Laron dwarves, cancer, diabetes and longevity

People with a peculiar form of dwarfism living in remote Ecuadorian mountain villages provide some interesting insights into longevity and protection against aging-related diseases like cancer and diabetes.

Those villagers are called Laron dwarves. They have a short height because of a mutation in a growth hormone receptor protein. This mutation prevents the liver to make IGF-1 (insulin-like growth factor-1).

IGF-1 is some sort of growth hormone, that makes the body grow. If you have a deficiency of it, you don’t grow any more.

However, these Laron dwarves don’t seem to contract cancer or diabetes. They seem to be almost completely protected against these otherwise very common diseases, which points to a role of IGF-1 in cancer and diabetes.

Other research has indeed shown involvement of IGF-1 in cancer and diabetes. The more IGF-1 circulating in your body the higher your risk of cancer or diabetes. Other studies show a link between IGF-1 and longevity. Lab animals like worms without IGF-1-receptors even have a double life  span.

Conversely, the more growth hormone, the more IGF-1 you make and the faster you seem to age.

Ironically, growth hormone is touted as a powerful remedy against aging everywhere on the internet, despite studies showing a clear link between growth hormone, IGF-1, cancer and diabetes.

Anyway, Laron dwarves provide scientists with yet some more tantalizing insights into the why of the aging process.

This is a movie about Laron dwarves and aging:

Is progeria a disease of aging?

Progeria is often called a dImageisease 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.

Picture: The Cell Nucleus and Aging: Tantalizing Clues and Hopeful Promises. PLoS Biology Vol. 3/11/2005. Creative Commons Attribution 2.5 Generic license.

Do antioxidants slow down the aging process?

pills-antioxidantsMany people believe that antioxidants slow down the aging process.

Antioxidants are said to curb aging by mopping up reactive free radicals that otherwise damage our DNA. Free radicals are produced as a side effect by our metabolism.

But more and more evidence shows that antioxidants don’t slow down aging. And that free radicals aren’t always the bad guys. Free radicals could even function as a warning sign, revving up the cell’s defense mechanisms, 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 a 5% increase in the 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. Meanwhile, aging seems much more complex than just free radicals damaging our cellular machinery.

References:

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. // Author: Kris Verburgh// Picture: cc Wikicommons

Alcohol and sleep: not always a good combination

Afbeelding

Alcohol can disrupt your sleep.

That may seem strange. After all, it is well known that a dash of alcohol can make it easier to fall asleep. For many people, alcohol is a regular nightcap.

However, research has shown that alcohol disrupts the sleep cycle. It makes sleep less deep and it reduces the time you dream, so next morning, you feel less recovered.

Additionally, alcohol can make you prone to snoring, and even increases your chances of developing sleep apnea. Sleep apnea is a disorder in which the throat muscles become too flaccid so that you can’t breathe enough oxygen, waking you up dozens of times during the night. You fall back to sleep immediately, so mostly you don’t remember anything about it.

Alcohol in moderation can be a healthy thing, but the time you drink is also important. Drinking alcohol in the evening can disrupt a good night rest.

References:

Critical Review Alcohol and Sleep: Effects on Normal Sleep. Irshaad O. Ebrahim et al. Alcoholism: Clinical and Experimental Research, 2013 // Author: Kris Verburgh// Picture: CC André Karwath

About this blog

science aging After a long silence, I’m planning to reignite this blog.

The subjects will be different: instead of science, philosophy and evolution in general (all written in Dutch),  I now will focus on health, aging and medicine, and all this in English.

Of course, now and then I’ll still write about evolution, or philosophy in general, but the tune of this blog has definitely changed.