Fibroid Risk Factor: Obesity
Alicia Armeli, MSEd, MSN, RDN, CHLC

ObesityBlog

Uterine fibroids are the most common tumor among women in their reproductive years with some studies reporting 20-80% of women developing fibroids by age 50.1,2 Given the widespread prevalence of these tumors, it’s important to be familiar with the risk factors involved.

Women who possess a hereditary link, who are African American, or who are within their reproductive years are at an increased risk for developing fibroids.2 Although we have no control over things such as our DNA or the number of candles on our birthday cake, there’s a risk factor that wasn’t mentioned; one that’s considered preventable—obesity.

Obesity and the Risk of Uterine Fibroids
According to the US Department of Health and Human Services, obesity refers to excess fat on the body. A person’s body mass index (BMI) is used to measure whether an individual’s weight correlates with his or her height. When a person has a high BMI, or is considered obese, it’s most commonly linked to the amount of fat on his or her body.3

The risk of uterine fibroids is two to three times greater in women who are obese.2
Studies have found that women with higher BMIs—particularly carrying excess fat in the abdominal area and having a body fat percentage of over 30%—were at an increased risk for fibroids.1

What Is the Connection Between Excess Fat and Fibroids?
Uterine fibroids are believed, in part, to be a hormone-related disease.4 Rates of uterine fibroids are seen to decline after menopause but some studies report that fibroids afflict women of all ages and more so in those who are obese—even after menopause.4,5

Obesity has been linked to higher rates of circulating estrogen and its production.6 For example, in premenopausal women, anovulatory menstrual cycles can happen more frequently. This causes prolonged amounts of time where estrogen is present without the compensatory effects of progesterone.7

Additionally, in obese individuals there’s found to be less serum hormone-binding globulin (SHBG) proteins that attach to sex hormones. When this occurs, it leaves more estrogen to circulate unbound and active. Obesity can also cause changes in estrogen metabolism and disruption in the communication between cells in the uterine wall, both of which can cause abnormally high estrogen levels.8

After menopause, obesity increases the amount of circulating estrogens due to estrogenic hormones produced by excess fat tissue.7

This definitely poses a problem but the solution also lies within.

What Can I Do?
Even a small amount of gradual weight loss, approximately 5-10% of your body weight, has been seen to lower the risk of chronic disease. This means if you weigh 200 pounds, losing 10-20 pounds could make a world of difference in the realm of prevention.9

Could it also help to decrease estrogen levels? A study published in the Journal of Clinical Oncology observed whether a weight-loss diet, an exercise plan, or combined diet and exercise would have any effect on estrogen and SHBG levels among postmenopausal women.10

Results showed after one year, diet was clearly effective but diet and exercise combined had the greatest effect on weight loss and hormone levels. Average weight loss with diet and exercise together saw an 11.9% reduction. Estrone and estradiol levels decreased by 11.1% and 20.3% respectively. Moreover, SHBG levels increased 25.8%. The authors of the study concluded that losing more weight had a greater effect on hormone levels.10

Slowly making small lifestyle changes can help with weight loss, uterine fibroid relief, and overall wellness. Talk to your doctor today about how healthy and sustainable weight loss can help you take control.

ABOUT THE AUTHOR Alicia Armeli has a Master of Science in Nutrition and Whole Foods Dietetics (MSN/DPD) and is a registered dietitian nutritionist, a certified dietitian, and a holistic life coach. In addition to writing, she enjoys singing, traveling abroad, and volunteering with her local animal shelter.

REFERENCES

1. Yang, Y., Yuan, H., Zeng, Q., & Li, S. Association of body size and body fat distribution with uterine fibroids among Chinese women. Journal of Women’s Health, 23(7): 619-626. doi:10.1089/jwh.2013.4690
2. US Dept of Health and Human Services, Office on Women’s Health. (2015). Uterine Fibroids Fact Sheet. Retrieved April 14, 2015, from http://www.womenshealth.gov/publications/our-publications/fact-sheet/uterine-fibroids.html?from=AtoZ
3. US Department of Health and Human Services, National Institute of Diabetes and Digestive and Kidney Diseases. (2012). Overweight and Obesity Statistics. Retrieved April 14, 2015, from http://www.niddk.nih.gov/health-information/health-statistics/Pages/overweight-obesity-statistics.aspx
4. Khan, A. T., Shehmar, M., & Gupta, J. K. (2014). Uterine fibroids: current perspectives. International Journal of Women’s Health, 6: 95-114. doi: 10.2147/IJWH.S51083
5. Sommer, E. M., Balkwill, A., Reeves, G., Green, J., Beral, D. V., & Coffey, K. (2015). Effects of obesity and hormone therapy on surgically-confirmed fibroids in postmenopausal women. European Journal of Epidemiology. doi 10.1007/s10654-015-0016-7
6. Sarwer, D. B., Spitzer, J. C., Wadden, T. A., Rosen, R. C., Mitchell, J. E., Lancaster, K., Courcoulas, A., Gourash, W., & Christian, N. J. (2013). Sexual functioning and sex hormones in persons with extreme obesity and seeking surgical and non-surgical weight loss. Surgery for Obesity and Related Diseases, 9(6). doi: 10.1016/j.soard.2013.07.003
7. Van den Bosch, T., Coosemans, A., Morina, M., Timmerman, D., & Amant, F. (2012). Screening for uterine tumours. Best Practice & Research Clinical Obstetrics & Gynaecology, 26(2): 257-266.
8. He, Y., Zeng, Q., Dong, S., Qin, L., Li, G., & Wang, P. (2013). Associations between uterine fibroids and lifestyles including diet, physical activity and stress: a case-control study in China. Asia Pacific Journal of Clinical Nutrition, 22(1): 109-117.
9. Centers for Disease Control and Prevention. (2011). Losing Weight. Retrieved April 15, 2015, from http://www.cdc.gov/HEALTHYWEIGHT/LOSING_WEIGHT/INDEX.HTML
10. Campbell, K. L., Foster-Schubert, K. E., Alfano, C. M., Wang, C., Wang, C., Duggan, C. R., Mason, C., Imayama, I., Kong, A., Xiao, L., Bain, C. E., Blackburn, G. L., Stanczyk, F. Z.,  & McTiernan, A. (2012). Reduced-calorie dietary weight loss, exercise, and sex hormones in postmenopausal women: randomized controlled trial. Journal of Clinical Oncology, 30(19): 2314-2326. doi:  10.1200/JCO.2011.37.9792