Gene or scene?

Name any aspect of what makes us who we are and chances are there’s an argument about how it’s shaped. Scientists have been nailing their colours to the mast on either side of the nature vs nurture debate for years. Take behaviourist John .B. Watson’s bold claim for example.

“Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in. I’ll guarantee to take any one at random and train him to become any type of specialist I might select.”

An argument he would of course later go on to prove by successfully raising The Village People. [Editor: This is categorically untrue.] He was very much Team Nurture is my point.

On the other hand there are some things which are mainly decided in-house. Things like eye and hair colour for instance are entirely down to the gene pool and you’re own particular brand of parental cocktail.

Until recently you might have assumed something as important as our eventual testosterone levels would have fallen into this category.

New research from Durham University however, points to our surroundings in early life playing a role in how high T can expect to get.

So which is it? Are testosterone levels an internal or external matter? Or does it take a little of column A and a little of column B to make ideal T?

When the going gets tough

In truth we already know that life circumstances can have an effect on male hormone levels. Marriage, stress and fatherhood are all things that can cause shifts through adulthood. This study though, was more about how your start in life influences levels of T later on.

Led by Dr Kesson Magid, a biological anthropologist at Durham Uni, the study collected data from 359 men. These guys fell into 1 of 5 groups.

  • Men who were born and raised in Bangladesh
  • Men born in Bangladesh but moved to the UK in childhood
  • Bangladeshi men who migrated to the UK as adults
  • Children born in the UK to Bangladeshi parents
  • Kids born in the UK of a European background

Bangladesh is one of the poorest countries in the world with malnourishment and growth stunting affecting 1 in 3 kids. To stop this hardship skewing results, researchers drew subjects from middle class, land owning Bangladeshi families

Magid and his team found that second generation Bangladeshi men, who both grew up and lived in the UK had significantly higher T levels than those who were born and remained in Bangladesh through childhood.

It also noted Bangladeshi men who grew up in Britain reached puberty earlier and generally grew taller.

The researchers’ theory is that the differences are down to the amount of energy our bodies can commit to producing testosterone. Which is vital in fuelling puberty and healthy development.

Even though Bangladeshi subjects were middle class, they are stil more exposed to illness, infection and nutrient shortage when compared to those in the UK. The extra effort the body uses to guard against this hurts T production.

Magid reports:

“The results of our study support the idea that the environment a man experiences in his youth affects his testosterone levels later in his life”

Family T

So are T levels really all about location, location, location? If you’re running low could you conceivably get a doctor’s note instructing your healthcare provider to go ahead and pick up the tab on your new life in Monte Carlo? Sadly not.

The Durham University scientists admit circumstances are just one piece of the hormonal puzzle. You’re always going to be at the mercy of the genetic lottery to some extent. Magid points out:

“There is a good amount of evidence that testosterone levels within populations do correlate with some genetic markers, and there is some inheritance of testosterone levels down family lines.”

It’s worth remembering that this study looked at the differences between populations, not the individual people in them.

First world problems

There’s good news and bad news here. The good news is most of us won’t have to face the challenges of Bangladesh. The bad news is evidence shows that even in more developed populations, T appear to be dropping.

As of right now no one is 100% sure of the exact reason for this is but there are plenty of theories.

Rising obesity levels in early life could be key, as excess body fat is known to inhibit male hormone. Stressful lifestyles may also play a part, as the stress hormone cortisol can block normal T production.

In reality, as with most things, what shapes our hormone levels isn’t all nature thing or all nurture, but a mix of factors. Genetics in part, sure, but also life circumstances and behaviour.

The takeaway then is, it’s possible to make a difference real to your levels. No matter where you’re from or what age you are, it’s a good idea to start boosting your T.

Most of us will be within the normal range for male hormone. But taking sensible steps to at the top of that inbuilt range naturally will bring a number of long lasting health and performance benefits. The earlier you start the better.

Write a comment