common to these cultures, the amount used by Westerners are vastly smaller and less frequent in terms of intake. It seems imperative to enlarge on this information in the future by including other countries with low cancer rates in this comparison of food items.
A recent study published on chemopreventive agents in cancer therapy focused on foods common to the diet in India. This country has a much lower incidence of cancer than the U.S. Garlic, ginger, soy, cucurmin, onion, tomatoes, cruciferous vegetables, chillies, and green tea all play important roles in their diet. It is believed these foods may be able to suppress the processes which initiate carcinogensis, and may even suppress metastasis.
- Role of chemopreventive agents in cancer therapy. (pdf format: you need Adobe Acrobat Reader to view this)
Comprehensive Cancer Center, Our lady of Mercy Medical Center, New York Medical College, Bronx, NY;
Cytokine Research Section, Dept. of Bioimmunotherapy, The University of Texas M.D. Anderson Cancer Center, Houston, Tx
Comparison of the ways foods are prepared in India to the U.S. will show not only the difference in type of food, but also the large difference in quantity of spices included in their dishes. Indian cuisine frequently uses tablespoons of certain spices where a pinch is the equivalent of the same spice used in Western food preparation. A quick glance at some traditional Indian recipes will make this apparent.
Another important consideration in looking at foods uncommon in the Western world for cancer prevention finds support in a recent study showed surprising results for the 5-a-day recommendation for fruits & vegetables in the diet. Researchers at the Harvard School of Public Health have completed a longer than 10 year study on more than 100,000 participants. The results show that at least 5 servings a day of fruits and vegetables does have the effect of a 28% lower risk of heart disease than risk to people who ate less than 1.5 servings a day. However, cancer risk was not affected by this amount of fruits and vegetables eaten. Some of the possible reasons this study did not show an impact on cancers are that cancers take a long time to show up, so longer follow-up may show more benefit, or that the foods eaten in childhood were not followed, only the foods eaten during the course of the study. There is known data that certain fruits and vegetables are effective on specific cancers. Lumping all fruits and vegetables together might hide the benefits. They know that higher intake of tomato-based products has a positive effect on prostate cancers. Also they have evidence that the cruciferous vegetables (cauliflower, cabbage, broccoli, mustard & collard greens) have a protective association against cancer, but only in men. Whether the types of cancers that occur in men are more responsive to these specific vegetables than the cancers which occur in women, or not, is not known yet. Since the effect is positive for heart disease, and for maintaining lower body weight (healthy weight is another good protection against many cancers) with larger amounts of fruits and vegetables in the diet, there is no reason to eat fewer of them. But for cancer prevention, it seems necessary to look further.
- Fruit and vegetable intake and risk of major chronic disease.
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Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA.
