By Sarah Trimble – Nutritionist
Polycystic Ovary Syndrome (PCOS) is the most common reproductive disorder affecting women, with around 10% of women suffering from PCOS. For a woman to be diagnosed with PCOS she should have 2 out of the following 3 signs and symptoms:
- irregular or absent ovulation
- elevated levels of male hormones testosterone and signs of high testosterone (i.e. acne, excess hair, balding of hair on head)
- multiple cysts on the ovaries
So the focus for a diagnosis of PCOS is on the imbalances it causes to reproductive function and reproductive hormones and we could be excused for thinking that PCOS is solely a reproductive disorder. However, there is more going on than meets the eye in PCOS, because we know that the root cause of these reproductive problems, for around 80% of women with PCOS, is in fact a metabolic imbalance called insulin resistance. PCOS could be considered a metabolic disorder with reproductive consequences.
What is insulin resistance?
The main role of the hormone insulin is to manage the metabolism of glucose. After we eat a meal containing carbohydrates the level of sugar (or glucose) in our blood rises, at this point insulin is released to signal our cells to take the glucose out of the bloodstream to be converted into energy. In insulin resistance the cells do not respond to this signal and as a result blood glucose levels remain high. The body then produces more and more insulin to try and get the glucose into the cells leading to high levels of insulin being produced. Insulin has the ability to interfere with production of reproductive hormones, it causes the ovaries to produce higher levels of testosterone while increasing luteinising hormone (LH), which further stimulates the ovaries to produce even more testosterone. Insulin also causes a drop in follicle stimulating hormone (FSH) which leads to inadequate maturation of follicles, lack of ovulation and cyst formation on the ovaries.
Addressing and improving insulin resistance should be the primary focus of any nutritional and lifestyle interventions that aim to address PCOS. Dietary and lifestyle changes can significantly improve insulin resistance, reducing the amount of insulin produced by the body. Once the amount of insulin being produced drops the hormonal imbalances that are caused by elevated insulin levels will improve.
Dietary changes to support PCOS
Eat slow carb rather than low carb
The first dietary change that must be made in addressing PCOS is to choose carbohydrate-based foods that release energy gradually and slowly and do not cause a huge spike in blood glucose levels – this dietary approach is sometimes referred to as a low Glycaemic Load (GL) diet. So swap refined carbohydrates such as white bread, white rice and crackers for higher fibre and slow release carbohydrates such as wholegrain bread, rye bread, brown rice, oats and wholegrain pasta. Avoid sugary treats and soft drinks as these will result in a rapid spike in blood glucose levels that results in a significant insulin production. By changing the type of carbohydrates you choose and significantly reducing sugar consumption within days the body will begin to produce less insulin and degree of insulin resistance will improve.
Add in some good quality protein
An important way to help manage blood glucose levels after a meal is to eat a source of quality protein at each meal and snack, avoiding meals that are completely carbohydrate based such as bowls of breakfast cereal, toast and jam or pasta with tomato sauce. Protein takes longer for the body to digest and doesn’t cause blood glucose levels to increase. Therefore, by adding a source of protein to each meal and snack we slow down the time it takes to digest and release energy from that meal or snack – resulting in a sustained and steady release of blood glucose after that meal and lower blood glucose levels. Great sources of protein to include in your diet are eggs, Greek yoghurt, nuts and seeds, fish, chicken, lean meat and beans and lentils.
Very high protein diets, such as ketogenic or paleo diets are sometimes recommended for women with PCOS as they can produce impressively rapid improvement in symptoms. However, the research indicates that such benefits are often short term as these diets are difficult to sustain in the long run. If you are changing your diet when trying to conceive it is always important to consider if you will be able to sustain those dietary changes throughout pregnancy.
Food Swaps for PCOS
|Toasted white bread and jam||Toasted rye bread with peanut butter|
|Cornflakes||Porridge topped with chopped nuts and apple|
|Croissant||Sourdough bread with scrambled eggs|
|Banana||Greek yoghurt with berries|
|White bread sandwich||Wholegrain pitta stuffed with chicken and salad|
|Vegetable soup||Minestrone soup with beans or lentil soup|
|Packet of crisps||Handful of nuts|
|Biscuits||Oatcakes topped with nut butter or hummus|
|Chocolate bar||Few squares dark chocolate and a small handful nuts|
|Risotto||Stir fry with salmon/ prawns and brown rice|
|Pasta with tomato sauce/ vegetarian sauce||Pasta dish with tuna/ prawns, grass fed beef|
Time how you eat
Time-restricted eating has become popular in recent years and rightly so, it has been shown to provide significant health benefits and this is partly because it reduces insulin production and helps to reduce insulin resistance. Time-restricted eating is an approach to eating that involves eating all your meals within a restricted window of time (usually 8-10 hours) so that for the majority of a day your body is in the fasted state. When you are in the fasted state your body is not producing insulin, so women with PCOS are recommended to have an overnight fast of at least 12 hours.
One piece of research found that women with PCOS saw significant improvement in hormonal imbalances (54% reduction in insulin and 50% reduction in testosterone) by eating their largest meal of the day at breakfast (around 900 calories) and smallest meal at dinner time (around 150 calories) for 90 days along with a 12 hour fast overnight.
Introduce anti-inflammatory foods
The elevated levels of blood glucose and insulin that women with PCOS experience also promote inflammation in the body. Then this inflammation can make insulin resistance worse so a vicious cycle develops of insulin resistance causing inflammation that then promotes further insulin resistance.
This inflammation can contribute to a number of the symptoms that we associate with PCOS. Yet, we also know that inflammation has a negative impact on our reproductive health and chances of conceiving. Eating a diet rich in anti-inflammatory foods is an important way of breaking this vicious cycle of insulin resistance and inflammation.
Anti-inflammatory foods include: omega-3 fats from oily fish, spices especially ginger and turmeric, mushrooms, green leafy vegetables, extra-virgin olive oil, green tea.
Pro-inflammatory foods should be reduced in the diet at the same time. These include: processed foods containing vegetable oil or sunflower oil, margarine, high fat red meat, processed meats, alcohol, sugar.
Key Foods for PCOS
Together with the dietary guidance already discussed specific foods deserve special mention because eating them has been shown to support a big improvement in women with PCOS.
Cinnamon – the spice cinnamon helps to treat and improve the insulin resistance that is the root cause of PCOS. In one study women eating 0.5g of cinnamon with each meal for 6 months saw an improvement in the regularity of their menstrual cycle. Try adding cinnamon to porridge or breakfast cereal or have a cup of cinnamon tea after meals.
Flax seeds – flax seeds can improve levels of a hormone carrier called Sex Hormone Binding Globulin (SHBG), which is often low in women with PCOS. Eating 30g of milled flax seeds every day improved insulin resistance and inflammation in women with PCOS.
Extra Virgin Olive oil – olive oil is rich in monounsaturated fat (also found in rapeseed oil, avocado and almonds) and eating a diet rich in monounsaturated fat can improve insulin resistance and promote hormone balance in PCOS.
Green Tea – green tea can support hormone balance in 2 ways for women with PCOS: it can improve levels of SHBG and reduce levels of testosterone. Aim to drink 2-3 cups of green tea daily.
It’s not just diet
While dietary changes should be the primary focus of an approach to improve PCOS, however, by combining these dietary changes with specific lifestyle changes you can further support PCOS.
Check your vitamin D levels
Women who live in Northern Europe are at risk of vitamin D deficiency and there is a close relationship between vitamin D deficiency and PCOS symptoms. Women with PCOS who have lower vitamin D levels have a higher level of insulin resistance, which then drives the hormonal imbalances in this condition. Testing for and treating vitamin D deficiency can have an improvement in PCOS symptoms and also support fertility in general. Our main source of vitamin D is sunlight (hence why we are at risk of deficiency in Northern Europe) so adequate supplementation is needed to treat deficiency.
Regular exercise is an important way to bring about an improvement in insulin resistance. However, instead of sweating it out on the treadmill try and focus your exercise regime around resistance training. Resistance training, where we lift weights or pull against resistance that could be our own bodyweight, dumbbells, resistance machines etc. is more effective than cardiovascular exercise in improving insulin resistance so aim to incorporate resistance training into your exercise regime as much as possible.
Ever wondered why you can’t stop eating sugary foods the day after a bad night’s sleep? It’s because insufficient sleep (less than 6 hours) can have a negative impact on insulin and blood glucose levels, making insulin resistance worse. Not getting enough sleep on a regular basis could, therefore, contribute to PCOS symptoms so make an effort to get a good night’s sleep, no late night Netflix binges.
Address your Stress
At the beginning I mentioned that for around 80% of women PCOS is caused by insulin resistance, the other 20% of women with PCOS actually suffer from an imbalance in their adrenal gland function that contributes to the condition. Our adrenal glands main function is to produce adrenaline and the stress hormone cortisol, however, they also produce a certain amount of sex hormones too. If we are under sustained and prolonged stress then the function of the adrenal glands can get out of balance leading to increased testosterone production from the adrenal glands. The stress hormone cortisol also promotes insulin resistance, so all manner of hormonal imbalances can be exacerbated because of stress and improvement experienced from dietary changes can easily be negated if we are under a lot of stress.
Stress reduction techniques can be very individual, one person will find meditation beneficial, another going for walks in nature. The key is to find the stress reduction technique that works for you and making time for it.
Support your gut microbiome
I’ve come to this point last, but supplementing the gut microbiome could be the most important change you make in an effort to improve PCOS. As we’ve explained insulin resistance is the root cause of the various hormonal imbalances seen in PCOS, but in recent years we have begun to understand that an imbalance in the gut microbiome (the name for the population of GOOD bacteria that live in our gut) could actually be the root cause of this insulin resistance. Women with PCOS have been found to have imbalances in their gut bacteria that contributes to increased release of glucose into the bloodstream after a meal and also promotes inflammation. Correcting this imbalance should be a priority in any treatment protocol for PCOS.
A key way to support the gut microbiome is to supplement with a high quality probiotic, especially one that contains the bacteria Lactobacillus Rhamnosus GG as this bacteria has been shown to improve blood glucose levels and insulin resistance.
Dietary changes can also support an improvement in the balance of the gut microbiome:
- Eat fermented foods such as live natural yoghurt, kefir, sauerkraut, kombucha, or miso daily.
- Eat a large variety of fruits and vegetables, don’t just focus on the same fruits and vegetables daily. We should aim for 30 different plant-based foods in a week.
- Eat plenty of soluble fibre from whole grains and beans and lentils – soluble fibre feeds our good bacteria.