So what’s behind this?
Alongside genetics (your likelihood of developing PCOS is increased if your mother, sister or aunt has the condition), experts think insulin resistance plays a role in the development of PCOS in 50-75 per cent of cases. But first, a quick science lesson: Insulin is a hormone that enables the body to metabolise glucose so it can be used for energy; insulin resistance is when your body doesn’t respond to it properly, causing the pancreas to overproduce it in an attempt to dial down glucose levels. This surplus in turn causes the ovaries to release androgen hormones.
There’s no cure for PCOS, so treatment is focused on balancing hormone levels and improving symptoms through lifestyle change, medication and – for some – weight loss. Managing body weight can be hard for those with PCOS, with evidence suggesting that the condition not only makes weight gain more likely, but that high levels of body fat amplify insulin resistance and, with it, the spectrum of PCOS symptoms. This explains why weight loss – even as little as 5 per cent – can improve insulin levels, period regularity, fertility and androgen levels.
But while many women with PCOS and insulin resistance have a higher body weight, some don’t, meaning dietary changes that target resistance specifically – as opposed to general weight loss interventions – matter.
Some studies suggest that a low glycaemic index (GI) diet can be helpful (GI being a measure of how quickly a carb-containing food raises blood sugar levels). High-GI foods (such as white bread, sweetened drinks and biscuits) are digested quickly and raise blood glucose rapidly, causing a corresponding peak in insulin, while low-GI foods (think: vegetables, fruits, rye bread, oats, beans and lentils) trigger the opposite effect: a slower rise in blood glucose and a lower insulin peak.
Even better? One 2013 study found that a low-GI diet can improve insulin sensitivity, independent of any weight change. While GI isn’t a perfect model (hate to break it to you, but ice cream and chocolate are considered low-GI as they contain fat, which slows carbohydrate absorption), there’s also evidence linking low-GI diets with a lower risk of heart disease and type 2 diabetes – conditions that women with PCOS are at a greater risk of.
Another potential insulin sensitivity hero? The DASH (dietary approaches to stop hypertension) diet.
Originally designed to counteract high blood pressure, it emphasises fruit, veggies, whole grains, lean meat and low-fat dairy. A 2015 trial found it improved insulin levels and abdominal fat in overweight women with PCOS. Both diets prioritise fibre: important, as a low intake has been correlated with an increased risk of insulin resistance in women with PCOS.
The bottom line? While there’s no silver bullet, a focus on good nutrition (eating a variety of fruit, veggies, whole grains, pulses, lean protein and low-fat dairy) can help to balance those hormones. And support your wider health, too. Now that’s some delicious news.
Three Low-GI Winners
High-fibre, low-GI and a good source of protein, lentils hit all the right notes. Throw into lunchtime salads or use ‘em in curries and stews.
Most nuts are low-GI. Team a small handful or a slick of nut butter with a piece of fruit for a satisfying, energy sustaining PM snack.
Good all-rounders thanks to their fibre and vitamin content. Aim for three to five handfuls per day.