This post was written by one of our contributors; dietitian – Maeve Hanan

Polycystic ovary syndrome (PCOS) is a hormonal disorder which is thought to affect roughly one in ten women (1, 2). Many of the symptoms of PCOS are related to high levels of male hormones in the body. This article will explore nutrition and lifestyle factors related to the management of PCOS.



Does Weight Impact PCOS?

Excess body fat, particularly around the abdomen, is linked with insulin resistance (3). This means that body cells can’t use insulin properly, which triggers insulin production followed by increased production of male hormones (4, 5). However this works in both directions, as higher level of testosterone in the body can lead to more fat being stored on the abdomen.



For those who are overweight, losing roughly 5-10% of body weight has been seen to help with reducing insulin resistance (6). For women with PCOS, a similar amount of weight loss has also been linked with normalising periods, reducing inflammation and improving fertility (7, 8). Losing 1 – 2 lbs (1/2 – 1kg) per week is often a safe and realistic target, although this depends on the individual.



However, weight loss isn’t the only factor involved, and PCOS also occurs in women within the healthy weight range. Focusing on weight can also be unhelpful for some women, especially those who have a history of dieting – which is common in those with PCOS. Therefore independent of weight loss, a healthy diet is encouraged for women with PCOS in order to maximise overall health, and reduce the risk of heart disease and diabetes.



So for those who are overweight, losing weight can help with improving the symptoms of PCOS, but a healthy diet is encouraged regardless of weight.



Diet and PCOS

Healthy eating is encouraged for women with PCOS in order to improve symptoms, maintain a healthy weight and reduce the risk of heart disease and diabetes (1, 9). Many of the principles of healthy eating with PCOS follow the Eatwell Guide.



A low glycaemic index (GI) diet has also been specifically linked with reducing insulin resistance, improving hormone levels and regulating periods in those with PCOS (9, 10). A low GI diet can usually be achieved by replacing refined carbohydrate foods (like sugary food and drinks, white bread, white rice etc.) with wholegrains and higher fibre options. For more information about the low GI diet, see this factsheet from the British Dietetic Association (BDA).



Carbohydrate cravings are commonly reported in women with PCOS, which may be related to rises and falls in blood glucose levels (11). Eating regular meals which are quite evenly spaced out over the day can help to stabilise blood glucose levels. Including high fibre foods, protein and fat sources at meals can also help (opting for unsaturated fat most of the time for heart health is advised) (1, 11). Eating sweet foods less often, can also help to reduce the longer-term urge for these in some cases.



In terms of meal size, one study found that eating most calories at breakfast, followed by lunch then dinner, improved fertility, insulin and hormone levels in women with PCOS who were within the ‘healthy’ body mass index (BMI) category (12). Although this is only one study, other research has found health benefits related to eating bigger meals earlier in the day, such as improved insulin levels and reduced inflammation (13). This is thought to be related to syncing up our meals with our body clock (which is also known as our ‘circadian rhythm’)



There is some evidence that an ‘anti-inflammatory diet’ may help to reduce inflammation and PCOS symptoms (14). An ‘anti-inflammatory diet’ is similar to the Mediterranean diet. This diet specifically includes: plenty of wholegrains, beans, pulses, fish, fruit, vegetables, nuts, olive oil, herbs, spices and green tea. This diet is also usually low in foods like processed red meat, sugary food and sugary drinks.



Women with PCOS often have low magnesium levels, which is an important mineral involved in many body functions including regulating: insulin levels, blood pressure and mood (15, 16, 17). Getting enough magnesium may also help to reduce symptoms related to PMS (premenstrual syndrome) (18).



Magnesium can be found in the following foods:

Pumpkin seeds

Brazil nuts

Almonds

Cashew nuts

Peanuts 🥜

Sunflower seeds

Soya beans

Wheat-based foods

Cooked spinach 🥬

Marmite

Zinc deficiency can also be common with PCOS. Getting enough zinc has been seen to improve a number of symptoms related to PCOS including: PMS, fertility issues, hair loss on the head and excess hair growth on the face (19, 20, 21)



Zinc is found in:

Oysters

Shellfish – especially crab and lobster 🦐

Red meat 🥩

Cashew nuts

Chickpeas

Baked beans 🥫

Fortified breakfast cereals 🌾

There are also individual dietary factors to consider. For example, some women who have a very heavy period may need to increase their intake of high iron foods, such as: red meat, eggs, leafy green vegetables, iron-fortified breakfast cereals, dried fruit, beans, tofu and certain nuts and seeds (see this food factsheet for more information about this). Others may need support with restoring balance to their diet, or working on their relationship with food if they have been on a number of diets over the years.



Overall, a healthy low-GI diet which is similar to the Eatwell Guide or Mediterranean style of eating is associated with improved outcomes for women with PCOS. Spacing meals out over the course of the day, rather than having one or two big meals, may help to stabilise blood sugars and reduce food cravings. And following the saying “breakfast like a king, lunch like a prince, and dinner like a pauper” might have further benefits.



Do Supplements Help?

There is some evidence that the following supplements may improve symptoms related to PCOS:

Folic acid: may help to reduce inflammation for women with PCOS (22).

Inositol: may help with fertility, hormone levels and cholesterol (23).

Vitamin D: has been linked with reducing insulin resistance and inflammation (24).

Omega-3: may improve fertility, insulin, glucose and cholesterol levels (25).

Cinnamon extract: has been seen to improve periods and insulin levels (26). A cheaper alternative is to add 1-2 teaspoons of cinnamon to the diet per day.

Chromium picolinate: may improve blood sugar and hormone levels (27).

Alpha-lipoic acid: possibly linked with improved insulin sensitivity (28).

N-acetylcysteine: may improve hormone balance, ovulation and fertility (29).

It is important to mention that although there is some exciting research related to specific supplements and PCOS, not all of this evidence very robust. When considering any supplements it always important to discuss this with your dietitian, doctor or pharmacist to ensure you are doing this in a safe way.



It is a good idea for most people in the UK and Ireland should consider taking a daily 10 microgram vitamin D supplement during the winter months for bone and muscle health – and this may have extra benefits for those with PCOS (30). Those who are trying to conceive should also take a folic acid supplement until the 12th week of pregnancy.



Lifestyle Factors

Stress hormones (such as cortisol) can worsen insulin resistance, which can worsen the symptoms of PCOS (9, 30, 31). Therefore, it is important for women with PCOS to prioritise relaxation and stress reduction.



There is some evidence that cinnamon extract An alternative option is to have 1-2 teaspoons of cinnamon per day.



Those with PCOS often report difficulty sleeping, which may be related to hormonal disturbances and insulin resistance (32). But good-quality sleep plays an important role in our wellbeing. For example, poor sleep worsens mood and immunity, and is also associated with a higher risk of heart disease, diabetes and obesity (33). Good ‘sleep hygiene’ can be helpful when trying to achieve 8 hours of restful sleep. This includes: getting into a good sleep routine, relaxing before bed and tweaking your sleep environment (see here for more information on this).



Exercise is associated with numerous health benefits, including a reduced risk of (34):

Heart disease and stroke

Breast cancer and colon cancer

Type 2 diabetes

Osteoarthritis, hip fracture and falls

Depression

Dementia

For women with PCOS, regular moderate-intensity exercise for 12 – 24 weeks has been linked with: improved ovulation, reduced insulin resistance and roughly 5 – 10% weight loss (35).



Public health guidelines recommend at least 30 minutes of moderate-intensity physical activity (like fast-paced walking or cycling) 5 days per week, plus strengthening exercises on at least 2 days per week. Some people may need to build up to this gradually, and others may comfortably include more activity than this in their week. See here for more information about staying active.



Although it is important for all of us to get enough sleep, exercise regularly and manage stress, these factors can also be a vital part of the treatment of PCOS.



Summary:

PCOS is a condition which can impact hormone balance and fertility. Losing weight (if overweight), following a healthy diet, and establishing a regular meal pattern can help to reduce the symptoms associated with PCOS. There is some evidence that certain supplements may be helpful for women who have PCOS, but it is always best to speak to your dietitian, doctor or pharmacist before trying a new supplement. However most in the UK and Ireland should consider taking vitamin D supplements during winter, and folic acid when planning a pregnancy. It is also particularly important for women with PCOS to get enough exercise and sleep, as well as managing stress levels.



References

(1) Irish Nutrition and Dietetic Institute (2015) “Polycystic Ovary Syndrome (PCOS)” [accessed via: https://www.indi.ie/fact-sheets/fact-sheets-on-women-s-health/542-polycystic-ovarian-syndrome-pcos.html]

(2) Barthelmess & Naz (2014) “Polycystic ovary syndrome: current status and future perspective” [accessed via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4341818/#R1]

(3) Riccardi et al. (2004) “Dietary fat, insulin sensitivity and the metabolic syndrome” [accessed via: https://www.sciencedirect.com/science/article/pii/S0261561404000263]

(4) Nestler et al. (1998) “Insulin Stimulates Testosterone Biosynthesis by Human Thecal Cells from Women with Polycystic Ovary Syndrome by Activating Its Own Receptor and Using Inositolglycan Mediators as the Signal Transduction System” [accessed via: https://academic.oup.com/jcem/article/83/6/2001/2865383]

(5) Baptiste et al. (2010) “Insulin and hyperandrogenism in women with polycystic ovary syndrome” [accessed via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3846536/]

(6) Mahkos et al. (2016) “Effects of Moderate and Subsequent Progressive Weight Loss on Metabolic Function and Adipose Tissue Biology in Humans with Obesity” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/26916363]

(7) Legro et al. (2016) “Benefit of Delayed Fertility Therapy With Preconception Weight Loss Over Immediate Therapy in Obese Women With PCOS” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/27172435]

(8) Moron et al. (2007) “C-Reactive Protein before and after Weight Loss in Overweight Women with and without Polycystic Ovary Syndrome” [accessed via: https://academic.oup.com/jcem/article-abstract/92/8/2944/2597513]

(9) British Dietetic Association (2016) “Food Fact Sheet – Polycystic Ovary Syndrome (PCOS)” https://www.bda.uk.com/foodfacts/pcos.pdf

(10) Marsh et al. (2010) “Effect of a low glycemic index compared with a conventional healthy diet on polycystic ovary syndrome” [accessed via: https://academic.oup.com/ajcn/article/92/1/83/4597432]

(11) (2007) “Diet and nutrition in polycystic ovary syndrome (PCOS): Pointers for nutritional management” [accessed via: https://www.tandfonline.com/doi/abs/10.1080/01443610701667338]

(12) Jakubowicz et al. (2013) “Effects of caloric intake timing on insulin resistance and hyperandrogenism in lean women with polycystic ovary syndrome” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/23688334]

(13) Jakubowicz et al. (2013) “High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/23512957]

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(15) Sharifi F et al. (2012) “Serum magnesium concentrations in polycystic ovary syndrome and its association with insulin resistance” Gynecol Endocrinol.

(16) Boyle et al. (2017) “The effects of magnesium supplementation on subjective anxiety and stress-A systematic review” Nutrients.

(17) Han (2017) “Dose-response relationship between dietary magnesium intake, serum magnesium concentration and risk of hypertension: a systematic review and meta-analysis of prospective cohort studies” Nutr J.

(18) Quaranta et al. (2007) “Pilot study of the efficacy and safety of a modified-release magnesium 250 mg tablet (Sincromag) for the treatment of premenstrual syndrome” Clin Drug Investig.

(19) Siahbazi (2017) “Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trial” J Obstet Gynaecol Res.

(20) Jamilian et al. (2016) “Effects of Zinc Supplementation on Endocrine Outcomes in Women with Polycystic Ovary Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial” Biol Trace Elem Res.

(21) Hessam (2016) “Combination of oral zinc gluconate and topical triclosan: An anti-inflammatory treatment modality for initial hidradenitis suppurativa” J Dermatol Sci.

(22) Asemi et al. (2014) “Metabolic response to folate supplementation in overweight women with polycystic ovary syndrome: a randomized double-blind placebo-controlled clinical trial” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/24828019]

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(24) Tehrani et al. (2014) “The effect of calcium and vitamin D supplementation on menstrual cycle, body mass index and hyperandrogenism state of women with polycystic ovarian syndrome” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/25535503]

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(26) Kort & Lobo (2014) “Preliminary evidence that cinnamon improves menstrual cyclicity in women with polycystic ovary syndrome: a randomized controlled trial” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/24813595]

(27) Amooee et al. (2013) “Metformin versus chromium picolinate in clomiphene citrate-resistant patients with PCOS: a double-blind randomized clinical trial” [accessed via: https://www.ncbi.nlm.nih.gov/pubmed/24639797]

(28) Masharani et al. (2010) “Effects of Controlled-Release Alpha Lipoic Acid in Lean, Nondiabetic Patients with Polycystic Ovary Syndrome” [accessed via: https://journals.sagepub.com/doi/abs/10.1177/193229681000400218]

(29) Thakker et al. (2014) “N-Acetylcysteine for Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials” [accessed via: https://www.hindawi.com/journals/ogi/2015/817849/abs/]

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(33) NHS Choices (2018) “Why lack of sleep is bad for your health” [accessed via: https://www.nhs.uk/live-well/sleep-and-tiredness/why-lack-of-sleep-is-bad-for-your-health/]

(34) NHS Choices (2018) “Benefits of exercise” [accessed via: https://www.nhs.uk/live-well/exercise/exercise-health-benefits/]

(35) Harrison et al. (2010) “Exercise therapy in polycystic ovary syndrome: a systematic review” [accessed via: https://academic.oup.com/humupd/article/17/2/171/692261]