In my last video, I looked at whether protein supplementation has benefits for those doing
resistance training.
I showed you that there is some benefit, even if it isn’t as much as people expect.
But could protein powder have negative effects on the body?
Today I’m going to have a look at the science behind 3 common concerns about a high protein
diet: can a high protein diet cause kidney damage, accelerate hair loss or make Acne
worse.
Let’s jump straight into it!
Number 1: Does a high protein diet cause kidney damage
The main job of the kidneys is to filter our blood to remove fluids and waste products.
One way that we measure the health of the kidneys is to look at the Filtration Rate,
which is a measure of the flow of fluid through the kidney.
In a healthy kidney, the filtration rate remains high so that any toxins or waste products
in our blood are quickly removed from the blood.
In people who have kidney damage, the filtration rate is reduced and there is a risk that waste
products build up in the blood.
We know that within 1 hour of high protein consumption like drinking a protein shake,
there is an increase in the kidney filtration rate up to 30%.
In people who already have kidney damage, the kidneys struggle to cope with this extra
workload and in the long term there can be some worsening of kidney damage.
This is the origin of the theory that protein shakes cause kidney damage.
It was thought that if a high protein diet could have some negative effects in people
who already have kidney damage, then maybe it could also have some negative effects in
people who are healthy.
But this is where the logic falls down.
Just because something is true in people who have kidney damage, doesn’t mean that it’s
also necessarily true in healthy people.
We know that a healthy kidney has an incredible ability to adapt.
You may have heard that people can live with only one kidney, and that’s because a healthy
kidney can easily adapt to a higher workload without any consequence.
In fact, a recent article published in November 2018 specifically looked at the effect of
a high protein diet in healthy people.
They researchers found that high protein diets do not appear to have a negative impact on
kidney function in healthy adults.
Number 2: Does a high protein diet cause hair loss?
In men, hair loss occurs because of a combination of genetics and the effect of testosterone.
Most of the testosterone in a male body is made in the testes and travels to the hair
follicles in the blood.
Here, testosterone is converted into a molecule called Dihydrotestosterone also known as DHT.
In men who are genetically at risk of hair loss, this DHT converts large hair follicles
that produce long hair, into smaller follicles that produce very thin hair.
In women, there is some testosterone produced in the ovaries and the process of hair loss
is thought to be similar to that of men, but researchers aren’t a 100% sure yet.
I couldn’t find any direct research looking at protein intake and hair loss, so we can’t
concretely answer this question.
But one thing that we can look at is whether protein intake causes an increase in Testosterone
levels.
Because if there is an increase in testosterone, then it is possible that protein intake may
increase the risk of hair loss in those who are already genetically at risk.
To answer this question, I found a couple of small studies that looked at the effect
of protein supplementation on hormone levels.
Both of these studies indicate that protein intake had no effect on testosterone levels.
This isn’t definitive evidence by any means, but it does suggest that protein intake itself
probably doesn’t have a direct impact on hair loss.
Since the science is a bit sketchy on this point, please do post in the comments if you’ve
had an experience that would be useful for other people to know.
Number 3: Can a high protein diet make acne worse
Acne is super common with some estimates suggesting that 73% of people have had acne at some point
in their life.
There are multiple factors that contribute to acne like your genetics, normal skin bacteria,
your immune system and your sensitive to hormones.
But could a high protein diet make acne worse?
Just like the hair loss question, I couldn’t find any direct research looking at protein
intake and acne.
So let’s look to see if there’s any indirect evidence that could provide some hints about
protein intake and acne.
In the skin, sebaceous glands are microscopic organs produce an oily substance called sebum,
that normally works to lubricate the skin.
In acne, sebum accumulates over a skin pore and converts it into a whitehead.
Some key hormones that influence the activity of sebaceous glands are testosterone, DHT
and another molecule called Insulin-like Growth Factor, also referred to as IGF.
Testosterone, DHT and IGF all increase the activity of sebaceous glands and can therefore
make acne worse.
We know from earlier that protein probably doesn’t increase testosterone levels, so
let’s cancel them out of the picture.
What about IGF?
Well there is some evidence that milk consumption could increase the levels of IGF and therefore
lead to worse acne.
There have been a handful of case reports of acne getting worse in young people who
were using whey protein.
So it is possible that whey protein may contribute to worsening acne.
This again is not definitive scientifically because the quality of the evidence is quite
low.
The only suggestion that we have is if you have severe acne, you may want experiment
with using sources of protein other than dairy or whey.
For example you can try soy based protein or plant based protein.
Again since the science doesn’t provide a strong answer to this question, please do
post in the comments if you have an experience that would be useful for other people to know.
As always if you’re worried about kidney damage, acne or hair loss, please do talk
to your doctor to get specific medical advice for your particular situation.
In one of my previous videos I looked at the relationship between diet and heart health.
If you’re interested in learning more, click on the video to your right, and the one below
it is what YouTube thinks you should watch.
Thanks for watching and I’ll see you in the next one.