Move aside coconut oil, your time in the superfood spotlight has passed. Today it is all about apple cider vinegar. It is the latest all-natural, all-wholesome, all-singing, all-dancing superfood that will save you from just about anything that ails you. With claims ranging from sterilising your toothbrush right through to treating diabetes and melting away waistlines, in this blog post, I look behind the apple cider trend to see what the science has to say.
Apple cider vinegar is one of the latest additions to the superfood revolving door family. But there is nothing new under the sun about apple cider vinegar: it has been an ingredient in folk medicine for centuries.
Let’s take a step back first and talk about vinegar in general. What you’re getting in apple cider vinegar is just a dilute form of good old acetic acid – that’s vinegar in the common tongue. Vinegar is made by fermenting alcohol or sugar in the presence of acetic acid bacteria. Any flavouring or colouring in the vinegar will come from the food source of it. And that food source can range from all sorts of things such as rice, wholegrains, grapes, alcohol or….apples.
How apple cider vinegar is made
To make apple cider vinegar, the apples are chopped up, covered with water and left until the natural sugar ferments and makes ethanol. The second stage is when acetic acid bacteria convert the ethanol into acetic acid.
And there you have it: apple cider vinegar. There is nothing that special about this process as it can be repeated with dozens of different foods.
Apple cider vinegar has a distinctive cloudy brown colour due to it being unstrained and containing strands of material called “the mother”. The mother is a mixture of proteins, yeast and bacteria that look a bit like cobwebs floating in the liquid.
Many people attribute apple cider vinegar’s proposed health effects to the mother. And there is a plausible reason for this as the mother could be a potential probiotic. But, the importance of the mother as a probiotic doesn’t have a lot of research studies to back it up at this time.
So, if I left the story here, it would just be a nice tale about a condiment you may care to keep in your pantry and which you can make some pretty zesty salad dressings with.
But enter the Internet. A Google search for apple cider vinegar reveals all sorts of amazing health claims: from cutting your risk of cancer to even getting rid of dandruff. But the most common claims centre around its benefit for weight loss and controlling blood sugars. So, let’s delve into those ones. And spoiler alert: they are the only ones that have even a skerrick of science behind them.
Apple cider vinegar the fat blaster
The claim that a shot of apple cider vinegar will melt away body fat surprisingly does have a very small amount of scientific evidence behind it. Albeit from just two human clinical trials.
A 2009 study from Japan showed that a group of overweight men and women who took two tablespoons of apple cider vinegar each day for 12 weeks saw a small benefit on body weight of just under 2 kilograms. While waist circumference and blood triglycerides fell too compared to people who weren’t drinking apple cider vinegar.
A more recent study randomly assigned 39 people to follow a restricted-calorie diet with or without apple cider vinegar for 12 weeks. While both groups lost weight, the apple cider vinegar group did lose a bit more: by a bit under 2 kilograms.
These two studies are certainly interesting, but was it thanks to the metabolic miracle that is apple cider vinegar? Most likely no.
There have been several taste studies finding that drinking vinegar can induce a slight feeling of nausea and a lessening of appetite. That is hardly surprising. That does not in any way negate that apple cider vinegar may have a small benefit on weight loss. But the mechanism here is probably making a person feel a little ill and reducing their appetite. You can drink plain old private-label supermarket vinegar and get the same results if you want to.
Not to discount other benefits, there could be an advantage for weight loss by regulating blood sugar levels which is an interesting area I’ll explore next.
Keeping your blood sugar in check
Another claim that is hard to miss is that apple cider vinegar will reduce blood sugar and insulin levels. This is a rare situation where there is actually some reasonable evidence to support the claim. But spoiler alert: it is nothing miraculous to do with apple cider vinegar: it’s related to the acetic acid, for which any vinegar will do the trick.
Way back in 1987, Japanese researchers found that giving a small group of healthy volunteers vinegar containing 5 percent acetic acid could blunt the rise in blood glucose after having a dose of sucrose on an empty stomach. Likewise, another small study in 2005 found that different levels of acetic acid could also blunt blood glucose and insulin responses in healthy volunteers after a meal of white bread while also increasing feelings of fullness.
There have been other studies in this area too, and the sum of the findings was included in a systematic review published in 2017. And the conclusion? The pooled analysis of studies revealed a significant reduction in glucose and insulin in people who consumed vinegar compared with a control group. Note here though that there is no mention of ‘apple cider vinegar’ in the research. It was just generic vinegar that it relates to, which of course apple cider vinegar falls under the umbrella of because of its acetic acid content.
Apple cider vinegar for diabetes?
Most of the research in the area of blood glucose regulation has been done with healthy volunteers, but there have been some small studies in people with type 2 diabetes. And here, it seems there is also a small benefit on blood sugars with improved fasting blood glucose levels.
Vinegar may help facilitate the production of hormones involved in glucose regulation, reduce the activity of carbohydrate-digesting enzymes, improve insulin sensitivity and even increase blood flow to tissues. But a key point is that the benefit of vinegar seems to apply to meals that contain starch mostly – it will do very little for high-fat meals.
So, does this mean everyone should be drinking vinegar shots with their meals? No. If you don’t have diabetes, your blood glucose is regulated just fine. But if you do have type 2 diabetes, there is likely not as great a benefit. That’s because the underlying condition is already a symptom of impaired glucose regulation and insulin resistance. So vinegar can’t overcome all of that. But you absolutely must talk to your doctor if you are considering trialling apple cider vinegar for diabetes especially if you are taking medications to help treat diabetes.
What else can it do?
What about all those other health claims you may have read about for apple cider vinegar? Just about all of them are not supported by much evidence nor is there any strong reason why apple cider vinegar should even give these benefits over and above any other type of mild acid.
Because of apple cider vinegar’s antimicrobial properties (albeit fairly weak compared to well-established disinfection agents), it is often suggested as a natural cleaner for the home. And yes, it will do the job as a cleaner as the acid is effective against mould. But so are salt, lemon juice, hydrogen peroxide, tea tree oil and baking soda.
Apple cider vinegar because of its low pH works great against alkaline grime such as hard water and mineral deposits as well as soap scum. But again here, supermarket private-label vinegar will work just as well.
Taking the smile from your dial
Dubious and reasonably well-supported health claims aside, there is a pretty compelling reason not to be taking apple cider vinegar as a daily health tonic.
Apple cider vinegar has a pH of around 3, so it can dissolve the tooth structure when it comes into contact with teeth. If the erosion is severe, this can lead to the need for extensive and expensive dental care. And the risk is not just a theoretical one, because in at least one clinical trial with vinegar, it monitored dental erosion over 8 weeks. And erosion increased by 18 percent in those taking a daily shot of vinegar.
If you still want to take a daily shot of apple cider vinegar as a health tonic (or any other type of vinegar), please dilute it first.
What it all means
Apart from it making a nice salad dressing or even a handy all-purpose domestic cleaning agent, there aren’t that many compelling health reasons to be taking apple cider vinegar. But at least some of the claims about it have some evidence behind them – albeit they relate to any form of generic vinegar, rather than anything special about one made from apples. So perhaps ask yourself if any of it is worth it if it means taking a shot of apple cider with each of your meals.