What’s the Best Diet to Follow for PCOS?

Confused about what to eat when battling with PCOS? 

“Cut out gluten…” 

“Ditch the dairy…” 

“Stick to keto…”

There’s no shortage of opinions on social media and the internet when it comes to this topic. 

Notice we said opinions…

Most of what you read is not much more than well-intentioned advice from those who have seen positive results after making a certain trendy dietary change that has worked for them. 

That’s great! But…

Does one person’s dietary success apply to ALL the other women out there with PCOS?

All too often, we’ve seen women with PCOS who have tortured themselves trying to stick to the latest fad or whatever has worked for their friend. Ready to break that cycle? 

Here’s a quick overview of what you’ll discover:

As we discussed in last week’s post, lifestyle changes are the first-line treatment for women with PCOS. In doctor-speak, that means don’t just throw medications at the problem!

Unfortunately, we know that’s not what most women struggling with PCOS experience when they go to the doctor…

We strongly believe that women with PCOS should be provided knowledgeable information about incorporating certain dietary changes (and exercise too) to help improve their symptoms… all while allowing enough time for these interventions to make a difference. 

Of course, when symptoms are severe (e.g., hair growth on your face, uncontrollable cystic acne, or other medical issues like insulin resistance), pharmacologic treatment (prescription medications) may be required alongside lifestyle modifications.

When it comes to prescription medications, we always tell our patients, the treatment depends on the goal. But no matter what you and your physician decide, optimizing your diet plan will help improve your symptoms and increase the chance of treatment success (more on that in just a moment!).

But before jumping into all things nutrition, we thought it might be helpful to briefly review the prescription medications most commonly prescribed for PCOS. 

The goal here is to give you a balanced view of the risks and benefits of each, so you can make your own decision as to what is best for you as an individual. This means making sense of the information your doctor gives you as well as the “knowledge” social media influencers present in your feed. 

Please know that we never recommend using medications to simply cover up your PCOS symptoms. Taking a holistic approach that addresses the root cause of your unique situation is what our programs at OvulifeMD are all about. 

Combined oral contraceptive pills (OCPs)

Benefits:

Often considered by many providers to be the first-line treatment for PCOS, oral contraceptive pills (OCPs) can help manage symptoms in multiple ways. 

Firstly, they regulate menstrual cycles, which means you can say goodbye to that unpredictable bleeding pattern and prolonged endometrial exposure to unopposed estrogen (which is associated with a higher risk of endometrial abnormalities as we discussed last week).

Further, the estrogen component within OCPs actually increases protein production of sex hormone-binding globulin (SHBG), which does exactly what the name says – it binds up sex hormones. Physiologically, when a hormone is bound to a carrier and not circulating freely in the blood its effects aren’t nearly as strong. In this case, when the amount of SHBG increases, the amount of circulating free testosterone decreases. This means fewer hyperandrogenic symptoms including hair growth and acne that are commonly associated with PCOS.

Of note, while the menstrual cycle regulation is experienced immediately,  it takes at least 6 months to see the full effects of OCPs in terms of improving hyperandrogenic symptoms. So before you think it’s not working, you have to give it time!

Risks:

Now if you’ve spent any amount of time researching the topic, you know that OCPs do have some side effects. The most commonly mentioned side effects include an increased risk for blood clots and stroke. More recent evidence has also noted increased rates of depression among women taking OCPs (1).  

Finally, as you know OCPs prevent pregnancy, which isn’t necessarily a side effect per say, but it will certainly impact your fertility. There are those that suggest OCPs can disrupt your fertility upon discontinuation, but that is a topic for another day…

Antiandrogens

Benefits:

Whereas the anti-androgen effects of OCPs occur via a secondary mechanism of action, there are drugs that specifically have anti-androgen effects by way of blocking hormone receptors (thereby blocking the androgen function directly) or inhibiting enzymes that prevent the conversion of certain hormones into more potent androgens.

Some of these include drugs like spironolactone, flutamide, finasteride (all oral medications), and the topical cream, eflornithine. 

These are typically used for excessive, bothersome hair growth and treatment-resistant acne.

Risks:

Although each of these can be incredibly effective, particularly when used in conjunction with lifestyle modifications and OCPs, they are also teratogens (meaning they can cause birth defects). So, again when pregnancy is the goal, these are not an option.

Another thing to be aware of is the ability of some of these medications to cause electrolyte imbalances along with breast swelling and tenderness. 

Insulin sensitizers

Benefits:

Given that insulin resistance is known to play an important role in the pathophysiology of PCOS, researchers initially thought medications that reduce insulin resistance would help. 

Metformin is a medication that not only makes your body more sensitive to insulin but also acts to decrease the liver’s production of glucose.

While early data was promising and suggested higher ovulation rates and improved metabolic features in women with PCOS, large well designed randomized controlled trials confirmed that metformin alone was inferior to standard ovulation induction agents like clomiphene citrate or letrozole (2).

When metformin was used in combination with clomiphene citrate, ovulation rates were higher than with clomiphene alone but were no better than letrozole alone which has been shown to have the highest live birth rates in women with PCOS (2,3).

So where has the data left us with recommendations for metformin use in women with PCOS?

Expert recommendations suggest that:

Risks:

Although metformin is considered by many to be a miracle drug, due to its insulin-sensitizing properties (among others), it doesn’t come without its own side effects and risks. Common side effects include gastrointestinal (GI) upset including nausea, vomiting, and diarrhea (which may play into its role in weight loss) and abdominal discomfort.  

Long-term use has also been associated with vitamin B12 deficiency so it’s important to keep that in mind as well, particularly if the goal is pregnancy. 

Food As Medicine

As you can see, medications have their time and place when treating PCOS. However, they are certainly not without their potential adverse effects. 

Dietary changes, on the other hand, don’t come with these worrisome side effects – not to mention they can improve your overall health and fertility too!

But how are you supposed to go gluten-free, dairy-free, low-carb, high-protein with a splash of grapefruit juice every day for life?

Well… you’re not!

That’s why we’re going to cover which diets have actually been shown to be effective for PCOS, and in more than just one person (yes, we are implying that just because one woman cut out dairy, doesn’t mean it will work for all women with PCOS).

First of all, we think it’s important to start by pointing out that everyone is different. 

That may sound cliche, but it’s true. 

Just because the ketogenic diet or going gluten-free worked for your friend, doesn’t mean it’s going to work for you. Yes, we’ve been there too… It’s completely normal to get excited when you see positive results in someone else’s life. 

So when it comes time to choose an optimal PCOS diet plan, our goal here is to discuss which diets have been backed by actual scientific data and explain why one diet may be more effective than another. 

And remember from our initial post in this series, an effective diet should ultimately check 3 boxes:

The reality is we have a lot left to learn but we don’t want you believing every new fad you see on the internet, or torturing yourself counting calories and eating food that doesn’t taste good or make you happy.

Because guess what? It doesn’t have to be that way.

A full literature review is outside the scope of this blog post… and it would likely make your eyes completely glaze over, so we’re going to summarize the high points here.

When looking at the data regarding diet and PCOS, the types of diets studied include things like:

Unfortunately, most of these diets all have one thing in common – they are quite difficult to maintain over the long term… anyone who’s tried a low carb diet knows just how tempting bread, pasta, and baked goods can be after just a week.

And the liquid meal replacement eating plan? Been there, done that, and personally, we think they’re miserable.

So which diet has been shown to improve clinical outcomes AND is actually easy to AND has been associated with an improved quality of life? 

Say hello to the low glycemic load diet.

As we reviewed back in our Decoding the Fertility Diet Series — the one about carbohydrates — glycemic index basically refers to how a particular carbohydrate affects your blood sugar over time compared to sugar.

Glycemic load simply takes into account the serving size of a particular carbohydrate making it a more practical measure to use. 

In the general population, low glycemic index diets have been associated with a lower risk of (5):

Does that list look familiar? 

It’s essentially the list of associated comorbidities that women with PCOS are at risk for. So in this context, it seems to make sense to consider a low glycemic load diet to optimize PCOS outcomes.

When looking at studies that simply altered JUST the quality of carbohydrate consumed (not calorie restricting in any way, data has shown that increased intake of low glycemic load carbohydrates in women with PCOS has resulted in (6):

This study was a non-randomized control trial of PCOS women with overweight or obesity and had a macronutrient breakdown of about 50% carbohydrate, 23% protein, 27% fat. Women in the study also engaged in physical activity 30 minutes per day for 5 days per week or aimed for 10,000 steps per day, which certainly may have potentiated some of the effects.

Needless to say, that seems doable, right?

Another study found that as little as 12 weeks of this type of intervention has shown improved insulin sensitivity in women with PCOS without any calorie restriction! By simply swapping out high for low glycemic load carbs, clinical benefit was achieved (7).

Further supporting these findings, a more recent study showed that women with PCOS who had the highest intake of high-glycemic-index carbs had a higher body mass index (by nearly 6 points) and waist circumference (difference of over 10 cm), regardless of the same daily caloric intake, compared to women who consumed the least amounts of high glycemic index carbs (8). 

Simply swap out high and medium glycemic load foods with low glycemic load foods… could it really be that easy?

Well, we think that is one of the biggest parts of optimizing diet for PCOS as elevated insulin levels and insulin resistance is thought to be a central part of the pathophysiology of PCOS and this is one of the most effective ways to mitigate that.

These carb swaps should be incorporated as a part of an otherwise whole foods-based diet that’s rich in fruits, vegetables, plant-based proteins, omega-3 rich fish, and the occasional high-quality, high-fat dairy.

In terms of relative amounts of macronutrients, benefits have also been shown with about 40% of calories coming from carbohydrates, 30% from protein, and 30% from fat in women with PCOS with improved:

The majority of “low carb” studies in women with PCOS have also implemented caloric restriction (up to 1000 calorie deficit per day) which must be taken into account when interpreting the above findings. Regardless, this relative macronutrient breakdown is a good target to keep in mind when starting with swapping out the quality of your carbohydrate (10). Basically, don’t just consume 100% of your calories from low glycemic load carbs. Fat and protein are important too.

So give it a try- start by simply swapping out the type of carbohydrate you eat! Give it one month and see how you feel. We’ve included a quick reference graph here so you can make some simple food swaps starting today. 

And again, remember… focus on nutrition, NOT “dieting.” This is a lifestyle change, not a short-term fix. Let’s make it count!

We totally understand if you haven’t seen or heard much about a low-glycemic diet in the past. It’s certainly not as sexy as other diets and it doesn’t get much love on social media. 

So before we wrap up our conversation on nutrition and PCOS, we wanted to address some of the more trendy diets we commonly get asked about from our patients…

What about gluten? Should I go gluten-free too?

To date, there’s NO evidence-based research that demonstrates a clear connection between PCOS and gluten-free or gluten-laden foods (type it into PubMed and see how many results come up). With that said, we recognize that just because there aren’t any papers published at this time, doesn’t mean there’s not something worth looking at. 

We promise to tackle a full review of gluten later, but from an integrative/functional medicine standpoint, here’s what we know…

PCOS is thought to be partially a state of increased inflammation and insulin resistance. And it has been suggested that regular consumption of gluten-containing products can contribute to chronic inflammation (11). Therefore, the theory is that reducing gluten consumption (or avoiding it altogether) could potentially lessen inflammation in PCOS. However, more research is definitely needed before making broad recommendations that all women with PCOS should go gluten-free. 

One more quick point about gluten, if not appropriately executed, consuming strictly gluten-free foods can result in deficiencies of key nutrients, including pro-fertility nutrients iron and folate. So please do your homework and speak with a nutritionist before you decide to go gluten-free. 

Bottom line… There’s a significant lack of evidence to support a gluten-free diet for all women with PCOS. The best nutritional approach in this situation, as with most, is a personalized one – if eating gluten doesn’t make you feel good, stay away from it. Make a plan that works for you.

Isn’t keto best for women with PCOS?

The next most common question we hear is, “but I heard keto was best for women with PCOS?”

You’ve probably seen this one all over your social media account.

If you need a quick refresher on the ketogenic (“keto”) diet- you can find that here.

But what has the data actually shown when it comes to keto and PCOS?

First of all, it’s important to note that, similar to gluten, data is limited in this area. Second, using keto for weight loss versus using it to boost your fertility are two different goals and this should be taken into consideration when examining the literature and considering it for yourself.

With that said, let’s take a look at what we found…

A small study looked at 11 women with PCOS (BMIs > 27) who limited their carbohydrate intake to 20 gram/day or less for 6 months (12). Of the initial 11 women, only 5 completed the study.  And although researchers found an overall improvement in body weight, testosterone levels, and insulin levels, the individual outcomes of the 5 women were less than exciting (1 experienced an increase in testosterone, 1 experienced no change in the diabetes marker A1c, and 1 experienced an increase in their A1c). 

We have to admit, it’s hard to make any sweeping generalizations or conclusions based on 5 women.

A more recent study of 14 women underwent a modified ketogenic Mediterranean diet (KEMEPHY diet) supplementing with “food supplements and liquid herbal extracts” for 12 weeks (13). This study also noted reduced body weight as well as improved androgen levels and measures of insulin resistance. However, the effects of the Mediterranean-type diet, “food supplements”, or “herbal extracts” cannot be disentangled from the “keto” portion of this diet and limits its generalizability. Another small study of 18 women suggested improvement in fatty liver symptoms in women with PCOS but didn’t assess pregnancy-related outcomes (14).

We’re not saying this data isn’t helpful, it’s just important to keep in mind the primary outcome wasn’t pregnancy in either of these studies and these small numbers of women were followed for relatively short periods of time. Additionally, quality of life, anxiety, and depression scores were not assessed which are vitally important to any lifestyle change you might take on.

Bottom line: Data is severely lacking when it comes to keto for PCOS.

Although pharmaceutical medications have their time and place, dietary lifestyle modifications are some of the best first-line treatments for PCOS.

To quickly recap, the right dietary choices for PCOS can help with:

Focus on consuming a diet rich in low glycemic load carbohydrates including things like whole grains, fruits, and vegetables. In terms of relative amounts of macronutrients, benefits have also been shown with about 40% of calories coming from carbohydrates, 30% from protein, and 30% from fat. And although we say “diet” we really want you to focus on nutrition and eating patterns. NOT “dieting” in this traditional sense of the word. This is a lifestyle change, not a short-term fix. Let’s make it count.

And if you want to boost your fertility too, follow a pro-fertility diet with increased intake of plant-based proteins and food sources rich in omega-3 fatty acids. 

It’s also important to note that any amount of exercise can help too, but more on that in an upcoming post… but start by making a plan that works for YOU.