Is there a link between obesity and breast cancer?

We all know about the obesity crisis and its myriad knock-on effects to both our personal health and national economy. And we’re particularly aware of the link between obesity and cancer. But what about breast cancer?

There are three reasons why obesity causes cancer which are commonly agreed upon by the medical community.

Obesity increases oestrogen levels

As well as being the primary female sex hormone, which helps develop and regulate the female reproductive system, oestrogen also acts as a medication, a mood-booster, an appetite-suppressant, an anti-inflammatory, and a key factor in bone development and maintenance of bone mineral density – in both men and women.

However, another thing that oestrogen can do is make certain cells in the body divide when they shouldn’t – and uncontrolled cell division is effectively what cancer is. Post-menopause, the ovaries – the prime producer of oestrogen – shut down. But if you’re piling on the pounds and gaining weight, your fat cells take over and becomes the main source of oestrogen production.

Obesity disrupts the metabolism

As you can imagine, the metabolism – the network of body-regulating transformations which convert food to energy – is an incredibly complicated set-up, and one which can be easily upset by obesity and the extra fat cells it produces. When we take on extra fat cells, there is a risk that they can snuff out our metabolism’s ability to process glucose – and scientists have drawn a link between high glucose levels and an increased risk of cancer.

Obesity increases inflammation

One reaction our bodies experience when we take on extra fat is to summon specialised immune cells called macrophages to deal with dead and dying fat cells. The downside to that is that they release cytokines – a cocktail of chemicals which ultimately causes a condition called chronic inflammation, which causes cells to divide, and can bring on ailments such as pancreatitis and Crohn’s disease, which can increase the risk of cancer.

Obesity and breast cancer

However, when it comes to breast cancer, things become complicated. Certain studies claim that being overweight or obese before menopause actually modestly decreases the risk of breast cancer when compared to women with a leaner body shape. However, after menopause, being overweight or obese increases the risk of breast cancer and we have to factor into these findings that most instances of breast cancer occur after menopause.

In short, we know that there is a clear link between obesity and a higher risk of cancer – the jury is still out on how it does it exactly, but it’s worth remembering that cancer is just one of the many life-threatening ailments brought on by obesity, which includes heart disease, diabetes and strokes.