A new study by the World Health Organization (WHO) has found that postmenopausal women who are overweight and have heart disease may be at a significantly higher risk of developing breast cancer than those without heart issues. The study, published in the journal CANCER, tracked over 168,000 women from across Europe and the UK and shows how excess weight and heart health are closely tied to cancer risk.
Obesity and cancer: A double trouble for older women
It’s already known that a higher Body Mass Index (BMI), a measure of body fat based on height and weight, is a risk factor for breast cancer after menopause. But this new study took a deeper look: what happens when obesity is combined with cardiovascular disease (CVD) or type 2 diabetes?
Here’s what the researchers found:
- Every 5 kg/m² increase in BMI led to a 31 per cent higher risk of breast cancer in women who had heart disease.
- The increase was 13 per cent in women without heart disease.
- Type 2 diabetes didn’t significantly impact the weight-cancer link, suggesting that heart disease and excess weight together are the more dangerous combination.
What the study looked at
The researchers analysed data from two large health databases: the European Prospective Investigation into Cancer and Nutrition (EPIC) and the UK Biobank. None of the participants had heart disease or diabetes when the study began. Over an average follow-up period of 11 years, about 6,800 women developed breast cancer.
Based on the findings, overweight women with heart disease may face 153 extra breast cancer cases per 100,000 women each year.
Why heart health matters for cancer prevention
“Obesity and heart disease are already known health risks on their own,” said Dr Heinz Freisling, the study’s lead author from WHO’s International Agency for Research on Cancer. “But when combined, they could significantly raise the risk of developing breast cancer.”
He suggested that women with a history of heart disease should be included in future weight-loss trials aimed at preventing breast cancer, not just cardiovascular problems.
How obesity affects heart health
Carrying too much weight puts strain on the heart. It can lead to:
- High blood pressure
- High cholesterol
- Inflammation
- A higher risk of strokes and heart attacks
Over time, obesity can damage blood vessels, reduce heart function, and increase the likelihood of developing chronic heart disease, a condition that now appears to amplify breast cancer risk in older women.
How to calculate your BMI
To check your BMI at home:
Metric method:
- BMI = weight (kg) ÷ [height (m)]²
- For example, if you weigh 70 kg and are 1.65 m tall:
- BMI = 70 ÷ (1.65 × 1.65) = 25.7
- Imperial method (using pounds and inches):
- BMI = (weight in pounds ÷ height in inches²) × 703
BMI Categories:
- Underweight: Less than 18.5
- Normal: 18.5–24.9
- Overweight: 25–29.9
- Obese: 30 or more
Prevention is better than cure
This study adds to growing evidence that obesity is linked to at least 12 types of cancer, including uterine, liver, kidney, and colorectal cancers. Overweight women are more likely to develop larger and more aggressive tumours, making early prevention all the more urgent.
If you’re postmenopausal and have heart disease, it’s especially important to maintain a healthy weight, exercise regularly, and go for regular cancer screenings.
