Even short trips to space can change an astronaut’s biology — a new set of studies offers the most comprehensive look at spaceflight health since NASA’s Twins Study.

Sub: Science and tech

Sec: Space sector

Context:

New research uses twins to discover how one year on board the International Space Station affects the human body.

What is NASA Twins Study?

NASA selected astronaut Scott Kelly for a one-year mission, during which he spent a year on board the International Space Station from 2015 into 2016.
Over the same time period, his identical twin brother, Mark Kelly,, remained on Earth.
While examining blood samples of both astronauts it was found that the telomeres of Scott in space increased in length and got quickly shortened when he returned to earth and overall astronauts had shorter telomeres after spaceflight than they did before.
With age telomeres get shortened because of a variety of factors, including stress.
The length of telomeres can serve as a biological indicator of the risk for developing age-related conditions such as dementia, cardiovascular disease and cancer.
During studies made on the Inspiration4 mission that lasted only three days, it was found that even short trips, like a weekend getaway to space, will lead to changes in telomere length.
A similar study conducted on high-altitude mountain climbers found that while climbing Mount Everest, the climbers’ telomeres were longer and after they descended, their telomeres shortened.

Telomeric RNA:

Telomeric repeat–containing RNA (TERRA) is a long non-coding RNA transcribed from telomeres – repetitive nucleotide regions found on the ends of chromosomes that function to protect DNA from deterioration or fusion with neighboring chromosomes.
Studies on various astronauts suggested increased levels of telomeric RNA, termed TERRA.
Telomerase is an enzyme that maintains telomere length.
Together with laboratory studies, various findings tell us that telomeres are being damaged during spaceflight.

Why do telomeres length changes in space?

Telomeres are sensitive to oxidative stress.
The chronic oxidative damage that astronauts experience when exposed to space radiation around the clock likely contributes to the telomeric changed length.

What is oxidative stress?

Oxidative stress is an imbalance of free radicals and antioxidants in your body that leads to cell damage.
It plays a role in many conditions like cancer, Alzheimer’s disease and heart disease.
Toxins like pollution and cigarette smoke can cause oxidative stress, while foods rich in antioxidants can help reduce it.

Plant telomeres in space:

As per the study published in Nature Communications, unlike people, plants flown in space did not have longer telomeres during their time on board the International Space Station.

The plants did, however, ramp up their production of telomerase, the enzyme that helps maintain telomere length.