Vinegar - health tonic or tasty condiment?

Vinegar has been around for centuries. Before modern disinfectants and antiseptics it was used domestically for home remedies and for cleaning surfaces. I still use some in my washing machine. Its name comes from the French "vin aigre" literally sour wine.

What is vinegar?

Vinegar is basically acetic acid in water, although it does also contain other substances such as vitamins, minerals, amino acids, and phenolic compounds (caffeic acid, ferulic acid and catechins). Acetic acid (E260) is the product of fermentation of alcohol by acetic acid bacteria (acetobacter) in the presence of oxygen(1). Chemically is is very simple (CH3COOH). The other minor constituents are responsible for the many different types of vinegar you come across. If your vinegar is home made, unfiltered and unpasteurised then you may find a residue of cellulose in the vinegar. This is called the mother and is produced by the bacteria that are responsible for converting the alcohol into vinegar. This is pictured to the right. Some people ascribe many of the health benefits of vinegar to the mother.

Vinegar strength is measured in grains, which represent the amount of acetic acid present in the vinegar. As such, 50 grain means 5% acidity and 60 grain means 6% acidity. If you look at the vinegar in your cupboard you will probably find an acidity figure on the bottle. To qualify as a vinegar you need at least 4% acidity. Typical values are between 5-8%. Note that the actual pH of the vinegar does not equate to the acidity. 

Vinegar production often involves filtration and sometimes pasteurisation. The filtration removes vinegar eels which are small worms that feed off the bacteria that ferment vinegar. The filtration process may also reduce the amount of bacteria present in the vinegar. This may affect its health giving properties. Pastuerisation involves heating the vinegar to around 85C. This will destroy most bacteria present and any enzymes present in the vinegar. This prevents any further changes in the acidity of the vinegar. It may affect the possible health benefits of the end product.

Types of vinegar

There are many different types of vinegar. They are all based on different starting ingredients or production processes. Some have multiple health claims made for them, others are popular in gourmet cooking and some are mostly used in cleaning.

Some of the key differences to look out for are whether the vinegar contains bacteria (which may confer extra health benefits), its level of acidity and its colour. In addition it is worth knowing which dishes each type of vinegar can be used with, and also which vinegars are associated with certain health claims.

Apple Cider vinegar

Cider vinegar is a brown gold colour and has a number of health claims associated with it. They include improved skin and hair, sunburn treatment and heartburn relief. Sometimes used as a crabmeat dip.

Balsamic vinegar

Authentic balsamic vinegar is dark brown in colour and originates from Italy where it is aged in wooden casks for at least 12 years. Typical prices are £12 per 250ml. Some very expensive balsamic vinegars are over 100 years old. Cheaper balsamic vinegars, typically £3 per 250ml are likely to be white wine vinegar with colouring and balsamic flavouring. 

Distilled or white vinegar

White vinegar has a typical acidity of 5%. It is used in cleaning. It is also used as a base in most commercial uses of vinegar. Ketchup, salad dressings, pickles and mustards normally contain it.

Malt vinegar

A light brown vinegar made from malted barley that is turned into beer. The vinegar is produced when the beer is fermented by aerobic bacteria (as with all vinegars), and then aged. It is often used in the UK with fish and chips.

Rice vinegar

Found in China and Japan, rice vinegar is made from different types of rice, normally white. Sometimes red and black rice are used, leading to red and black coloured vinegars. It is traditionally used in stir fries and oriental salad dressings. It is also used with sushi rice.

Red wine vinegar

Typically a deep red colour. Used in vinaigrettes, salad dressings and as a marinade for meat.

White wine vinegar

Typically a very light brown or off white colour. White wine vinegar will normally have about 7% acidity. It is used in a number of recipes and is considered more mellow than red wine vinegar. 

Vinegar and health

Apple cider vinegar gets a lot of health related publicity, it is however true that other vinegars are often equally effective. This is in part because some of the benefits of vinegar relate to acetic acid.

Benefits for weight loss and diabetes

There is evidence from human trials that vinegar in amounts as small as 15mg per day can reduce blood sugar levels. A test on 12 Swedish volunteers established that blood sugar levels were significantly reduced after a breakfast of white bread, when vinegar was added. There was a corresponding drop in their appetite levels also. The size of the blood sugar reductions increased when the amount of vinegar was increased(2). To mimic this use 30g of vinegar dip for your bread. Alternatively use 15g olive oil and 25g of vinegar.

As appetite goes down it is likely that vinegar could help with weight loss.

Cardiovascular benefits

There is some direct evidence that vinegar may help lower blood pressure (3). There is also evidence from the epidemiological Nurses study (note: epidemiological studies deal with association not causation and have to be interpreted with care). This Nurses study showed reductions in fatal heart attacks for nurses who consumed vinegar and oil dressings. The same benefits were not noted for mayonnaise dressings(4). The study authors thought that the omega 3 fatty acid, a-linolenic acid in the oil may have been responsible for the benefit. I would doubt this, as the mayonnaise also contained a-linolenic acid. Instead, if the effect was real, I would expect that the vinegar was more likely responsible. The difference between mayonnaise and vinegar + oil being explained by the presence of a greater amount of trans-fats in the mayonnaise.

Coughs and colds

Oxymel - a mixture of 1 part of vinegar with 4 parts of honey was commonly used for coughs and colds until recently. There is not much scientific evidence whether it works or doesn't.

Other uses

Vinegar is used in coastal locations for jellyfish stings as it inactivates their nematocysts (small harpoons they stick into you). It does reduce the pain, although if you can immerse the affected area in warm 42C water this may be more effective after a period of about 5 minutes. Don't use it with a Portuguese Man o' War sting however, as this is different and will get worse with vinegar.

Caution!

Being highly acidic, vinegar if taken too often, or in too strong a concentration can damage the food pipe (oesophagus) and your tooth enamel. I would generally advise its use with food to gain health benefits rather than drinking it neat as a medicine.

DrDobbin says:

The evidence that vinegar can help control blood sugar levels and appetite is strong. There is also some evidence to support the idea that it improves cardiovascular health. I may well consume more vinegar in future. When I'm eating bread with a balsamic vinegar dip I'll make sure I dip generously. Hopefully my fellow diners won't mind! 

Further references

1) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1785201/

2) http://www.ncbi.nlm.nih.gov/pubmed/16015276

3) http://onlinelibrary.wiley.com/o/cochrane/clcentral/articles/706/CN-00708706/frame.html

4) http://ajcn.nutrition.org/content/69/5/890.long