Comment by FollowingTheDao

> it seems our systems are balanced to regulate cancer during our youth and reproductive years

Yes, the most important question, and an easy answer if you know where to look. What is it that we lose when we age?

Mineral and vitamin deficiencies can accelerate the mitochondrial decay of aging

https://pubmed.ncbi.nlm.nih.gov/16102804/

Age-associated B vitamin deficiency as a determinant of chronic diseases

https://www.cambridge.org/core/journals/nutrition-research-r...

Emerging Roles of Vitamin B12 in Aging and Inflammation

https://www.mdpi.com/1422-0067/25/9/5044

There is more if you want to look. Lots more.