Obesity and cancer are related in ways you never imagined: Link explored

Obesity and the risk of cancer (Image via Unsplash/Fuu J)
Obesity and risk of cancer (Image via Unsplash/Fuu J)

Obesity is characterized by the unhealthy and excessive distribution of body fat beyond safe levels.

It's also associated with various lifestyle disorders, including type 2 diabetes mellitus, non-alcoholic fatty liver disease, high blood pressure, stroke and cardiovascular disease.

Preliminary studies have indicated a strong relationship between obesity and an increased risk of cancer. Although excess body fat is not one of the biological causes of cancer, it can still increase the risk due to several factors. In this article, we discuss how different types of cancers are associated with fat gain and lifestyle disorders.


Can obesity cause cancer?

Excess body fat can promote cancer cell proliferation (Image via Unsplash/National Cancer Institute)
Excess body fat can promote cancer cell proliferation (Image via Unsplash/National Cancer Institute)

Waist circumference, waist-to-hip ratio, waist-to-height ratio and fat percentage measured by dual-energy X-ray absorptiometry (DXA or DEXA) or imaging with CT or PET can help with body composition analysis.

According to the CDC, an adult with a BMI of 25.0-29.9 is considered overweight and an adult with a BMI of 30.0 or higher is considered to be obese. A body composition diet can help prevent fat gain.

High levels of body fat have been linked to a higher risk of as many as 13 types of cancer, including:

  • Adenocarcinoma
  • Breast cancer
  • Cancer in the colon and rectum
  • Uterine cancer
  • Gallbladder cancer
  • Upper stomach cancer
  • Kidneys
  • Liver
  • Ovaries
  • Pancreas
  • Thyroid
  • Meningioma in the brain
  • Multiple myeloma

Other risk factors include hormone fluctuations, mutations in genes, long-lasting infections and tobacco and alcohol use.


Obesity-related cancers

Adipose tissues can release excess hormones (Image via Unsplash/Towfiqu Barbhuiya)
Adipose tissues can release excess hormones (Image via Unsplash/Towfiqu Barbhuiya)

Fat tissue (adipose tissue) produces excess amounts of estrogen in women and has been found to be associated with an increased risk of breast, endometrial and ovarian cancers.

An increased blood level of insulin and insulin-like growth factor-1 (IGF-1) has been found to be associated with colon, kidney, prostate and endometrial cancers. Chronic inflammatory conditions in obesity have been found to be linked with DNA damage, which is a risk factor for cancer. Fat cells produce hormones called adipokines, which can stimulate cancer cell proliferation.


Obesity and breast cancer

Hormonal fluctuations are associated with breast, ovarian and uterine cancers in women.

Excess body fat is associated with metabolic syndromes and hormonal fluctuations, so obesity can be a potential risk factor for breast cancer in women. The risk increases significantly after menopause due to several physiological changes in the endocrine system. A higher body fat percentage in women can increase the risk significantly.

The following signs and symptoms of breast cancer must be kept in mind for early diagnosis:

  • Breast lump
  • Change in the size, shape or appearance of a breast
  • Changes to the skin over the breast
  • Newly inverted nipple
  • Peeling, scaling, crusting or flaking surrounding the nipple (areola) or anywhere else on the skin
  • Redness or inflammation anywhere in the breast

These signs can help with early diagnosis and treatment, thus saving lives. Women with obesity face a higher risk of breast cancer and must be aware of these symptoms.


Latest research on obesity and cancer

A balanced and varied diet can reduce risk of cancer. (Image via Unsplash/Katie Smith)
A balanced and varied diet can reduce risk of cancer. (Image via Unsplash/Katie Smith)

Recent studies have indicated that diet and lifestyle play a major role in the development and proliferation of cancers. Chronic inflammation associated with obesity is a major risk factor for cancer and has been linked with several other disorders too. Scientific studies suggest that an improved lifestyle can reduce these risks significantly.

Maintaining an ideal bodyweight along with a safe body fat percentage can reduce inflammation and hormonal fluctuations. A healthy lifestyle can also prevent DNA damage caused by free radicals. Antioxidants found in various foods and supplements prevent excessive DNA damage, and a diet consisting of unprocessed foods can help with DNA repair too.

Excessive consumption of ultra-processed foods has been linked to obesity and must be avoided for overall health. Try to substitute these foods with freshly prepared meals for better health. Remember to consult a doctor immediately if you notice any signs or symptoms of cancer.


Indranil Biswas is a nutritionist and personal trainer with a diploma in dietetics and personal training with a specialization in sports nutrition and strength training.


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Edited by Bhargav