“Obesity is a complex disorder involving an excessive amount of body fat. Obesity isn’t just a cosmetic concern. It increases your risk of diseases and health problems, such as heart disease, diabetes and high blood pressure. Being extremely obese means you are especially likely to have health problems related to your weight. The good news is that even modest weight loss can improve or prevent the health problems associated with obesity. Dietary changes, increased physical activity and behavior changes can help you lose weight.” Mayo Clinic.
I want you to note that according to the Mayo Clinic, obesity is a complex disorder. Cancer patients know that weight gain, even obesity, can be due to chemotherapy, steroids & the cancer itself. Obesity is also linked to genes, environmental factors, inactivity, stress, depression, unhealthy diet, individual behavior & lifestyle choices.
Today I will be discussing cancer risk & risk of re-occurrence linked to dietary obesity. Obesity is either measured by your Body Mass Index~BMI~and/or your waist measurement. Simply put you are taking in more calories than you expend with exercise.
Measure your waist by placing the tape measure about an inch above your belly button. For women, a healthy waist measurement is less than 31.5 inches, and for men, it’s less than 37 inches.
Obesity is diagnosed when your body mass index (BMI) is 30 or higher. Your body mass index is calculated by dividing your weight in kilograms (kg) by your height in meters (m) squared. This chart is easier to check than doing all that math 🙂
***BMI doesn’t know the difference between body fat & muscle. Muscular athletes would be under the obese category. Children, pregnant women, & nursing mothers can’t use this chart either.
Check with your doctor before deciding you are at risk.
We know that about one third of the most common cancers can be prevented through diet, maintaining a healthy weight and exercise.
Why is excess body fat linked to cancer? It is difficult to design a research study involving obesity & cancer risk. The diet chosen for the control group will have a major affect on the cancer risk as well as the participants lifestyle choices. It is important to understand what type of research is being used; most studies are observational.
Observational studies Here researchers observe the effect of a risk factor, diagnostic test or treatment without trying to influence what happens. Such studies are usually “retrospective” — the data are based on events that have already happened. Most workplace health research falls into this category.
Cohort study: For research purposes, a cohort is any group of people who are linked in some way and followed over time. Researchers observe what happens to one group that’s been exposed to a particular variable — for example, the effect of company downsizing on the health of office workers. This group is then compared to a similar group that hasn’t been exposed to the variable.
Case control study: Here researchers use existing records to identify people with a certain health problem (“cases”) and a similar group without the problem (“controls”).
Results from observational studies have given scientists enough information to state that there is a link. The NCI has published the following:
The National Cancer Institute states: “Several possible mechanisms have been suggested to explain the association of obesity with increased risk of certain cancers:
- Fat tissue produces excess amounts of estrogen, high levels of which have been associated with the risk of breast, endometrial, and some other cancers. Dairy, organic & raw included, has estrogen & your body would store the excess in body fat.
- Obese people often have increased levels of insulin and insulin-like growth factor-1 (IGF-1) in their blood (a condition known as hyperinsulinemia or insulin resistance), which may promote the development of certain tumors. Dr. Hyman has discussed insulin resistance as a problem for all chronic diseases. I recommend reading this article. Just click on his name.
- Fat cells produce hormones, called adipokines, that may stimulate or inhibit cell growth. For example, leptin, which is more abundant in obese people, seems to promote cell proliferation, whereas adiponectin, which is less abundant in obese people, may have antiproliferative effects.
- Fat cells may also have direct and indirect effects on other tumor growth regulators, including mammalian target of rapamycin (mTOR) and AMP-activated protein kinase.
- Obese people often have chronic low-level, or “subacute,” inflammation, which has been associated with increased cancer risk.” This last bullet point is about chronic inflammation in the body. We have talked about this and the importance of a plant based, anti-inflammatory diet.
Does weight loss influence cancer risk & re-occurrence? A limited number of observational studies have looked at the connection between weight loss and cancer risk. They have found decreased risks of breast cancer and colon cancer among people who have lost weight. The problem with this type of study is that they were not able to distinguish between intentional weight-loss and weight-loss due to the participants other health problems. For example: diabetes, heart disease, & dietary sensitivities.
An important study from UCSD : Diet and Exercise Key to Surviving Breast Cancer, Regardless of Obesity “We demonstrate in this study of breast cancer survivors that even if a woman is overweight, if she eats at least five servings of vegetables and fruits a day and walks briskly for 30 minutes, six days a week, her risk of death from her disease goes down by 50 percent,” said the paper’s first author, John Pierce, Ph.D., director of the Cancer Prevention and Control Program at the Moores UCSD Cancer Center. “The key is that you must do both.” This study has led UCSD to continue with other studies for weight loss & cancer. If you are interested in participating in future studies with UCSD: Healthy Eating Program Research Studies lists links.
Now you know the health risks of being obese & even overweight. If you are a cancer survivor or a person interested in decreasing the risk of cancer here are some questions you should be asking. How do you SAFELY lose weight? How do you MAINTAIN your weight loss or your present healthy weight? Come back next week & I will answer both questions & more!
In the meantime here is an excellent article chronicling the changes in American women’s body image for the last 100 years. This is well worth reading. Share the article with women you know: friends, daughters & granddaughters!
WOMEN’S BODY IMAGE AND BMI~100 years in the U.S. “By the end of the 20th century, female beauty standards in America have remained unrealistic and extreme, with popular images of thinness being more out-of-reach for the average woman than ever before. This trend has been reflected in many first-world nations, although women in certain developing nations lack this widespread anxiety over their weight.”
Until next week!…..Mary
Additional resources for this post:
- Cancer Research UK
- Obesity & Cancer PDF ASCO
- American Institute for Cancer Research
- World Cancer Research Fund International
- Mayo Clinic: Obesity