My theme the last few weeks has been the signals that trigger the body’s self-destruction with age. The easiest to target are molecules that circulate in the blood. Last week, I covered a few that decrease in blood concentration as we age, and that cripple our defenses. This week, I’ll talk about signals that increase as we age, and that activate self-destruction. There are two principal mechanisms of active self-destruction: inflammation and apoptosis=cell suicide. Both mechanisms are important to the healthy functioning of the body. Inflammation is our first defense against invading pathogens. Apoptosis elimnates diseased and cancerous cells before they can become a problem. But in old age, both are co-opted for self-destruction. Healthy tissues in the body are destroyed by apoptosis, and inflammation leads to arterial damage and heart disease, DNA damage and cancer.
The blood signals, too, are have helpful roles earlier in life, but turn traitorous with age.