Apple Cider Vinegar - Complete Guide to Benefits and Research
Apple cider vinegar has been used for centuries in cooking and as an all-natural remedy for a variety of ailments. Spend any time walking through your local grocery store, and you begin to realize just how popular this particular vinegar is, given the numerous brands of cider vinegar littered across the shelves. What's more, the consumption of the vinegar is believed to deliver all kinds of benefits, including weight loss, reduced blood sugar levels, and improvements in symptoms of type II diabetes. There's even an entire diet based around apple cider vinegar too! Related - 10 Potassium-Rich Foods You Should Eat But, what's the real deal with this ancient culinary ingredient? Does it really enhance weight loss or is it just a tasty liquid that adds some zip to your daily salad? Let's find out!
What is Apple Cider Vinegar?As you probably have guessed, apple cider vinegar is a vinegar ("sour wine") produced from crushed apples. Once the apples are smashed, the liquid is squeezed out at which point, bacteria and yeast are added to the liquid to initiate the fermentation process. Here, the natural sugars in the apple liquid are converted to alcohol. A second fermentation is conducted where the alcohol developed from the first fermentation is subsequently converted into vinegar by acetobacter, an acetic acid-forming bacteria. Acetic acid, along with the malic acid naturally occurring in apples, gives the cider vinegar its distinct tart, sour flavor. Apple cider vinegar is packed with a plethora of vitamins, minerals, amino acids, and various other pro-health compounds. More specifically, apple cider vinegar is naturally rich in calcium, phosphorous, sodium, potassium, chlorine, magnesium, iron, and B vitamins. Apple cider is typically found in two forms, pasteurized and unpasteurized. The primary difference between the two (aside from the pasteurization process) is that pasteurized apple cider vinegar contains pectin and malic acid. But even more important than that, the unpasteurized variety also "mother" - the active component of cider vinegar that's responsible for its multitude of health benefits. Given that apple cider vinegar is loaded with all sorts of beneficial nutrients, it's easy to see why many people promote its use as a worthwhile ingredient to include in one's diet. In fact, there's a whole fad diet built around apple cider vinegar that's gained quite the following recently.
Apple Cider Vinegar DietSo, what's this apple cider vinegar diet all about? Do you just consume nothing but bottles of vinegar each day? Not quite. The apple cider vinegar "diet" isn't like all the other typical fad diets you've seen splashed across the newsreels over the years. All it takes to follow the apple cider vinegar diet is to add a bit of the vinegar to each of your meals throughout the day. More specifically, mix together one tablespoon of apple cider vinegar plus eight ounces water and drink before your three main meals of the day (i.e. before breakfast, lunch, and dinner). The "catch" is that you can't use any old vinegar for the diet. It must be a raw, unfiltered (unpasteurized) vinegar, which means it still contains the pectin, malic acid, and "mother" compound thereby giving you Proponents of the diet have made all sorts of claims in regards to consuming the vinegar drink daily including decreased appetite, weight loss, and greater protein utilization. But, are these claims rooted in fact, or is the hype around the Apple Cider Vinegar diet mostly a bunch of hot air. Let's find out!
Apple Cider Vinegar ResearchApple cider vinegar has been touted as a cure-all for all sorts of things (most recently weight loss), so let's see what the scientific community has to say regarding apple cider vinegar:
Reduced Blood SugarSeveral studies have been conducted in regards to vinegar consumption and its relationship to postprandial (after meal) glucose levels. Those studies found that consuming vinegar resulted in markedly lower blood glucose levels following a meal.  However, those studies weren't using apple cider vinegar, just plain old white vinegar (acetic acid). But, a couple more recent studies have investigated apple cider vinegar's effects on blood glucose and the results are encouraging. Specifically, subjects consumed either two tablespoons cider vinegar or two tablespoons water with one ounce of cheese prior to bed. The following morning, blood glucose measurements were taken, and researchers found that the group consuming the apple cider vinegar exhibited a 46% lower blood glucose reading than the placebo (water) group.  A second cider vinegar study found that participants consuming apple cider vinegar along with a high carb meal, consisting of orange juice and a buttered white bagel) had better blood glucose and better insulin sensitivity readings when compared to a placebo group consuming the same meal.  So, based on these findings, apple cider vinegar is useful for lowering blood glucose and enhancing insulin sensitivity, making it useful for individuals with diabetes or those classified as "pre-diabetic."
Carb AbsorptionOne study has shown that consuming apple cider vinegar does NOT interfere with carbohydrate absorption.  So, those claims you see about cider vinegar being an effective carb blocker are fiction.
Delayed Gastric EmptyingConsuming apple cider vinegar before or during your meal may increase satiety, as it has been shown to delay gastric emptying.  In other words, the amount of time it takes your meal to travel through your GI system is prolonged, leading your to feel fuller faster, and thus less likely to overeat.
Detox"Detox" diets are all the rage these days. People often jump on these detox diets to rid their body of toxins that have accumulated from all sorts of things, the food they eat, the environment they're in, etc. Cider vinegar has been proposed as an effective cleansing agent for the body due to its high acidity and low pH level. However, your liver and kidneys are your natural "detox" organs, and in an otherwise healthy individual, those organs will take care of any dastardly toxins that creep into your body. Furthermore, a comprehensive literature review concluded that there was no evidence that detox diets remove toxins from the body.  In other words, apple cider vinegar (or any other food) does NOTHING to remove toxins from your body.
Weight LossHere's the biggest reason people have been flocking to apple cider vinegar -- weight loss. Research has shown that acetic acid ingestion (not cider vinegar) prevents fat accumulation and increases fat oxidation.  However, that study was conducted in rodents (i.e. rats). To date, only one study has investigated vinegar's effects on weight loss in humans. The study involved 155 obese Japanese individuals and found a dose-dependent response in those who consumed vinegar. Individuals consuming 30ml of vinegar lost 1.9kg of weight, while individuals consuming placebo saw no change in weight. A middle group consuming 15ml of vinegar lost 1.2kg of weight.  However, that study was had the subjects self report their nutrition, which is known to be highly inaccurate when it comes to actual food ingestion vs reported food intake. So, the claims of weight loss directly resulting from apple cider vinegar consumption are unfounded and not backed by any research study completed to date.
Cardiovascular HealthAnimal studies have shown that vinegar consumption did show reduced triglyceride levels and oxidative stress, but no human studies have been conducted regarding the effects of regular vinegar consumption and cardiovascular health or mortality.
CancerObservational studies on the link between cider vinegar ingestion and cancer are mixed, as two different research studies have shown that regular vinegar consumption both increases and decreases cancer.  So, any claims regarding vinegars cancer-combating abilities remain ambiguous at best.
Other ClaimsCider vinegar has also been said to combat a number of other afflictions including allergies, inflammation, and oral health. But, none of these claims have been substantiated through research, and thus, remain unproven.
Any Dangers Associated With Apple Cider Vinegar?Apple Cider Vinegar is pretty harmless stuff, generally speaking. However, one interesting piece of research found that tablets containing the vinegar posed significant risk to the soft tissues of the body including the mouth, throat, and stomach.  Additionally, research has shown that consuming too much apple cider vinegar can lower potassium levels in the body, which isn't good for the crucial sodium-potassium balance needed by the body. 
TakeawayAt the end of the day, apple cider vinegar is tasty and appears to be healthy. It's even useful for the "all natural" crowd as a chemical-free cleaner, due to its high acidity. But, apple cider vinegar is by no means a "cure-all" or "miracle weight loss" aid, as it's often touted. It poses some benefits for those with blood sugar issues, and may support weight loss by increasing satiety. So, if you enjoy the taste of apple cider vinegar, continue to use it on your salads freely, just don't expect any huge changes to happen as a result of consuming it.
1) Ebihara K, Nakajima A: Effect of acetic acid and vinegar on blood glucose and insulin responses to orally administered sucrose and starch. Agric Biol Chem 52: 13111312, 1988 2) Brighenti F, Castellani G, Benini L, et al: Effect of neutralized and native vinegar on blood glucose and acetate responses to a mixed meal in healthy subjects. Eur J Clin Nutr 49: 242247, 1995 3) Sugiyama M, Tang AC, Wakaki Y, et al: Glycemic index of single and mixed meal foods among common Japanese foods with white rice as a reference food. Eur J Clin Nutr 57: 743752, 2003 4) Johnston CS, Buller AJ: Vinegar and peanut products as complementary foods to reduce postprandial glycemia. J Am Diet Assoc 105: 19391942, 2005 5) White AM, Johnston CS. Vinegar Ingestion at Bedtime Moderates Waking Glucose Concentrations in Adults With Well-Controlled Type 2 Diabetes. Diabetes Care. 2007;30(11):2814 LP-2815. 6) Johnston CS, Kim CM, Buller AJ. Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin Resistance or Type 2 Diabetes. Diabetes Care. 2003;27(1):281 LP-282. 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. 9) 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. 10) Kondo, T., et al., Acetic acid upregulates the expression of genes for fatty acid oxidation enzymes in liver to suppress body fat accumulation. J Agric Food Chem, 2009. 57(13): p. 5982-6. 11) Fushimi, T. and Y. Sato, Effect of acetic acid feeding on the circadian changes in glycogen and metabolites of glucose and lipid in liver and skeletal muscle of rats. Br J Nutr, 2005. 94(5): p. 714-9. 12) 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. 13) Shimoji, Y., et al., Extract of Kurosu, a vinegar from unpolished rice, inhibits azoxymethane-induced colon carcinogenesis in male F344 rats. Nutr Cancer, 2004. 49(2): p. 170-3. 14) Radosavljevic, V., et al., Non-occupational risk factors for bladder cancer: a case-control study. Tumori, 2004.90(2): p. 175-80. 15) Hill LL, Woodruff LH, Foote JC, Barreto-Alcoba M. Esophageal Injury by Apple Cider Vinegar Tablets and Subsequent Evaluation of Products. J Acad Nutr Diet. 2017;105(7):1141-1144. doi:10.1016/j.jada.2005.04.003. 16) Johnston CS, Gaas CA. Vinegar: Medicinal Uses and Antiglycemic Effect. Medscape General Medicine. 2006;8(2):61.