Episode 108 Transcript – Apple Cider Vinegar

Leah:

Hello and welcome to The Ideal Nutrition Podcast. I am Leah Heigl, and I am here with my co-host Aidan Muir. And today we will be talking about apple cider vinegar and its effects on different health outcomes. So topics we will be touching on include weight loss, blood glucose management, cancer, digestion, as well as some potential side effects of taking apple cider vinegar itself.

Aidan:

So starting with weight, because this is something I do see a lot of people saying the cider vinegar can help with, but I think the first step when it comes to understanding whether something even has potential to help with weight loss is understanding the principles involved in weight loss to start off with. Calories in, calories out. I know it’s cliche. I know everyone talks about it and stuff like that, but understanding that does help us filter whether something even has merit from a mechanistic perspective. Apple cider vinegar obviously isn’t necessarily promoted as something that’s going to change our calorie intake. It’s usually something that’s just added in addition to what people are already doing, and it doesn’t have any mechanism that is proposed to influence calories out. So it’s not influencing cycle, that calories in, calories out. So it doesn’t really have merit there.

Somebody listening to this might be like, “Oh, well maybe it could increase fat oxidation,” but once again, we’ve spoken on previous podcasts how fat oxidation doesn’t necessarily translate to fat loss. So looking at it from that perspective, the mechanisms don’t necessarily make sense. But when we look at the research, that’s also quite underwhelming too. I know I’m starting on a negative note, but it’s underwhelming. If you type in apple cider vinegar for weight loss into Google and you look at a bunch of different articles, you will see that when people are talking about it as a tool that could help with weight loss, they’re often linking to a 12-week Japanese study that had about 155 participants. It didn’t involve apple cider vinegar, it involved vinegar, which is basically what is promoted to be the thing that is going to be helping with all of these things, but the apple part of it is usually just for flavor.

So it was a study on vinegar, and this resulted in a weight loss of 1.7 kilos over 12 weeks. So you could listen to that and be like, “Oh, maybe it does help a little bit like that.” That’s not crazy, but it’s also something that could be helping, but it’s obviously a bit more nuanced than that. For context, participants consumed about 500 ml of liquid ranging from zero to 30 ml of vinegar inside that liquid per day based on whichever group they were put in. But in general, they lost that 1.7 kilos. Intake was self-reported, which is I don’t say a red flag, but it’s obviously a variable we need to consider.

Within four weeks post-trial on average, people have regained 1.4 kilos. So once again, that’s worth mentioning as well. And I say this not as a joke, but as a legitimate way of looking at this, nausea is a common symptom from apple cider vinegar. If we ever see these small losses, although I’ve mentioned one study, there’s a lot of studies that are showing around one kilo weight loss over 12 weeks or anything like that. Is nausea you explaining that? It’s-

Leah:

Just slightly reducing calorie intake because you’re feeling nauseous?

Aidan:

Yeah.

Leah:

The next aspect we will look at is from a slightly more positive note, which is always great, and that’s looking at blood glucose level management. So apple cider vinegar actually does seem pretty promising for reducing blood glucose levels, and the mechanism here is that the acetic acid in the apple cider vinegar helps with delaying gastric emptying. So although this mechanism requires that apple cider vinegar needs to be consumed nearer to meal times, it actually could be something that is somewhat of relevance to people with diabetes or just insulin resistance itself. And where you are struggling to manage your blood glucose levels, having apple cider vinegar around meal times could actually be a small win.

One example is seen in a study where they gave participants vinegar prior to the consumption of 50 grams of white bread, and blood glucose levels were raised 31% less when the vinegar was taken around the time of the carbohydrate intake. So like I said, not particularly relevant for the population as a whole, but somewhat relevant for people that struggle with blood glucose management.

Aidan:

That’s easily the most clear-cut one. That’s a very common finding in the research that we find, that consistently it reduces any raises in blood glucose levels post-eating. So if there’s anything you see somebody talking about apple cider vinegar for, and they do mention that, that’s actually something that we do consistently see in the research.

Cholesterol is a bit more complex. I recall when I had previously written about apple cider vinegar many years ago, I’d just brushed off, oh, I don’t really think it helps with cholesterol. I’ve softened my stance a little bit, being like maybe there’s a bit of potential. Animal studies look promising, but I’ve spoken about this. That’s not necessarily overly relevant for humans. I’d much rather see the research on humans, and we are fortunate that there have been at least nine relevant studies on this topic that a systematic review has looked at. And it concluded that it could help cholesterol, but it is more nuanced than that.

So the impact on cholesterol, total cholesterol, is tiny. So the wording of that systematic review used was that this significantly decreased total cholesterol, and unfortunately the units that they used it was American units, so I’m not overly familiar with it. I did the conversion just through Google, et cetera, and the absolute change that came out was 0.16 millimole per liter unless I’ve made a mistake. And adding context around that, so 0.16 millimole per liter, the goal of what we call primary prevention with cholesterol is keeping it below 4 millimole per liter. Secondary prevention, depending on what people are looking at, is either 5.5 millimole per liter or 6, and usually once people are above, say, 7 millimole per liter, doctors start talking about statins and being like, should we introduce statins? Or let’s try and solve this with diet first, and then maybe we’ll revisit statins down the line. So when you look at 4, 5.5, 6, 7, those type of numbers, 0.16, is-

Leah:

It’s like a drop in the ocean really.

Aidan:

Yeah. Is it statistically significant when you have a large sample size? Probably, but is it practically relevant? I’m not really sure. I would say not.

Leah:

Not particularly helpful, but a little bit more nuanced than maybe initially anticipated. So the next topic we will touch on is cancer. So some people do talk about utilizing apple cider vinegar for reducing just general cancer risk. But going back to being, I guess, slightly negative is there’s no direct convincing evidence indicating that apple cider vinegar does reduce cancer risk. The claim itself mostly stems from the concepts related to the alkaline diet, which is a whole wormhole in itself. I think we have covered that before. And so looking at a systematic review on the alkaline diet and looking at the research around that is, once again, no evidence to suggest that that diet itself reduces cancer risk, either. So overall, at this point in time, I would definitely not be backing the claim that apple cider vinegar reduces cancer risk in any way.

Aidan:

So there’s no direct research on vinegar and cancer, to the best of my knowledge, but the mechanism doesn’t really make sense. Even I think we talked about on that podcast where there’s people claiming that cancer cells can’t even grow in an alkaline environment. We’ve spoken about how much we can shift pH to the body anyway. We can’t make massive shifts, but I do believe there was one Petri dish study where they created an alkaline environment and cancer cells still grew. For what it’s worth though, saying the stuff that we can say with absolute confidence, there’s no research on vinegar specifically with cancer. I wouldn’t get too far ahead on that one.

In terms of digestion, digestion is a tough one because when somebody says their digestion has improved, how are we specifically measuring that? Don’t take that too literally in terms of somebody could say that their digestion has improved. That’s definitely a thing. But the reason why I’m using this concept of how we’re measuring it is when we’re looking at research and we’re looking at measuring specific outcomes, are we looking at things like reductions in IBS type symptoms, in terms of bloating and diarrhea or constipation or whatever? Are we looking at digestion improving in terms of things just moving quicker and stuff like that? People are digesting food more quickly, more efficiently, all of those kinds of things. With vinegar or apple cider vinegar specifically, there’s no research on this topic, to the best of my knowledge, in terms of measuring any of those symptoms or digestion specifically.

But there are some proposed mechanisms. One mechanism is delayed gastric emptying, but that could be interpreted from the other angle as well in terms of theoretically that is slowing digestion. If you slowed digestion, but it improved it in terms of digesting your food better, you could interpret that from both ways in terms of slower digestion could be better or worse, depending on how to look at it. The other mechanism that is specific to apple cider vinegar, so this is the ally. All the other stuff is mostly based on the acetic acid. But specific to apple cider vinegar and not just vinegar is that there’s a thing in apple cider vinegar called the mother, which is basically the cloud of bacteria at the bottom of apple cider vinegar. This could have a potential beneficial probiotic effect. At this stage, there’s obviously anecdotal outcomes. There’s a lot of people who’ve said, “I’ve done this, I feel better.” And without any research, we can’t really say anything. We can say that there’s potential mechanisms with the delayed gastric emptying and that probiotic thing, and that’s all I’ve really got to add on that topic.

Leah:

It’s a little bit of a complicated mixed bag, but I definitely have had clients take apple cider vinegar and be like, “My digestion is so much better.” I’m like, “Okay, cool. That’s great for you.” I wouldn’t go out of my way to recommend it though, and I think you stand in the same.

Aidan:

Yeah, and we’ll talk through that too.

Leah:

Same ballpark. So going on to the potential side effects or I guess caution warnings when it comes to apple cider vinegar, I want to talk around tooth enamel and other things in that vein. And so apple cider vinegar is acidic to the point that it can negatively impact your tooth enamel, if not dilute it. This is so clear-cut that it would actually be unethical to study in humans as part of an RCT, or a randomized control trial, but in vitro studies have demonstrated this effect quite clearly. So we do know that apple cider vinegar is acidic enough to definitely negatively impact the health of your teeth. The easy way to avoid this obviously would be somewhat dilute the apple cider vinegar instead of having it straight, or at a minimum, at least rinsing your mouth afterwards so you don’t have this acidic residue on your teeth for a long period of time. So that’s, I guess, just a little caution warning if there’s something you are going to try.

And then I also want to talk about what you’ve labeled esophagus stuff in our notes, but let’s talk through, I guess, impacts on the health of your esophagus. So there is no clear evidence that apple cider vinegar does have a negative impact on the esophagus, but we also always want to be erring on the side of caution, and here I’d like to note that the ingestion of vinegar is a common cause of throat burn in children. So even though we don’t have this clear-cut evidence to be like, “Apple cider vinegar is going to cause some burns in the esophagus,” I think we can assume that there may be some damage in some people if you were to take that undiluted and consistently.

There is also a case report of a woman who had an apple cider vinegar tablet stuck in her throat and was suffering from burns as much as six months later. So there is definitely, I guess, some area for caution when it comes to this.

Aidan:

At a minimum, it definitely makes sense to at least dilute it if you’re going down this route.

So now we’ll talk about how or if we would use it. Do you ever recommend apple cider vinegar?

Leah:

I have never recommended apple cider vinegar for any of these purposes.

Aidan:

It leads to an interesting point because I actually am in the same boat as you in, unless someone specifically asks. Because if you go back to that blood glucose thing, we can talk about this for a second, but the blood glucose thing, if we see these reductions in blood glucose levels, why are neither of us recommending it often?

Leah:

For me, it doesn’t apply to most of my clients who don’t have an issue with managing blood glucose levels. But even still, when I’m working with a diabetic client or someone with insulin resistance, I just think there is so much other stuff that we can do that has a better outcome than this. Although I do see it as potentially an easy win. And if someone brings it up for the management of blood glucose levels, I’m happy to talk through it, but obviously I’ll give those caveats of please dilute it and just stop those negative side effects.

Aidan:

That’s pretty much exactly where I’m at too. If somebody with type 2 diabetes is wanting to go down that route, I’m on board, like I said. But I also don’t go out of my way, and you could say there’s not really a great reason why I don’t go out of my way to do it, just beyond the fact that there’s so many other recommendations that I’m making that I do think have more impact. And it’s like if I have a priority list, this is lower on the list of priorities. And it’s like if I have a lot of sessions with somebody, it might be something that I bring up in a file later section on just because there’s things that I think will have more of an impact, but that doesn’t mean it may or may not have its place. If somebody’s interested in it, I’m on board, because at least it’s another thing we could be doing that could help improve the management that there’s buy-in to as well.

Leah:

Although I think to a certain degree, I think something like this, like apple cider vinegar, me recommending it, I feel like it somewhat reduces my credibility as a health professional, because it just does seem like a bit of an off-the-wall thing to recommend, even though we do see these kinds of positive outcomes in that case.

Aidan:

I’m pretty fine doing it. There’s a lot of things I do that I’m pretty confident will help. It doesn’t matter how it’s perceived or whatever. But I can see the logic.

Leah:

This has been episode 108 of The Ideal Nutrition Podcast. If you haven’t yet left a rating or review, that would be greatly appreciated. But otherwise, thanks for tuning in.