Is protein powder safe for fertility and pregnancy?

Many people consume protein powder as part of their regular diet. But can protein powder be harmful for fertility or during pregnancy? Here is what you should consider when choosing a protein powder.

Protein is one of the essential macronutrients. Our bodies require protein for many reasons, including tissue repair and growth, cell structure, hormones and immunity.

Considering the many crucial roles of protein, it pretty much goes without saying that we need adequate protein in our diets when it comes to fertility. A diet that lacks protein is likely to lack key fertility nutrients that are found in protein-rich foods like iron, zinc and vitamin B12.

During pregnancy, our protein requirements increase. We are now building a whole other person!

So, is it safe to use protein powder to help keep up your intake?

The bottom line is that a plain protein powder (in reasonable amounts, more on that below) is not likely to be harmful for fertility or during pregnancy.

The base ingredient of a protein powder is, obviously, protein. That might be a whey protein (derived from milk) or a plant-based protein like pea, brown rice or hemp. Provided this is manufactured in a clean and safe environment, that part is okay. (If your protein powder company provides information about third party testing and can provide confirmation that their products are free from any harmful environmental contaminants, even better)

However most protein powders on the market contain many more ingredients than just protein.

Some of the ingredients commonly added to include:

• Vitamins and minerals

• Caffeine-containing ingredients

• Artificial sweeteners

• Herbal supplements

Vitamins and minerals

It’s not “bad” to fortify food products with vitamins or minerals - indeed it can be helpful in some instances. However, during fertility and pregnancy you will be taking a set prenatal multivitamin. Some protein powders contain high amounts of certain vitamins or minerals. You don’t want to interfere with your pregnancy supplementation or risk taking too much of something which could potentially be harmful to you and/or your developing baby.

Caffeine-containing ingredients

The recommended maximum caffeine intake during pregnancy is 200mg per day (and I suggest aiming to stay under this limit when try to conceive as well). This amount will comfortably let you have 1 to 2 coffees a day, but not many more concentrated sources of caffeine. You don’t want additional caffeine sneaking in from protein powder. Your protein powder might have directly added caffeine, or something like green tea powder or coffee.

Artificial sweeteners

I don’t want to cause an exaggerated panic about artificial sweeteners. They are heavily regulated for use in foods. In Australia, Food Standards Australia New Zealand conducts safety assessments and publishes acceptable intake levels. However, it is also true that we don’t have a great deal of specific research on the effects of artificial sweeteners on fertility and pregnancy, so it’s a time of your life where you may want to exercise a greater degree of caution.

There are some studies in humans which suggest possible negative effects.

• Regular consumption of artificially sweetened drinks has been associated with an increased risk of preterm birth (Englund-Ogge et al., 2012).

• In couples undergoing assisted reproduction, regular consumption of artificially sweetened drinks was associated with reduced egg quality, implantation and pregnancy rates (Setti et al., 2018).

Are any artificial sweeteners safer than others? It’s hard to tell, because we have little evidence. The research I’ve mentioned above looked at artificially sweetened soft drinks and coffees. What sweeteners do they contain? Well as an example, Coke Zero contains a blend of the artificial sweeteners aspartame and acesulfame potassium (Ace-K).

That doesn’t meant that other artificial sweeteners are better or worse. There seems to be less information available about some of the newer options like stevia and monk fruit, though animal studies are starting to come out. I’m going to do a deep dive blog post just on artificial sweeteners soon as there’s so much to cover, so stay tuned!

Herbal supplements

It’s often an advertising point for protein powders - “contains X, Y and Z for these amazing benefits!” But adding herbal supplements to a protein powder may make it unsuitable for fertility and pregnancy. The majority of herbal supplements have not been tested for safety in pregnancy, so I can’t tell you specifically which ones are okay and which ones are harmful. No-one can! However, I think you probably don’t want to take unnecessary risks by using protein powder that contains herbal ingredients.

Do you need protein powder to meet your needs?

The other key consideration is whether you need a protein powder to meet your needs.

During pregnancy, Australian dietary guidelines recommend consuming 1g protein per kilo body weight, though other sources suggest a range of between 1g to 1.5g/kg of body weight. For a 70kg woman, this is between 70-100g protein per day. It is definitely possible to meet this intake just through food. If you use protein powder, you don’t need to have much.

Really high protein diets in pregnancy are not recommended, with potential adverse consequences for foetal growth (Blumfield and Collins, 2014). They may also increase the risk of anovulatory infertility (Chavarro et al., 2008) if you’re TTC.

That is why I said initially that a plain protein powder is likely okay but in reasonable amounts. You don’t need too much of it, and should get your protein from food as the first priority!

Key takeaways

• Look for a protein powder with the least number of additives.

• Plant-based or whey? That’s your choice, both are okay.

• Avoid powders that have added vitamins, minerals, herbal supplements and/or caffeine.

• It’s quite difficult to completely avoid artificial sweeteners in protein, but keep them to a minimum. As a starting point, try to avoid those sweeteners commonly used in soft drinks (like aspartame and Ace-K) as that’s what we have the human research on. You can always use unflavoured protein which may have no sweeteners.

• Don’t over-consume protein powder. It doesn’t need to go in your smoothie, and your oatmeal, and your baked snacks. It doesn’t need to be an every day thing.

• Contact the manufacturer to request further information on their products if it’s not clear.

• Ask your GP / obstetrician / nutritionist / dietitian for advice on whether the product is safe. Especially if you want to use a protein powder that maybe has an ingredient or two that you’re really just not sure about.

I wish I had a quick, clear cut answer for you on protein powders, but as you can see there are a lot of factors to consider! I hope this has shown you the main things to look out for. Please consult your healthcare professional for personal advice.

If you are looking for 1:1 support and you want to feel assured that you’re eating well to support optimal fertility or a healthy pregnancy - let’s chat! Book a complimentary 15 minutes discovery call with me to discuss your goals and what strategy will help you. I see clients worldwide!