If CAFFEINE does nothing for you at the gym,
then some new science suggest that it might have to do with your… genetics.
Let's check it out.
Caffeine is THE most widely used stimulant in the world.
And thanks to its strong track record in improving exercise performance,
it's also one of the most used fitness supplements in the world.
But even with plenty of science supporting it, not everyone benefits from taking it,
even for some that hardly ever use caffeine, which rules out the common issue of caffeine tolerance.
But, what about… your genetics?
You see, in humans, one enzyme is responsible for 95% of caffeine metabolism.
And what researchers discovered is that depending on the specific genotype we
carry for this CYP1A2 enzyme, the speed we metabolize caffeine greatly varies.
Theoretically, we'd want to metabolize caffeine as quickly as possible so that caffeine metabolites,
like paraxanthine, can more quickly interact with adenosine receptors, leading to the familiar
caffeine effects of improved alertness, cognition, and of course, performance.
And when we look at this new paper, which analyzed 13 studies on caffeine ingestion
and genotype interactions, it does seem that this plays out as expected.
AA and AC genotypes, which are considered the fast and intermediate caffeine metabolizers
respectively, observed small but meaningful improvements in exercise performance,
with AA faring non-significantly better than AC.
The slower, CC genotype, on the other hand,
surprisingly went the complete opposite direction and reduced exercise performance.
Now, fortunately, the researchers did discover a couple scenarios
exclusive to the CC genotype where some performance benefits can still be observed.
One scenario is taking a higher caffeine dose of 6 milligrams per kilogram of bodyweight,
which, however, equates to about 500 milligrams for the average adult male.
And the second is by having a bigger time gap, about 2 hours,
between consuming caffeine and working out.
But for all other measured scenarios, according to the data,
it does seem that genetics can play a role in exercise performance.
Buuut, there is a rather interesting twist.
And, it comes in the form of conflicts of interest.
Some studies analyzed in the paper have connections to conflicting funding sources,
most of which produced negative outcomes for the CC genotype.
When removing these conflicting outcomes from the analysis,
the reductions we initially observed with the CC genotype completely vanish.
To be clear, conflicts of interest do not automatically negate a study's findings,
but they can be more prone to biases.
Now, you're probably wondering, “Who exactly would benefit from having this negative genetic result?”
Well, if this genetic relationship with caffeine is indeed true,
then people would want to know their genetic profile,
which means taking a genetic profiling test, which is sold by genetic profiling companies.
Of the six conflicting studies, five involved researchers that were either
employed by or held shares in genetic profiling companies.
Also, for the sake of full transparency, this new paper has its own conflict of interest, where some
researchers received caffeine supplements at no cost for use in other, unrelated research.
Now, not sure that's in the same level as employment or ownership
in the company funding your study, but again, just being fully transparent.
But now taking everything into consideration with the current scientific literature,
we're essentially left with one conclusion,
and that is that we don't have a concrete conclusion about genetics and caffeine... yet.
I know that's not exactly the sexiest outcome,
but it's still very important to know, especially in an industry filled to the
brim with conflicts of interest leading to an abundance of questionable claims.
So if we want to better navigate through the fitness industry,
we should look at the full science as often as we can, even the less exciting parts.
Just to be clear, even after removing the conflicting data,
the research still shows that fast caffeine metabolisms have greater
outcomes, although no longer in a statistically significant manner.
So genetics may very well play a role, but we need more data.
But, what if we just pretend that conflicts of interest are not a problem,
would the overall results even warrant taking a genetic test for caffeine anyway?
Well, unless you're a professional athlete where every minute detail about performance matters,
the answer, in my opinion, is still... naaah.
And, the reason is simple. You can just find out yourself by just taking caffeine.
And even if you assume that you have the slower CC genotype, again, you can take a higher
dose if you're willing or wait longer before working out to offset that slower metabolism.
Knowing your specific genetic profile for caffeine just isn't worth it.
Plus, if you like to rock a tinfoil hat from time to time,
you wouldn't want your precious genetics in the hands of a third party anyway.
With all this said, I'll still definitely keep an eye out on the field of nutrigenomics. It
does seem fascinating and in the future, it might very well be a gamechanger.
But right now, at least for caffeine, we're not changing much.
If you enjoyed this video, please give it
a caffeinated thumbs up and share it with your gene-loving friends.
Subscribe for more and check out the original paper in the description.
As always, thank you for watching and don't forget to get your protein!