The condition of one's hair, fat processing and mental effort as one grows older

I notice that my hair is getting more and more grey - which is not a surprise! But what is a surprise is that my hair looks less grey (more black) when almost any vegetable oil or cream is applied. That leads me to conclude that the greyness is somehow connected with the shedding of fat from hair, or the inability of hair to absorb such fats from the hair roots, as they could do when I was younger.

Possibly this fat-absorption matter also has to do with hair thinning and hair loss?

Therefore, instead of surgical interventions by trichologists to improve hair density, colour and tone, I wonder if research should not rather focus on what causes hair roots to stop being efficient at processing the relevant fats?

Incidentally, I notice that my body has started shedding fat as I am growing older (even though the processing of fats as well as of carbohydrates by my body has slowed down - which, I think is the main reason why older people put on weight). Is that related to the shedding of fat by one's hair? If so, might hair loss and greying be an early indicator of ageing?

Further, I notice that, as I am growing older (not yet very old, only in my early 60s), it takes more effort to learn new things as well as to recollect facts, faces and names: the links and connections seem much weaker, and it takes more time and effort to travel along them.

Finally, I notice too that my mental energy is declining: I used to be able to work hard for up to 20 hours a day, now I can deal with probably ten.

I think back to when I was an athlete: the biggest battle for an athlete in a race or in the middle of training is actually in the mind (one gets mentally tired and ready to give up long before one has to do so physically).

It is the same now in relation to my ageing. Things that I used to do spontaneously and effortlessly now take the mental effort of making a decision before one can engage with them.

At present, thank God, once I have made the initial effort in deciding to engage, the momentum carries me through most tasks on most days.

But I can imagine that the time is not far off when it will require not only an effort to start engaging, but also that the momentum of the decision will carry me for shorter and shorter lengths of time, and less and less complex tasks.

To deal successfully with ageing may therefore be a matter of ensuring enough stimulation to keep the brain active by forcing it to be reactive - though I should expect from observation of other old (and older) people, that there is a limit to that too.