Likewise with doctors. I have had 4 doctors in my family (3 still alive), and I've spent many the family meal talking with them about health, longevity, and the mechanical/biology/chemistry behind how your body works and when it works best.
In any case, service life in cars is usually determined by a couple key things: The design of the system, driving conditions, and service. You may feel like you're being blown off when the mechanic says "obey the service intervals and avoid short trips", but that's 99.9% of what you can do to make the car last.
(Special corner cases are widely-understood and well-documented, such as the impact of very high operating temperatures in automatic transmissions during towing)
The conversation with the doctor/nurse should go something like:
You have diabetes. Your body has become insulin resistant because you ate too much sugary/starchy stuff. Eat less of it and you will get better.