Friday, April 30, 2010

My Anti-Cancer Eating Plan

Our media rarely stop buzzing with reports about anti-cancer foods. Each time a study suggests that a particular berry, nut or spice may have anti-cancer properties, journalists hail it as a new wonderfood and everyone rushes out to buy it.

As a nutritionist, I welcome information that heightens the public’s awareness about healthy eating. However, when recommendations are contradictory they can become counterproductive.

After years of being told to eat five fruits and vegetables each day, health-conscious eaters were stunned to learn recently that these foods apparently offer only scant protection from cancer. (I will address this in a separate post.) Similarly, while some research suggests that soy food has a cancer-protective effect, other investigations haven’t backed this up. Indeed, some observers warn that soy foods, which contain estrogen-like compounds, may actually stimulate estrogen-sensitive tissues and could thereby promote, rather than prevent, cancer.

It’s not surprising, therefore, that many people feel overwhelmed when trying to figure out what they should eat to help prevent – or recover from – cancer. Indeed, some are so confused by contradictory reports that they stop believing anything they read in the press and revert to their old eating habits, as a recent survey showed.

When putting together my Anti-Cancer Eating Plan, therefore, I decided to base my program on the most unambiguous and reliable data I could find: the World Cancer Research Fund’s Expert Report published in 2007, which analyzes tens of thousands of studies into the food-cancer link and offers practical recommendations based on the findings.

At first sight, the WCRF’s recommendations may seem a little conservative. For instance, their researchers could not find clear evidence that soy, green tea or turmeric – widely touted as anti-cancer foods – are in fact cancer-protective. At best, the WCRF concluded, “there is limited evidence suggesting that pulses, including soy and soya products, protect against stomach cancer and prostate cancer”. Green tea and turmeric were mentioned only in passing. Note: the WCRF report does not say that we should not consume these foods; it simply notes that there is not enough evidence to say that they offer protection from cancer.

What appeals to me about the WCRF’s recommendations, however, is that they are realistic and achievable for almost anyone. For whilst anti-cancer diets involving exotic, unfamiliar or expensive ingredients may suit some people, most of us when faced with excessively challenging dietary change give up and go back to our previous eating habits. Smaller but realistic steps in the right direction may be more effective and sustainable than drastic changes that don’t last. Besides – to some people, implementing just one or two of the WCRF’s recommendations (below) will feel plenty drastic!

My Anti-Cancer Challenge Eating Plan will thus be based on the following dietary recommendations issued by the WCRF:
  • Avoid sugary drinks and limit consumption of energy-dense foods (particularly processed foods high in added sugar, or low in fiber, or high in fat)
  • Eat more of a variety of vegetables, fruits, whole grains, and pulses such as beans
  • Limit consumption of red meats (such as beef, pork and lamb) to no more than 500 g (cooked weight) per week, and avoid processed meats
  • If consumed at all, limit alcoholic drinks to 2 for men and 1 for women a day
  • Limit consumption of salty foods and foods processed with salt (sodium); do not eat more than 6 g salt per day (about 1 teaspoon)
  • Don’t use supplements to protect against cancer (exceptions being women planning to conceive (folic acid); vitamin-D-deficient people, and people whose low appetite (illness) or low calorie needs (the elderly) restrict their nutrient intake (a good multivitamin).
Other suggestions and practical tips from the WCRF include:
  • Balance your plate: 2/3 of your plate should be of plant origin and 1/3 of animal origin.
  • Fish is a healthy alternative to red meat; eat it regularly. Some limited evidence has shown it may help to protect against bowel cancer. 
  • Poultry (chicken, turkey, duck – skinless where possible) and other lean meats such as rabbit and venison are healthy alternatives to red meat.
  • Cooking methods: baking, boiling and steaming are healthy cooking methods; other high-temperature cooking methods may alter the make-up of foods, especially meat. It is prudent not to consume burned or charred foods frequently or in large amounts.
In order to tailor the Anti-Cancer Challenge Eating Plan to my family’s needs I added a few more items:
  • Dairy foods: The calcium in milk may protect against bowel cancer, but milk consumption has been linked to an increased risk of prostate cancer. Moreover, my daughter is allergic to cow’s milk. Therefore I limit cow’s dairy and consume only goat’s and ewe’s milk cheese and yoghurt.
  • Foods rich in omega-3: This essential fatty acid is thought to have anti-inflammatory and anti-cancer properties. I eat omega-3-rich foods daily; these include oily fish (sardines, mackerel, salmon, anchovies, herring), ground flax seed, green leafy vegetables, and eggs, meat and dairy from animals fed an omega-3-rich diet. I avoid large fish (tuna, shark, swordfish) because of their potential contamination by mercury or other marine pollutants.  
  • Green and white tea: epidemiological studies and laboratory studies in animals and on human cancer cells suggest that green tea may protect against cancer. Since I enjoy its taste, I drink two to three large cups of green or white tea daily.
  • Vegetables and fruits: I eat a wide variety of vegetables and fruits, including all members of the cabbage and onion families, mushrooms, red and blue berries, citrus fruit, sea vegetables and carotene-rich vegetables & fruits (e.g. tomatoes, carrots, melon, winter squash, etc). I eat at least 5 portions a day, but I'd like to increase that to 8 a day in the course of the Anti-Cancer Challenge.
  • Herbs and spices: I make copious use of fresh kitchen herbs that I grow in my garden or buy at the market (parsley, thyme, coriander, chives, basil, rosemary, oregano) and which are rich in anti-oxidants. I use many different spices such as turmeric, pepper, chili, cinnamon, coriander, cumin, cardamom, paprika, saffron and ginger. The copious use of herbs and spices is a great way of boosting the flavor of many dishes without needing to use salt.  
  • I eat seasonal, locally-grown foods: In order to obtain the freshest produce, protect the environment and support the local economy, I buy most of my food (about 75%) at the nearby farmers’ market and directly from local producers. If it’s not in season (e.g. tomatoes in January, cabbage in July) I don’t eat it. I grow some vegetables in my own vegetable patch.
  • About 80% of the meals I eat are prepared at home, from scratch: I do not buy prepared meals or processed ingredients except for plain vegetables in jars or cans (e.g. tomatoes, lentils, beans) and occasional condiments (e.g. pesto, ). All meals are eaten at a table, with all family members sharing the same meal. The television is off while we eat and I do not eat in front of the computer or while driving.
Overall, I am happy to say that I already do most of these things. I rarely eat red meat (about 150 g per week at most) and consume lots of vegetables and fruits and small amounts of whole grains. I drink only red wine (a glass with dinner on weekends), and use very little salt in my cooking. 

Not taking supplements will be interesting; for the past 10 years I have taken a pretty high-dose multivitamin supplement and fish oil capsules, and I am curious to see whether not taking these will make any noticeable difference to my health and well-being. No longer being able to rely on the "health-insurance effect" of my supplements will make it imperative that everything that enters my mouth is as nutritious as possible - no room for "empty calories". 

Do you have any dietary cancer-prevention advice that you would like to share with readers? All suggestions welcome!

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