PCOS Nutrition FAQs: Gluten, Dairy, and Soy

Are you feeling confused about the mixed messages when it comes to PCOS nutrition?

Do you have to go gluten free? Do you have to cut out dairy? Do you have to do keto? At every corner of the internet there’s someone saying something different–and it can feel really overwhelming. Truth is, the issue is nuanced, and it’s important to look at the research.

In this article, we break down the current research around gluten, dairy, and soy with PCOS and provide specific recommendations for you.

Let’s dive in!

“Do I Have to Eat a Gluten-Free Diet if I Have PCOS?”

There is currently no research that shows a connection between a gluten-free diet and PCOS. This doesn’t mean a gluten-free diet has no merit for PCOS–it just means no research has been done in this area.

Let’s dig into what we know:

Women with PCOS have higher markers of inflammation than women without the syndrome¹. Some people suggest that avoiding gluten may alleviate some of this inflammation. And some women do find that their symptoms decrease once they go gluten-free.

However, it’s unclear whether this benefit is because they’re eating fewer carbs and calories when they go gluten-free, or if the benefit is from the gluten-free diet itself. 

When on a gluten free diet, most people are likely avoiding high calorie, processed foods like cookies, cakes, bagels, etc… So they might just be eating fewer calories and carbs in general, resulting in the positive effects on their PCOS symptoms. It’s unclear.

More research is needed before definitively saying all women with PCOS need to eat a gluten-free diet.

My recommendation: Before eliminating gluten entirely, try to reduce your overall carb intake first. If your goal is weight loss, reduce your overall calorie intake as well, and build healthy habits like exercising regularly. Nail the basics principles of weight loss, and focus on staying consistent.

[Related: How to Lose Weight with PCOS]

If that does not alleviate your symptoms, then try other approaches like a gluten-free diet for a few months, and see how you feel.

A gluten-free diet can be difficult to follow and challenging to adhere to long-term. It might not be something you want to jump into immediately. If it’s not followed correctly, a gluten-free diet can result in iron, folate, niacin, zinc, and fiber deficiencies.

Note: Every one of our PCOS clients who have lost weight have done so while eating gluten. It’s not necessary to cut it out for many people. But, if a gluten-free approach makes you feel better, go for it. The best nutrition approach is one that’s sustainable, realistic, and effective for you. 

“Can I Eat Dairy with PCOS?“

There are pros and cons for eating dairy with PCOS, and unfortunately research is very limited: There have only been two studies done around the link between PCOS and dairy. Neither are randomized control trials, and both were conducted with a very small number of women. In addition, most of the current research has been done with milk, not cheese or other dairy sources like yogurt.

That being said, let’s dig into what we know:


CONS of Eating Dairy With PCOS:

1. Dairy can increase insulin levels: Dairy products contain a hormone called IGF-1 (Insulin Growth Factor-1), which can result in high insulin levels when consumed.
   
2. Dairy consumption is linked to acne development: A few studies have indicated dairy may have a positive relationship on acne development–fat-free and low-fat milk were shown to have the most impact on acne development, compared to full fat milk or cheese.^3,4
   
3. Dairy consumption can increase androgens: Dairy contains a whole slew of growth hormones, including IGF-1 (mentioned above) and DHT (dihydrotestosterone), an androgen. Consuming high amounts of dairy may increase your overall levels of androgens in your body–which is not what we want with PCOS.
   

PROS of Eating Dairy With PCOS:

1. Dairy intake, specifically full-fat dairy products, has been shown to have a positive impact on fertility.⁵ This can be really important for women with PCOS.
   
2. Dairy can also be a great source of protein for vegetarians (cheese, Greek yogurt, etc).
   
3. Dairy can be a great source of Calcium and Vitamin D for women.
   

Conclusion:

Right now, there is no evidence that all women with PCOS need to cut out all dairy completely. It depends on a lot of individual factors.

For example, if you have acne related to PCOS, you may want to limit dairy–especially skim or low fat milk–to see if that has an improvement. Try cutting it out for two weeks, and slowly re-introduce it into your diet. See how your skin reacts and if it breaks out.

Others may be able to continue eating dairy in limited quantities. Because of it’s potential androgenic effects, we would suggest 1-2 servings a day, and make sure you are diversifying your protein sources to get a variety of different types of protein (especially if you are vegetarian).

If you’d like to cut it out and see how you’d feel, go for it. Try eliminating it for 2-4 weeks, and see how you feel. If you do cut out dairy, make sure you’re getting Calcium and Vitamin D elsewhere in your diet.

At the same time, make sure that you’re focusing on building an overall healthy lifestyle: Exercise, eat a variety of unprocessed, nutrient-rich food, and eat in an overall calorie deficit if your goal is weight loss.

Your overall behaviors and patterns will matter more than one specific food group.

There is no one-size-fits all approach here. Many of our PCOS clients lose weight and improve their PCOS symptoms while eating dairy regularly, while other clients feel better with a dairy-free approach.

“Can I eat Soy with PCOS?“

So far, research shows an overwhelmingly favorable link between soy and PCOS.

One randomized clinical trial⁶ divided up women into two groups, and had them each eat a different diet for 8 weeks. Both groups had to eat 0.8g protein per lb of bodyweight, but the control group ate 70% animal protein and 30% vegetable protein, while the test group had 35% animal proteins, 35% soy protein and 30% vegetable proteins.

At the end of the study, they found that the women who ate more soy protein had significantly:

• Lower BMI
• Decreased total testosterone levels
• Reduced triglycerides
• Lower insulin levels
  

Another study⁷ had women with PCOS supplement their diet with soy isoflavones (50mg a day for 12 weeks). The women who took the supplement had:

• Less insulin resistance
• Better hormonal status
• Reduced triglycerides, and
• Lower biomarkers of oxidative stress.

Other studies have also shown soy helped reduced testosterone and cholesterol levels in women with PCOS.^14,15

Soy has been shown to have positive effects on fertility, as well.^8,9,10

The only area where research is mixed is with hypothyroidism:

Women with PCOS have been found to have a higher incidence of thyroid disorders. Several randomized controlled trials have shown that high amounts of soy can cause thyroid disorders. However, other randomized trials show the opposite.^11,12

All in all, we would recommend eating moderate amounts of soy per week if you have PCOS, because of all the potential benefits. If you have hypothyroidism and PCOS, you may wish to avoid high amounts of soy, but you do not have to fear it completely. So far, the majority of research available shows that small amounts of soy does not impact thyroid function in those with or without thyroid disorders.

“Do I have to eat a low-carb diet if I have PCOS?”

A low-carb diet may be beneficial for women with PCOS—Especially for women with PCOS who have insulin resistance, which is around 80% of women with PCOS. 

However, the most important factor that improves PCOS symptoms in overweight women is weight loss overall, with the diet type being secondary. 

Two big systematic review have looked at all the link between a low carb diet and PCOS: The first review, by Moran et. al looked at various types of diets and their effects on PCOS, and found that a low carb diet resulted in improvements in insulin resistance, cholesterol, and more.¹⁶

The second systematic review, by Frary et al found that a Low Carb Diet had a 1-5% significant additional effect on weight loss compared to a standard diet.¹⁷ 

But both reviews found that weight loss overall resulted in better PCOS symptoms for overweight women. For women with PCOS,  just a 5-10% reduction in body weight can improve:

• Ovulation rates
• Conception rates
• Insulin levels
• Testosterone levels
• Insulin resistance 
• Satiety hormone

Conclusion: If you have PCOS and are overweight, focus first on reducing weight overall through creating a calorie deficit and building healthy habits. A lower-carb diet may certainly help you feel your best and optimize weight loss, but a calorie deficit overall is the most important.

If you opt for a lower-carb diet, you don’t have to go zero-carb or keto, but try reducing carbs slightly from where you are now and see how you feel. 

See this article here: How to Lose Weight with PCOS which describes steps to lose weight with PCOS.

Conclusion

PCOS nutrition can feel confusing, no doubt— Especially since research is pretty limited in this area. You may see many people online making blanket statements, telling you “you have to cut out XYZ if you have PCOS!” But the truth is, nutrition is nuanced and there’s no one-size fits all approach. The best nutrition strategy vary from person to person, and needs to balance what’s effective for your body, while being realistic and sustainable for your lifestyle. 

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