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..