I was a little surprised that there were a bunch of comments on the paragraphs about aging and how THC strips off that protective shield on the tips of chromosomes and leads to premature cell death, accelerating the whole aging process. The theory and biology of aging are really fascinating and there’s been a huge increase in our knowledge about the chemistry at work behind the scenes as we grow older. Since this is right up there in the thoughts of all of us “getting on in years,” let’s take a deeper dive into the topic. But before we get started, I have to confess that there’s a buzzkill coming—the title of this post. Sorry, there is no “secret antidote” to aging, but I’m pretty sure you already knew that. It’s one of those “teasers” that they throw at us on the radio and TV. “Stay tuned, don’t touch your dial, after this brief commercial break [that usually lasts half an hour] we’ll be right back with….BLAH BLAH.” You know the drill. There is only one thing you can do to avoid getting older, and that is to die young, and none of us wants to get anywhere near that issue. It’s like that old country tune that says everybody wants to go to heaven but nobody wants to go tonight. Hopefully the “teaser” worked and you’ll read on.
A while back one of the posts was on “The Fountain of Youth“ where I talked about new meds that slowed down some of the ill effects of getting older. We also talked about other factors in our environment and diet that accelerated aging in the post on “We’re Not Aging Well.” That, and the stuff about THC, was all about the symptoms of getting old; there wasn’t anything there about the basic process and science of aging, so let’s get to it.
There are three ways we think about aging. The first is appearance, and in these days of social media “influencers” that one gets the most attention, even though it’s the least important of the three. We all know what someone getting on in years looks like; those physical characteristics are what biologists call the “phenotype.” It comes from the Greek words phainein, which means “to show,” and typos, meaning ”type.” Phenotype is the most superficial sign of growing older, and just ask anyone in Hollywood how hard (and expensive) it is to grow old and try and hide it. It’s like what Billy Crystal used to say in his hilarious spoof on SNL, “You look marvelous, daaahling.”
The next way we think about getting older is calendar age, “hanging another year on the line.” But that doesn’t tell the whole story either, since there’s not really much correlation between how many notches in your belt and the most important of the three, your true “biological age.” “Biological age” is the most critical factor in aging since this is the one that determines our quality of life and how long we live. In spite of being so critical, it’s the one that doesn’t get any social media airtime. To understand biological age, it needs to be broken up into two components. The first is what you’ve inherited from your ancestors, your genetic makeup that scientists call your “genotype,” and the second is environmental influences. Environmental factors are all the things we’ve talked about in the past months, everything we eat, drink, breathe, smoke, and do (or not do—like exercise). The follow-up to Billy Crystal’s SNL pantomime of Fernando Lamas goes, “It’s better to look good than feel good.” Most of us would probably disagree; “feeling good” is determined by your biological age, which is what defines our whole quality of life. “Looking good” is just the window dressings of life.
The biology of biological aging comprises a collection of diverse molecular processes and cellular activities that are interrelated and act together to drive the aging process. Today’s science of biological aging focuses on “epigenetics,” which I talked about briefly last month and prompted the comments. It’s all about something called “telomeres.” That’s the scientific name for chemical tiny caps on the ends of chromosomes that prevent the tips from getting clipped off with each subsequent cell replication as cells get older. They’re like the little plastic tips on the end of shoelaces I mentioned last month when I quoted new evidence that smoking THC shears them off. Telomeres are composed of “repetitive nucleotide sequences”—the same chemicals in the DNA strands—that form a “cap structure” on the tips of DNA strands that function to prevent chromosomes from “fraying” at the ends. There’s nothing good about that since it deletes critical genetic information that leads to two bad things. One is early cell death since the cells can’t replicate accurately and don’t survive successive cell generations. As the bricks crumble, the whole body starts to fall apart. This type of gene damage has also been linked to almost all other age-related diseases, such as tissue and bone integrity loss, dementia, and organ failure. Like our airplanes as they reach TBO, as we age our body parts just wear out. But the other problem with it is even more dangerous. When chromosomes don’t get copied accurately, the incorrect information in the genes leads to cell mutations. Those mutations can change normal cells into cancer cells, and that’s why there’s an increasing incidence of cancer paralleling increasing age. It’s also why cancer can be so hard to treat since cancer cells are really very similar to the normal ones they mutate from. “Chemotherapies” targeted at killing cancer cells can also injure healthy body tissues.
As if all that is bad enough, another consequence of losing the protection of the telomere caps is the early death of “stem cells,” which are extremely sensitive to gene damage since these cells can’t survive without those protective tips. Everyone has heard about stem cells, those little cellular magicians that hang around in youth and health that have the remarkable ability to renew themselves or change into another type of specialized cell to regenerate any part of the body in need of repair or to heal from injuries. There are two different types of stem cells. The first kind are “pluripotent stem cells,” embryonic stem cells that turn into all different kinds of dedicated cells in the developing embryo to form each organ system. The others are non-embryonic or somatic stem cells called “adult stem cells.” These are the type of stem cells that carry on after birth and also have an incredible capability to differentiate into special organ cells to repair injuries and regenerate aging structures. But this requires genes with all their genetic information intact that allows them to differentiate into those specialized cells to repair and replace damaged organs like skin, liver, and bone marrow cells to make blood cells. This is the basis of all those new stem cell therapies to treat a wide variety of diseases. Without these reparative building blocks, the body can’t regenerate and recover from microscopic-level injuries that occur as cells age; hence, we break down and fall apart—welcome to getting older. This is such a central part of the molecular basis of aging that a recent journal article from the University of Texas states, “The issue of stem cell exhaustion is the cardinal feature of aging.” It goes on to give us a scientific mouthful, “Aging is a progressive degenerative state accompanied by tissue stem cell depletion, tissue inflammation, matrix alterations, cellular senescence (death), and metabolic dysfunction driven by epigenetics and chromosomal damage.”
Putting all this together, staying healthy as we age comes down to an invisible, microscopic process of maintaining chromosome length by sticking to a healthy lifestyle and being fortunate to have inherited a good set of genes from our parents. This allows the body to maintain the little telomere caps that protect precious information coded in genes and permit accurate cell replication. This is especially critical in stem cells since they are the only tools we have to fix or replace damaged, aging cells. All the topics we’ve talked about over the last few months come down to this thesis: bad habits, bad diets, and bad life choices contribute to chopping the tips from genes and chromosomes, losing crucial genetic information. That leads to early cell death, organ system breakdown, inaccuracies in cell replication causing cancers, and ultimately a shortened life expectancy. Avoiding this is quite a task requiring healthy habits, but modern science has some other tricks too and next month we’ll take a look into it. By then we’ll all be a little older, our chromosomes will be a little shorter, and we’ll have a few less stem cells. So try and keep your gene caps on, your chromosomes long, your stem cells churning away, and as always, FLY SAFE!
