Understanding Weight Loss and Cancer
- Weight loss injections like Ozempic (semaglutide), Wegovy, (semaglutide), and Zepbound (tirzepatide) are continuing to gain popularity—however worries about about cancer and public health continue to grow.
- The Centers for Disease Control and Prevention (CDC) says, “Being overweight or having obesity are linked with a higher risk of getting 13 types of cancer.” Some of these cancers include breast, colon, ovarian, and stomach (gastric).
- The National Cancer Institute (NCI) says fat tissue “produces excess amounts of estrogen,” which is associated with an increased risk of certain cancers, including breast, ovarian, and endometrial cancer. Obesity is associated with high levels of insulin, which can lead to colon, kidney, prostate, and endometrial cancer.
Various drugs used for weight loss exist, including Nova Nordisk’s semaglutide—sold under brand names Ozempic, Weygovy, and Rybelsu—and Tirzepatide, sold under the brand names Mounjaro and Zepbound. Others include Phentermine (Adipex-P, Lomaira), a prescription medication which lessens one’s appetite, Contrave (naltrexone/bupropion), and bupropion (the generic form of Wellbutrin).
Read MoreAnother weight loss drug on the market is also weekly injection, called tirzepatide, sold under brand names Mounjaro and Zepbound. Mountjaro was approved by the U.S. Food and Drug Administration in May 2022 to improve blood sugar control in adults with type 2 diabetes, as an addition to diet and exercise.
According to the Cleveland Clinic, Mounjaro works by increasing insulin levels in your body, which decreases your blood sugar (glucose). While you take this medication, you’ll undergo monitoring in the form of a simple blood test called the HbA1C (A1C) every 3 to 6 months. This test will measure your blood sugar control over the last 2 to 3 months.
Zepbound was later approved by the FDA in November 2023 for chronic weight loss management for adults with obesity. At the time of the approval, John Sharretts, M.D.,a director in the FDA’s Center for Drug Evaluation and Research, said in a statement, “Obesity and overweight are serious conditions that can be associated with some of the leading causes of death such as heart disease, stroke and diabetes. In light of increasing rates of both obesity and overweight in the United States, today’s approval addresses an unmet medical need.”
RELATED: What You Need to Know About Obesity
Meanwhile, prescription appetite suppressant Lomaira (phentermine) and Adipex-P (phentermine) are approved for people ages 17 and older for weight loss.
And back in September 2014, a naltrexone-extended release plus bupropion extended release was approved under the brand name Contrave as the fourth medication approved for long-term weight management in obese patients.
Other drugs approved for weight loss, according to the National Institute of Health (NIH), include orlistat (Xenical), phentermine-topiramate (Qsymia), liraglutide (Saxenda), and setmelanotide (IMCIVREE).
The NIH explains on it’s website, “The FDA has approved five of these drugs—orlistat (Xenical, Alli), phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave), liraglutide (Saxenda), and semaglutide (Wegovy)—for long-term use. A sixth approved drug, setmelanotide (IMCIVREE), is limited to people who have been diagnosed with one of three specific rare genetic disorders, which must be confirmed by genetic testing. You can keep taking these medications as long as you are benefiting from treatment and not experiencing serious side effects.
“Some weight management medications that curb appetite are approved by the FDA for short-term use only, for up to 12 weeks. Although some health care professionals prescribe them for longer periods, not many research studies have looked at how safe and effective they are for long-term use. Never take weight management medications if you are pregnant. If you are planning to get pregnant, you should also avoid these medications, as some of them may harm the fetus.”
Fred Hutch Cancer Center obesity researcher Anne McTiernan, MD, PhD, recently spoke with Fred Hutch News Service about obesity and it’s link to various cancers.
McTiernan said, “The holy grail has always been getting a medication to treat obesity. There are at least 13 types of cancer related to obesity including colorectal cancer, post-menopausal breast cancer, endometrial cancer, liver cancer, even some of the lymphomas and leukemias.”
The Role of Diet and Exercise in Cancer Risk
She also pointed out how observational studies have connected weight loss and reduced cancer risk, however, clinical trials have not yet done so.
“There have been trials focused on these medications’ effects on diabetes and cardiovascular disease treatment, but no trials have tested their effects on cancer risk,” she continued.
“Usually many years’ follow-up of large numbers of patients are needed to see cancer effects of a carcinogen or cancer-preventing intervention like a pill.”
Additionally, Fred Hutch/UW Medicine gastroenterologist and clinical researcher Rachel Issaka, MD, MAS, has hope that these weight loss drugs may have future success in preventing cancers.
He told the new service, “Given the association between obesity and colorectal cancer, it is plausible that GLP-1 mediated weight loss could reduce an individual’s risk of colorectal cancer.
“The current data does not support using GLP-1 agents as a colorectal cancer prevention strategy, but future longer-term studies might change this.”
Fred Hutch psychologist Jonathan Bricker, PhD, also advised that although these popular weight loss drugs have gained a lot of attention from their success, the best way to lose weight is through lifestyle and behavioral changes.
Dr. Ken Miller says a healthy diet and regular workout routine are important
He explained, referring to a recent JAMA study, “You shouldn’t take them alone, but in combination with a low-calorie, low-fat diet, non-processed food diet along with a program of exercise.
“As an adjunct to that, it does enhance weight loss and improves the durability of weight loss and that’s very encouraging.”
According to the U.S. Centers for Disease Control and Prevention (CDC), being overweight has been linked with a high risk of the following types of cancer:
- Adenocarcinoma of the esophagus
- Breast (in women who have gone through menopause)
- Colon and rectum
- Uterus
- Gallbladder
- Upper stomach
- Kidneys
- Liver
- Ovaries
- Pancreas
- Thyroid
- Meningioma (a type of brain cancer)
- Multiple myeloma
The CDC adds, “These cancers make up 40% of all cancers diagnosed in the United States each year. … Overweight and obesity can cause changes in the body including long-lasting inflammation and higher than normal levels of insulin, insulin-like growth factor, and sex hormones. These changes may lead to cancer. The risk of cancer increases with the more excess weight a person gains and the longer a person is overweight.”
The CDC states that approximately 42% of adults and about 20% of children and adolescents have obesity across the country.
Expert Resources On Healthy Living
- Facing Cancer: How to Turn Stress into Strength
- 8 Secrets to a Long, Healthy Life: Jacques Houot and the Fountain of Youth
- SurvivorNetTV Presents ‘How Not To Get Cancer: Diet’ — The Power of Prevention & Healthy Habits
- What to Know About Diet and Exercise if You Have Cancer
- Exercise and ‘Chemo Brain’: Can Physical Activity Save Breast Cancer Patients from Brain Fog During Chemotherapy?
- New Hard Evidence That Exercise Measurably Reduces Anxiety– 150 Minutes Per Week Makes The Difference
- Zero Booze is Best For Cancer Prevention & Five Hours Per Week Of Exercise! New American Cancer Society Prevention Guidelines
How Does Semaglutide Work?
Integral to blood sugar control, GLP-1 is a hormone released by the gut in response to food. It causes the pancreas to release insulin. A rising blood insulin level causes all the body tissues to start absorbing glucose (blood sugar) from the bloodstream, thereby lowering blood glucose levels. GLP-1 also prevents the release of glucagon, which is a hormone that raises blood sugar levels by stimulating liver cells to release glucose and helps people feel full for longer. These effects can also cause people to lose weight.
Modern studies on GLP-1 have shown that it has a role beyond glucose control. It modulates the immune system cells, including NK cells, in a way necessary for weight loss.
Semaglutide is a GLP-1 receptor agonist, meaning that it mimics the effects of GLP-1 in the body. Given as weekly subcutaneous injections It is normally prescribed to manage blood glucose levels in diabetic patients. It also leads to a significant amount of weight loss in these patients.
Although semaglutide has been approved for blood sugar control in people with type II diabetes, under the brand name Ozempic, and for weight loss under the brand name Wegovy, it has not been approved for use as an immune booster and cancer preventative. Thus, it should not be prescribed for that purpose.
Those taking it to control their diabetes or weight, however, can expect the additional benefit of improving their immunity. as per a recent study, and lowering their cancer risk, as a link between weight and cancer does exist.
Semaglutide Carries Side Effects
Semaglutide is an invaluable addition to the repertoire of drugs used to fight diabetes and obesity and strengthen the immune system, as demonstrated by the study. However, like all drugs, it carries side effects that must be considered by anyone contemplating treatment with semaglutide.
Side effects include:
- Nausea.
- Vomiting.
- Stomach Pain.
- Constipation or Diarrhea.
- Low blood sugar, which can cause dizziness, confusion, sweating, and headaches.
Most of these side effects can be managed with lifestyle modifications, such as eating more slowly and avoiding greasy and fried food.
Semaglutide can, occasionally, cause serious side effects, such as:
- Inflammation of the pancreas
- Gallbladder problems
- Kidney problems
- Allergic reactions
These side effects require prompt medical attention.
Although semaglutide has been approved for blood sugar control in people with type II diabetes, under the brand name Ozempic, and for weight loss under the brand name Wegovy, it has not been approved for use as an immune booster and cancer preventative. Thus, it should not be prescribed for that purpose. Those taking it to control their diabetes or weight, however, can expect the additional benefit of improving their immunity and lowering their cancer risk.
The current semaglutide landscape may change in the future as more and more studies discover its benefits beyond controlling diabetes and aiding in weight loss.
More On Obesity & Cancer Risk
In a previous interview with SurvivorNet, Dr. Stephen Freedland of Cedars Sinai Medical Center said, “Some of the best data we have is that obesity increases the risk of not just getting prostate cancer, but actually dying from prostate cancer. Obese men are 35 percent more likely to die from prostate cancer.”
While obesity or a person’s high weight will not always cause them to develop cancer, other conditions associated obesity, like diabetes and heart disease, can lead to complications from cancer treatment if a person already has cancer. In addition, these conditions can sometimes prevent patients from receiving the recommended first-line therapies, as well as increase a patient’s risk of undergoing surgery.
Dr. Andrea Tufano-Sugarman of NYU Langone Health explained to SurvivorNet the benefits of losing weight.
“While all cancers cannot be prevented,” she said, “losing weight is a great way to reduce one’s risk.”
Sugar, The Western Diet And Cancer Prevention
Dr. Tufano-Sugarman said that this is especially true for women; they lower their risk of developing breast cancer and endometrial cancer when they lose weight and keep it of.
Obesity has also been linked to a variety of health issues like type 2 diabetes, cardiovascular disease, gastrointestinal issues, mental health problems, cancer and reproductive health.
How Can Diet Affect My Cancer Risk?
Even without losing weight, adopting a more nutritious diet can help.
“Food choices, independent of weight loss, may also help to reduce risk,” Dr. Tufano-Sugarman said.
“Research has shown that the Mediterranean diet (rich in fruits, vegetables, nuts and legumes, fish and olive oil) is associated with a decreased risk of cancer. Whereas diets rich in red meat may be associated with an increased risk of colorectal and prostate cancer.”
According to the National Cancer Institute (NCI), fat tissue “produces excess amounts of estrogen,” which is associated with an increased risk of certain cancers, including breast, ovarian, and endometrial cancer. The NCI says a person who is severely obese is “7 times” more likely to be diagnosed with endometrial cancer.
Obesity is associated with high levels of insulin, which can lead to colon, kidney, prostate, and endometrial cancer. It can affect cancer survivors in various ways, including the chance of cancer recurrence and overall quality of life.
To learn more about your ideal healthy weight, determine your body mass index (BMI).
Body weight that exceeds what the body mass index deems appropriate for your weight and height can help determine body fat content. Although your BMI can help you learn if you are at a healthy weight, underweight, overweight, or obese, other factors may contribute to your overall health.
The NCI analyzed several studies to observe physical activity’s impact on overall cancer risk. The NCI says that “higher levels of physical activity are linked to lower risk of several types of cancer.”
Regular exercise, a balanced diet, and managing stress are some ways people can practice leading a healthy life. For cancer survivors, a healthier lifestyle alongside getting regular checks for recurrence may improve your quality of life.
Contributing: SurvivorNet Staff
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