Lactase

by Vivienne Baillie Gerritsen

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It cannot have always been easy to be the wife of Charles Darwin. Besides spending hours in his study elaborating his theory of evolution, Mr. Darwin was never very well. Ever since his return from his voyage on H.M.S Beagle in 1836, he suffered from numerous ailments such as bouts of vomiting, headaches, eczema, flatulence, heart palpitations, depression and joint pains – to name a few. Throughout his life, he sought advice from many doctors who prescribed diets to follow and medicine to swallow.

The cause of Charles Darwin’s ill-health has intrigued many a researcher – besides Darwin himself who kept a Diary of Health. Some have believed that his troubles were mainly psychosomatic, whilst others have suggested causes such as heart disease, chronic neuroasthenia, a duodenal ulcer or pigeon allergy. Recently, scientists suggested that Charles Darwin suffered from lactose intolerance. Indeed, all of his symptoms seem to match such a condition. What’s more, lactose intolerance can be inherited and many members of the Darwin family were prone to similar troubles.

Lactose intolerance is caused by a deficiency of lactase enzyme in the intestine. Lactase splits lactose into galactose and glucose, thus making it digestible. Tolerance to lactose is usually lost in humans after weaning. However, there has been a net tendency to preserve this faculty, especially in populations of the Northern hemisphere where dairy farming became popular about 10’000 years ago. Is this really what Darwin suffered from? Perhaps. One way to find out would be to carry out a test on his DNA. The thing is: he’s not with us anymore. But he may have left a telltale hair or something in one of his notebooks…

UniProt cross references
Lactase, Homo sapiens (Human) P09848
SwissProt
Protein Spotlight (ISSN 1424-4721) is a monthly review written by the Swiss-Prot team of the SIB Swiss Institute of Bioinformatics. Spotlight articles describe a specific protein or family of proteins on an informal tone. Follow us: Subscribe · Twitter · Facebook