It might come as a surprise that few people think about preconception health. And to be honest, when they do, it’s usually because of fertility struggles. Diet plays a huge role in how we feel and function, and provides the necessary building blocks to support conception.
Carbs and Fertility
Carbs might make up a significant part of your diet. When it comes to nutritional science, there’s a lot of learn about carbs, but I want to focus on 2 things: the glycemic index and glycemic load.
The glycemic index is a value assigned to a particular food on how fast or slow it causes an increase in your blood glucose level.
The glycemic load combined quality and quantity of carbohydrates. It’s calculated by the amount of food you eat and the glycemic index of the particular food.The glycemic load is also associated with higher risks of ovulatory infertility.
In PCOS, it’s been found that women will often consume foods with a higher glycemic index. When women reduce their carb intake (or perhaps choose carbs with a lower index and load), their insulin sensitivity will improve, testosterone will decrease, and ovulation will occur (this is important, because anovulation is a key symptom in PCOS).
Fats and Fertility
Let’s clear something up. Fat isn’t bad. Yes, some are better than others and there are some you should avoid completely. But you need fat to make hormones, help your eggs mature and to get that tiny blastocyst to implant!
Unsurprisingly, you should be avoiding trans fats. They increase insulin resistance, may prevent ovulation from happening, and decrease your chance of getting pregnant.
To get into specifics, omega 3 fatty acids are associated with progesterone production in the luteal phase (this is important!) and a reduced risk of anovulation. In women undergoing IVF, omega 3 fatty acid intake was associated with better embryo morphology.
Protein and Fertility
You should be eating at least 1g of protein per kg of body weight (more if you’re active). Protein comes in different forms: animal and vegetable. One study showed that ovulation was negatively affected by increased animal protein. While another study showed that although fish, eggs, and processed meats didn’t have an effect on ovulation, vegetable protein intake decreased anovulation. Blastocyst formation in assisted reproductive technology decreased in patients consuming more red meat. But it was positively affected by fish consumption.
Now before you head on off to the local fish monger, you want to pay attention to fish and mercury content (as it may interfere with hormones and fertility). Fish to avoid would be bigeye tuna, king mackerel and swordfish.
Soy protein often gets a bad rap, but can actually be beneficial in women seeking fertility treatments. Soy isoflavone supplements were associated with improvement in reproductive outcomes, increased live birth after clomiphene administration, and higher endometrial thickness and ongoing pregnancy rates after IVF and ICSI.
A couple things to consider before ordering your soy latte – choose organic, non-GMO soy. And if you have a thyroid condition, it’s best to avoid dietary soy altogether.
It might be obvious that a diet that leans towards fast food/processed foods and few fruits and vegetables is probably not the best. And when it comes to a diet in particular, adopting a Mediterranean diet (which basically has a foundation of vegetable and fruit, whole grains and fish) has shown to be effective in a few studies.
Pesticides and other chemicals in our foods may also affect reproductive success, so if possible, choose organic when you can. Basically, if any of the fruits and vegetables that you eat appear on the Dirty Dozen, eat the organic version instead.
When choosing meats, aim to get your meats from local farms if possible. And grass-fed and antibiotic-free are great options too.
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Chiu, Y., Chavarro, J. and Souter, I. (2018). Diet and female fertility: doctor, what should I eat?. Fertility and Sterility, 110(4), pp.560-569.