Progeria is often called a disease of accelerated aging. Patients mostly die of a heart attack at age 13, looking frail and old with bald heads, a wrinkled skin, a beaked nose, tin lips and tired looking eyes. It’s a very rare disease, afflicting about 1 in 8 million people. The official medical name is Hutchinson-Gilford syndrome.
However, some scientists believe that progeria isn’t in fact a disease of accelerated aging. They consider progeria a disease that resembles aging, but that isn’t really like the aging process itself.
After all, progeria doesn’t exhibit all the symptoms of the classic aging process. Patients with progeria don’t seem to have an increased risk of other typical age-related diseases, like dementia, cancer, cataract, diabetes, a declining immune system, increased cholesterol and triglycerides (fats), deteriorating eyesight or hearing loss.
Why then does progeria looks so similar to the aging process itself? This is probably because the final result of progeria is in some way the same as the aging process: massive loss of cells. As well as in progeria as in aging, cells everywhere in the body die and the final result of this massive cell die off is that the body looks old and frail.
In progeria, cells massively die because of extensive DNA damage. A malfunctioning protein in the nucleus of the cell makes the nucleus (that stores the DNA) unstable. This contorted and twisted nucleus damages the DNA inside it and causes the cell to die.
In aging, cells everywhere in the body also die, but this because of other ways of damage than only DNA damage. As we age, cells get damaged by protein agglomeration, advanced glycation end products, continuous growth signals, clogged up lysosomes and malfunctioning mitochondria, inevitably resulting in cells succumbing everywhere in our body, making our tissues and organs frail and weak.
So it’s possible that progeria isn’t really an aging disease, but a syndrome that only bears resemblance with the aging process. The same goes for other seemingly ‘accelerated aging diseases’, like Werners syndrome or Cockayne syndrome, which also mainly involve DNA damage.
While many people look at progeria and other progeria-like diseases as evidence that aging mainly involves DNA damage, those diseases in fact show that the aging process involves much more than only DNA damage.
Author: Kris Verburgh, MD
Picture: The Cell Nucleus and Aging: Tantalizing Clues and Hopeful Promises. PLoS Biology Vol. 3/11/2005. Creative Commons Attribution 2.5 Generic license.
We are often being told - especially by sellers of food supplements and skin cremes- that antioxidants slow down the aging process. Antioxidants would delay aging by mopping up reactive free radicals that otherwise damage our DNA. These dreadful free radicals are produced as a side effect by our metabolism.
But mounting evidence shows that antioxidants don’t slow down aging. And the free radicals aren’t always the bad guys. Free radicals can even function as a benign warning sign, revving up the cell’s defense mechanisms, like detoxification enzymes and repair proteins, protecting our cells against age-related damage.
Studies have shown that genetically modified worms that produce more free radicals, live 32% longer. Giving worms a weed-controlling herbicide that creates a surge in free radical production makes these worms even live 58% longer.
While free radicals aren’t always bad, antioxidants can be damaging. A large meta-analysis of 230 000 patients has shown that people who take antioxidants have an increased rate of death.
In conclusion, taking antioxidants isn’t always a good thing. Of course, when you are deficient of certain antioxidants, you do have to take them to replenish the ranks. But taking extra antioxidants to slow down the aging process doesn’t seem to work unfortunately. Meanwhile, aging seems much more complex than just free radicals damaging our cellular machinery.
Author: Kris Verburgh, MD
A Mitochondrial Superoxide Signal Triggers Increased Longevity in Caenorhabditis elegans. Wen Yang, Siegfried Hekimi. PLoS Biology, 2013.
Is the oxidative stress theory of ageing dead? Pérez VI et al. Biochim Biophys Acta, 2009. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. Bjelakovic, G. et al. JAMA, 2007. Picture: cc Wikicommons