Do Organ Meats Boost Male Fertility? | FAMM Research Series

Full Transcript: Episode 598

Lisa Hendrickson-Jack:

This is the Fertility Friday podcast, episode 598.

I’m excited for today’s episode because we’re going to get into a little bit of the bias that exists in research. And this is definitely a theme of the FAM research series. We want to be able to appreciate the research that we have available to us. We want to be able to dive into it, but we also want to be able to look at it with a critical eye and recognize what the data really says and be able to see the researcher’s perspective. So it’s not to say that the researchers are incorrect or that if you have a different perspective, you’re correct, but it’s really helpful when looking at data to be able to see and acknowledge the perspective that person is coming from. And then especially if you are yourself into reading research and learning how to interpret complex data points and all that, you do want to be able to see that perspective that the person is coming from and understand how that can affect how this person would be looking at data. And if you can get there, that’s a really useful and important place to be at because you can have the same data and you can have two people interpret the exact same data in different ways. And so we are going to talk about that today with today’s study.

So the topic that we’re going to be talking about today, the question is, does organ meat boost male fertility? This is something that I’ve spoken about on the podcast generally. I’ve talked about liver and organ meats for a very long time. This is something that I wrote about in the fifth vital sign and most recently this is something that Lily and I tackled in Real Food for Fertility in a number of different ways. So in Real Food for Fertility we present a lot of evidence behind a variety of key nutrients that support fertility and also a lot of evidence for specific foods that are associated with improved fertility outcomes. And that’s one of the reasons why so many people appreciate our work because we really go deep into what the research has to say. And sometimes in order to get to that research, you have to read past the abstract to see what the data actually shows.

So the study that we’re going to be looking at today is called Meat Intake and Reproductive Parameters Among Young Men. This study was so interesting. I remember when I was looking at it and I was writing the sperm quality chapter and I remember Lily and I were going back and forth and I remember messaging her and being like, “What is going on here with this study?” They hid the most interesting data points behind the abstract. They don’t even mention it. And in fact, based on the study results, they could have named the study something completely different. So I’m going to leave that as a little bit of a cliffhanger and just kind of get into it.

So when I was talking about bias and understanding where the researchers are coming from, one of the reasons why I was doing that is because it’s clear from the beginning of the study that the researchers bore a hypothesis. So what I can do as well is just kind of read their hypothesis so that you understand what their mindset is going into this study. So right here in the study itself, it says we hypothesized that higher red meat consumption would be associated with lower semen quality parameters. And so they talk a little bit about the reason why they feel that red meat is bad overall like as a category. And one of the things that they talk about is that there are potentially residual hormones in the meat. So they’re kind of going into it saying like we think that red meat as a category is bad for fertility. That’s their hypothesis.

And so the way that they went about it — this is a cross-sectional observational study. They looked at 189 healthy men between the ages of 18 and 22 years old at the University of Rochester in New York. And they divided the meat into different categories. So they looked at processed red meats and they defined processed red meats as including things like hamburgers, hot dogs, bacon, salami, and bologna. And then unprocessed red meats they defined as beef, pork, ham — just meats that are not processed. Organ meats had their own category and that was defined as liver from beef, calf, pork, chicken, or turkey. And then poultry, chicken or turkey, and then fish total intake. So they divided all of the different meats into these categories and then they were kind of looking at how the consumption of these meats impacts various parameters. They had these men give semen samples and they measured the ejaculate volume, the sperm concentration, total sperm count, motility, and morphology. They also measured hormones and a few different things. And then they of course looked at their dietary records to determine their consumption of the various types of meats.

So let me go over what the results are and then we’ll talk about it because like I said, this is like the gift that keeps on giving.

So they did find that the men in the study who consumed processed red meat had a lower total sperm count. The ejaculate volume decreased significantly — so there was a lower volume. And otherwise they said they didn’t find any associations with sperm concentration, motility, or morphology. But overall there was a bit of a lower sperm count for the men who consumed processed meat.

Interestingly, the men who consumed unprocessed red meat — so just red meat that isn’t hot dogs and things like that — there was no negative association with semen parameters at all. And actually there was a slight but not statistically significant increase in certain parameters. So the sperm concentration increased slightly from about 43 to 55 million sperm per milliliter. Morphology from about 8% to about 10%. And progressive motility, meaning the sperm that are swimming forward, increased a little bit from 56% approximately to 61%. But other than that, there weren’t a lot of differences. So they found that the processed meat consumers on average had lower total sperm count, but the unprocessed red meat showed no negative association. And there was this slightly increased but not statistically significant result. Basically that’s showing that the red meat was not associated with lower semen parameters at all.

Now, this is where it gets interesting. Organ meats actually had a statistically significant positive association across all of the key sperm parameters. So there was an increase by about 53% in total sperm count. There was an increase of about 41% of sperm concentration. And there was about an 8% increase in higher progressive motility. And they did their statistical analysis, and these associations remained after they kind of accounted for certain factors like animal fat, protein, cholesterol, and micronutrients. So they did their statistical analysis and even with that statistical analysis the positive association remained. In terms of poultry and fish, there was no significant associations with the semen parameters or hormones.

Now, what is fascinating about this is that finding itself is really interesting — that the organ meats were associated with such significantly improved sperm parameters, and also that unprocessed red meat was associated with slightly positive sperm parameters. So what we have here, if you remember the hypothesis, the hypothesis was that red meat consumption as a category would have a detrimental effect on sperm parameters. We have a situation where the results of the study are contradicting what the researchers thought was going to happen.

When I saw those results and I was messaging Lily and we were having this conversation about it, I was like they could have named this paper “Organ Meat Significantly Increases Sperm Parameters,” but that’s not what they did. Not at all.

So if you actually pull up the study — we always link the study, so if you want to jump into the show notes page, fertilityfriday.com/598, you’ll find it — but if you go and you look at the abstract, this information isn’t even shown. They didn’t even report it in the abstract. They also didn’t report in their abstract the result of unprocessed meat. They actually chose the one parameter, the one factor that agreed with their hypothesis, and that’s all that they put in the abstract. So in the abstract they say, okay, well there was this negative association with processed meat.

And one thing to keep in mind is that there certainly is a bias against red meat. This is not to say that there aren’t issues with conventional meat production — obviously, there are issues with conventional meat production and meat quality and things like that — but there is a bias in research against red meat. And Lily had a whole section on the Mediterranean diet in Real Food for Fertility that is worth a read if you’re wanting a little bit of clarity on what the research has to say about it.

So the reason I bring up this kind of bias against processed meat is because there are other factors that could be playing a role in the reason why processed meat was associated with lower sperm count. Because if you remember, processed meat didn’t lower sperm concentration, motility, or morphology. There was no association there. It resulted in a lower total sperm count, but it actually didn’t significantly have a detrimental effect on all these other factors. And so one additional way to look at this — if you did a study where they were kind of looking at the processed meat, you would want to also find out the other things that these people are consuming. For example, if you have a population that’s consuming a lot of processed meat, it is also possible that they’re consuming more sugary beverages or refined carbohydrates or seed oils, omega-6 fatty acids, and potentially less fruits and vegetables. So you want to be able to identify if it’s really the meat that’s the issue, or if that population also tends to consume other foods that are known to be detrimental.

So if we get back to the study, I’m actually going to read a little bit from the author’s conclusion because I do think this is telling. So the authors say, “We investigated the association of meat intake with semen quality parameters and reproductive hormone levels among young men. We had hypothesized that meat consumption would be associated with poor semen quality parameters and this relation would be stronger for meats where higher level of hormone residues have previously been documented. In support of our hypothesis, we found that processed red meat intake was inversely related to total sperm count.” However, they continue: “In contradiction to our hypothesis, we also found that organ meat intake was associated with higher sperm count, sperm concentration, and motility.” Now in this particular section they don’t also note that unprocessed meat was not associated with a negative sperm outcome. They go on to say, “Our results should be interpreted with caution as they may represent chance findings or in the case of total sperm count, residual confounding by abstinence time.”

So what you’re seeing here is that these researchers had a really strong opinion that this is what was going to happen. And then when they ran the analysis and did the study and saw the results, the results contradicted what they thought. They hung on to the one piece of data that supports their hypothesis. They don’t necessarily go critically into it to see if there could have been any confounding factors because that just supports their hypothesis. And then when they see results that not only contradict, but where it would appear as though based on the results that organ meat actually has a positive impact on sperm — I mean, that’s great news, isn’t it? We found something that could significantly improve sperm parameters. No. They promptly dismiss those results and say that it’s probably chance and it could be something else.

This is why at the beginning of the episode I was talking about understanding researcher bias — because research articles are written by human beings, and human beings have biases. I mean, if I were to write a research paper, I know I have my own biases as well, and I would have to acknowledge those potential biases and how that could affect my interpretation of the results. But this is a really interesting example of how a researcher’s perspective can change how they report on those results. If you had a researcher who actually had the hypothesis that organ meats improved sperm parameters, the discussion around the results would have been completely different because that would have been their hypothesis and their assumption and their expectation. Because if you think that there could be a positive association between organ meats and sperm parameters, you’re going to look for other studies that might be showing the same thing or you’re going to hypothesize different things. When you read the discussion of a research paper, it’s a really fascinating piece of the paper because that’s where the author is kind of going in and telling you, well, I think that this is why these results are this way. And that’s really the part of the study that you get to see where the biases come out. And especially when you have a paper where the results are not what the author expected, you often see the author trying to explain them away.

So this study really highlights a couple of things. First and foremost, it shouldn’t be shocking that organ meats are associated with an increase in sperm parameters when you understand the nutrients that are required to support sperm development — namely nutrients like vitamin A, zinc, B12, folate, choline, selenium. You could really go on and on. But particularly, vitamin A retinol has a really significant role in sperm parameters. Also, nutrients like CoQ10 — there’s so much research on CoQ10 and how it supports mitochondria and the role that it can play in supporting sperm parameters, improving motility, morphology, and overall count. And organ meats are rich in these nutrients. In fact, liver and heart meat are the richest natural sources of CoQ10. So it’s really not shocking that the men who consumed organ meats had better sperm parameters overall. They were supporting their sperm parameters with these key nutrients that are found in high quantities in organ meats.

And even the result that red meat overall had a slightly improved result — the men who consumed red meat had a slightly higher overall sperm parameters, though it did not reach statistical significance. Again, what are the things that men are told to consume? What are the nutrients that are studied when we’re looking to improve sperm parameters? Well, here’s one — L-carnitine. Where is that found? Primarily in the largest quantities in red meat. So it’s really interesting how quickly these researchers are downplaying their results and kind of just overlooking it because it didn’t hit their hypothesis, instead of it sparking some curiosity and having them look at, well, why is this?

This was definitely something I spent a lot of time on when I was writing Real Food for Fertility and writing the sperm chapter. I just remember thinking, the researchers’ conclusion could have been very different. And of course, one study does not end a topic — it’s not the be all and end all. But when I see studies like this that don’t match the researcher’s hypothesis, it’s interesting. Their conclusion was kind of like, well, there was probably just some sort of error, some sort of issue. They totally explained it away. But a different research team could also have said these results, though they were not what we were expecting, do suggest that there could be a positive association between organ meat consumption and semen parameters. This warrants further study. But that’s not what they said.

So if you’re interested to learn more about sperm parameters, how normal parameters have been defined by the World Health Organization, and how those parameters differ from optimal parameters, as well as how to support and improve sperm parameters based on what the research really says, then you’ll love Real Food for Fertility. We have a whole chapter on sperm quality. In that chapter alone we have over 250 notes and citations, often with multiple studies cited within each citation number. So it’s a really extensive evidence-based exploration of sperm parameters, and a discussion of this study is included, but there are many more. If you haven’t grabbed your copy yet, realfoodforfertility.com — you can get the first chapter for free. And of course you can grab your copy on Amazon, and we also have it in an audiobook version.

I know that our FAM practitioners love our FAM research series episodes, and these episodes often spark discussions within our Fertility Awareness Mastery Mentorship certification. So if you are loving the research that we talk about, analyzing it, going through it, then you’ll absolutely love FAM also because we take it to a whole other level. Our practitioners have access to all of the full text references that we reference when we are talking about fertility awareness strategies, our FAM protocols, even the FAM research series.

So remember to look at research critically. Consider the author’s perspective and their biases and where they’re coming from. And when possible, review the whole study. If you’re an abstract person and you just read the abstract and think you’re getting the skinny on the study, you would be wrong a pretty significant portion of the time. It is incredible how many times the abstract does not include some of the most interesting findings, and also how researchers can kind of gloss over certain findings if it doesn’t match their hypothesis. This is certainly a very egregious example of it, but it’s certainly not the only example.

So with that said, I hope that you have a wonderful week, a wonderful weekend, whenever you’re tuning into the show. And of course, as always, until next time, be well and happy charting.