What is the best diet for PCOS?

What is PCOS?

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. In fact, it is estimated to affect up to 13% of this population group worldwide.(1)

PCOS is a complex condition including reproductive, endocrine and metabolic abnormalities. These can include irregular ovulation, reduced fertility, insulin resistance, fatty liver and imbalanced blood lipids. Such abnormalities can increase the risk of developing type 2 diabetes and cardiovascular disease. Between 30 and 75% of women with PCOS carry excess weight, in fact obesity can compound symptoms of PCOS whilst weight loss can alleviate symptom severity.(1)

In 2018, the Centre for Research Excellence in PCOS published international evidence-based guidelines for the assessment and management of PCOS. The Guidelines recommend that all women with PCOS can benefit from lifestyle intervention including diet, exercise and behavioural strategies. Nonetheless, the optimal diet for PCOS management and improvement of symptoms is not yet well-established. Instead, there are general dietary principles which can help women to manage symptoms.(2)

Unfortunately, there are significant gaps in knowledge around the diagnosis and management of PCOS. This is true across multiple areas of medicine, from obstetrics and gynaecology to dermatology. Furthermore, women with PCOS often have to go through multiple inconclusive healthcare visits and delays before they obtain an accurate diagnosis. 

Female patients with PCOS report dissatisfaction with the treatment and recommendations received as well as a lack of satisfactory treatment options. Overall, it is clear that there is still much to be done around PCOS to ensure that women receive adequate diagnosis and support in an efficient and timely manner.(3)

What are the symptoms?

Women who experience symptoms of PCOS usually tend to notice them in their late teenage years and early 20s. 

Symptoms can vary widely between women and (thankfully) not all women experience all symptoms. In addition, each symptom can vary in severity from mild to more severe. Certain women may only report menstrual problems, be unable to conceive, or both. 

Some of the most common symptoms of PCOS include: irregular/missed periods or amenorrhea, difficulty conceiving due to irregular or lack of ovulation, excessive hair growth typically on the face, weight gain, thinning hair or hair loss, oily skin and acne. If you have any of these symptoms and suspect that you may have PCOS, contact your GP who can help you.(4)

How does PCOS impact fertility?

When it comes to female infertility, PCOS is one of the most common causes. Others include endometriosis, fibroids, obesity, severe stress, and very low body weight. In fact, many women first find out that they have PCOS when they are trying to conceive and after a few unsuccessful attempts. 

During the menstrual cycle, the ovaries release an egg into the uterus, this is ovulation. It generally occurs once every 28 days in a regular cycle. However, women with PCOS typically have irregular cycles, thus they either don’t ovulate or do so infrequently. Therefore, irregular or absent periods make it challenging for women with PCOS to fall pregnant. 

Related reading

• How to increase progesterone
• How to balance hormones

What are the long-term effects of PCOS?

PCOS is typically associated with cardiometabolic disease. However there is a lack of evidence supporting the magnitude of the association between the two conditions. Is PCOS truly a risk factor for cardiometabolic disease? And if so, to what extent? 

A group of researchers conducted a systematic review and meta-analysis in order to determine whether women with PCOS have a long-term risk of developing cardiometabolic disease.(5)

Cardiometabolic outcomes include cardiovascular disease, stroke, myocardial infarction, hypertension,type 2 diabetes, metabolic syndrome and dyslipidemia. 

The study found that women with PCOS had increased risk of hypertension, higher levels of total cholesterol and lower levels of HDL (good) cholesterol compared to women without PCOS.

Given that women  with PCOS have a substantially increased  risk for future hypertension and type 2 diabetes, it’s an important factor for clinicians to consider. 

Although PCOS is generally diagnosed in younger women who are typically at low risk of cardiometabolic disease, it’s an important factor to consider for later in life. Prevention beats treatment wherever and whenever possible. Future studies are needed in order to establish cardiometabolic screening protocols and management for women with PCOS in order to minimise the risk of cardiovascular disease. 

What foods should you eat if you have PCOS?

There is no miracle diet or one-size-fits all diet approach to PCOS. However there are some general healthy eating principles which can improve your PCOS symptoms and better manage your condition.

Glycaemic Index

You may have heard about GI, also known as Glycaemic Index. This is a ranking system which shows the rate at which your blood sugar levels increase following the consumption of carbohydrates. Carbohydrates with high GI ratings will make your blood sugar levels spike quickly, which can subsequently lead to sugar crashes. Over time, large variations in blood sugar levels can lead to insulin resistance. 

A note on insulin and insulin resistance

Our pancreas makes insulin, which is a hormone. Insulin helps the glucose in our blood to enter cells in our muscles, fat and liver where it is used for energy production. Glucose normally comes from the food we eat, however in times of need such as during starvation, our liver can produce glucose. When we eat food, our blood sugar (glucose) rises and our pancreas releases insulin into our bloodstream. Consequently, insulin lowers our blood glucose to maintain it within the normal range. 

So what happens when you are “insulin resistant”? Insulin resistance refers to when the cells in your muscles, fat and liver do not respond normally to insulin and struggle to take up sugar from your blood. Consequently, your pancreas needs to produce more insulin so that glucose can enter your body’s cells from the bloodstream.  

If your pancreas makes enough insulin to compensate for your cells’ reduced response to insulin, this will ensure that your blood glucose levels do not increase beyond the healthy range. 

There is a condition known as “prediabetes” which refers to when your blood sugar levels are higher than they should be, however not high enough to qualify for diabetes. Prediabetes can occur in individuals who have insulin resistance or whose pancreas is not producing enough insulin. This can occur in women with PCOS. Over time, the extra glucose in your bloodstream can lead to developing type 2 diabetes. 

For this reason, maintaining healthy blood glucose levels is essential for women with PCOS.

Regular meals can also help to maintain blood sugar levels stable, thus reducing the risk of insulin resistance. Eating regular balanced meals and avoiding skipping meals is a great place to start in order to keep your blood sugars in check.

Go for low GI

On the other hand, low GI foods have less of an impact on blood sugar levels, causing them to rise more slowly. This can be useful to reduce PCOS symptoms. In fact, consuming low GI foods can improve your insulin levels, thus reducing insulin resistance. Examples of low GI foods  include most whole fruits and vegetables, beans, pasta, minimally processed grains, low-fat dairy and nuts. Some easy swaps from high GI to lower GI include swapping white rice for brown rice, instant oats for steel-cut oats, and white bread for wholegrain bread. 

There is evidence to show that low GI diets in women with PCOS  improve their body’s sensitivity to insulin. Moreover, eating low GI foods has been linked to increased menstrual regularity.(4)

Balance your meals

In addition to choosing lower GI foods, eating balanced meals and snacks can also help to improve insulin levels. You can do this by adding protein and fats to low GI carbohydrates. In fact, did you know that by adding some healthy fats to a carbohydrate-based meal  you can actually lower the GI of the overall meal?

This is known as “glycemic load”. Eating balanced meals helps to keep you feeling fuller for longer as well as reduce cravings for perhaps unhealthier less nutritious foods. Aim to include lean protein, healthy fats, high fibre low GI carbs and an abundance of fruit and vegetables. 

Omega-3 fats

Women with PCOS may have higher than normal levels of inflammation. Omega-3 fats are known to fight inflammation in the body. 

Therefore, if you eat fish, including a couple of portions of oily fish per week into your diet can be a great way to manage inflammation. Examples of oily fish include salmon, tuna, mackerel and sardines. 

Plant-based sources of Omega-3 are also great to include in your diet, especially if you don’t eat fish. Great sources include seaweed, chia seeds, flaxseeds and walnuts. 

In addition, if you are trying to conceive, it is essential that you are meeting all of your nutrient require