Obesity and Cancer

Being overweight has always been notoriously known for heart issues and there has been direct link between obesity and risk of heart disease but the research facts tell a story far from that. Obesity and cancer risk are equally interlinked as obesity and heart disease.

The cancer risk increases with the increase in weight and also with the time duration you have been overweight for.

Obesity and cancer risk

A good amount of research on obesity and cancer risk has proven that there is indeed a good link between obesity or being overweight and the risk to develop cancer.

However more research is still needed to understand this link well. Research shows that excess body fat increases your risk for developing 13 different types of cancer:

  • Adenocarcinoma of the esophagus, pancreatic & gall bladder cancer(three of the hardest to treat cancers).
  • Breast (in women who have gone through menopause) & bowel (two of the most common cancer types)
  • Colon and rectum.
  • Uterus.
  • Upper stomach.
  • Kidneys.
  • Liver.
  • Ovaries.
  • Thyroid.
  • Meningioma (a type of brain cancer).
  • Multiple myeloma.

More than 90% of obesity linked cancers occur in men and women who are 50 years old or older. Breast cancer after menopause is the most common obesity associated cancer among women.

Colorectal cancer is the most common obesity associated cancer among men.

It’s still less clear that exactly how being obese increases the risk factor for obesity and more research is ongoing. Experts believe that the single biggest factor is inflammation which is caused by the visceral fat – the fat that surrounds your vital organs.

The problem with excessive visceral fat is that it affects certain major processes in your body which primarily includes how your body manages hormones, like insulin and estrogen.

High inflammation & its associated effects can lead to an increased cancer risk by affecting how and when cells divide and die which is exactly the whole story of cancer development. When the normal stable rate of new cell formation and old cell death is disturbed, the risk for cancer development takes the place.

How does obesity cause inflammation?

Visceral fat cells are large and they are high in number. This excess amount of fat doesn’t have much room for oxygen. And this low-oxygen environment works as a trigger for inflammation.

Inflammation is our body’s natural response to injury and disease. For example, if you get a deep cut, the area around the cut becomes red and painful. This minor inflammation around the wounded area is considered healthy as it helps the body to repair the damaged tissue and aids with the healing process.

But long-term inflammation caused by excess visceral fat can damage your body in a number of ways and increasing the risk for cancer is just one of them.

Cancer occurs when cells reproduce uncontrollably. This damages the surrounding cells. The more this continues, the higher is the risk that a tumor will form.

Obesity and Cancer link with Insulin

The link between inflammation and insulin – the hormone that regulates blood sugar – is complex.

Inflammation caused by obesity decrease the body’s ability to properly respond to insulin. This is termed as insulin resistance. When the body fails to respond to insulin properly, it produces more insulin to make up for that.  

This increase in insulin due to insulin resistance further triggers an increase in the number of cells produced, which can lead to cancer.

Increased insulin also affects other processes one of which is how hormones like estrogen are controlled. The increased insulin can lead to more available estrogen, which increases cancer risk.

Chronic inflammation can increase oxidative stress and do DNA damage which is another factor for cancer development.

How does more estrogen increase cancer risk?

Basically, higher estrogen levels lead to increased cell production, which has a high tendency to result in tumor growth.

Estrogen is necessary for our body to function. In females, the ovaries are the main source of estrogen. In males, an enzyme converts testosterone to estrogen. However, fat cells in both men and women can also make estrogen. This is the reason why too much estrogen is commonly seen in obese people.

In females, high estrogen levels are linked to an increased risk for post-menopausal breast, endometrial and ovarian cancers.

Other factors linked in Obesity and Cancer

  • Obesity could impair tumor immunity and cause changes in the mechanical properties of the scaffolding tissue that surrounds developing tumors.
  • Fat cells produce hormones called adipokines which can stimulate or inhibit cell growth. For example, an adipokine called leptin in the blood increases with increasing body fat, and high levels of leptin can promote unusual rate of cell division
  • Another adipokine, adiponectin, is less abundant in people with obesity than normal people and may have antiproliferative effects that protect against tumor growth.
  • Fat cells may also have direct or indirect effects on other cell growth and metabolic regulators, including AMP-activated protein kinase.

Obesity and Cancer: What you can do?

One of the most important things you can do to decrease your cancer risk is to maintain a healthy weight.

These are the daily life steps you can take to prevent obesity:

  • Active lifestyle: Ensure to have 150 minutes of moderate activity or 75 minutes of vigorous activity a week.
  • Have more of a plant based diet: Fill a minimum 2/3 of your plate with non-starchy vegetables, fruits, whole grains or legumes (beans and peas), and only 1/3 or less with animal protein.
  •  Limit your alcohol intake to to one drink per day if you are a woman, and two drinks per day if you are a man.
  • Take adequate rest: Fatigue can affect all of your body balance and defences and make you want to eat more, and make unhealthy choices and take unhealthy amounts.

Being obese or overweight decreases your body’s ability to work well. Maintaining a healthy weight is essential for reducing your risk for cancer.


Obesity and Cancer risk can go hand in hand as shown by research. Obesity increases inflammation which is a welcome for cancer. Maintaining a healthy weight is very important to avoid cancer.

FAQ(Frequently Asked Questions)

What are cancer fighting foods ?

Apples, Berries, Cruciferous vegetables.
Carrots, Fatty fish, Walnuts, Legumes.

Does losing weight decrease cancer risk?

Losing as little as 5% to 10% of your total body weight can reduce your risk of developing cancer.

What are the chances of getting cancer ?

The incidence rates for cancer occurence increases as we age, from fewer than 25 cases per 100,000 people in age groups under age 20, to about 350 per 100,000 people among those aged 45–49, to more than 1,000 per 100,000 people in age groups 60 years and olde

My name is Amanpreet Kaur Samra. M.S. Biochemistry. I'm the founder and writer of this blog. I have been teaching Biochemistry for a good number of years. I started this blog because I have always been very passionate about writing, in particular about Nutrition and Healthy Weight Loss.

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