Humans infected with parasites could behave in surprising ways. Michael Mosley infected himself with tapeworms and leeches to find out more.
Over the last couple of months I have been deliberately infecting myself with a range of parasites in an attempt to understand more about these fascinating creatures. Perhaps the greatest surprise is the extent to which parasites are able to subtly (and sometimes not so subtly) manipulate their host to their advantage.
The first parasite I experimented with was a beef tapeworm, taenia saginata. This parasite only infects humans and cattle. In Victorian times women would, allegedly, swallow tapeworm eggs as a way of losing weight. This would almost certainly have been a waste of time as tapeworm eggs are not infectious to humans. They first have to be eaten by a cow or bull, where they form a cyst, and it is only if we eat raw, infected meat that we acquire a worm.
Eve if you were infected would you lose weight? Despite hosting three worms I actually put on weight. It could be that the tapeworms were actually encouraging me to eat more, or it could be that I was unconsciously compensating for them there. Either way, they don't seem to be a great weight loss aid.
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