Tonic water and other tropical posts mixed the powder with soda and sugar, and tonic water was created. The first commercial tonic water was produced in 1858. The mixed drink gin and tonic also originated in British colonial India, when the British mixed their medicinal quinine tonic with gin. Since 2010, at least four tonic syrups have been available in the US. Consumers add carbonated water to the syrup to make tonic water, allowing drinkers to adjust the flavor intensity. Medicinal tonic water originally contained only carbonated water and a large amount of quinine. However, most tonic water today contains less quinine
Human genetic resistance to malaria Human genetic resistance to malaria Human genetic resistance to malaria refers to inherited changes in the DNA of humans which increase resistance to malaria and result in increased survival of individuals with those genetic changes. The existence of these genotypes is likely due to evolutionary pressure exerted by parasites of the genus "Plasmodium" which cause malaria. Since malaria infects red blood cells, these genetic changes are most commonly alterations to molecules essential for red blood cell function (and therefore parasite survival), such as hemoglobin or other cellular proteins or enzymes of red blood cells. These alterations generally protect red blood