From your DNA and genomes to your risk of disease and determinants of health; the physiology between different races can differ massively.
Although we are all one species, millions of years of geographic ancestry and biological reproduction have led to a number of differences between people of different racial backgrounds – it’s what makes you your own person with your own genetic characteristics.
From muscle and bone, to hair an skin, it’s well known that physical differences occur between races. Even your hormones are different.
But what about your primary hormone levels such as testosterone? Could they differ based on race?
In this article we take a look.
The difference between race and ethnicity can sometime make biological identity seem like a complicated subject.
But it doesn’t need to be.
When we talk about someones race we’re talking about a person’s physical characteristics – their body shape, bone structure, skin and eye color. The kind of stuff given to you by your parents.
This is different to ethnicity, which is more about regional culture, ancestry and the language that they speak.
So for example, a person’s race could be black, white or Hispanic. Their ethnicity though could be American, British or Italian.
Millions of years of geographic ancestry have resulted in genetic differences between races.
It’s well known that both black and white people for example differ in a number of physical characteristics.
For example, black people are considered to have more muscle and bone mass. Numerous meta-analyses and clinical studies have reported that in both men and in women, black people have more appendicular muscle (arms and legs), greater bone mineral levels and lower body fat [1].
And it’s differences like these that can often be seen in the potential for sporting success.
For example, the bone and muscle structure of black people may be a reason why they tend to fare much better in sprinting events, whereas their lower buoyancy (due to heavier bones) leaves them less competent swimmers compared to white people.
Key Point: Black people tend to have greater muscle and bone mass when compared to any other race.
Not only are a range of different physical characteristics when it comes to different races; there are also different potential health risks.
For example, when it comes to metabolic diseases, you’re three to five times more likely to suffer from diabetes if you’re of either African-Caribbean or South Asian descent compared to white Europeans.
And if you’re a black man you’re at a 70% greater risk of heart disease compared to white people after the age of 45 – 50% for women.
For the last few decades, black men have seen the highest incidences of prostate cancer – around two-thirds higher than other races [2].
According to one study, ‘prostate cancer in African Americans is more aggressive and common than in any other racial group’ [3].
And although scientists don’t know exactly what the cause of such racial differences is, it is thought to be down to a combination of:
Many of the current theories around the higher risk of prostate cancer in black males relate to the role of testosterone.
But is there a difference between testosterone levels and race in the first place?
Let’s see what the research says…
Key Point: You are at higher risk of metabolic and cardiovascular disease and prostate cancer if you are a black man.
Here are the studies you need to know about most…
In order to investigate the differences in prostate cancer risk, body composition and bone mass between races, investigators from the New England Research Institute in Watertown, Massachusetts [4], recruited just under 1900 men.
Including black, white and Hispanic volunteers aged between 30 and 79 years old in the Boston area, the research team interviewed each of the men and obtained a range of blood tests.
The tests included:
What did the research team find?
From the large number of volunteers and the thorough range of blood tests that were taken, researchers concluded that there were no significant differences between T, SHBG or DHEA levels between races.
The only statistical finding was that black men had slightly higher levels of DHT and DHT to testosterone ratio – but this wasn’t thought to be in any way a predictor of health risk of body shape.
In this research study [5], clinicians used a longitudinal analysis (this is where participants of a study are monitored over a period of time rather than in just one session) to look at the differences in the T and SHBG levels of over 1,000 black and white men.
Over an 8-year period, the research team looked at changes to hormone levels. They also looked at any potential relationship with other markers of race such as body mass and waist circumference.
What were the results?
The results found that both racial groups saw a drop in T levels after the age of 24 – this was attributed to an increase in obesity (particularly belly fat).
Black men were seen to have an average 3% higher testosterone level than white men.
But, once factors like waist circumference had been factored in, that difference became insignificant. Remember, black men typically have lower levels of body fat and more lean mass.
The study concluded that in young black men, testosterone levels are highest – but once belly fat levels are factored in this differences disappears.
Based at the Albert Einstein Medical Center in Pennsylvania, Philadelphia [3], researchers used a group of men to assess differences between races for:
The reason why PSA was measured was that in this study was that the 52 men (aged around 70 years old) either had prostate cancer or were at high risk due to low levels of the protein.
The result?
Even when the men were categorized into cancer status, there were no changes to any of the measured markers, including testosterone.
There were no correlations between race, hormone levels or prostate health