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Older man

It’s inevitable. If we live long enough, we grow old. But why is that? And why do some people seem to age so much better than others? For example, though my husband is 11 years my senior, he is irritatingly younger than me per a biological age lab test.

Research on aging and the practice of anti-aging medicine has been exploding. I’m not referring to the plethora of cosmetic procedures aimed at mitigating the outward appearance of aging, but rather peering inward at a cellular level to learn how we might actually influence this process.

According to the Max Planck Institute for Biologic Aging, researchers have uncovered several cellular and molecular hallmarks of aging.

• Genomic instability—DNA in our cells is constantly being damaged and then repaired, though not completely, and over time damaged DNA accumulates.
• Telomere degradation—Our DNA strands are protected on the ends by telomeres akin to the plastic caps on shoestrings. With age, these protective ends deteriorate leaving DNA more vulnerable to damage.
• Epigenetic changes—Epigenetic literally means “on top of genes.” Genes are turned on and off through an epigenetic phenomenon known as methylation. As we age, our DNA methylation patterns shift such that genes we want “on” are turned off and vice versa. This phenomenon is one of the ways biological age is tested in the lab—the “methylation clock”. 
• Protein homeostasis/loss of autophagy—Proteins are responsible for most biochemical reactions. Damaged proteins are removed by a process known as autophagy.  With time, we acquire more damaged proteins and autophagy dwindles, resulting in both loss of protein function and accumulated waste. 
• Deregulated Nutrient Sensing—Nutrients act as signaling molecules helping cells to function optimally.  As we age, these signaling processes degrade leading to all sorts of metabolic issues from insulin resistance to dysregulated lipid metabolism. 
• Mitochondrial dysfunction—The energy factories of our cells, mitochondria, become damaged as we age causing diminished cellular energy and numerous disturbances in cell function. 
• Cellular senescence—As individual cells incur damage they stop dividing, lose function and what’s worse hang around releasing inflammatory molecules and other substances impairing organ function.
• Exhaustion of Stem Cells—Stem cells have the ability to replenish organs and structures with healthy cells. Stem cells dwindle with aging.
• Altered intercellular communication—Cells communicate through signaling molecules such as hormones and cytokines. As we age these signaling mechanisms begin to falter leading to system breakdown.
• Immune Dysfunction/ Inflammation— With age, our immune system tends to become less capable of protecting us from infection while at the same time producing unhelpful chronic inflammatory states. The term “inflammaging” is sometimes applied.
• Imbalance of the intestinal Flora—I have discussed the critical importance of the gut microbiome in previous articles. With age there tends to be loss of the good gut bacteria with increases in the harmful or pathogenic bacteria.

These interrelated hallmarks of aging have a domino effect and the magnitude of factors at play might cause one to throw their hands up and cease making an effort. Yet there is hope! Knowledge of the physiology of decline helps us understand how we might run interference—not in search of Ponce De Leon’s fountain, but rather in seeking an optimized “healthspan.”

You too can obtain biological age tests such as the "methylation clock” that affords insight into your age as impacted by epigenetics. Genes matter for sure, but you can influence epigenetic factors that modify gene expression, and this may very well matter more. As the saying goes, “genes load the gun, but epigenetics pulls the trigger.” Moreover, there are strategies for inducing autophagy, supporting mitochondria, mitigating inflammation, mobilizing stem cells, protecting telomeres and more. Biological aging can be forestalled and sometimes even reversed. More to come in future articles, but meanwhile, I’m working hard on catching up with my younger older husband.