Smart people, do you know the answer to this?

The hair are basically dead cells. How comes when you have a better diet they look better then? And not just from the base but the whole hair length?

Today I was talking to some people, you know, some homeopath-tarots kind of folk.
One of them said that hair are alive like branches, I said well actually it's just dead cells, and I've been asked this

@arteteco My guess is this: your hair doesn't look better when you have a better diet. If it does, it's a placebo effect. I'd test that first.

@arteteco Another theory: when you have a better diet, you're more likely to take better care of yourself in general, and therefore you take better care of your hair, causing your hair to look better.