Dairy, dairy, quite contrary.
Fancy new intro music!
And a lot of dairy related content. In this episode I dive into dairy, and talk about its role in bone health, cancer, inflammation and heart disease.
I've found it pretty difficult to find simple, unbiased information around dairy online, so I'm hoping this episode helps clarify a few things for people! Turns out the case for dairy isn't as black and white as some may want you to believe.
Anyway, hope you enjoy this one. It's pretty gouda.
Welcome back to the Bite Me podcast. I thought it might be best to start with an easy non-controversial topic like dairy intake. Lots to get through in today's episode, we're going to be going through bone health, cancer, inflammation, and heart health because I feel like those are the four main areas where dairy's impact gets questioned or is a little bit confused. So I apologize in advance for the density of this episode, but we're going to dive right into it. First of all, dairy's impact on bone health. I feel like that's probably the first place we all go. We get told as kids, drink your milk, you grow up big and strong. That's how you get strong bones. That's probably largely due to the calcium and the vitamin D and I guess the protein content found in milk and most other dairy products. When looking through the literature, I found it a little bit surprising that it seems that we can be pretty confident that dairy intake does increase something or improve something called bone mineral density in kids and teenagers.
But we're much less confident about its effect in adults. There's sort of evidence going both ways. There's some showing that dairy can be protective of fracture risk and then others showing that it provides no protection whatsoever. In the adult population, it appears that yogurt and cheese is going to be slightly more beneficial. If there is going to be any benefit versus say something like milk. So I would kind of sum up bone health being for kids and teenagers. It does appear to improve bone mineral density, probably because they're in quite a high growth stage. And for adults, it's weak evidence at best to show that it will protect against fracture risk. And there's also a bit of discrepancy between different populations as well. So different ethnicities seem to have a different impact, have a different response to dairy intake in their diet.
So bone health, I would say for adults, neutral at best. Moving on to cancer, the big topic that gets talked about all the time. And I just want to start by saying as well with cancer, one of the biggest difficulties is, cancer is not one does disease, right? There are so many different cancers that have so many different mechanisms of development and all of the different things that feed into that. So talking about cancer as an umbrella term is already for me, a little bit of a red flag, if I can use that term. So I'm going to talk specifically about, I'd say the two main cancer types that come up when we're talking about dairy and that is breast cancer and prostate cancer. So one for the females, one for the males, I guess. Starting with breast cancer, again, looking through the literature, I feel that the evidence is mixed on whether dairy consumption increases or decreases at your risk for breast cancer.
And again, there appears to be a few sort of... We need to apply some context. When looking at higher milk consumption in postmenopausal breast cancer, it appears that if you're having a high intake of milk, so that's something like 500 mils plus per day. And if we're looking at the risk with some hormone positive breast cancer versus hormone negative breast cancer, that does appear to be a little bit of an increase in risk, if you are consuming high amounts of milk and you are fitting that population. However, in other big meta analyses, big studies of groups of studies, it looks like lower fat or fermented dairy can almost be protective when we're talking about premenopausal cancer, right? So I know again, mixed information, mixed evidence, and I think that's why it's important to always look at the context, the population that we're talking about.
Are you premenopausal or postmenopausal? Do you have a family history of hormone positive or hormone negative breast cancer? All of these things I would say would play into whether dairy consumption is something that you should be concerned about in relation to your medical history or something that you should be focused on in relation to your medical history. The next cancer type, like I said, prostate cancer, again... Well, actually, no, I would say that I'm less neutral about this. There's definitely some mixed reviews, but I would say overall, the evidence is leaning towards dairy, especially milk, but dairy slightly increasing your risk of prostate cancer. This is largely, it appears due to something called IGF-1, which is a hormone which increase levels of IGF-1 have also been linked to increase risk of prostate cancer and dairy appears to increase your blood levels of IGF-1.
So again, we have to put this in the context of the other potential benefits that dairy could provide, which I'll talk about later, but also you need to look at your medical history and if you have a family history of prostate cancer, that might change how you feel dairy fits into your life. Hopefully, I've covered cancer relatively, succinctly there. Like I said, it's a broad area. Those are the two main ones that pop out all the time for me though. The other topic of inflammation, dairy being inflammatory, pro-inflammatory, all of those sorts of words. This one is very, very easy to talk about. There is no evidence to show that dairy is inflammatory, none. There's actually some evidence to show that it might be slightly anti-inflammatory. Basically, what we would be looking at is blood markers of inflammation.
If you want to be nerdy, CRP, TNF alpha, IL-6, these are all just blood markers of chronic sort of systemic inflammation. And it appears that dairy can actually reduce some of those. So one of the reasons why dairy gets blamed for inflammation, I think, or well, unfairly blamed for inflammation is because lots of dairy foods are high in something called saturated fat, right? And high saturated fat is associated with inflammation and associated with a decreased, oh, sorry, an increased risk of cardiovascular disease. So coronary heart disease, heart attacks and strokes, right? And so it can on paper, at first be confusing because it's like, well, we're trying to reduce our intake of saturated fat, but dairy is actually quite high in saturated fat. What's going on here? And that's why it's also really important to think about dairy is a heap of different products, right?
Dairy is not one product. Dairy is butter, is cream, is milk, is cheese, is yogurt, is ice cream, et cetera, et cetera. And it's important to sort of stratify, to piece those out and to look at individual kind of, I guess, families of dairy products or types of dairy products, because when we break them down like that, we can actually get a better understanding of whether this specific dairy product impacts heart health or whether this other specific dairy product impacts heart health. And in a sec, I'll talk about why there might be differences between those products. Coming back to dairy's impact on heart health, again, there appears to be a bit of a mix of evidence. There's some positive, there's some neutral, there's not a heap showing a real negative, unless we're talking about some specific dairy products, which I'll go through in a second. Overall, it appears that low fat dairy cheese and fermented dairy products appear to have the best impact on lowering your risk of coronary heart disease or stroke.
So if that is of interest to you and your family history and your lifestyle, I would be looking at more low fat dairies, cheeses and fermented kefir, some properly made yogurt, those sorts of things. They appear to have a small, positive impact on reducing your risk of cardiovascular diseases. Milk and other for fat dairy pretty much appears to be, I would say neutral. Okay. You all know what neutral means. I don't need to go into that. The milk and the for fat dairy don't appear to have a positive or much of a negative effect. I just totally described what neutral means anyway, sorry guys. So like I said, at first, you might be thinking, but Jono, a lot of dairy's high unsaturated fat. Doesn't high saturated fat intake increase my risk of heart disease?
And there's tons of evidence showing that that is the case. But when we're looking at certain types of dairy, there's two kind of explanations or hypotheses, so basically, scientific guesses as to why they may not be having that same impact. The first is calcium can actually decrease your absorption of fat. Most dairy foods are high in calcium. So the hypothesis is kind of saying that the calcium content of that dairy product is meaning, you're not absorbing as much saturated fat. So it's kind of going all the way through you. And that would be one way of reducing the impact of saturated fat in that product. Another really common hypotheses that seems pretty strong is referencing something called the milk fat globule membrane and basically, what you can visualize that as is, all of the saturated fat molecules in a dairy product, start in this little circle, in this sphere.
And it's surrounded by this membrane. I guess, think of a balloon and inside the balloon is all of the saturated fat. Now in certain, typically less processed dairy products, the milk fat globule membrane, that's a mouthful, maintains, it doesn't get broken down. And so again, a lot of that saturated fat just goes the whole way through and we don't absorb it. However, with more churning and more processing, particularly churning in dairy products. And so that's more in the world of butter and cream and ice cream that milk fat globule membrane, the balloon pops and a lot of its content spill out into the food. And so we can absorb a lot more of it. So that's why there was, I think it was Finland, there's a population study over 20 or 30 years where they reduced butter consumption and drastically decreased their incidence of cardiovascular disease.
So in that scenario, I would say, well, butter actually appears to quite negatively affect heart health, but that's because butter is churned and the milk fat globule membrane doesn't really have the same structure that it does in other things such as cheese, milk, yogurt, cheese, I've forgotten dairy. I've talked about dairy too much. It's already been 10 minutes, come on, Jono. What's going on? So again, coming back to heart health, I would say very important to break apart which types of dairy products we are talking about.
If we are talking about your more processed, more churned dairy products, they appear to have a negative effect on heart health because we absorb a lot of that saturated fat and in your less processed, less churned dairy products, they appear to have a neutral to potentially protective effect against cardiovascular disease. So the million dollar question is, do I need to be eating dairy? And if you look at the Australian guide to healthy eating, it says, I think two, sometimes three serves per day, depending on as you age, I think they bump that up to three because of the risk of osteoporosis.
I would say that, no, you do not need to be eating dairy to be healthy. There's a very big asterisk there. And that is assuming that you're covering the major nutrients that milk provides. Okay. So if you don't wish to consume dairy for whatever reasons, whether it be a sensitivity, a taste, an ethical preference, I don't think that you are going to see a big impact or any impact on your health, providing you are covering your bases on, I would say the big four, there's other things, other smaller micronutrients that milk still provides, but the big four areas I'd be looking at, would be your protein consumption, your calcium intake, your vitamin D intake, and trying to cover some of the benefits that the fermentation in dairy can help with, right? So I would say, quote on quote, the probiotic content of that dairy product.
Now, the good news is you can find protein elsewhere. If you want to replace the very high quality protein that is in dairy, right? So dairy is one of the best sources of protein on the planet, but so you can also get protein from meat, poultry, fish, soy, beans, legumes, protein powder, plenty of vegetables, mushrooms and broccoli contain higher amounts of protein as well. If you want to be making sure that you're covering your calcium bases, which you should for muscle contraction and bone health, and host of other things. Nuts, seeds, fish with bones in it, green leafy vegetables, that certain types of tofu that are set in calcium can provide tons of calcium as well. We also want to be looking at your vitamin D intake, whether that be from mushrooms, fatty fish, eggs or potentially maybe needing a supplement.
And then from the probiotic perspective, there are other fermented foods. Are you looking at kimchi or Sakura or Tempe? All of those things also potentially provide that extra benefit that fermented food can provide. So to sum up, because that's what I'm supposed to do. I would say if you enjoy dairy, you absolutely can include it. And it will have positive benefits on your health providing we're looking more at your fermented dairy yogurts, cheeses versus tons of butter and ice cream and probably not having more than one to two glasses of milk per day. However, if you don't wish to consume dairy, you can absolutely get those same benefits from other products.
And I would recommend that you go back and have a listen to that list to make sure that you're covering your bases. So I apologize in advance for the... Not in advance. I apologize for what you've just listened to and how fast it was. But hopefully you've got a lot from it. If you have, I'd love for you to throw it up in your Instagram stories, tag me, share it around. I know dairy can be a contentious issue, so it would be awesome to get a bit more quality information out there. Like, subscribe, et cetera, blah, blah, blah. Leave a review. Thanks guys. Bye.
Episode Links & References
- Impact of dairy products and dietary calcium on bone-mineral content in children: results of a meta-analysis
- Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies
- Potential role of milk fat globule membrane in modulating plasma lipoproteins, gene expression, and cholesterol metabolism in humans: a randomized study