Nutritional Strategies to Optimize Fertility With PCOS (Episode 509)

Full Transcript: Episode 509

Lisa Hendrickson-Jack: This is the Fertility Friday Podcast, episode number 509. Today I’m sharing episode number two in our two-part series — my interview with Lily Nichols, co-author of our new book, Real Food for Fertility. In today’s episode, Lily dives into some of the nutritional strategies for maintaining optimal fertility, and we highlight PCOS as kind of a case study to show why balancing blood sugar and optimizing both macro and micronutrient intake is essential for optimizing fertility. But we also share why these strategies are important for all women seeking to optimize their fertility, regardless of whether or not they have PCOS.

Before we jump in, I’ll share a little bit about Lily. Lily Nichols is a registered dietitian/nutritionist, certified diabetes educator, researcher, and author with a passion for evidence-based prenatal nutrition. Her work is known for being research-focused, thorough, and critical of outdated dietary guidelines. She is founder of the Institute for Prenatal Nutrition, co-founder of the Women’s Health Nutrition Academy, and the author of three books — Real Food for Pregnancy, Real Food for Gestational Diabetes, and of course our new book, Real Food for Fertility. Lily’s bestselling books have helped tens of thousands of mamas and babies, are used in university-level maternal nutrition and midwifery courses, and have even influenced prenatal nutrition policy internationally. So without further ado, let’s go ahead and jump into today’s episode.

And I’m excited to be back again with Lily Nichols for our part two throwdown on Real Food for Fertility. Welcome back.

Lily Nichols: Happy to be here. Let’s do this.

Lisa: All right. Well, so in our first episode together, I had a ton of fun. We were able to really talk a little bit more about the process of writing and share some behind the scenes. But in today’s episode, we wanted to get into some of the nitty-gritty details, and especially some of the details that you went into in your sections of the book. We have on the agenda today to talk a little bit about PCOS and to talk a little bit about protein, because you found some really interesting data. Share with us what you found about the significance of protein in fertility and how it relates, especially to women with PCOS.

Lily: Well, I’ve long been a proponent of people consuming enough protein for many reasons, even outside of the childbearing and pre-childbearing years, just because of its effect on satiety and blood sugar regulation. It just makes a very tangible difference when people get enough protein, and so many people I find are undereating. So I went into this maybe a little naive because I’m coming at it from the assumption that protein is important, but I wasn’t sure how far off the recommendations are for supporting optimal fertility compared to what our recommended dietary allowances are. Fertility is a little bit trickier to nail down than pregnancy.

So I went at it from a couple of different angles — looking at the blood sugar perspective and how that affects fertility, looking at ovulatory function and what we observe in large observational studies, looking at it mechanistically from what’s going on with individual amino acids and how that affects the menstrual cycle, ovulation, conception, and early embryogenesis. Looking at it from all of those angles, I could say that optimal protein intake for supporting fertility, reproductive hormone levels, menstrual cycle function, and supporting optimal micronutrient intake — we need more protein than the standard recommendation. And actually it aligns pretty closely with the data that we have on pregnancy. Outside of pregnancy, leading up to pregnancy, supporting fertility, you probably want to aim for at a minimum the protein levels I’m recommending for early pregnancy in Real Food for Pregnancy. Women who are more physically active need to aim even higher. The most successful dietary intervention trials for PCOS were those that modified the macronutrient ratios in a way that they were eating more protein — specifically airing toward more protein and fat and less carbohydrates, or at the very least, better quality low glycemic carbohydrates.

Lisa: So I think a lot of our listeners are familiar with PCOS, but maybe share a little bit about the metabolic issues that arise with PCOS, and why the dietary change and the focus on protein would be so important.

Lily: To highlight one of the areas I was really focusing on: the insulin resistance component, which actually ties into the other metabolic components. The majority of PCOS cases involve some level of insulin resistance — anywhere from 50 to 70 percent of women with PCOS are insulin resistant to some degree. And depending on which of the four phenotypes — A, B, C, or D — levels of insulin resistance can differ. The reason this matters is that you have insulin receptors all throughout your body, including on the ovaries. If our bodies are exposed to high levels of insulin day in and day out, meal after meal for a really long time, the body starts to become insulin resistant — it stops responding like it normally would to insulin, and then the body has to pump out even more insulin to get the same blood sugar-lowering effect. When we can bring insulin levels down — which we usually need to do by not spiking blood sugar as frequently and as high — then over time we’re not only lowering insulin levels but also lowering insulin resistance.

It’s really tricky to bring blood sugar levels down without consuming enough protein. By and large, carbohydrates are the biggest macronutrient that’s going to spike your blood sugar. Protein and fat will trigger a fairly small release of insulin — in people who are not diabetic, the blood sugar surge caused by protein is really, really small. So if we can get the levels of insulin and insulin resistance down, you start to see the other metabolic issues going on with PCOS also improve — chronic inflammation and oxidative stress come down, androgen levels come down as well. It’s all related. That’s why I tend to focus from that angle first, because it works.

Lisa: When you talk about eating more protein, I think a lot of women might think they have to eat more food. We had one of our advanced reviewers who said one of her biggest takeaways was the plate method — the reorganizing of the macros. For anyone who’s like, is she telling me I have to eat a whole bunch more food, how does this work?

Lily: You can eat a whole bunch more food depending on what the food is. You might actually be able to eat more food. You don’t necessarily have to, and your satiety will probably shift a little bit as you pay attention more to your macronutrient ratios. My plate method is a little more fine-tuned by macronutrient groups versus food groups. It’s really quite simple: when we shift the ratios of our fats, carbohydrates, and protein toward a type of plate that is not so heavy in carbohydrates, we’re going to improve our blood sugar and insulin levels. A typical American meal is very carb-centric — based around pasta, potatoes, rice, or bread — with just a little protein and some vegetables.

If we can shift that toward a small portion of pasta taking up maybe a quarter of the plate, a larger portion of meatballs — three ounces at minimum, maybe four to six ounces of protein depending on your size and activity level — and then a large salad or a large portion of cooked vegetables, the effect on your blood sugar and insulin levels is a completely different animal. You don’t have nearly the carbohydrate load, you don’t get nearly the blood sugar or insulin spike, and your satiety levels are so much better because protein and fiber are so filling. For women with PCOS especially — particularly uncontrolled PCOS, where we’re still seeing the effect on the menstrual cycle, which is primarily delayed ovulation leading to a really long cycle — some of these women may be seeing cycles that are 45 or 60 days, or even longer.

Lisa: You shared some really interesting research on how dietary interventions have had a positive impact on these markers. Did you want to talk about that?

Lily: The majority of fertility-focused dietary intervention trials we have are actually on women with PCOS. There are quite a few out there with a fairly wide array of interventions. Most focus on shifting energy intake like a calorie-restricted diet, and some focus more on shifting macronutrient intake. As a whole, even in studies where you just modestly reduce the carbohydrate intake by 10 to 15 percent, you see significant improvement in a lot of the parameters we’re worried about with PCOS.

Here’s one example worth mentioning. Women with PCOS were given one of two diets — the standard diet or a high-protein diet. The high-protein group had 113 grams of protein per day and 155 grams of carbohydrates, versus the standard diet’s 78 grams of protein and 265 grams of carbohydrates. The women in the high-protein group experienced greater weight loss — 17 pounds versus 7 pounds — a reduction in body fat, and significantly improved blood sugar levels after six months. Other trials using more strictly low-carb approaches, like a ketogenic diet, have seen even greater improvement. One study kept carbs at 20 grams per day for 12 weeks — the participants lost an average of 21 pounds, 18 of which was body fat. It significantly improved sex hormone profiles, blood sugar and insulin levels, markers of insulin resistance, and blood lipids. As a whole, the takeaway is shifting the balance toward slightly less carbohydrates and better quality carbohydrates, more protein, and eating fat rather than fearing it.

Lisa: What’s really helpful is that in the second study you mentioned, the participants did lose weight as an effect of the diet — but it’s more nuanced than just saying “lose weight.” We’re going a little deeper into what is the root of the issue — the insulin resistance — and talking about how to control blood sugar. Then as a byproduct of improving metabolic health, you’re seeing these benefits. And in our PCOS chapter, we talk quite a bit about how insulin disrupts ovulatory function, so you really understand why it’s so crucial to focus on that piece of it.

I also wanted to ask you about caloric restriction. Many women with PCOS have heard that the whole solution is to lose weight. Our recommendations are a bit different — and why at least from my perspective, those two competing goals don’t work well together.

Lily: It overlaps into our considerations about hypothalamic amenorrhea. If you restrict calories too much, you will disrupt the menstrual cycle and you’ll disrupt hormone production. One study I can reference: if you start restricting calories and you get around a 25 percent energy deficit, that reduction by itself is associated with significant reductions in estrogen and progesterone levels. And if you’re eating low fat, you can throw that off as well even in the presence of sufficient calories, because you need fat to build your steroid sex hormones. Put people on a low-fat, low-calorie diet and it’s like a double whammy to the cycle.

Not everybody with PCOS is overweight — that’s another myth we go into in the book. And it’s also just not necessary to deprive yourself and be miserable as a means to achieve weight loss; it’s usually not sustainable either. When you look at yo-yo diets, you lose weight for a little while and then it becomes so unbearable to be starving all the time that you eat again and gain weight again. We didn’t actually solve the issue; we just starved you for a while. And in somebody who’s already experiencing a disrupted menstrual cycle, why would we make it worse by adding another mechanism to disrupt the cycle?

Lisa: This really stands out in my work when looking at the menstrual cycle. Instead of being hyperfocused on a woman’s size — which is something that happens a lot to women with PCOS, where they’re looking for help and the doctor just focuses on the weight — one of the great things about looking at the menstrual cycle as a vital sign is that it gives us a more objective marker. If we focus on supporting this woman to achieve optimal hormone balance and can get the menstrual cycle back in line through reducing insulin resistance and balancing blood sugar, some of the other issues may fall into line. Over time, the weight may improve as you improve the insulin resistance — just like in the study you mentioned — but the menstrual cycle keeps us focused on what actually matters.

Lily: The conventional approach is focusing so much on the weight versus seeing the weight as a symptom of something being metabolically out of balance. We don’t really focus on weight very much in the book at all. It’s just naturally that as you improve your metabolic health — when you eat more protein your metabolic rate goes up, when you choose better quality carbohydrates your total carbohydrate intake usually comes down a little bit, which again improves your metabolic rate — you’re improving your micronutrient intake as well. We’re taking a more holistic approach. I don’t want people to be depleted by the time they conceive. The last thing we want you to do is come into pregnancy feeling depleted. We want your nutrient stores at their peak before conception.

Lisa: You argued that blood sugar regulation is not only important for individuals who have an overt metabolic issue like PCOS. Share why the whole concept of blood sugar balance and macro ratios is important for everybody.

Lily: I’ve been in the blood sugar space for most of my career since I’m also a diabetes educator, so I personally see this rippling out to just about every possible health issue. When your blood sugar levels are out of balance it naturally leads to a state of inflammation, which disrupts just about everything — cardiovascular system, hormone balance, muscle repair, liver function — it’s an emergency when your body is experiencing really high blood sugar on a regular basis. From the fertility component specifically, we do know that there are delays in conception observed in women who have blood sugar levels even on the higher end of the so-called normal range. Even blood sugar elevations that are below a diagnostic threshold for pre-diabetes or diabetes can actually be problematic.

We know from pregnancy work that high blood sugar levels can actually be teratogenic — they can cause birth defects particularly early in pregnancy when the organs are forming, and about half of that period you don’t even know you’re pregnant yet. We also know that as a whole, elevated blood sugar levels can affect your hypothalamic-pituitary-ovarian axis — how your brain and reproductive organs are communicating with one another. Add in male factor: it affects sperm quality. Look at egg quality studies and outcomes from assisted reproductive technology interventions and you see poor outcomes as blood sugar levels rise. So I’m a proponent of everybody aiming for blood sugar balance — it just makes you feel better on a day-to-day basis, and from the standpoint of fertility it can greatly improve your chances of conception.

Lisa: I wanted to ask about carbohydrate recommendations, because there are some practitioners who suggest there’s a minimum amount required and that we shouldn’t go too low. We tend to recommend more of a lower-carb approach as a way of balancing blood sugar to support overall hormonal health, with the understanding that you’re getting sufficient protein and fat which naturally crowds out the excess carbohydrates, and that you’re getting enough food overall. But many practitioners recommend something like, “you shouldn’t eat less than a certain number of carbohydrates.” Can you speak to that?

Lily: I feel like it was hard to condense the carbohydrate section because there were so many qualifying statements necessary. In the women’s health space, some people have talked about there being a minimum threshold of carbohydrates required to induce a luteinizing hormone spike which triggers ovulation. The number commonly given is 130 grams per day. I spent months looking into this question to see if there was more than the one study people cite about this. And in fact, there is not. The only evidence given to back this claim is a study that tested not a low-carbohydrate diet, but a low-calorie diet on menstrual cycle disturbances.

It was a well-done controlled feeding trial. In that study, they found that when you restricted the calories too much, the menstrual cycle was disturbed — you see a short luteal phase start first, and then when calories get restricted beyond a certain level, ovulation stops. But this study was not low in carbohydrates. It was low in calories. Carbohydrates made up 57 percent of energy intake. That is not a low-carbohydrate diet. Carbohydrate recommendations in our dietary guidelines are 45 to 60 percent of calories. They were not testing a low-carb diet; they were testing a low-calorie diet. I was actually not able to find any evidence in the literature to support the idea that a low-carb diet — specifically in the context of a diet that is providing enough calories — is harmful to hormone balance or fertility. The PCOS studies are a perfect example where we often see improvements in ovulatory function when carbohydrates are restricted, but again, in the context of a diet that has enough energy.

Can a low-carbohydrate diet screw up your cycle? Yes, it could — if your interpretation of low carb is low calorie. Low carb does not mean low food. And I would also say: if you are the type of person who finds yourself so much more satiated on a low-carb diet that you’re accidentally eating fewer calories, you might need to be diligent about actually eating enough food. If your cycle gets disrupted, you might want to up your carbs or your overall calories because you might be accidentally undereating. But there is not a study showing that low carb messes up your luteinizing hormone spike. It was a low-calorie study. It’s unfortunate that has been perpetuated everywhere as fact. It’s just not the case.

This whole concept that 130 grams is a magical minimum number doesn’t even make sense in the context of global diets. If you go to latitude extremes like the Arctic, you can’t even if you tried eat 130 grams of carbohydrates per day for a very large portion of the year because nothing is growing — the ground is frozen over and you’re eating animals. If none of these women over the course of history had enough luteinizing hormone to ovulate, those populations would have died out because they couldn’t reproduce. And that is not what happened. Clearly our bodies can adapt to all sorts of different levels of macronutrient ratios.

Lisa: So as we bring this to a close — for the listener who’s wondering, what are the foods? Maybe summarize some of the general recommendations and what listeners can expect when they grab a copy of Real Food for Fertility.

Lily: From the title, Real Food — essentially we’re talking about a whole-food diet that includes some specific nutrient-rich foods to make sure you have enough micronutrients, vitamins, and minerals to optimize your hormone levels, reproductive function, and prepare your body for pregnancy. For animal foods: meat, poultry, fish, seafood, dairy products. For plant foods: really the whole gamut — vegetables, fruit, nuts, seeds, legumes, whole grains in moderation. We do have a chapter that specifically focuses on some nutrient-dense foods to emphasize even more because of their nutrient density: organ meats, eggs with the yolks, certain types of seafood, certain types of dairy products, fermented foods for their probiotic content and microbiome benefits, and produce that is particularly nutrient-rich and full of antioxidants.

Throughout the book, we’re weaving in the nutrition component into everything. The first part is very heavily nutrient-focused — this is the dietary structure. Then we get into the specifics on how those things play into potential menstrual cycle issues, egg quality, sperm quality, PCOS, hypothalamic amenorrhea, a variety of reproductive and fertility challenges. And then we tie it together with sample meal plans and recipes — all different recipes than from either of my other books. Some of the major takeaways from our advanced review team — including from dietitians — were: I had no idea how macronutrients affect the menstrual cycle, and I didn’t know this research on carnitine or taurine and how that affects ovulation. There is a lot of information in this book that just has not been written about before.

Lisa: And hasn’t been put together, because a lot of our audience knows something about the menstrual cycle but they don’t really know Lisa-level menstrual cycle information. We’re really thrilled about the book and how it turned out. We invite you to head over to realfoodforfertility.com and all the links will be there for you to grab your copy. You can also search for it on Amazon. Lily, thank you so much for coming to the show again — as the guest I’ve had the most times. You’re my most repeated guest.

Lily: I’m really getting up there, right?

Lisa: We’re somewhere around eight appearances. I’ll link all your previous episodes for the listeners who want to hear more from you. Thanks so much for being on the show and I’ll talk to you soon.

Lily: Talk to you soon.