It is a no brainer in the science community that the best place for humans to live is the planet earth, at least for the time being. Perhaps, with time, if Elon Musk and others succeed, we may pack to Mars or some other planet with high chances to support life. This is perhaps why it is more than a little surprising to find several positive effects of living in space for an extended period of time.

^{Pixabay CC0}

A while ago, I went all out to write about how some little materials found at the edges of the chromosomes could be the key to Living Young Longer. They call it Telomeres. As discussed in the post, Elizabeth Blackburn, discovered that aging begin at a cellular level. her discovery was that the length of the telomeres found at the tip of our chromosomes determines how old we are or at least how long we have yet to live. This means that the telomeres are longer in younger people and gets shorter for older people.

To make a long story short, every living organism is made up of or or more cells and these cells contains hereditary information that is necessary for regulating how the cell functions and how information is encoded in new or next generation cells. It turns out that these hereditary materials are contained in what is called nucleic acids which is basically a 5-carbon sugar and some other stuff :) Depending on the type sugar, the resulting hereditary material could be a simple ribose, in this case we have ourselves a Ribonucleic Acid (RNA). Or we could have a deoxyribose sugar, in which case our hereditary material is Deoxyribonucleic Acid (DNA). Complete or part of the genetic material of a living organism (which we all are) is contained in a molecule of the DNA called Chromosome. Sorry, the ongoing is just me trying to cover the basics.

The gist of the matter is that scientists have discovered that not only does living in space make your telomeres longer, it also increases your height such that a set of twins with identical twins would record differences in height when one has been in space for a period of up to one year. Furthermore, a change in the genetic expression of the space twin up to 7% was noted. To understand how hopeful the scientists were when they made this discovery, you really need to appreciate how telomeres helps the lifespan of a living organism at a cellular level.

^{Wikimedia Commons:Mark and Scott Kelly at the Johnson Space Center Houston Texas}

We, humans, according to evolution have come a long way. We have evolved from single cell and since then, our cells have been dividing and replicating itself until now that we have billions of cells. Yet, what happens at the cellular level, still to a large extent, determines what happens to a human being. It turns out that as the cells divide, the genetic materials that would determine the function of the new cells are copied through the DNA which is contained in the chromosomes.

We can kid ourselves that the division would continue forever but if you have been to earth, you'd know that there are always problems and according to Sir Edgar Alan Poe, they never "singly come". So what happens is that the tip of the chromosomes suffers attrition as the replication occurs. As the ends of the chromosomes (telomeres) are frayed, the DNA which is supposed to control the functioning of the cell would literally put out a contract on the cell: "Time to Die" and the cell must obey and die. Of course, the human being made up of billions of these cells does not die, at least not immediately. But the continuous death of cells would cause signs of aging such as wrinkled skin, greying hair, Alzheimer's and loss of memory due to death of brain cells.

So when the scientists found that the telomeres of the space twin was longer than the other twin, they thought they may have just figured out another way for longevity: after grinding on earth, you can just take a trip to the International space station and chill out for one year while you grow significantly younger. Not so fast! Hold your horses or your spaceships!

This whole discovery was made when NASA decided to study the possible height change and other physiological changes that space travel causes on the body. They did the study by observing the Scott and Mark Kelly twins both of which are astronauts for the past three years. When NASA began the study in 2015, they sent Scott to the International Space Station while they observed Mark on earth. Scott was out for a year while his brother was monitored on earth. What NASA discovered was that spending a long time in a zero-gravity space has the tendency to cause the spine to stretch. In other words, the space between the vertebrae would expand gradually because it is no longer under the constant gravitational pressure to be compacted. The height that the individual who has spent an extended time in space would gain could be in the range of a few centimeters to a couple of inches. Thank you NASA for proving me right: it was all those times that I carried heavy load on my head that is responsible for my inability to measure up to six feet :)

So in the case of Scott and Mark, Scott came back about two inches taller than his brother in addition to having telomeres that made it seem that he was younger than Mark. In addition to that, the 7% change in Scotts gene expression was attributed to certain mental stress associated with living in space. Unfortunately for those of us that are hoping to take advantage of this information, no real permanent causes of the changes were found except the usual culprit - gravity. The height gained in space is soon lost on earth after some time under gravity and the telomeres soon return to normal after living on earth for a while. A likely explanation of the reason for elongated telomeres is an explanation offered by Elizabeth Blackburn after studying the telomeres of a group of caregiving women:

The longer they have been under this stressful conditions, the shorter their telomeres - researcher, Elizabeth Blackburn.

In other words, even though pressure makes diamonds much harder than stones and makes them shine brighter as each day goes by, gravity is not good for your telomeres even though they may be good for everything else.

Conclusion...

Even though we may not be able to go to space in order to gain a few inches in height and gain youthful telomeres, we have it within our power to avoid stressful conditions that can shorten our telomeres and make us age faster eventually. Elizabeth Blackburn found out that living conditions such as long-term marriages and other positive associations, good diet and exercise, maintaining a positive attitude could help one replicate the conditions that Scott's telomeres were when he came back and this does not have to change as long as we maintain the conditions that created it in the first place. This is the way to long-lasting youthfulness. As for replicating that height gain, your guess is as good as mine. Please let me know when you find out how :)

References

1. Life Science | Scott Kelly DNA Twin Study
2. Wikipedia | Cell Theory
3. Geneed | Chromosomes