Biomedicine Update: Want to Live Longer? – Want to Change Your Personality? – Read On

Two articles appeared today that made me look twice. One was a study that showed how testosterone contributed to aging in males. The second focused on the influence of infections on brain chemistry.

Extending Lives in Males

If this were a how to guide you would be saying “ouch” once I told you the secret.

The secret to longevity in males is:


That’s right. Even better, become a Korean eunuch.

Scientists studying Korean historical records have found that eunuchs castrated in childhood lived longer lives than their than non-castrated Korean male neighbours.

The results of the study entitled, “The Lifespan of Korean Eunuchs,”  has been published in Current Biology. It seems that sex hormones and the drive to reproduce impact longevity in males. The study looked at genealogical records of 81 eunuchs and calculated that on average they lived between 14.4 and 19.1 years longer than non-castrated Korean males of equivalent socio-economic status.

The study correlated its research observations with evidence in males of other mammalian species that showed shorter lifespans versus females. The culprit, it concludes, is testosterone, the male hormone which it states impacts the male immune system. And because castrated males don’t generate testosterone they live longer.

The study relied on a genealogy record of eunuch-family histories called the Yang-Se-Gye-Bo, written in 1805 by Yoon-Muk Lee. In this record are the birth dates, place of birth and death dates of 385 court eunuchs. To come up with its comparisons the study tracked 81 lifespans against non-eunuch males with similar social and economic status living in the same time periods. Three of these eunuchs lived to become centenarians. Interestingly the rate of centenarian eunuchs from these records is 130 times higher than that found in nations of the Developed World today.

Current rates for centenarians in Japan, the country with the highest number is 1:3,500.

The ratio of centenarians to the population in the United States is 1:4,400.

So, in conclusion, for all my male readers who want to live longer you know what to do. Yikes!

Korean eunuchs in castration and aging study

Want to Overcome Shyness, Get Toxoplasmosis

Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii and can be found in humans worldwide. Cats are the most common hosts although birds and other mammals can be infected and transmit the disease to humans.

In North America the most common cause of human infections comes from carelessly handling cat litter. Symptoms usually begin to show up a week or two after exposure. These include enlarged lymph nodes in the head and neck, fever, headaches, muscle pain or a sore throat. For people with compromised immune systems, toxoplasmosis can be very dangerous.

But a recent study has discovered a previously unknown symptom of this parasitic infection. It appears that Toxoplasma gondii causes infected men and women to become more extroverted and less conscientious. Apparently the parasite affects brain chemistry manipulating the behaviour of those it infects by increasing dopamine and altering other hormone levels.

Those with toxoplasmosis have higher rates of traffic accidents. Males infected by the parasite were less conscientious. Schizophrenics showed higher than normal infection rates suggesting that the parasite may alter their brain chemistry contributing to the condition.

Toxoplasmosis infects about 22.5% of Americans aged 12 or older today. Not all are infected by handling cat litter. Undercooked or contaminated meat, unwashed fruits and vegetables, and contaminated soil are also sources of the parasitic infection.

The study appeared in the European Journal of Personality.

pregnancy and toxoplasmosis

Pregnant women should never handle cat litter. Congenital toxoplasmosis can cause hydrocephaly in the fetus of an infected mother to be.                               Source: New York Times



Len Rosen lives in Toronto, Ontario, Canada. He is a researcher and writer who has a fascination with science and technology. He is married with a daughter who works in radio, and a miniature red poodle who is his daily companion on walks of discovery. More...