Welcome to the world of exercise and dietary science. It’s not great, largely because there’s no money in it and blinding is frequently impossible. This is why meta analysis is so popular.
Protein supplements alone is like a $30B dollar market and protein foods in general is >$100B. You'd think they would find some money in there. By comparison, the hair loss market is less than $10B and they have been putting out a few really high quality studies over the years. But I guess people affected by hair loss have higher agency than others.
The thing is that investing in large scale nutrition studies has no payoff. If Optimum Nutrition hypothetically proved conclusively that 1g protein/lb body weight grew more muscle than .8g, any growth to the industry would be general and not specific to their company. Basically there’s no return on investment.
A new baldness fighting drug gets patent protection and exclusive market rights.
I guess that’s an interesting comparison. There are decades of studies about protein intake, but many (most?) seem to be small.
If I had to guess, in addition to there being basically no money in it, it’s probably hard to get people to sign up for strictly compliant diets for long periods of time. Letting someone roll your head with a Dermaroller a couple times per week is comparatively a small investment in time and effort.
I can't imagine shaving your head and regularly treating it with betadine and saline before dermarolling for three months takes less effort than adding a daily protein shake to someone's diet. Dermarolling is also not pain free. So people suffering from hair loss absolutely have higher agency here.
You can’t just add a protein shake to someone’s diet and pretend that’s a meaningful measure. If the goal is to demonstrate that a higher protein diet is meaningful, then you need to pretty strictly track total protein (and probably total calories).
> So people suffering from hair loss absolutely have higher agency here.
That’s valid. Guys suffering hair loss are likely a lot more motivated than guys who opted into a protein study for $100 or whatever.
Most studies are actually done by having people just write down what they eat (or even just take a photo) in an app. This stuff is trivial. Applying a dermaroller and scalp products correctly at home is pretty complicated by comparison.
