I see a lot of fitness influencers – both on Instagram and on Pinterest – recommending that people take apple cider vinegar (ACV) pills or shots. I’ve been recommended by a previous coach to use ACV as a salad dressing of sorts to encourage fat loss – while it was pretty delicious, I have not been and still am not completely sold on its advertised weight loss benefits. I’m always skeptical whenever I see Pins like these:
People claim that ACV also has other benefits, such as reducing acid reflux, fighting allergies and clearing sinuses, and relieves constipation. While those are claims worth looking into, this post will focus specifically on ACV’s purported effects on the metabolism – pH, cholesterol, lipid profile, blood sugar levels, and fat loss.
In rats fed a high cholesterol diet, ACV had a protective effect against oxidative stress (what anti-oxidants help reverse) and lowered blood levels of lipids. A more recent study measured the amount of oxidative stress in obese rats fed a high fat diet, and found that ACV supported the body’s natural antioxidant system. A different group of investigators found that the rats that were given ACV had lower levels of liver damage and hepatic steatosis (fatty liver). What’s more is that ACV was found to decrease levels of bad cholesterols and increase the level of good cholesterol in both normal rats and rats that were given diabetes.
Furthermore, a more recent study showed that rats fed a high fat diet and ACV lost weight, as well as inches off their waistline, and ate less food. These rats also saw decreases in blood sugar and cholesterol levels. The researchers concluded that ACV must have a ‘satiating’ effect – meaning, you feel full.
All of these benefits sound great – better blood sugars, better cholesterol levels, increased antioxidants, weight loss, and appetite suppression – but these studies were all done in rats that were either fed to have diabetes or to be obese, or given a high fat diet. While rats are great for beginning to understand how a body’s metabolism works, it’s only the beginning. Many promising treatments work extremely well in rats, and then end up being useless in clinical trials in humans. So let’s look at the evidence:
Kondo et al (2009) had 175 obese subjects take either 0, 15, or 30mL vinegar (0, 750mg, 1,500mg acetic acid; respectively). This was a double blind clinical trial, which is the gold standard for testing interventions in humans. Surprisingly, the subjects lost weight even though they didn’t change their food intake (as described in a food diary) or increase the amount of steps they took (measured by a pedometer). “Body weight, BMI, visceral fat area, waist circumference, and serum triglyceride levels were significantly lower in both vinegar intake groups than in the placebo group.” The average weight loss in 12 weeks appeared to be 1.2 kg for the 15-mL group and 1.9 kg for the 30-mL group, with both groups regaining some weight 4 weeks after their last dose of ACV. The authors theorized that the vinegar must have increased the metabolism of fat (the enzyme in question, AMPK, is an important regulatory molecule that turns other enzymes on/off). No one knows for sure why it works, and it’s a bit baffling.
Because the study only went on for 12 weeks, it’s hard to draw conclusions about the long term effects of ACV supplementation. Would the benefits diminish after months of taking it? In other words, is ACV only good for short term weight loss? There’s no evidence proving it one way or the other. Furthermore, it was only in obese subjects – it may be that ACV has no effect in people of a normal BMI or athletes, but there’s no way to know until another thorough study is done.
Other than this one study, ACV has not been shown to improve blood lipid profiles in humans. Interestingly, in healthy subjects, taking a shot of ACV with their meal (some bread in this experiment) was shown to increase satiety and also slow the rate of glucose absorption in healthy subjects. This may be because it delays gastric emptying – if your stomach empties slower, you feel fuller longer. Both of these studies had the subjects eat some form of carbs with the ACV. Suddenly, the idea of taking honey with your ACV shot doesn’t seem so crazy. Even though honey is pretty calorie dense, it may be lowering the total number of calories that you consume in a day because it may help you feel full for a while.
In conclusion, ACV has great potential to be helpful in your weight loss. Given that ACV is fairly low cost, is relatively safe, and has been shown to have weight loss benefits (either through causing you to feel fuller and thus eat less, or by increasing the amount of AMPK) in a few well-conducted clinical trials, it’s probably worth a shot (heh) to take some ACV a day with your carbs. Make sure you chase with water or something afterwards, as it is fairly acidic. I would love to see more research done on this, because it’s so cheap and shows a lot of promise. Until then, I don’t see the harm in it.
What other health foods/claims would you like to see me investigate with a literature search? Please contact me or let me know in the comments!