This post was updated on September 8th, 2022
By Kym Campbell, BSc. | Updated September 8th, 2022
During my free 30-Day PCOS Diet Challenge, I ask participants to stop eating sugar, gluten, and dairy. Many of the most successful participants find that these three changes make a big difference.
What we have instead is a confusing landscape of information. In this article I share the most important facts about PCOS and dairy, so you can decide what’s best for you.
If going gluten and dairy free is something you want to try, then this free 3-Day Meal Plan is a great way to get started. I run my 30-Day Challenge four times a year though, so hopefully, you don’t have long to wait until the next one begins.
1. Dairy, Insulin Resistance, & Type 2 Diabetes
The USDA recommends 3 cups of dairy per day for everyone over the age of 8. This is in keeping with the belief that milk and its derivatives are healthy.
But the truth is a little more complicated.
Several studies have suggested that dairy may reduce the risk of insulin resistance and type 2 diabetes. But there are many ambiguities about these benefits. For example, a 2020 literature review could not determine a beneficial effect on insulin sensitivity in women with PCOS. It may, in fact, be a predictor of insulin resistance .
This is the case for dairy generally, but there’s a clearer result for yogurt and fermented dairy. Many studies have shown that these foods reduce the risk of developing type 2 diabetes [2-4]. This benefit is likely due to the probiotic effects of the live cultures they contain [5, 6].
2. Dairy’s Impact On Fertility
There’s been a lot of research on the influence of dairy on female fertility. Results have varied significantly.
One large study found that each daily serving of low-fat milk products increased the risk of ovulatory infertility by 11%. But adding one serving of whole milk reduced the risk by 50% . This difference has been attributed to high-fat milk having less impact on raising insulin-like growth factor 1 (IGF-1) levels . Higher concentrations of IGF-1 produce a negative effect on ovarian function.
More recent studies challenge these findings. At best, any associations between dairy intake and fertility appear to be small .
3. Dairy Is Bad For PCOS Acne
The mechanisms are well-understood. Dairy increases IGF-1 levels. This elevates androgen levels and works through other pathways to cause the development of acne. Leucine, a common amino acid in dairy proteins, also contributes to the problem .
The dairy protein casein stimulates IGF-1 to a greater extent than whey . This suggests that casein-rich foods like cheese are likely to promote acne. But whey proteins can impact insulin levels providing a different path to promote acne. This may be why whey protein powders can aggravate acne in athletes [14, 15].
In my experience, the exclusion of dairy can be great for reducing acne. I often see these benefits in women that take part in my free 30-Day PCOS Diet Challenge.
4. Dairy Can Cause Inflammation
Systematic reviews of clinical trials show that dairy products have weak anti-inflammatory effects. But for people with milk allergies, dairy drives up inflammation [16, 17].
From what I’ve seen, a lot of women with PCOS have an intolerance to dairy that they’re not aware of. These same women also often have gluten intolerance. In both of these cases, a subclinical intolerance can damage the intestinal wall lining. This causes inflammation .
Chronic inflammation is one of the underlying mechanisms that cause PCOS [19-24]. Because of this, the consumption of dairy products can be a major problem for women with an unknown intolerance. This is why I recommend all participants in my free 30-Day PCOS Diet Challenge abstain from dairy for at least 30 days. The benefits of removing inflammatory foods are a key reason for success stories like Raynetta’s.
It’s not just lactose that can cause a sub-clinical dairy intolerance. The whey and casein proteins can also be poorly tolerated. Any dairy products that contain added sugar are also more likely to exert an inflammatory effect. This is why sugar features on my list of seven foods to avoid with PCOS.
Butter and ghee are the only dairy products I use in my PCOS recipes. These ingredients contain only trace amounts of lactose, whey, and casein. They are generally well-tolerated in all but a few with extreme dairy allergies.
5. The Calcium Argument Is Weak
One of the most common reasons people say that dairy is healthy is that it’s a great source of calcium. The problem is that there are big holes in this argument.
In 2020, researchers analyzed the relationship between milk consumption and several health outcomes. This included the risk of fracture, heart disease, allergies, and cancer . According to one of the authors, “The basis of calcium recommendations is… fundamentally flawed…”.
They present a compelling argument why the recommended calcium intake of 1,000 mg/day is unnecessarily high. For example, in countries like Peru with low calcium intakes, only 200 mg/day is needed. The explanation here is that the body absorbs more calcium when it’s less available in food.
Other researchers agree. An independent team from the University of Arizona reviewed the science of dairy too. They recommended that dairy be ditched as a separate food group. Instead, they said that dairy should be included in the protein category as one of many choices .
Many non-dairy sources can provide adequate calcium to support a PCOS diet. This includes chia seeds, almonds, tofu, and white beans. Spinach, broccoli, and kale are also high in calcium. Fish is one of the best sources though. A 3 oz (85 g) can of sardines with bones, for example, contains 325 mg of calcium. A can of salmon has 180 mg.
So, Should Women With PCOS Avoid Dairy?
It’s unclear if consuming dairy is good or bad for insulin regulation. However, it can cause inflammation in some women, and exacerbate other PCOS symptoms. Any pros or cons from dairy on fertility are likely to be small. But we know that dairy makes PCOS acne worse.
The evidence in favor of dairy for PCOS is strongest for yogurt and other fermented foods. These dairy products appear to lower the risk of type 2 diabetes. This is likely due to the probiotic cultures they contain.
Given the limitations of what can be found in the scientific literature, my recommendations for women with PCOS are simple. You need to find out if you feel better with or without it for yourself.
I recommend an elimination period of at least 4 weeks. But longer is better. Butter and ghee are okay to consume, but avoid everything else during this time.
During your elimination period, pay close attention to your gut health and PCOS symptoms. If things get better, then there’s a good chance dairy isn’t right for you. But you can confirm by reintroducing.
When you re-introduce, I recommend going hard. Eat as much dairy as you want. Make sure to consume a few glasses of milk each day. Then see how you feel. If you notice any gut discomfort, constipation, or diarrhea, then treat this as a signal. Mood, concentration, and energy levels may also be affected if dairy isn’t right for you. If acne, hair, or other skin issues get worse, again, you’ve got another signal.
This process of self-experimentation can be repeated on different types of dairy products. If you notice a reaction to milk, but you’d still like to eat yogurt or kefir, then test these foods in isolation. Same with cheese. Keep in mind that soft cheeses contain a lot more whey and lactose than hard cheeses. Parmesan cheese, for example, is mostly casein and fat. It has very low levels of whey and lactose. Depending on your sensitivities, you may find that you can better tolerate hard cheeses than soft ones.
The Bottom Line
There’s no one-size-fits-all answer when it comes to dairy for women with PCOS. Potential pros and cons depend on the type of dairy product and personal circumstances. But there are compelling reasons to try a dairy-elimination diet. Doing so can enable you to better manage your symptoms. Many women with PCOS have a sub-clinical dairy intolerance. An elimination diet is the best way to find out if you’re one of them.
To take part in a group elimination diet sign-up for my next free 30-Day PCOS Diet Challenge. You’ll receive gluten and dairy-free PCOS meal plans, recipes, and shopping lists. You’ll also get video lessons delivered within a supportive group environment. Alternatively, get started today by downloading my free 3-Day PCOS Diet Meal Plan.
Ready To Take Action?
Which dairy products to avoid for PCOS? During any elimination diet, I recommend avoiding all dairy apart from butter and ghee. This includes cheeses, yogurts, kefir, cream, and milk.
Where can I find a PCOS gluten and dairy-free meal plan? I have several resources listed in the Ready to Take Action section above. I recommend starting with my free 30-Day PCOS Diet Challenge and my free 3-Day PCOS Meal Plan.
Is soy milk good for PCOS? Soy milk is likely better for PCOS than cow’s milk. Soy, however, also has several nuances worth considering. Some of these are described in the FAQ section of my Foods to Avoid with PCOS article.
Is low-fat milk for PCOS better? No. High-fat milk is likely to be better for women with PCOS. Milk fat improves insulin regulation, and reduces the risk of ovulatory infertility.
What’s wrong with lactose-free milk for PCOS? Lactose-free milk is better for PCOS if your dairy intolerance is limited to lactose. If you have a sub-clinical sensitivity to whey or casein proteins though, lactose-free milk will likely make your symptoms worse.
What’s the best milk alternative for PCOS? Unsweetened nut and seed milks are best. Anything non-dairy with minimal sugar is likely to be suitable though. This includes oat milk.
What about milk powder for PCOS? Milk powder is essentially the same as the milk from which it was produced. The only difference is that water has been removed. There has also been modest degradation of the protein quality during the drying process. I recommend women with PCOS avoid milk powder unless they have completed an elimination diet first.
Since 2010, Kym Campbell has used evidence-based diet and lifestyle interventions to manage her PCOS. After getting her symptoms under control and falling pregnant naturally, Kym now advocates for dietary change as part of any PCOS treatment plan. Combining rigorous science and clinical advice with a pragmatic approach to habit change, Kym is on a mission to show other women how to take back control of their health and fertility. Read more about Kym and her team here.
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