Soda water is the common name given to carbonated water. It is plain water into which carbon dioxide has been dissolved, and is the major ingredient in most soft drinks. Soda water, also called seltzer water or sparkling water, has a distinctive fizzy and slightly salty taste. It is also known as club soda, although this may contain table salt and other minerals to give it the salty taste. Soda water or club soda is commonly used as a mixer for alcoholic drinks, but it can be drunk alone.
Tonic water is carbonated water which has been flavored with quinine to give it a bitter taste. Tonic water got its name from the medicinal quality of quinine and was originally used to fight off malaria, since it was intended for use in tropical regions like Asia and Africa, where malaria is prevalent. This drink originated in Colonial India when the British mixed tonic water with alcohol, preferably gin, to make it more palatable. Today, the quinine content in tonic water has been reduced by 25% to 50% and sweeteners have been added, making it less bitter. The British are the inventors of the popular cocktail, gin and tonic. Tonic water with lemon added is known as bitter lemon, and is more popular in Europe than in the United States.
Soda water is the original name given to carbonated water until World War II. During the Great Depression, it came to be known as two cents plain as it was the cheapest drink on the market and actually cost two cents. Later, when flavors were added the cost went up to five cents. In the 1950s the terms sparkling and seltzer began to be used. Carbonated water was originally used for health reasons, namely indigestion. A study was undertaken to prove the effectiveness of drinking carbonated water to relieve indigestion and constipation. At the end of the trial, the people who had been treated with carbonated water scored higher than those treated with tap water.
Plain soda water is a form of low carb water since it contains no calories, and is therefore hailed as a suitable drink for those on a weight-loss diet. There is a lot of information out there about the effectiveness of drinking lots of water as a means of losing weight, although this claim has not been substantiated. Carbonated water has also been blamed for dental erosion and bone fractures, however this too has not been proven and carbonated water is believed to be as harmless as plain water. Therefore, by observing proper nutrition and drinking water, be it plain or carbonated, one can lead a healthy life.