Overweight and obesity are associated with 13 different types of cancer. Here’s how fat tissue is linked to cancer growth and approachable ways to achieve healthy weight loss.
Maintaining a healthy weight is one of the best things you can do for your body. Commonly associated with reducing the risk for heart disease, studies have shown that it also plays a key role in cancer prevention.
According to the CDC (Centers for Disease Control and Prevention), being overweight is linked to the development of 13 different types of cancer – accounting for nearly 40% of all cancer incidences in the U.S. alone.
The answer as to why those who are overweight, or have obesity, are more susceptible to cancer is complex, but to better understand the risk and what we can do, we spoke with dietitian Sara Spinner, RD, bariatric surgeon Marc A. Neff, MD, and medical oncologist Ana María López, MD, MPH, MACP.
Excess Weight Fuels Cancer Growth
Hormones, inflammation, and fat all play important roles to help the body function, but can stimulate cancer development (carcinogenesis) and spread (metastasis) in excess, says Sara. It’s like the age old adage: too much of something isn’t always a good thing. Various factors go into healthy cells turning cancerous, but fat tissue itself – also known as adipose tissue – can host many dangers, such as:
- Increased estrogen levels and insulin-resistance, both of which are linked to breast, endometrial, ovarian, colon, kidney, and prostate cancers.
- Chronic inflammation, impacting surrounding tissues and organs, and sometimes causing DNA damage.
- Increased risk of weight-related comorbidities. Gastrointestinal conditions, in particular, such as GERD (gastroesophageal reflux disease), Barrett’s esophagus, and gallstones are linked to GI cancers.
Additionally, metabolism – or how we process food into energy – is closely intertwined with carcinogenesis, explains Dr. Lopez. “We’ve learned so much about cancer over the past two decades, but one of the most significant findings is that cancer is a metabolic illness. When metabolism is impaired, cancer risk increases.”
What We Eat Counts
Research shows that in the United States, over 80,000 new cancer cases are caused each year by poor diet alone (independent of obesity, inactivity and other risk factors).
Diet directly affects the production of adipose tissue and inflammation levels, especially when high in saturated fats, sodium, and added sugars. So, what’s the cancer prevention diet? “Unfortunately, there’s not one regimen. There’s no magic pill, but there are certain foods we should work to avoid or limit our consumption of, and others we should implement more frequently,” continues Sara.
Foods to Avoid/Limit:
- Alcoholic beverages
- Processed/cured meats (ham; bacon; salami; sausage; hot dogs; etc.)
- Red meats (beef, pork, and lamb)
- Charred foods (i.e., foods that have been grilled for too long)
Foods to Eat More:
- Plant-based foods, including leafy green/cruciferous veggies; fruits; beans; nuts; and whole grains
- Fish and poultry-based proteins, which Spinner likes to call “fins and feathers.”
Not only can a healthy diet as such help prevent cancer, but if you are diagnosed with cancer, it can aid in the effectiveness of treatment and reduce the risk for reoccurrence.
How We Move Counts Too
When it comes to prevention of chronic illness – cancers and much more – eating healthy needs to be complemented with physical activity, says Dr. Lopez. “Unfortunately, so much of life is sedentary. We’re setting our bodies up to fail. The way we move, just like what we eat, is a choice we make.”
Food is meant to energize you, so you should spend that energy in purposeful ways, suggests Dr. Lopez. Moving doesn’t have to be mundane. It should be something you enjoy, or else you’re never going to want to do it.
Try to go for a walk and really take in your surroundings – the birds, blossoming flowers, or even the falling snow. If you’re watching television, stand up and walk in place. If you watch young children or grandchildren, don’t just watch them play, get up and move with them. There are countless ways to integrate mindful movement into our everyday lives, says Dr. Lopez.
Barriers to Care
Aside from the physical impacts of adipose tissue and dietary habits, there are other indirect factors that can increase cancer risk, adds Dr. Neff, such as poor screening, poor dosing, and overall poor management of risk factors. “Many who have obesity avoid or delay appropriate preventative care, due to weight biases and discrimination. You push it off once, and it turns into a vicious cycle. It’s not only about keeping your weight in check, but also about healthcare systems providing sensitive and accessible care, where these patients can feel comfortable.”
The Benefits of Weight Loss on Cancer
Studies have shown that losing as little as 5-10% of your overall body weight can reduce your cancer risk significantly. Other improvements include:
- Better cancer detection and screening – Mammograms and imaging in general is easier to read, and physical exams are easier perform. Some imaging methods, such as MRIs and CT scanners, aren’t built to support people of a certain weight.
- Fewer surgical complications/risks – Excess adipose tissue contributes to more frequent wound infections, blood clots, fluid build-up, and post-operative pneumonia in recovery.
- More precise surgeries – Less adipose tissue helps surgeons perform procedures (i.e., remove tumors) with clear margins.
- Effective dosing of chemotherapies – Many medications are weight-based, and few studies have been completed on appropriate dosing (i.e., to minimize side effects) for those with a BMI (body mass index) greater than 40.
Obesity as a Disease Process, Not a Choice
In 2013, the American Medical Association officially recognized obesity as a disease process – which requires treatment and prevention — breaking the societal stigmas that surround it, says Dr. Neff. “Obesity has notoriously been misperceived as a problem caused solely by being inactive and eating too much. While these can be contributing factors, there are often more underlying causes.”
When we consider genetics alone, there are more than 50 different genes associated with obesity. Some experts view obesity as a type of storage disorder, continues Dr. Neff. Bodies store energy differently, and two people can consume exactly the same thing, but one person is predisposed to absorb and store it as fat, while the other isn’t.
Everyone faces different psychological and socioeconomic factors as well. Metabolisms are different. Medication regimens are different. This all needs to be considered when trying to lose weight, notes Sara. “Achieving healthy weight loss means reaching a weight your body is comfortable at. It takes structure, consistency, and often medical care. It’s about adopting small changes to your diet and movement patterns to promote better health in the long term.”
Will being overweight or having obesity guarantee you’ll develop cancer? No, but it does increase your risk, and staying on track with weight and lifestyle habits is something you have control over, adds Sara. You have the power to take a proactive approach, even if you just take it one day at a time.