5 things you should know about obesity and breast cancer

Obesity and being overweight is a major problem the world over. But in India, more than 135 million people are obese^[1].  

And obesity comes with a myriad of health concerns including, diabetes, hypertension, Heart disease, osteoarthritis, gall bladder disease and most strikingly cancer. It has been linked to an increased risk of breast cancer, endometrial cancer, ovarian cancer and a whole host of other cancers. 

The link between obesity and cancer has been established. In fact, a study found that weight, height, and body mass index (BMI) have been associated with breast cancer risk ⁽¹²⁾. 

Here are  five things you should know about obesity and breast cancer:

1.       Obesity and breast cancer are linked

Dr Ashay Karpe, Medical oncologist and haematologist, Sunrise Oncology Centre says, ” weight gain, obesity, lack of breastfeeding, infertility and hormone treatments are all risk factors, that put women at risk for breast cancer.”

A higher BMI (Body Mass Index) in postmenopausal women is associated with a modest increase in the risk of breast cancer. In fact, obese postmenopausal women, have a 20% to 40% increase in the risk of developing breast cancer, when compared to a woman of normal weight⁽¹¹⁾. 

Obesity and breast cancer are so closely linked, that it is even a risk factor in obese men.

There are a number of ways in which obesity increases your risk of developing cancer:

1. Higher toxins stored in fat. When one is obese, she has a higher than normal amount of fat tissue in their body. This tissue can store toxins and may serve as a constant source of carcinogens ⁽²⁾. 
2. Higher estrogen production. Body fat is a base for endogenous estrogen production and storage. This excessive estrogen could increase the risk of breast cancer ⁽³⁾. This is especially true for women with visceral or abdominal obesity, who have higher levels of free estrogen. 

Obesity in women also increases the amount of bioavailable estrogen in their body. This estrogen has been known to promote tumour growth. And it may occur either directly or by modulating steroid activity, both of which have been found to increase the risk of breast cancer. ⁽⁴⁾

2.       Obesity & hormones form a bad combination that increases your risk of breast cancer

Women who have used hormone replacement therapy during menopause or those who have certain other kinds of tumours that are fuelled by hormones like estrogen and progesterone are at a higher risk of suffering from breast cancer.

3.       The fat around your belly could put you at greater risk of breast cancer

Central obesity (obesity around the central region of your body) is strongly linked to insulin resistance, in healthy individuals as well as in those suffering from breast cancer. 

A number of studies have also shown that higher insulin and (or) C-peptide levels are linked to insulin resistance (with or without the presence of diabetes), and pose an increased risk of cancer recurrence and death in women, who have early-stage breast cancer.

This is an especially striking finding because it is commonly seen that breast cancer can be cured if caught early. 

3.      Weight loss can help lower your risk of suffering from breast cancer

If you are overweight or obese, losing weight can help improve your chances of suffering from breast cancer. In fact, multiple studies have found that women who lose weight after the age of 50 and keep it off, have a lower risk of breast cancer than women whose weight stays the same. 

There have been a few studies that have shown that losing weight may help improve outcomes in women with breast cancer and reduce the risk in younger women⁽⁵⁾. 

4.      Obesity is also linked to breast cancer outcomes 

Studies have indicated that obesity may worsen a number of factors that play into surviving cancer, including, quality of life, recurrence of cancer, the progression of cancer and prognosis. It has also been found that obesity increases the risks of treatment-related lymphedema in breast cancer survivors. 

5.      Breast cancer can be prevented 

Making certain lifestyle changes is all it takes to prevent breast cancer.  Exercising, not gaining too much weight, breastfeeding, avoiding alcohol and smoking, protecting yourself from exposure to radiation and limiting the dose and duration of hormone therapy can all go a long way preventing the onset of breast cancerYou may also like to read:

You may also like to read:

Breast cancer: Could you be at risk?

Cancer Screening: Why it’s better to be diagnosed early

Yes, cancer can be prevented; here are 6 things that can help

References

1. Singh P, Kapil U, Shukla N, Deo S, Dwivedi S. Association of overweight and obesity with breast cancer in India. Indian J Community Med. 2011;36(4):259-262. doi:10.4103/0970-0218.91326
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