It’s always amusing to see two pseudosciences combined into one greater pseudoscience – it’s like chocolate and peanut butter. It’s not uncommon because those who would embrace one pseudoscience are likely to follow the same flawed logic and process to accept others. My colleague David Gorski has termed this effect “crank magnetism.”

Take, for example, Gian Paolo Vanoli. He has been making international headlines recently because of his claim that vaccines cause homosexuality, which he insists is a disease. The story appears to have been first picked up in English by the Huffington Post – all other reports of this story I have found cite this article as their source.

Because of the date of this article (4/1) I wanted to make sure I had another source, but the only other sources are in Italian. The story does seem to check out – here is one article: Gian Paolo Vanoli: Cricket on the urine that has been around the world. 

You have to love Google translate. At first I thought that perhaps “cricket on the urine” was some Italian metaphor, but from reading the rest of the article it seems they are talking about this story making its way around the world. The only other reference in the article I can find to urine is the fact that Vanoli is an advocate of urine therapy. I have no idea what the cricket reference is to. (Perhaps I can be enlightened by an Italian reader.)

In any case – the story appears to check out. Here is the full quote from Vanoli laying out his “theory.”

The vaccine is introduced into the child, the child then grows and tries to find its own personality, and if this is inhibited by mercury or other substances present in the vaccine which enter the brain, the child becomes gay. The problem will especially be present in the next generations, because when gays have children, the children will carry along with them the DNA of their parent’s illness. Because homosexuality is a disease, even though the WHO has decided that it is not. Who cares! The reality is that it is so. Each vaccination produces homosexuality, because it prevents the formation of one’s personality. It is a microform of autism, if you will. You will see how many gays there will be in the next generation, it will be a disaster.

That’s quite a chain of logic he has there. First, mercury has been removed from the routine childhood vaccine schedule in the US and many other countries. Some flu vaccines, which are optional, still contain thimerosal, but many single-dose vaccines do not. Removing mercury from vaccines, by the way, did not reduce the incidence of autism, as the anti-vaccine community predicted.

Vanoli then makes a very confused argument about DNA. He says that mercury gets into the brains of children so that they do not develop as they should. Then he talks about them passing on their gay-DNA – well, which is it. Do vaccines affect the brain or the DNA? Perhaps Vanoli believes in the inheritance of acquired characteristics. If he were a bit more savvy he might have invoked epigenetics, but perhaps I shouldn’t give him any ideas.

He also assumes that whether or not someone will be homosexual is determined after birth. Homosexuality appears to be a multifactorial phenomenon with both genetic and developmental factors, but probably determined by birth. There is no evidence that hetero vs homosexuality is determined significantly by child development.

The notion that homosexuality is a disease has been rejected by the WHO and by psychiatric organizations because it does not fit any reasonable definition of the term disease, or even disorder. Homosexuality does not correlate with psychological pathology. Historical beliefs that it did were largely based on simple bias and prejudice. A landmark 1982 review by Gonsiorek concluded:

 “Homosexuality in and of itself is unrelated to psychological disturbance or maladjustment. Homosexuals as a group are not more psychologically disturbed on account of their homosexuality”

Vanoli is also making the classic mistake of confusing correlation with causation – he assumes that increasing homosexual prevalence correlates with increasing use of vaccines because the latter causes the former. Even if the correlation were true, this would be the weakest and most tenuous of links, as you could correlate the rise of many phenomena over the last 20-30 years with vaccines, by nothing but coincidence.

But – the correlation is not even real. Surveys of the prevalence of homosexuality over the years has not indicated any clear increase, let alone a pattern that matches vaccine use. There are many ways to operationally define homosexuality – identity, attraction, and behavior, for example. It’s not a simple dichotomy. But looking at the surveys over the years the number hovers around a 3% average for all people. Homosexuality appears to be a consistent phenomenon throughout history and throughout the animal kingdom – not unique to humans.

Vanoli’s claims are absurd and pseudoscientific at every level. If reports are accurate, however, he does not appear to be motivated by homophobia. He says he endorses gay marriage and equal rights. He appears, rather, to be motivated by medical quackery.

Not surprisingly, Vanoli is an advocate of alternative medicine and is somewhat of a guru. He advocates urine therapy, which he says can cure cancer, and apparently is also an HIV denier.

In the end this is just a medical crank with yet another cranky idea, promoting anti-vaccine hysteria in order to promote his pseudoscientific “alternatives.”