Vinegar

Vinegar is a fermented liquid consisting of about 5% to 20% acetic acid (CH₃COOH; also written as C₂ H₄ O₂) with distilled water and trace chemicals. Vinegar gets its name from the French words “vin aigre,” or sour wine. Although vinegar is not alcoholic, the acidic acid is produced by fermentation of ethanol by acetic acid bacteria (mother of vinegar), a similar process to that used in distilling wine. White vinegar, also called distilled vinegar, is clear vinegar made by fermenting corn or apples and distilled water. It is also sometimes produced using another type of vinegar such as malt vinegar. Apple cider vinegar, usually a light golden-brown, is fermented apple cider that contains probiotic organisms and enzymes with a range of health-promoting properties. Although white vinegar and apple cider vinegar contain acetic acid, vinegar taken internally as food or medicine has an alkalizing effect on the body that can neutralize body pH (percent hydrogen). One tablespoon of apple cider vinegar has only 3–5 calories and less sugar than apple cider or apple juice.

The U.S. Food and Drug Administration (FDA) has different designations and definitions for types of vinegar, mainly for labeling purposes. Vinegar, Cider Vinegar, and Apple Vinegar are defined as products made by the alcoholic and subsequent vinegar-producing (acetous) fermentations of the juice of apples. The FDA requires that anything labeled vinegar must contain four or more grams of acetic acid per 100 milliliters of liquid.

Other types of vinegar in different parts of the world include malt vinegar made from fermenting grains, rice vinegar made in Asian countries and used primarily in cooking, cane or sugar vinegar made from fermenting sugar cane, and coconut vinegar produced by fermenting coconut juice.

Apple cider vinegar has an exhaustive list of health benefits, many that have been known and practiced for centuries. It is reported to help regulate blood glucose levels, enhance weight loss, lower cholesterol levels, improve skin health, soothe sunburn, reduce gastroesophageal reflux symptoms such as heartburn, reduce blood pressure, and improve the health of the gastrointestinal tract by adding beneficial probiotic bacteria. In addition, apple cider vinegar is used to reduce cold and allergy symptoms, whiten teeth, make hair shine, and serve as a natural deodorant. However, many of the health claims are anecdotal and have no scientific research to support them. Some of the benefits that are advertised are from animal studies or poorly conducted research.

Vinegars are produced in a fermentation process that lasts several weeks or longer. Modern methods, however, may use bacterial cultures and special fermenting equipment to speed oxygenation and subsequent fermentation. The first step is always fermentation of the base ingredients (e.g., apples, apple cider, corn, or grain) to promote the growth of acetic acid bacteria, followed by fermentation of the ethanol the bacteria produce. Further processing increases the yield of acetic acid and turns the liquid into vinegar. Sometimes other types of acid such as tartaric or citric acid are added during processing to speed the fermentation and increase the final yield. White vinegar is clear at the finishing point. Apple cider vinegar will be a light golden brown color much like cider. Unfiltered apple cider vinegar may have a silky sediment, a residue from the mother of vinegar, floating on the bottom of the container.

Both white vinegar and apple cider vinegar are used in cooking and for home remedies, cleaning, and various personal uses. White vinegar is clear; apple cider vinegar is light golden-brown. Both have a pungent smell. White vinegar is intensely sour compared to the sweet-sour taste of apple cider vinegar, and it also has the higher acetic acid content (typically about 8% compared to 5%). Both are available as organic products produced with ingredients that have not been contaminated with pesticides and do not contain genetically modified organisms or synthetic additive. Raw apple cider vinegar has been unheated during processing and has kept the mother of vinegar intact. Many healthcare practitioners and individuals believe that the mother of vinegar is even more beneficial to health than the apple cider vinegar, but this has not been demonstrated in scientific studies.

Among the many long-trusted health claims for apple cider vinegar, the evidence is mainly anecdotal or from lay sources and has not been substantiated by scientific studies. Studies of some of the health claims provide evidence to support a range of health benefits previously reported only by users. The most studied health benefits of vinegar consumption include:

Scientists are trying to authenticate the health claims made for apple cider vinegar, looking especially at possible antibacterial, antifungal, and antiviral properties as well as its cell-killing (cytotoxic) capabilities. A basic laboratory study found that apple-cider vinegar had effective multi-antimicrobial activity against certain common pathogens when used at full strength, and the antibacterial action remained effective at 25% concentration. Apple cider vinegar needed to be full strength for use as an antifungal agent. The phenolic contents of apple cider vinegar were also shown to have antioxidant properties. In vitro (laboratory tests outside the body), apple cider vinegar also exhibited in toxicity in a suspension of normal living cells at concentrations as low as 0.7%. Nevertheless, human studies are still needed to determine the clinical benefits of apple cider vinegar.

Although the health benefits of apple cider vinegar are of great interest among consumers and professionals, the lack of scientific evidence for many health claims limits professional recommendations. Yet, widespread usage continues along with lay reports of effectiveness, particularly for the use of vinegar as an aid to weight loss. Long-term studies are needed to demonstrate the benefits and possible side effects of vinegar use over time.

Typical dosage suitable for use in humans is to dilute one or two tablespoons of apple cider vinegar in 8 ounces of water and consume before meals. For weight loss and to maintain blood glucose levels, study protocols advise moderating carbohydrate intake and increasing fiber and protein intake. For weight loss, two tablespoons of vinegar a day in water for at least 12 weeks is reported to result in a loss of about four pounds without any other dietary or lifestyle modifications. Dosage may vary depending upon the desired health effects and the health status of the individual, including whether any chronic conditions are present. Individuals are advised to consult with their physicians before adding a vinegar regimen to their regular diets for any reason.

Vinegar, either white or apple cider vinegar, should not be used undiluted directly on the skin or at full strength in the body (e.g., as a gargle or a douching liquid) because its acidic content is strong enough to irritate delicate tissue on direct contact. Individuals are advised to consult a dermatologist before applying vinegar to the skin.

For individuals with diabetes, using vinegar to help maintain blood sugar levels and reduces the rate at which food leaves the stomach and enters the intestines for digestion and nutrient distribution, which may worsen symptoms of delayed gastric emptying (gastroparesis) common in type 1 diabetes. Appropriate dosage of vinegar must be determined by the individual's physician.

Exceptionally large doses of vinegar (greatly exceeding the recommended two tablespoons a day) taken over a long period of time (years rather than months) may cause low potassium levels, other abnormal blood chemistries, and depletion of bone stores of calcium and minerals.

Although vinegar is a natural tonic, using too large a dose regularly or too much white vinegar or apple cider vinegar generally as a health remedy may produce side effects. For example, when used to help maintain blood sugar levels, it reduces the rate at which food leaves the stomach and enters the intestines for digestion and nutrient distribution, a condition called gastroparesis.

Other digestive disturbances caused by apple cider vinegar in some individuals include feelings of fullness, digestive upset, or decreased appetite. Although these symptoms may promote eating less and weight loss, they may also be uncomfortable and, in some people, may deplete necessary calorie intake.

Using vinegar full strength on skin or taking it full strength orally or vaginally may cause burns. Skin, vaginal tissue, and esophageal burns have been reported.

Apple cider vinegar may reduce potassium levels, which can increase the effects of digoxin (Lanoxin) and cause dangerous side effects. In addition, because apple cider vinegar reduces potassium levels and insulin also reduces potassium, taking vinegar while also receiving insulin may result in electrolyte imbalance and serious symptoms. Dosage of apple cider vinegar should be determined by a physician in individuals with type 1 diabetes who require insulin. Apple cider vinegar may also interact with certain antidiabetic medications such rosiglitzone (Avandia), glyburide (Micronase), and tolbutamide (Orinase), among others, and a physician's advice must be sought before adding a vinegar regimen.

Large amounts of apple cider vinegar are contraindicated in anyone taking water pills (diuretics) because both reduce potassium levels.

See also Diabetes mellitus ; Diuretics and diets ; Gastroesophageal reflux disease (GERD) ; Obesity .