Is it worth the hype?

Alright, it has been a minute since I have written a blog post, but I find writing quite enjoyable and wanted to get back into it, and I may have gotten a little carried away with the length of this one. I wanted to kick it off with a topic that I get asked about a lot – what is the deal with Apple Cider Vinegar? Is it actually helpful in weight-loss? What about the Apple Cider Vinegar gummies?

To be honest, I didn’t know a lot about Apple Cider Vinegar; other than it tasted horrible and was a version of vinegar. As a good little scientist, I embarked on learning more about it so I could relay that information to YOU.

Apple Cider Vinegar, I will be referring to it as ACV from here on out, has a number of potential health claims. As with most ‘natural’ products, the internet warriors have taken it upon themselves to extrapolate and greatly exaggerate any potential benefits and findings. This is usually done in an attempt to create a product/scam that they can turn around and sell at a ridiculous profit.

Anywho, I will get off my soapbox and get back to the matter at hand. Diving into the research, I found that most of the health claims are unsubstantiated and, in some cases, blatantly wrong. For some claims, there was some decent research, and there continues to be ongoing research.

ACV is getting a lot of attention as a weight-loss miracle because Obesity is on the rise and is becoming a growing public health concern. While we are getting better at managing Obesity and even finding several useful medications in treating it, those medications and therapies come with side effects, and not everyone can tolerate them.

So people want/need something that is going to be helpful but also tolerable and safe. And, “Ta-Da” we have people chugging apple cider vinegar like grandpa Gary chugs his eggnog and rum at Christmas. Again, I would argue that ACV really isn’t that tolerable, same with eggnog and rum, but we can debate that at a later date.

What is Apple Cider Vinegar (ACV)?

So what even is ACV? Well, as you probably guessed, it is a sibling of the vinegar family, and it is made from apples. I know, “Thanks, Dr. ‘Captain Obvious’ Dan.”

Basically, what happens is apples are crushed to extract the apple juice. Bacteria and yeast are then added to start the fermentation process by converting the sugars from the apples into alcohol. Unfortunately, they don’t just stop there, and they decide to continue the fermentation process. A different bacteria then turns the alcohol (through some process that I no longer remember from organic chemistry) into acetic acid or vinegar (the active ingredient), and voila, you have ACV.

Now for vinegar itself, I am sure you have heard your grandma or another wise older individual talking about its use as a cleaner or some other kind of home remedy, which certainly has some validity as it is acidic and acid can kill bacteria. Other people use vinegar to ruin perfectly good french fries. So right out the gate, some of the claims around ACV, I think we could be reasonably assured, likely have some truth.

Here are the claims that have been made about ACV:

• Lowers insulin and blood sugar levels
• Increases metabolism
• Decreases appetite
• Lowers blood pressure
• Reduces fat storage and burns fat
• Decreases cancer risk
• Anti-microbial (kills bacteria)
• Lowers cholesterol
• Improves heart health
• Aids in heartburn

This list is by no means exhaustive, and the deeper you go into a google search the more claims there are, most of which no longer make any sense.

But what does science actually show?

ACV as a Disinfectant

Let’s start with what is likely to be true. A study by Gopal et al. took ACV, created many different concentrations, and tested ACV’s ability in killing various types of bacteria, many of which could be harmful to humans, yeast/fungi, and the influenza virus. They also looked at the cytotoxicity of ACV (cytotoxicity is the ability of a chemical to kill living cells – so how harmful it might be to human tissues).

What they found is ACV is quite effective at killing a number of bacteria not just at high concentrations of ACV but at low concentrations as well. ACV, however, did not stack up as well against yeast/fungi – this makes sense as these are necessary to create ACV in the first place. There was also no activity against influenza – so it won’t be removing the common flu from your household surfaces. While I didn’t specifically look into it, I would assume the same holds true for #COVID – influenza and COVID are kind of related. Think distant cousin twice removed.

What about the cytotoxic effects? As expected, even at low concentrations, ACV can be harmful. Again, it is an acid. Now all the above was done in a petri dish on a benchtop in a lab. So as for whether it would kill off the bacteria causing an active infection in your body if you drink it, I would argue NO and might actually make things worse. So don’t forgo antibiotics to chug ACV. Ok? Cool.

ACV the key to Reducing Inflammation and Cholesterol?!

Next up, a study by Halima et al. looked at ACV in inflammation as an antioxidant and its effects on cholesterol. Which has been linked to Obesity and excess adipose (fat) tissue. The idea is that if we can use a ‘natural’ remedy to reduce cholesterol and metabolic stress, why not?

In this study, the authors looked at rats. They had 3 groups. The first group was provided with a standard diet (control group), the second group was fed a High Fat Diet (attempting to simulate similar conditions seen in human individuals eating a high-fat diet and/or have obesity), the third group was fed a High Fat Diet with ACV added. The poor little guys were then sacrificed, so their tissues and blood could be examined.

What they found was interesting. First, there was less weight gain in the ACV group, and the ACV group was also eating fewer calories daily than the non-ACV group. The authors speculated that ACV prevented weight gain and suppressed appetite. Now it wasn’t entirely clear how ACV was given to the rats, i.e. added to their food or otherwise. But as I have mentioned and will continue to mention, if you have ever tried ACV, you can probably attest that you would eat less of the food provided to you if ACV was mixed in with it. Unless you like the taste of appley acid. No pain, no gain, right?

Anywho, they also found there was a reduction in liver enzymes and other inflammatory markers in the ACV group – which may suggest a reduction in fatty liver and oxidative damage. There was also an improvement in cholesterol levels. Levels and such were still worse than the control group; therefore, ACV didn’t negate all the harmful effects of the high-fat diet but maybe some? Now, the authors proposed a number of potential mechanisms and hypotheses as to why the above occurred, but we are still left with several unanswered questions. Like, does the same happen in humans?

Please DO NOT stop your Chemotherapy to take ACV

Ok, what about the anti-cancer and anti-tumour claims? Can I forgo the horrible, big pharma driven, yet life-saving and remarkable advancement of science called Chemotherapy? Sorry no, please continue with chemo, or if you decide not to, please stop telling others to do the same.

What I found in the realm of anti-cancer properties was underwhelming. As with most remedies that claim to be beneficial in cancer treatment or prevention, the research has been done in a petri dish in a lab. Mainly because giving someone appley acid instead of proven chemotherapy treatment is unethical. While ACV was shown to kill cancer cells in a dish (remember it’s cytotoxic), it doesn’t mean it will do it in the body. Capisce?

ACV and Diabetes

Now for my friends that are dealing with diabetes. What can ACV do for blood sugars? There were a few studies done in humans that showed when ACV was given there was a reduction in blood sugar levels after eating a meal. This was attributed to the fact that ACV seems to slow gastric emptying – how quickly food moves from your stomach to your small intestine. So sugars from your food are absorbed more slowly over a greater period of time.

The slowing of gastric emptying likely explains the reduction in appetite as well –  food sits in your stomach for longer, therefore, you can’t/don’t feel like eating as much. And hey, we have a class of obesity medications that do this as well, at least temporarily, called GLP-1 receptor agonists – Ozempic and Saxenda are two of the best examples. *cough, cough* I am still waiting for my big pharma payout…..

 Now, the above all sounds great, but we don’t know what this means for people who don’t have diabetes. As well for those that have diabetes, in particular those with diabetes, this may make your blood sugars unpredictable and ultimately lead to low blood sugars (This actually happened to a few of the patients involved in the above-referenced studies). So I urge avoiding or using extreme caution if this is you. We don’t have enough science to show how much it affects blood sugar levels.

So after about 7 or 8th animal study and 3rd or 4th terrible human trial, each attempting to prove one of the above claims, I got a little bored. While all important to some degree in understanding the totality of evidence around ACV, they were not providing any further clarity on the benefits of ACV and whether the benefits apply to the general human population.

So I then skipped ahead to a few studies that were of decent quality and included humans! Yay!

ACV and Weight-loss. The truth you’ve been waiting for!

One study by Kondo et al. was one of the better ones I found. In this study, they looked at Japanese patients that were classified to have obesity. Just a minor aside here, the definition of obesity is a little different in Japan. There a BMI of 25-30 is considered obese, but in North America this is classified as overweight. We won’t get into the details around that today. In reality, it doesn’t really matter, but I just wanted to give you the heads up in case you go read the study yourself.

Anyways, back on track. This study was a randomized, double-blind, placebo-controlled trial, meaning everyone was mixed up and randomly assigned to a specific group, either got acetic acid or didn’t, and nobody had a clue what was going on. Kinda like going on a blind date, ordering drinks that taste so good, you don’t know if they have alcohol or not, and someone ultimately goes home disappointed and sober.

There were 150 people involved over a 12 week treatment period plus a 3-week pre-treatment and 4 week post-treatment period. The authors created 3 groups: 1) Placebo group, 2) Low dose vinegar 15mg (750mg of acetic acid), and 3) High dose vinegar 30ml (1500mg of acetic acid). If you remember ~5000 words ago, I said acetic acid is the active ingredient in ACV.

It was great this study had a control group. People tend to be more adherent and engage in more healthy behaviours if they think someone is watching (the studies around handwashing on this are terrifying). If they believe they might be getting an extra oompf to help them lose weight, who wouldn’t want to take advantage of that. A control group helps to eliminate bias.

The exciting part. What did they find?

On average, there was ~1-2kg weight loss in the ACV groups over the 12 weeks, so at best <0.5lbs/week. This is not unreasonable. In my practice, I usually aim for 0.5-1lb/week, but that depends on a number of factors, i.e. the amount of weight to lose, etc. Now I have to mention that once the patients finished the 12 week trial with ACV, they promptly gained all the weight they lost back in the 4-week post-treatment period. This trial was very short (12 weeks), and, in reality, we need treatment studies that are 1 year or greater to show the true effectiveness of a treatment. 

Anywho, the study also found there was a decrease in triglycerides – triglycerides are different from ‘bad cholesterol’ (LDL). They seem to have a link to increasing one’s risk of heart attacks and strokes if elevated, so decreasing them is a good thing!

That was about it for benefits. The other factors that the authors looked at, including blood pressure, blood sugars or other cholesterol markers, had no benefits with ACV. These benefits were seen in animals, but not in humans? O-M-G. Maybe ACV isn’t quite as magical as Karen claims? In humans, at least? Maybe, if you have a pet rat named Rodney, giving him some ACV might extend his life.

ACV is an Acid

So if you are still not convinced that ACV might not be the best thing since sliced bread, let’s talk about the very real potential harms. First off. Its acid – acetic acid. Now it’s not like the movies where someone will dissolve away to nothing from the inside out, but it might cause damage to your teeth and esophagus – especially if you happen to be a barbarian and drink it straight. The internet ‘experts’ recommend diluting it with water and using a straw to circumvent this. There is also some data to say that ACV can affect your electrolytes, especially potassium, which is important for muscle contraction and making sure the ol’ ticker keeps pumping. So again, probably best not to use if you are on medications that can affect your potassium levels (i.e. blood pressure meds). Finally, for my friends with diabetes, as I mentioned above, you need to be careful as this product can affect blood sugar levels and make them unpredictable.

Final Thoughts

Is this your magical ticket to weight-loss and extraordinary health benefits? NO. The data is sparse, mostly in animals, and there isn’t anything long term to say it is beneficial. I am personally not a fan of paying money to consume acid.

“What about the ACV gummies and capsules, Dr. Dan?” I only spent a brief amount of time looking at this – I would say they are available to make ACV more palatable and safer? Maybe? And after a quick glance, most of the gummy/capsule products show a single gummy or capsule has 500mg of ACV with 5% acetic acid – which is ~25mg of acetic acid. Do you recall the study from above that looked at 750mg or 1500mg of acetic acid consumed daily was needed to get 1-2kg weight loss? Either my math is way off (which is entirely possible, I did fail calculus) OR the gummies and capsules are significantly underdosed and you are better off eating edible gummies. At least that way you will have more fun.

If you made it this far, I am sorry to burst your ACV bubble. But, as I always say, good nutrition, activity, sleep, and good mental health are going to be the ultimate winners in helping you lose and maintain weight loss.

References

1. Halima, B. H. et al. Apple Cider Vinegar Attenuates Oxidative Stress and Reduces the Risk of Obesity in High-Fat-Fed Male Wistar Rats. J. Med. Food 21, 70–80 (2018).
2. Gopal, J. et al. Authenticating apple cider vinegar’s home remedy claims: antibacterial, antifungal, antiviral properties and cytotoxicity aspect. Nat. Prod. Res. 33, 906–910 (2019).
3. Hlebowicz, J., Darwiche, G., Björgell, O. & Almér, L. O. Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus: A pilot study. BMC Gastroenterol. 7, (2007).
4. Johnston, C. S., Kim, C. M. & Buller, A. J. Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects with Insulin Resistance or Type 2 Diabetes [10]. Diabetes Care vol. 27 281–282 (2004).
5. Kondo, S., Tayama, K., Tsukamoto, Y., Ikeda, K. & Yamori, Y. Antihypertensive effects of acetic acid and vinegar on spontaneously hypertensive rats. Biosci. Biotechnol. Biochem. 65, 2690–2694 (2001).
6. Kondo, T., Kishi, M., Fushimi, T., Ugajin, S. & Kaga, T. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Biosci. Biotechnol. Biochem. 73, 1837–1843 (2009).
7. Kondo, T., Kishi, M., Fushimi, T., Ugajin, S. & Kaga, T. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Biosci. Biotechnol. Biochem. 73, 1837–1843 (2009).
8. Martínez-Zaguilán, R. et al. Acidic pH enhances the invasive behavior of human melanoma cells. Clin. Exp. Metastasis 14, 176–186 (1996).
9. Darzi, J., Frost, G. S., Montaser, R., Yap, J. & Robertson, M. D. Influence of the tolerability of vinegar as an oral source of short-chain fatty acids on appetite control and food intake. Int. J. Obes. 38, 675–681 (2014).
10. Frost, G. et al. The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism. Nat. Commun. 5, (2014).
11. Yamashita, H. et al. Improvement of obesity and glucose tolerance by acetate in type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Biosci. Biotechnol. Biochem. 71, 1236–1243 (2007).
12. Sakakibara, S., Yamauchi, T., Oshima, Y., Tsukamoto, Y. & Kadowaki, T. Acetic acid activates hepatic AMPK and reduces hyperglycemia in diabetic KK-A(y) mice. Biochem. Biophys. Res. Commun. 344, 597–604 (2006).
13. Yamashita, H. Biological Function of Acetic Acid–Improvement in Obesity and Glucose Tolerance by Acetic Acid in Type 2 Diabetic Rats. Crit. Rev. Food Sci. Nutr. 56, S171–S175 (2016).