We've known for many years that consuming copious amounts of certain specific fruits and vegetables reduces our risk of developing various types of cancer. But a recent study reminds us that this protective effect is not linked to all fruit and vegetables. Some foods contain larger amounts of anticancer molecules. Thus we need to be attentive to our choices.
Lifestyle and Cancer:
Cancer is not a disease whose origin is principally genetic, as many people continue to believe. It is a pathology that is closely linked to a range of lifestyle factors, particularly smoking and obesity (which stems from our sedentary habits and our dietary choices). Several studies have shown a direct link between the regular consumption of certain fruits and vegetables and a reduction in risk of developing various types of cancer.
Protective studies showing links between consumption of specific foods and the incidence of cancer in human populations:
Source: Beliveau, Gingras, Blaslyk, Eating Well, Living Well: An Everyday Guide for Optimum Health
It's particularly important to specifically include these in our diet, because not all fruits and vegetables share the same potential for active prevention against cancer. There are major differences in their levels of anticancer components. In some cases the phytochemical components that provide the greatest cancer-preventing activity are present only in a few, very specific fruits and vegetables. For example, the isoflavones of soy, the resveratrol of grapes, the curcumin of turmeric, the isothiocyanates and indoles of broccoli and the catechins of green tea are all anticancer molecules whose distribution among plants is extremely restricted.
In other words, even though all fruits and vegetables are an integral part of a balanced diet, only some of them can truly influence the risk of cancer.
Quality, Not Quantity
The importance of including these foods in our diet is fully illustrated by results of studies that examine the global risk of cancer according to the total quantity of fruit and vegetables consumed, without regard for specific types. For example, a study of more than 100,000 American health professions did not establish that total consumption of fruit and vegetables was linked to a reduction in the risk of cancer (1). However, within this same population researchers have observed a significant reduction in the risk of bladder cancer in men who consumed large amounts of cruciferous vegetables (2), and a significant reduction in the risk of prostate cancer following regular consumption of tomato-based products (3). A European study of 400,000 people has just produced similar results. Total consumption of fruit and vegetables is not associated with a significant reduction in the total risk of cancer (4). However, results previously obtained from this same population show that certain fruits (particularly citrus fruit) considerably reduce the risk of stomach cancer (5).
These observations indicate that the development of various types of cancer is modulated differently by the specifics of the fruits and vegetables consumed, rather than by the quantity of overall consumption. This is very important, because in the United States fully half the fruit and vegetables consumed are relatively poor in protective impact (potatoes, iceberg lettuce, canned tomatoes), while the per capita consumption of plants rich in anticancer molecules -- such as cruciferous vegetables -- is barely 1 %. Increased consumption of foods that contain high amounts of anticancer molecules (cabbage family, garlic family, green tea, small fruit, citrus fruit, tomatoes and carrots), and which are thus able to target several distinct processes essential to the growth of cancer cells, is absolutely essential in order to reduce significantly the risk of certain cancers.
All fruits and vegetables are excellent for overall health. They protect, for example, against cardio-vascular disease. But in the case of cancer, we continue to emphasize that their protective effects are specific to certain fruits and vegetables.
Richard Beliveau Ph.D. and David Servan-Schreiber, M.D., Ph.D
Dr. David Servan-Schreiber wrote the best-selling Anticancer, A New Way of Life.
He regularly posts Anticancer research & insight on his Facebook Page & Twitter Account
Visit Anticancerbook.com for the complete Anticancer Lifestyle Guide
Richard Beliveau Ph.D. wrote Foods to Fight Cancer: Essential foods to help prevent cancer
Sources:
(1) Hung HC et al. Fruit and vegetable intake and risk of major chronic disease. J Natl Cancer Inst. 2004; 96:1577-84.
(2) Michaud DS, Spiegelman D, Clinton SK, Rimm EB, Willett WC, Giovannucci EL. Fruit and vegetable intake and incidence of bladder cancer in a male prospective cohort. J Natl Cancer Inst. 1999 ; 91: 605-613.
(3) Giovannucci E et al. A prospective study of tomato products, lycopene, and prostate cancer risk. J Natl Cancer Inst. 2002 ; 94: 391-398.
(4) Boffetta et al. Fruit and vegetable intake and overall cancer risk in the European Prospective Investigation into Cancer and nutrition (EPIC). J Natl Cancer Inst. 2010; 102:1-9
(5) Gonzalez CA et al. Fruit and vegetable intake and the risk of stomach and oesophagus adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST). Int J Cancer. 2006; 118: 2559-66
Follow David Servan-Schreiber, M.D., Ph.D. on Twitter: www.twitter.com/servanschreiber
http://graciouslivingdaybyday.com/
Moreover, how many comparisons were made, and how many studies were there that did not show a connection? Discussions of diet and health seem rife with type 1 errors, and people with with axes to grind ready to seize on them.
That said, almost all medical professionals recommend a diet rich in fruits and vegetables, and T. Colin Campbell, in one of the largest studies of the effect of nutrition on health - The China Study - demonstrates strong correlation between increase in consumption of animal protein with increases in diseases of affluence, namely cancer, diabetes, obesity and heart disease. So eating a plant-based diet with a variety of fruits and veggies is the best course. And lay off the animals - it's not only good for your health, it's good for the environment, and of course, for the animals!
A basic problem with large studies like the China Study-- a problem that is almost never discussed-- is that 100% of the population will die, of something. Decreasing one cause of death is a net gain only if there is not a corresponding increase in another cause. In the western world it is approximately true that if you are over 60 you will die of either cardiovascular disease or cancer. Reducing your odds of getting one increases the odds you will get the other-- and VICE VERSA: it seems perfectly possible that a carcinogen could show up as protective against heart disease, for example. I'm not sure that it's possible to fully correct for this effect with statistics.
The overall picture that is emerging from studies of diet and health is that most people in western societies can expect only very modest health benefits even from extreme modifications of their diet.
"A huge nine-year study of diet and cancer, involving nearly a half-million Europeans in 10 countries, finds only a very weak association between intake of fruits and vegetables and cancer incidence. The study is in the current issue of the Journal of the National Cancer Institute."
http://www.npr.org/blogs/health/2010/04/fruits_and_veggies_prevent_can.html
No, that's not what the study says. And you say it in your own post:
> finds only a very weak association between intake of fruits and vegetables and cancer incidence
From the article:
"Those who get an extra two servings of fruits and veggies a day lower their cancer risk by only four percent. "
4% may be small, but it's not "none." And if you read it further, you'll see they lump all people against all cancers, rather than specifics.
In the same thread as mssreader above, what is the effect of REMOVING certain foods from diet, rather than adding? Two extra f/v servings a day can't counteract possible carcinogens in other foods.
Many fruit and vegetables may improve transit times and stool weights. Reduced stool weights and prolonged transit times typical of Western societies result in physical efforts during defecation and injuries to autonomic nerves - often at T1-2 (chest) and T10-L2 (pelvis) that supplies everything from splenic flexure of the colon to the anus as well as the pelvic contents. We know that 20-30% of adult Western bowel movements are preceded by straining 0 oftern every day of the month before a successful outcome is achieved (0.3% only achieve once per month).
IF the primary preganglionic injury to the autonomic nerves is the initiator then this may take place many years before the onset of disease. Also the co-contents of the "poor" Western diets may contribute e.g. dairy products (www.janeplant.com) There is much to consider in this question.
http://www.westonaprice.org/Plants-Bite-Back.html
Let's take the nightshade family, which includes tomatoes. For some people, the anti-nutrients in nightshades can cause symptoms from pain to nasopharyngeal carcinoma and stomach cancer.
For a review of the subject, see: http://www.westonaprice.org/Nightshades.html
Let's move on to the brassica family, including broccoli, cauliflower and cabbage. They are potent goitrogens that can interfere with thyroid function, leading to a host of illnesses, and have caused thyroid cancer in animals. See:
http://www.westonaprice.org/Bearers-of-the-Cross-Crucifers-in-the-Context-of-Traditional-Diets-and-Modern-Science.html
Then there is the phytic acid in nuts, beans and seeds that can wipe out your mineral balance, and the oxalates in spinach and soy that can cause kidney stones and worse.
For a further discussion and references on what nature did intend humans to eat, see "The Original Diet."
Roy Mankovitz, Director
http://www.MontecitoWellness.com
Please don't present anything from the Weston Price Org. as scientifically proven- it is just one other fad diet...
I wish you the best of health.
the more fruit and vegatables anyone eats the more healthy they will be/
period.
I wish you the best of health.