Vinegar has been around in human culture for thousands of years. In fact, its first recorded use was about 5000 years ago. In the year 400 B.C., Hippocrates, the father of modern medicine, prescribed the mixture of honey and apple cider vinegar for treatment of various diseases. In prophetic medicine, Prophet Muhammad strongly recommended eating vinegar in the Prophetic Hadeeth: “vinegar is the best edible”. It has been widely used during wars for disinfecting the wounds of soldiers before pharmaceuticals came along and is commonly referred to in all the folk and traditional medicine for many health conditions. More recently vinegar has been found in many long living human cultures including being a big part of the Mediterranean diet which may account for some of the benefits of this diet.
A variety of natural vinegar products are found in civilizations around the world. It is a sour traditional fermented food that is used in pickles, sauces and beverages, as well as in various food-processing procedures and as a specialty food ingredient. Vinegar is produced from fruit juices such as grape, apple, plum, coconut, and tomato, rice, and potato. It is made by crushing the fruit and squeezing out the liquid. Bacteria and yeast are added to the liquid to start the alcoholic fermentation process, and the sugars are turned into alcohol. In a second fermentation process, the alcohol is converted into vinegar by acetic acid-forming bacteria.
Although vinegar can be made from any fruit, apple cider vinegar is the most common vinegar used in western folk medicine. Traditionally, apple cider vinegar is made with a long fermentation of apple juices and pulp, of around 1 month, and is fuelled by species of acetic acid bacteria from the fruit and the environment. As a result, acetic acid is the main ingredient of apple cider vinegar, around 3–10% and gives vinegar its characteristic taste and smell. In addition, some of the other ingredients include, polyphenols, like carotenoids, catechin, ephicatechin, as well as gallic acid, citric, lactic, malic and tartaric acids, chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, pectin, probiotics and prebiotics 1-5. Vinegar also contains various minerals such copper, potassium, sodium, chloride, phosphorus, calcium, magnesium, as well as vitamins A, B1, B2, B6, C, E and, complex carbohydrates and fiber, amino acids and numerous beneficial enzymes to help with digestion. Many of the ingredients in vinegar such as the phenolic compounds are also found in the starting material (i.e., the fruit), or may be introduced to it by aging the vinegar so large differences exist in content of phenolic compounds among vinegars. Overall vinegar is an extremely well rounded nutritious food.
While vinegar products are widely used around the world, the scientific information about the health effects of vinegar as a traditional medicine is only now catching up and supported by many scientific studies. Over the past 20 years the research on vinegar has shown many positive effects on health 2,3 such as an antibacterial effect, cardiovascular benefits, reduction in blood pressure, an antioxidant and anti inflammatory effect, regulation of blood sugar and anti-diabetic effect, reduction and prevention of obesity 6-8, a healing effect on injuries, and a positive effect on brain and cognitive functions 1,9 and on bone health 10.
Historically vinegar was used in the treatment of diabetes before any pharmacologic glucose-lowering therapy 11,12. Recent studies indicate that vinegar improves insulin sensitivity in healthy volunteers, diabetics and obese individuals 8,13,14. In type 2 diabetics vinegar reduces the after meal peak in circulating sugar (hyperglycaemia), insulin and fatty acids (triglycerides) 11,12,16, which in turn reduces the level of blood sugar reacting with the red blood cells (haemoglobin A1c) which is damaging to the blood cells in patients with type 2 diabetes 17.
More specifically the blood glucose/sugar-lowering effect of vinegar was evident when vinegar was ingested with complex carbohydrates, but to a lesser extent with simple sugars (monosaccharides) 13,18 and vinegar reduced the after meal sugar spike (postprandial glycaemia) in patients with type 2 diabetes when added to a high, but not to a low, glycaemic index meal 15. This suggests that vinegar is more effective in controlling blood sugar and triglycerides best in the processed carb rich diet compared to when you just take it with simple healthy meals.
While there appear to be many mechanisms by which vinegar reduces glucose levels not everything is fully understood yet. However, what we do know is that vinegar/acetic acid delays gastric emptying, slowing down the digestion and absorption of sugars and fats 19,20; it slows the breaking down of more complex sugars (disaccharide) in the small intestine and suppresses the absorption of carbohydrate 21; lowers free fatty acid in the blood leading to improved insulin sensitivity, increased blood flow to the peripheral tissues and increased satiety, leading to lower food intake 22. In a study of 12 healthy volunteers vinegar served with a portion of white wheat bread containing 50 g available carbohydrates reported a significant dose-response relation for blood glucose and serum insulin; the higher the acetic acid level, the lower the glucose and insulin. Furthermore, the rating of stomach fullness was directly related to the acetic acid level 8.
Vinegar also increases glucose uptake in skeletal muscles 23 and ingestion at bedtime has also been shown to decrease fasting glucose levels in the morning in humans with type 2 diabetes, suggesting an effect of acetic acid on reducing glucose production and increasing the rates of glycogen synthesis (storage) in the cells 24. Vinegar also stimulates the blood flow and capillary recruitment to the muscles 25,26. Much of this occurs through epigenetic processes and induced gene expression 27.
Apple cider vinegar and other fruit vinegars also have a protective effect on the liver, protecting it from metabolic damage associated with metabolic syndrome and diabetes type 2 28-31. These findings suggest that these vinegars may prevent high fat diet-induced obesity and obesity-related cardiac complications 32.
A large number of studies have also shown the cardiovascular benefits of vinegar 33. In a study of rats with high blood pressure both vinegar and acetic acid decreased blood pressure 34. The studies show that even acute consumption of apple cider vinegar (which is rich in antioxidants and anti inflammatories) causes significant reduction on some risk factors around the build up of plaque in the arteries 35 and reduced atherosclerotic lesions in the aorta, among rabbits on fat diets 36. Vinegar also decreases circulating blood fat (triglyceride) levels 37,38,39 and protect from fat accumulation in liver 40,41 in obese 38and/or type 2 diabetic 42 humans . It also decreases fat levels in skeletal muscle 43 which is a common feature in diabetes and insulin resistance. Apple cider vinegars, regardless of the production method, decreases triglyceride and very low density lipoproteins (VLDL) levels in all groups when compared to controls without vinegar supplementation. A number of studies have also shown the benefits of vinegar on the cholesterol profile even in animals consuming a high cholesterol diet 36,37 and the polyphenols (catechins) present in apple vinegar have been shown to inhibit the LDL oxidation in endothelial cells 44 which make up the lining of the cell wall and may be the precondition for plaque build up.
As a result of its improvement on blood circulation vinegar is likely to have a benefits for many cardio vascular illnesses, even Alzheimer’s (which is just another cardio vascular disease), but as yet the research is only circumstantial. Vinegar has also been shown to be an effective treatment for varicose veins taken internally and applied externally. In a study randomized controlled trial of 120 patients application of vinegar lead to reduction in cramps, pain, leg fatigue perception, edema, itching, pigmentation, weight feelings in the leg, and visual ratings 45. Even though vinegar does not remove the problem veins entirely, the effects they have can reduce symptoms, reduce complication development, or reduce aesthetic concerns.
Vinegar has been shown to reduce osteoporosis 46. Vinegar is a rich source of minerals, such as calcium, manganese and magnesium, which are important in sustaining optimal bone mass. Moreover, the acetic acid content in vinegar has also been shown to promote the absorption and retention of calcium 47.
Consuming apple cider vinegar has also been shown to to have many anti oxidative effects throughout the body including reducing eye lens oxidative injury, a characteristic of the developments of cataracts, by stimulating one of the main antioxidant systems in the body called glutathione peroxidase in mice 48.
Vinegar also helps with digestion and has been recommended to people with digestive troubles for hundreds of years. Common thought is that it helps to prime the gastro-intestinal system for digestion and experience shows that people suffering from reflux (GORD) are more likely to have low levels of gastric acid, not too much acid and one teaspoon (diluted) of vinegar before a meal can assist with digestion. However, this is unlikely to be a result of the pH of the vinegar but may be due to other compounds such as enzymes, prebiotics and probiotics to assist digestion or that it promotes the release of bile acids to assist with the digestion of fats.
In the future our medical doctors will tell their patients to go and have 30-50 ml of organic apple cider vinegar a day spread over two meals to prevent and help treat the major health conditions we are confronted with today rather than put them on multiple drugs that have deadly side effects.
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