Thursday, 18 April 2013

Operation Big Belly: Food glorious food

Before you read this blog post, I would like you to try an exercise for me; don't worry, it won't hurt. Take a few moments out of your hectic schedule, close your eyes and think of food.

Did you just carry on reading? I do hope not.

What pictures came into your mind’s eye? If you are like me, you just visualised a glorious spread of triple-layered chocolate cakes, sugary sweets, calorific candies and all things scrummy. If, on the other hand, you are more similar to my virtuous husband, you pictured grilled chicken, salads and rice. No, I don't get it either - why think salad when you can think chocolate? The point is, there are many different ways to fill your tummy but, when it comes to artificially making babies, does it really matter?  

First off, before we get started on our mission, I would like to introduce the ground rules. Well, all serious operations require rules, don’t they?

Operation Big Belly's ground rules:

  • Only scientific data from peer reviewed journals  will be included
  • All studies discussed will be available on PubMed
  • No-one shall take my opinion as anything other than the ramblings of a fool – I am not a medical professional
  • When the rules are broken, all good rules need breaking, it shall be noted

Okay then, if you are ready and sitting comfortably then let's get started.

The first important thing to note is the surprising scarcity of scientific data on the topic of IVF and diet. Type "IVF" and "diet" into PubMed and you will be rewarded with only 47 abstracts and, when you examine the results closely, most of the results are not really relevant. In fact, after quite a serious search, I found a only three studies which examine the role of diet in IVF success. Not very impressive, is it?   

During my investigations, I found that all three studies were conducted at the Department of Obstetrics and Gynaecology at the Erasmus University of Rotterdam. Now, I have always liked the Dutch but I was beginning to like them even more and I was keen to know all about this group of researchers. So, I dug a little deeper and discovered that most, but not all, of the work was done as part of a PhD thesis by a wonderfully intelligent student named Marijana Vujkovic. She really is a clever girl; I have read her thesis, although not every single word, so that, if you don't want to, you don't have to. Let's take a look at what I found out:

The most recent study, published in 2012, found that following the Netherlands Nutrition Centre(NNC)dietary recommendations could increase the chance of ongoing pregnancy, after IVF or ICSI, by as much as 65%. Amazing, right? Just so you know what to be eating, the NNC's recommended dietary food wheel is below: 

And, in 2010, our friend Marijana Vujkovic published a paper, in the Journal of Fertility and Sterility, which described a study indicating that following a Mediterranean diet, i.e. one with a high intake of vegetable oils, vegetables, fish and legumes, increased the probability of pregnancy, in couples undergoing IVF or ICSI, by a pretty respectable 40%. Wow, that's good too, isn't it?

What more can these Dutch scientists tell us?

Well, in their third, and final, study the Dutch researchers revealed a link between women with diets high in omega-3 and potentially improved IVF outcomes. Women with diets rich in omega-3, which is primarily found in fish and fish oils, had higher day 2 estradiol levels, which corresponded with embryos that had improved morphology, than women with with lower levels of omega-3.

I think we have learnt quite a bit from our Dutch friends but I am not quite finished; I am about to break two of Operation Big Belly's ground rules. The study I am about to discuss hasn't been formally published in a peer reviewed journal and can't be found on PubMed, but the results were presented at the European Society for Human Reproduction and Embryology's meeting and widely reported in the British press (see below), so I am going to include it too.

An analysis by a team at Harvard School of Public Health, they must be very clever people, identified that women who consumed high levels of saturated fats, such as animal fats, produced a lower numbers of mature eggs during IVF cycles. Whereas, diets that were high in unsaturated fats, such as olive oil and avocados, were associated with an increased number of, and when I say increased number I mean more than three times as many, live births.

Well, wait a minute, isn't that almost the same result as the researchers from Rotterdam found when they looked at Mediterranean diets? Do you know, I think it is.

Without further ado,I would like to take this opportunity to unveil Big Belly's IVF diet tips:

Words of caution: The results discussed here come from very small studies, we are talking about hundreds of women not thousands. So, it is entirely possible that, in the future, larger studies may prove these studies to be entirely false. However, at the moment, there are no other data so we're just going to have to take their word for it. Also, there is no evidence in any of these studies that changing your diet before an cycle IVF helps. It is possible that you may need to be on these beneficial diets for a long time, maybe even a lifetime, for you to get a better IVF outcome.

I should also mention, there are several other studies that have investigated links between diet and infertility, rather than IVF. However, that was not my topic here and, for that reason, I have not included them. Also, there are many, many animal studies that, whilst very interesting, can't really tell me if eating donuts will stop my IVF from working, so I chose not to discuss them either. But, do feel free to investigate these other studies yourselves.

One final thing before I sign off; what is all this stuff about pineapple? I mean, I get the theory - pineapple contains bromelain which aids implantation - but where, oh, where did the theory come from? It is a very widespread notion; a quick search on a popular trying-to-get-pregnant website yields 1088 hits! Nearly all posts by people who swear by it. I have searched high and low and I can't find the source of this "fact" anywhere. I did find a paper published in 1969 which examined the impact of bromelain on the uterine lining, but it didn't indicate that it would help with implantation. I can really find no scientific evidence that pineapple helps people get pregnant at all - I wish I could, I really wanted this one to be true. If you can find any papers on the subject, please send them my way.



  1. Awesome stuff, Ana! What fantastic research on your part...I will definitely be checking them out. I can't believe those studies saw that much of an increase in IVF success (and take home babies) by diet change. Good on you for also mentioning the small-ness of the studies...but they are still certainly important. :)


  2. Girrrl, you know I'm printing this out and reading it over and over and over.

  3. Just found your site, after much research, i would suggest to avoid all starchy carbs, breads, cereals, pasta. Our society is overloaded with these foods, leading to high glucose levels throwing our bodies out of whack. You want carbs? eat veggies and fruits. Add high fat dairy here and there, along with protein from fish/chicken and you'll be good to go.