Diet and Adult Leukemia Risk

Review of Cancer Epidemiol Biomarkers Prev 2002;11(8):777-781.

A study published in the journal Cancer Epidemiology Biomarkers & Prevention examined how diet and nutrition affect the risk of adult leukemia. The findings of this study indicate that people eating at least three to four servings of vegetables per day appear to have 44% lower risk when compared to people eating less vegetables. This article review discusses the findings of this study. We provide PRACTICAL information on what these findings mean. Most importantly, we provide ideas for using this information in a dietary plan to reduce risk of adult leukemia. Factors such as age and genetics cannot be changed, but diet and nutrition can. This type of information will allow people who are at risk of adult leukemia to take concrete and practical steps to decrease their risk of this disease.

Note: Numbers appearing at the end of sentences indicate research references. References are listed at the end of each article.

Background

Only a very small portion of adult leukemia is due to known risk factors, which include exposure to certain chemicals and radiation (1-5). This means that many unknown factors must account for the remainder of adult leukemia cases. This is why it is important that researchers continue to study this disease. A few studies have suggested that there may be a connection between what we eat and risk of adult leukemia (6-9). The latest and largest study on this topic, published in the journal Cancer Epidemiology Biomarkers & Prevention looked at the relationship between certain dietary factors and risk of adult leukemia (10). It is hoped that this type of research will identify diet and nutrition factors that may increase or decrease risk of this disease. Factors such as age and genetics cannot be changed, but diet and nutrition can. This type of information will allow people who are at risk of adult leukemia to take concrete and practical steps that may lower their risk of this disease.

What The Study Found

For this study (10), 35,221 women, ages 55 to 69 years, were asked about their diet and nutrition habits. This information was used to classify these women based on the amounts and types of foods they reported eating. Information on other important factors including weight history, health habits, medical history, and family medical history was collected and accounted for in the study. Researchers followed up with these women for a period of 14 years after collecting the initial diet information. Researchers determined who developed leukemia over this 14-year period. All of this information was analyzed to see if the women's diets appeared to be related to their risk of later developing leukemia. One positive result came out of this study.

The researchers found that women who ate about 18 to 28 servings of vegetables each week had 44% lower risk of leukemia when compared with women who ate less than 18 servings of vegetables each week. In other words, eating about two and a half to four servings of vegetables per day, on average, reduced risk of later developing leukemia by almost half.

What do these results mean?

If we assume that the women studied are similar to most women, then this study tells us that eating two and a half or more servings of vegetables each day may reduce risk of adult leukemia in women. Most of the women in this study were white, post-menopausal women living in Iowa. This means that we cannot get information from this research on diet and leukemia risk in non-white women and men. As well, this study cannot prove cause and effect, it only tells us that there is an association between eating vegetables and later developing leukemia. It is important to remember that an association is not causation (cause and effect).

Another concern is that the researchers only asked these women about their diet at one point in time. Sometimes diet changes over time. This might mean these results do not tell us about long term eating habits and their effect on risk of adult leukemia.

On a positive note, these findings do agree with at least one other study (8) that tells us that vegetables may be protective against adult leukemia.

How can I change my diet to reduce my risk of adult leukemia?

As mentioned, this study does not prove cause and effect, but it does tell us that eating vegetables may be one good way to reduce risk of adult leukemia. More positively, there are no down sides to eating more vegetables. Thousands of studies tell us over and over that eating more plant foods, including vegetables, fruit, legumes, and whole grains can reduce the risk of many types of cancer (11), as well as heart disease (12), the two biggest killers in the United States. So remember, regardless of the weaknesses of the research reviewed here (10), it does support a diet change that can be important for better health in many aspects! Not only may this change reduce risk of adult leukemia, but also it will improve health overall.

General Goals

This research tells us that it is important to eat at least two and a half servings of vegetables everyday. Eating four servings per day is an even better goal.

In summary, make it your goal to eat two and a half to four servings of vegetables every day.

What is a serving of vegetables?  

• 1 cup, loosely packed raw green leafy vegetables or 1/2 cup cooked greens
• 1/2 cup chopped of any other vegetable, cooked
• 6 oz of 100% vegetable juice (low sodium is a good option)

Tips On How To Eat More Vegetables

• Think about vegetables FIRST! Instead of picking meat, chicken or fish and deciding what to have with it, think about what VEGETABLE you want to have and plan your meal around that food.
• Try ethnic dishes such as stir-fries. This is a good way to focus on vegetables instead of meat. The bulk of a stir-fry is fresh, lightly cooked vegetables, with a little meat for flavor and protein.
• PLAN for how you will eat more vegetables. Eating more vegetables won't just happen, you have to make it happen.
  • Take baby carrots with you to work for a snack.
  • Prepare three to four days of chopped mixed vegetables such as green and red peppers, radishes, celery and baby tomatoes at a time. This makes it easier to eat these foods every day.
• Rely on frozen produce during the off-season. Frozen vegetables contain as many vitamins, minerals and other healthy nutrients as fresh, and sometimes even more! Frozen is a better option than canned - canned vegetables do not taste as fresh and often have added salt (sodium).
• Lightly steam your veggies. This method of cooking results in the healthiest food. Avoid boiling and other 'heavy' cooking methods because these decrease the vitamins, minerals and other nutrients in vegetables.
• Keep little 6 oz cans of low sodium vegetable juice handy for a quick serving of vegetables.
• Snack on baby carrots and humus; you get both vegetables and legumes (beans) with this snack.
• For a tasty salad, steam several cups of frozen or fresh vegetables (cauliflower, carrots, broccoli, Brussels sprouts), until tender and crisp; Add 1/4 to 1/2 cup of salad dressing; Mix well and refrigerate until chilled; Instead of store-bought salad dressings, try your own mix of balsamic or apple cider vinegar and olive oil.
• Improve the nutrition value of your family's favorite main dish casserole by adding one cup of frozen mixed vegetables.
• Stuff your favorite potato with antioxidant-rich toppings such as stewed tomatoes, green and red peppers, onions, broccoli, and low-fat or soy cheese. Try a sweet potato instead of a white potato and you get even more nutrition value. 
• Get acquainted with green leafies. Try adding a few leaves of kale, chard, mustard greens, collard greens, dandelion greens, or any other green leafy food to your regular salad. Try our recipes for Sweet Spicy Kale to get more green food into your diet.
• Replace snack foods (pretzels, chips, crackers, etc.) with vegetables & fruits. Purchase pre-chopped and pre-washed vegetables and fruit, if you are busy. These may cost more, but if you eat them, it is worth the investment in your health!
• Focus on variety; The more color you eat in your plant foods, the better. 
• Eat all colors of plant foods including orange, red, green, yellow, blue, purple, and dark green; Think of carrots, sweet potatoes, peppers, eggplant, kale, collard greens, spinach, etc.
• Try to have three-quarters of your plate covered by vegetables and other plant foods including fruit, whole grains and legumes.

Healthy & Easy Vegetable Recipes

Spicy Broccoli, Cauliflower, and Tofu Stir Fry

Super Carotene Smoothie

Sweet Spicy Kale

NOTE: If you are in cancer treatment, these diet changes may not be right for you.

References

1. Glass DC, Gray CN, Jolley DJ, Gibbons C, Sim MR, Fritschi L, Adams GG, Bisby JA, Manuell R. Leukemia risk associated with low-level benzene exposure. Epidemiology. 2003;14(5):569-77.

2. Beaumont M, Sanz M, Carli PM, Maloisel F, Thomas X, Detourmignies L, Guerci A, Gratecos N, Rayon C, San Miguel J, Odriozola J, Cahn JY, Huguet F, Vekhof A, Stamatoulas A, Dombret H, Capote F, Esteve J, Stoppa AM, Fenaux P. Therapy-related acute promyelocytic leukemia. J Clin Oncol. 2003;21(11):2123-37.

3. Shilnikova NS, Preston DL, Ron E, Gilbert ES, Vassilenko EK, Romanov SA, Kuznetsova IS, Sokolnikov ME, Okatenko PV, Kreslov VV, Koshurnikova NA. Cancer mortality risk among workers at the Mayak nuclear complex. Radiat Res. 2003;159(6):787-98. 

4. Bhavnani M, Azzawi SA, Yin JA, Lucas GS. Therapy-related acute promyelocytic leukaemia.
Br J Haematol. 1994;86(1):231-2.

5. Linet MS, Cartwright RA. The leukemias. In: Schottenfeld D, Fraumeni JF, Jr., eds. Cancer Epidemiology and Prevention. 2nd ed. New York, NY: Oxford University Press; 1996:841-892.

6. Visani G, Baravelli S, Tosi P, Manfroi S, Remiddi C, Tura S. Slimming diet and the development of acute leukemia: a possible relationship? Report of three cases. Leuk Lymphoma. 1997 Jun;26(1-2):181-3.

7. Hursting SD, Margolin BH, Switzer BR. Diet and human leukemia: an analysis of international data. Prev Med. 1993 May;22(3):409-22.

8. Kwiatkowski A. Dietary and other environmental risk factors in acute leukaemias: a case-control study of 119 patients. Eur J Cancer Prev. 1993;2(2):139-46.

9. Middleton B, Byers T, Marshall J, Graham S. Dietary vitamin A and cancer--a multisite case-control study. Nutr Cancer. 1986;8(2):107-16.

10. Ross JA, Kasum CA, Davies SM, Jacobs DR, Folsom AR, Potter JD. Diet and risk of leukemia in the Iowa Women's Health Study. Cancer Epidemiol Biomarkers Prev 2002;11(8):777-781.

11. World Cancer Research Fund. Food, Nutrition and the Prevention of Cancer: a global perspective. Washington, DC: American Institute for Cancer Research; 1997.

12. Srinath Reddy K, Katan MB. Diet, nutrition and the prevention of hypertension and cardiovascular diseases. Public Health Nutr. 2004;7(1A):167-86.

Publish Date: 02/2004