Overweight, Obesity, and Leukemia Risk

Overweight, Obesity, and Leukemia Risk

Review of Cancer Epidemiol Biomarkers Prev. 2004;13(11 Pt 1):1810-13.

A study in the journal Cancer Epidemiology, Biomarkers & Prevention looked at the connection between being overweight or obese (significantly overweight) and risk of leukemia in adult women. This study suggests that women who are overweight or obese have a significantly greater risk of a type of leukemia known as acute myelogenous leukemia (AML). We provide practical information on what these results mean. We provide ideas for how this information can be incorporated into a dietary plan aimed at helping you maintain a healthy body weight. These dietary changes can be used to focus on the goal of minimizing cancer risk, including risk of leukemia.

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

Background

The number of people in the United States who are overweight or obese (significantly overweight) has increased dramatically in the past few decades (1). This is a serious problem because being overweight or obese can greatly increase the risk of heart disease, high blood pressure (hypertension), diabetes, stroke, pulmonary dysfunction, deep vein thrombosis, poor wound healing, osteoarthritis, and many other serious conditions (2-8). Studies tell us that overweight and obesity increase the risk of many common cancers as well, such as cancers of the breast, prostate, and colon (9-19).

The possible connection between obesity and less common cancers, such as leukemia, is not as well studied (20). In addition to this, only a very small portion of adult leukemia is due to known risk factors, which include exposure to certain chemicals and radiation (21-25). This means that many unknown factors must account for the remainder of adult leukemia cases. For this reason, it is important that researchers continue to study the potential causes of leukemia. A study in the journal Cancer Epidemiology, Biomarkers & Prevention looked at the connection between being overweight or obese (significantly overweight) and risk of leukemia in adult women (26).

What The Researchers Studied

For this study (26), the researchers used information on height and weight that they had collected on a health questionnaire from 37,627 healthy women. Information on other important health-related factors including tobacco and alcohol use (smoking & drinking), history of diabetes, diet, and physical activity (exercise) was collected and accounted for in the study.  

The researchers used a measure called Body Mass Index to determine who was overweight and obese in this group of women. Body Mass Index (BMI) is a way to measure body weight, while taking into account a person's height. For this reason, BMI is better than simple body weight for telling us whether or not a person is overweight or obese. Health experts believe that a BMI of 25 kilograms per meter squared (kg/m2) or higher means a person is overweight. A BMI of 30 kg/m2 or higher means a person is obese (27). On average, being 30 lbs or more over ideal body weight will place a person into the obese category.

To determine your BMI, please see our Body Mass Index Calculator.

The researchers followed these women for an average of 14.3 years to see who developed leukemia and whether the risk of this disease was related to being overweight or obese (significantly overweight).

What The Study Found

First, the researchers found that women who were overweight had a 60% increased risk (1.6 times the risk) of leukemia when compared to women who were of normal weight. In other words, women who had a Body Mass Index (BMI) in the range of 25 to 29.9 kg/m2, which is classified as being overweight, had a 60% greater likelihood of developing leukemia when compared to women who were not overweight.

Second, the researchers found that women who were obese also had a 60% increased risk (1.6 times the risk) of leukemia when compared to women who were of normal weight. In other words, women who had a Body Mass Index (BMI) of 30 kg/m2 or higher, which is classified as being obese, had a 60% greater likelihood of developing leukemia when compared to women who were not overweight.

Third, when the researchers looked at the risk of two major forms of leukemia separately, they found that being overweight or obese greatly increased risk of one particular type of leukemia known as acute myelogenous leukemia (AML). 

Women who were overweight had a 90% increased risk (1.9 times the risk) of AML when compared to normal weight women. In other words, women who had a Body Mass Index (BMI) in the range of 25 to 29.9 kg/m2, which is classified as being overweight, had an increased risk of a type of leukemia known as AML.

Women who were obese had nearly two and a half times the risk (2.4 times the risk) of AML when compared to normal weight women. In other words, women who had a Body Mass Index (BMI) of 30 kg/m2 or higher, which is classified as being obese, had a greatly increased risk of a type of leukemia known as AML.

What do these results mean?

If the women in this study are like most women, this study tells us that being overweight or obese can increase the risk of leukemia. Specifically, being overweight or obese appears to increase the risk of a type of leukemia known as acute myelogenous leukemia (AML).

One concern with this type of research is that the results cannot prove cause and effect. The study only tells us that there is an association between being overweight or obese and increased risk of leukemia. It is important to remember that an association is not causation (cause and effect).

Also remember that the researchers did not directly measure the height and weight of the women in the study. They had these women fill out questionnaires and it is possible that some of the women did not report their height and weight accurately. This could affect the results of the study.

However, on a positive note, this is a very large study and several other important health factors were also taken into consideration when the researchers looked at the connection between body weight and risk of leukemia. As well, the results of this study do agree with other research that tells us that being overweight or obese may increase the risk of leukemia in both women and men (28-32).

In summary, the study reviewed here has some flaws, but it does provide more support for the connection between overweight, obesity and risk of leukemia. More importantly, there are NO downsides to maintaining a healthy body weight! There are many downsides to being overweight and obese.

Taking Control To Reduce Cancer Risk

Use the following guidelines to get started on making your better health a priority today.

Examine Your Risk

Look at your current height and weight and be honest with yourself about whether you are overweight or obese. This may be harder than it sounds!

Researchers have found that many overweight and obese adults do not know that they are above a healthy body weight (33-35). This means they may not even realize that their health is at risk!

This is the first step to managing weight and improving health, including reducing cancer risk! How do you know if you're overweight or obese? You can use a measure called Body Mass Index (BMI). BMI is a way to measure body weight, while taking into account a person's height. 

To determine your BMI, please see our Body Mass Index Calculator.

• If your BMI is 25 kilograms per meter squared (kg/m2) or higher, you are overweight.
• If your BMI is 30 kg/m2 or higher, you are obese.

Find A Supportive Health Care Provider!

This is one of the most important things you can do to help yourself succeed. Research tells us that many health care providers have a very negative view of men and women who are obese (36). When you want to lose weight and improve your health, the last thing you need is a health care provider who is critical and unsupportive!

• Talk to your doctor honestly about your desire to lose weight and improve your health.
• Tell him or her that you would like help with your goals.
• Ask for a referral to a weight loss specialist such as a Registered Dietitian.
• If your doctor is not supportive of your goals or places the focus on blaming you for being overweight, consider finding a more supportive health care provider.

Modify Your Views & Goals

One of the most important things you can do to increase your chances of success with weight loss is to view these changes as A GIFT!

• Losing weight to improve your health is NOT a punishment. It is a gift.
• Realize that weight loss won't be easy, but when you succeed, you will feel better, you will have a better quality of life, you will decrease your risk of many serious diseases, and you will live longer!
• This is a gift to you, but it is also a gift to your family and friends. Anyone who cares about you will benefit from the gift of health that YOU give yourself by maintaining a healthy body weight!
• Make your goal IMPROVED health, NOT 'looking better'. While improvements in appearance are a great benefit of weight loss, focusing on the HEALTH benefits of weight loss will help you meet your goals today and for the longterm!
• Health benefits include ANYTHING that will help motivate you. This can include sleeping better; having less joint & muscle pain; having more energy; lowering your risk of cancer, heart disease, high blood pressure, diabetes, stroke and other serious conditions; improving your sense of well being and self-image; and just about any other health improvement you can think of. Weight loss will help with all of these goals!!

Eliminate High Calorie/Low Nutrition Foods

New research is telling us that certain parts of our diet might be contributing a lot to the problem of obesity. One potential obesity contributor is high fructose corn syrup. Studies tell us that the eating a lot of high fructose corn syrup may be making the obesity problem worse (37,38).

What is high fructose corn syrup?

High fructose corn syrup is a sweetener found in many commonly eaten foods and beverages. One of the biggest contributors to the higher levels of high fructose corn syrup in our diets is soda pop. There are many other sources of high fructose corn syrup too. To address this problem...

• DROP THE POP habit. Soda pop is nearly pure high fructose corn syrup. This includes both 'brown' and 'clear' regular soda pops.
• Let me say that again. DROP THE POP habit. Regular soda pop is nothing but PURE sugar, in particular, high fructose corn syrup. Worse yet, it is liquid, which means it affects your body more quickly than sugar in foods.
• When you switch from regular soda pop to water, decrease the amount of soda pop you drink slowly. This will help prevent symptoms of caffeine withdrawal, such as headaches.
• If you do not like plain water, try carbonated water that does not contain high fructose corn syrup. Look at the label. If the water contains calories, PUT IT BACK. Instead pick a brand that does not contain calories. Plain, flavored or carbonated water will not contain calories.
• Small amounts of diet sodas are ok, but they do not add anything of nutritional benefit to your diet. For this reason, think of a diet soda as a treat, not a daily necessity.
• Other sources of high fructose corn syrup include fruit punches (6 ounces of 100% fruit juice is ok to count as one serving of fruit per day); baked goods such as doughnuts, cookies, cakes, candy bars, hard candy, and other desserts; jams; jellies; sauces and dressings; and many other highly processed foods such as instant meals and snack foods.
• What are highly processed foods? Think of foods that are as close to their 'natural form' as possible, such as fresh vegetables and fruit. Now think of a more processed food, for example, a corn chip. A corn chip is made of corn, but it's NOT a whole food, it is highly processed! To make a corn chip, first the corn is picked, then ground and crushed. Next the fiber portion of the corn is thrown out. Then the corn is fried in processed fat (hydrogenated fat). Next it is treated with artificial flavors, dyes, and preservatives. This hardly looks like corn anymore!
• Now think of corn on the cob. It is picked, shipped, and ends up on your dinner table! It is not processed. It is a WHOLE food. The less processing that a food undergoes before you eat it, the better it is for you.
• Make dessert an OCCASSIONAL treat. There is nothing wrong with having a sweet treat now and then. Just make sure 'now and then' only means 2-3 times per week.

Watch Portion Sizes

• If you do eat in restaurants, watch your portion sizes! Instead of eating everything on your plate, try asking for a 'to go' box at the BEGINNING of your meal. Place a portion of the food into the 'to go' box and then enjoy the rest of your meal.
• When eating at home, try measuring your portion sizes for a while. For example, a serving of pasta is 1/2 cup cooked. Try measuring this out to see what it looks like. If you want more than one serving, this can be ok, just be sure you KNOW you are eating more than one serving. Sometimes, just being aware of what you are eating can help you make better choices.

Get Moving

• Talk to your health care provider about a good exercise plan for you.
• Be sure you receive clearance from your doctor BEFORE beginning an exercise plan!!
• Exercise plans do not have to be fancy or very hard. Simply taking a long, brisk walk each day can be enough to aid with weight loss and make you healthier.
• Find an exercise buddy such as a family member or co-worker. It is harder to skip exercise when you plan to meet someone for it.
• Schedule exercise, even 10 minutes, into your day. WRITE IT on your calendar. If you don't make time for it, you won't do it.

More Tips For Maintaining A Healthy Weight  

The first thing to remember is that weight loss is not easy. Don't be hard on yourself if you've struggled with maintaining a healthy weight. This is a health concern for many people. If you've tried to lose weight in the past and have not succeeded, don't give up! Just because you haven't met your weight loss goals in the past does not mean you won't be able to succeed this time!

Many, many people struggle with weight loss. Nobody is immune from the difficulty of making healthy food choices when confronted with fast food restaurants and vending machines! However, by changing the way you think about food and health and improving a few habits, you CAN succeed at weight loss. Use the tips below to get started on the road to maintaining a healthy body weight.

• Consult with a Registered Dietitian (RD) or receive support from a weight loss organization such as Weight Watchers©. Either of these approaches will work to help you develop a sensible and successful weight loss plan. 
• Be sure you think about weight loss and healthy eating as a lifestyle rather than a temporary diet. This is important! For long-term weight loss success, you must change your eating and exercise habits permanently.
• For basic tips and ideas on getting started with healthy weight loss see the Prevent Weight Gain patient education material in the Customized Patient Education section. 

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

References

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Publish Date: 12/2004