Chris Kresser on Fertility and Nutrition


You’ve probably noticed Chris Kresser around the Paleosphere lately. He’s been on Robb Wolf’s podcast, he has his own very informative podcast, and he’s cited on blogs for the in-depth research he does. He’s known for getting to the bottom of health problems, including digestive disorders, thyroid health and fertility. In fact, to further emphasize his dedication to his science-based approach to finding answers, he signs his emails “Chris Kresser, Investigative Medicine.” He’s a licensed acupuncturist and practitioner of integrative medicine. He sees clients at his San Francisco Bay Area office and via Skype around the world.

I came across Chris Kresser when I was doing some research on thyroid health, something I’ve struggled with myself. Since then, I’ve been particularly grateful for his information on women’s health, but I’ll let him tell you about that in the interview below. I’ll just say that if you’ve been struggling to get pregnant or if you’re pregnant and not feeling so great, Chris Kresser is a fantastic resource.


Paleo Plan (PP): What is your profession?

Chris Kresser (CK): Integrative medicine practitioner. I use modern lab tests to determine the underlying cause of health problems, and then diet, supplements, and herbal medicine, and lifestyle modification to address them.

PP: What kinds of patients do you work with most often?

CK: I work with a wide variety of people from all over the world, but I specialize in helping people who haven’t been able to find help anywhere else.

PP: Do you recommend a Paleo-type diet for your patients?

CK: I recommend my own blend of Weston A. Price principles, Paleo, and elements of the Perfect Health Diet. That could be described as Paleo + bone broth/fattier cuts of meat + raw dairy + white rice.

PP: How did you come across the Paleo(ish) way of eating, and do you eat this way yourself?

CK: I follow the same approach I recommend to my patients above. I came across Paleo/Primal online.

PP: How do you see in your practice that eating this way affects people who are having trouble conceiving?

CK: The main causes of infertility from a nutritional perspective are A) not enough of the right foods/nutrients, and B) too much of the wrong foods/nutrients. The dietary approach I recommend solves both of these problems by nourishing the body with the right macro- and micronutrients, and eliminating the food toxins that cause health problems – including infertility. For example, vitamins and minerals like vitamin A, vitamin D, vitamin B12, folate, iron and choline and biotin, as well as the essential fatty acids EPA & DHA, all play crucial roles in reproductive health – yet some of them are difficult to obtain even in the context of a “healthy” diet. Vitamin A is only found in significant amounts in organ meats, which were favored by our ancestors but aren’t commonly eaten today. Vitamin D and EPA and DHA are only present in significant amounts in cold-water, fatty fish. Unfortunately, a recent study found that up to 40% of women don’t eat the recommended amount of fish each week.

Reproductive health is dependent on certain key nutrients. For example, in 40% of cases of a couple’s inability to conceive, male infertility is the cause. Vitamin B12 deficiency is associated with low sperm counts and motility in men, and low vitamin B12 can cause atrophy of the tubules where sperm is produced, which in turn causes poor sperm development. DHA and EPA are crucial for fertility in both men and women. Studies show low levels of both of these fats are associated with infertility in women, and infertile men have lower concentrations of EPA & DHA in their sperm. In both women and men, too much sugar can promote infertility by causing insulin resistance and changes in estrogen and testosterone levels. There are many more mechanisms at work, but suffice to say that proper nutrition is the key to boosting fertility.

PP: Some women and health practitioners (myself not included) still believe that eating Paleo is somehow dangerous. Do you think it’s dangerous in any way for a woman who’s trying to get pregnant to eat this way?

CK: It’s not dangerous at all. How could it be? This is the way human beings ate for 2.5 million years, and the fact that we’re here having this conversation suggests that eating a Paleo diet during pregnancy is perfectly safe – and effective! There’s no “one-size-fits-all” approach to macronutrient ratios during pregnancy, but one thing women should know is that they will become naturally insulin resistant during pregnancy. This is due to the developing baby’s need for glucose. So while I generally recommend a high-fat, moderate-carb, moderate protein diet during pregnancy (i.e. 50-60% fat, 20-30% carb, 15-20% protein), some women will need more carbohydrates than they would otherwise need when they’re not pregnant. Also, studies have shown that protein intakes in excess of 25% of calories may be harmful to the fetus, so I’m not a fan of ultra-high protein diets during pregnancy. This is not a concern for most people [on a Western diet], since protein intakes usually hover between 13-17% of calories without any effort or calorie counting. It’s very hard to eat more than 25% of calories as protein – you really have to work at it.

PP: And are there certain macronutrient guidelines you’d suggest to a woman who’s trying to get pregnant?

CK: Fat is a crucial nutrient during pregnancy – especially long-chain saturated fats (animal fats). These are the core structural fats in the body, and they comprise 75-80% of the fatty acid of most cells. They’re the primary storage form of energy for humans, they’re more easily burned for fuel than polyunsaturated fats, and they’re a cleaner (less potentially toxic) source of energy than glucose. Many of the important micronutrients in fruits, vegetables and meats are fat-soluble. This means they can’t be absorbed and utilized by the body unless we’re eating enough fat. For example, in one study researchers split volunteers into two groups. One group ate salad with fat-free dressing, the other group ate salad with oil and avocado. The group that ate fat with the salad absorbed between 7-18 times more nutrients than the one that ate the salad with fat-free dressing. And a Swedish study in 2009 found that eating fruits and vegetables did not lower the risk of heart disease – unless they were eaten with fat.

PP: I know you and your wife recently had a baby – congratulations! Can you say anything about the way this diet affected you and your wife during and before her pregnancy?

CK: I think our diets played a big role in our ability to conceive, and how healthy and vital Sylvie (our daughter) was at birth and has been since. Both Elanne and I have autoimmune disease, and we’re a little older than most people are when they start trying to conceive (I’m 37, Elanne is 40). So we were starting from a place where many doctors might have advised us to go straight to reproductive technology. But I think we were able to conceive, and Sylvie has been so robust, because of our nutrient-dense diet. She was 8 lbs, 5 ounces at birth and she’s nice and chubby (like a healthy baby should be)!

PP: Where can we find you online and in person?

CK: My website is, and my podcast is on my site and in iTunes.

PP: How can people learn more from you?

CK: Subscribe to my blog and listen to my podcast. Those are the main ways to get to know my work.