Oncology Nutrition Preventative nutrition and health

Apple Cider Vinegar – the burning truth

Posted on 2 Mar 2020

I was on the phone to a friend overseas the other day who was telling me about his current nutrition regimen. One aspect that stuck with me was his ritual of drinking apple cider vinegar (ACV) each morning to ‘help with digestion’. Now this is by no means the first time I have heard this daily practice which prompted me to share some knowledge with you all.

If you type ‘’the benefits of ACV’’ into google you will find the following claims:

ACV assists with weight loss, reduces belly fat, facilitates blood glucose regulation, kills bacteria, reduces inflammation and even prevents (or cures) cancer! Naturally my science mind was sceptical and decided to delve into the evidence behind it all!

Weight management

There has been one study to investigate the effects of ACV and weight loss in humans (1). This study looked at obese Japanese participants who were assigned to various groups, including ingestion of 15 mL vinegar, 30 mL vinegar or placebo, over a 12 week period. Now, before we discuss the results, I want you to know this study was poorly designed as the participants self-reported their intake, and trust me from experience, most people will either under or over report what they’re eating! Whilst the group who consumed the 30mL ACV lost the most weight (1.9kg) vs 15mL ACV (1.2kg) vs placebo group (unchanged), what was identified was that when they ceased the ACV they had regained the weight that had been lost. As dietitians, we encourage lifestyle changes that promote sustainable weight loss and healthy living, consumption of ACV was shown not be a practice that promotes these sustainable changes.

Some positive effects on weight loss were seen in animal studies, however if you have read any of our previous blog posts you will be aware that we can’t translate this into practice as the human body is quite different to that of a mouse (thank god!).

One positive effect ACV had was on appetite suppression and increased satiety. But wait for it… The reason it helped suppress appetite was because the ingestion of ACV contributed significantly to nausea (2). Now I don’t know about you but I’d rather hold on to that extra kilo or two and not experience nausea.

Please note that since that Japanese study was undertaken in 2009, there have been no reputable studies showing that ACV assists with weight loss. Therefore we can safely say that although it may increase satiety (through nausea – no thanks!) much more research is needed in this area to confirm if it shows favourable weight loss outcomes.

Improves digestion

Absolutely no evidence, not even in animal models! Sorry guys but if you think that ACV is helping you to digest and absorb your food better (as stated by Dr Google and many others) the literature suggests that this is not the case. What I do often see in practice is the profound impact of the ‘placebo’ effect. People often believe that because they are taking a particular remedy (e.g. ACV) that they are experiencing the desired outcome. Now don’t get me wrong, I am a huge fan of the placebo effect, if it makes you feel better, why stop? Just be aware of the research – knowledge is power!

Detoxification

Now if you haven’t heard of ‘detox diets’ these days, you’re probably living under a rock (a rock I’d like to live under sometimes). I just did a quick google search and uncovered a specific ‘apple cider vinegar detox program’! This program claims that the consumption of ACV will help to remove dangerous toxins from the body. Now anyone who understands the way the body works will realise this claim is completely ridiculous! An individual with a healthy liver and kidneys will be able to remove toxins from their body, irrespective of their food or drink consumption.

One of my favourite papers that has been published to date (linked here), shows that there is absolutely no diet, pill or supplement that can remove toxins from the body (3)! Amen! Therefore save your money on detox diets, supplements or potions and try to implement some healthy lifestyle changes. Hit us up if you have any questions, we are always happy to help!

For more info on the GI including more GI lowering hacks and cheeky tips AND a comprehensive GI shopping list to help keep your heart glowing with the best carbs for you, get your hands on our OnCore GI guide today!

Antibacterial

When I was sick with tonsillitis last year, one common remedy people recommended (with the best possible intentions – thanks everyone) was to gargle ACV because of it’s supposed antibacterial properties which were going to ‘kill the bacteria on my tonsils’. Now I must be honest, I was feeling pretty rubbish and was willing to try anything to help my poor throat, even though deep down I knew it was another Dr. Google recommendation.

The research on the antibacterial effects of ACV has been focused on the bacteria found in food. It’s shown that ACV needed to be consumed at a specific temperature and in combination with sodium chloride in order to have any effect on the bacterial load of the food (7). The way vinegar acts to kill bacteria in food and on a petri dish is very different to its ability to kill bacteria in our bodies.Therefore we can not confidently say that ACV will have an antibacterial effect in the human body.

To date the correlation between ACV and its antibacterial function within the human body is yet to be studied. What is also interesting is that ACV tablets have also been found to cause oesophageal injury (8)! Whilst the acidity may help in some ways, it may also harm. Now I am really happy I didn’t start gargling or swallowing ACV to kill the bacteria in my throat!

Inflammation

The data looking at the benefits of ACV on inflammation is limited. There is currently one animal study looking at colitis (an inflammatory bowel condition) in mice (9), however this has not been investigated in humans. Therefore there is absolutely no way we can insinuate that drinking ACV will reduce any inflammation in our bodies (sorry to burst your bubble to everyone who is drinking their ACV in the morning to help reduce inflammation, I have no doubt there is many).

Cancer

I’m saving this for last because I had to have a big old LOL when I looked at some of the claims that ACV reduces your risk of cancer, and can also cure cancer! As expected, there is little evidence to support this.

The majority of the research has been in the lab or animal studies (limitations of this explained earlier in the blog). The two studies that have been conducted in humans showed mixed results. One study found that vinegar was associated with an increased risk of cancer (specific to bladder cancer risk) (10) and the other showed a decreased risk (specific to oesophageal cancer risk) (11). What is contradictory is the study I mentioned earlier highlighted that ACV can cause oesophageal injury (8), which makes this topic very confusing to draw conclusions! It also shows us that one small study is not enough to make such generalised claims regarding overall cancer risk and ACV! Please also note the studies mentioned looked at a number of different vinegars from the vinegar family, not ACV specifically.

As these studies both had opposing results and there are no other studies published that looked at cancer and ACV intake, I think we can safely say that at present, there is insufficient evidence to support the claim that ACV reduces cancer risk or can cure cancer.

Summary

So in summary, most of the health claims about ACV are not well supported by the current scientific literature. The only substantiated claim is that it can slow gastric emptying, which may assist with glycaemic control. However, be aware there are many ways to control your blood sugar levels, including choosing low glycaemic index carbohydrates, combining protein or fat with your carbohydrates, cooking and cooling starchy foods to increase the amount of resistant starch present, and much more. ACV is not the only solution!

Now I’m not saying to cut out ACV if you enjoy the taste, it is a good idea to dilute it to reduce the risk of eroding your tooth enamel or burning the lining in your oesophagus. And remember… Just because the latest instagram influencer starts her day with ACV, it doesn’t mean you should! When it comes to your health, be skeptical and don’t be afraid to ask questions!

Kondo, T., et al., Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Biosci Biotechnol Biochem, 2009. 73(8): p. 1837-43.
Darzi, J., et al., Influence of the tolerability of vinegar as an oral source of short-chain fatty acids on appetite control and food intake. Int J Obes (Lond), 2014. 38(5): p. 675-81.
Klein, A.V. and H. Kiat, Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet, 2015. 28(6): p. 675-86.
Johnston, C.S., et al., Examination of the antiglycemic properties of vinegar in healthy adults. Ann Nutr Metab, 2010. 56(1): p. 74-9.
7. Salbe, A.D., et al., Vinegar lacks antiglycemic action on enteral carbohydrate absorption in human subjects. Nutr Res, 2009. 29(12): p. 846-9.
8. Hlebowicz, J., et al., Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus: a pilot study. BMC Gastroenterol, 2007. 7: p. 46.
Entani, E., et al., Antibacterial action of vinegar against food-borne pathogenic bacteria including Escherichia coli O157:H7. J Food Prot, 1998. 61(8): p. 953-9.
Hill, L.L., et al., Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products. J Am Diet Assoc, 2005. 105(7): p. 1141-4.
Shen, F., et al., Vinegar Treatment Prevents the Development of Murine Experimental Colitis via Inhibition of Inflammation and Apoptosis. J Agric Food Chem, 2016. 64(5): p. 1111-21.
Radosavljevic, V., et al., Non-occupational risk factors for bladder cancer: a case-control study. Tumori, 2004.90(2): p. 175-80.
30. Xibib, S., et al., Risk factors for oesophageal cancer in Linzhou, China: a case-control study. Asian Pac J Cancer Prev, 2003. 4(2): p. 119-24.