Lessons From Space

Roughly 60 miles above the planet lies a mysterious environment known simply as “space."

While our understanding remains limited in comparison to its vast complexity, what we do know is this: space is harsh. And on the surface, seemingly incompatible to human existence.

Not only is space devoid of oxygen (which proves pretty important for human life), it lacks the gravitational environment of earth and is teeming with radiation.

Yet, humankind has often looked towards space as the next frontier for exploration and our fascination with what lies beyond our atmosphere has inspired years of intensive research.

Interest in space and astrological phenomena dates back to ancient times when people built mythological stories around named constellations—many of which are still prevalent today.    Practical use of the night sky to tell time and navigate would come a bit later, but would play a major role in early travel and farming.

The desire to conquer space would continue into modern times and the race to travel into the unknown would became a contentious battle between the United States and the Soviet Union. The Soviet Union made the first break with the 1957 launch of “Sputnik,” the first satellite to orbit the earth. But, the United States wasn’t too far behind, with the successful launch of the satellite “Explorer” in 1958. In 1961, Soviet Yuri Gargarin made a successful orbit around the earth, marking the first human to leave earth. Efforts by both sides quickly focused next on the moon. The United States would ultimately prove successful in that area, when astronauts Neil Armstrong and Buzz Aldrin stepped foot on the moon in 1969.

While our knowledge of space has increased with greater exploration, one question that continually gets raised is the biological effects of space travel on humans. Years of research and observation of those who have traveled into space have shown deleterious effects from the harsh, foreign environment. But, why?

Mitochondria In Space

Time spent in space is known to negatively impact health, resulting in what has been called “geriatric stress”—i.e. advanced aging (1). The most common impacts include, “bone and muscle mass loss, central nervous system issues, immune dysfunction, and cardiovascular health risks,” inflammation and an increased risk of cancer (1).

Understanding the negative effects on biology and the mechanisms for altered function is an important goal for NASA and other researchers. The coming world of space exploration involves longer missions, further from earth. Keeping astronauts healthy and functional is critical for safety and success in such endeavors. To date, several explanations exist as to why space seems to advance aging so rapidly.

However, an article published by NASA researchers in November of 2020 focuses in on a single, common factor—one that kept “popping up” when studying the biological effects of space travel. Unsurprisingly, that common factor is mitochondrial function and the harsh influence exerted by space. 

Mitochondria are the tiny organelles present in each cell responsible for producing energy in the form of Adenosine Triphosphate (ATP), the energy currency for human function. The role of mitochondria has often been seen more simplistically and insignificantly, but deeper research has uncovered mitochondrial function as a key factor in disease—particularly diseases of modern day.

Using “4 human cell models, 13 different tissues (11 mouse and 2 human), 2 mouse strains (C57BL/6 and BALB/C), and space missions ranging from 2006 to 2017, culminating in the measurement of astronaut blood and urine metabolites, as well as transcriptional data from the NASA Twin Study,” the researchers were able to analyze the effects of space on human physiology. Based on their analysis, the universal mechanism for dysfunction came back to altered mitochondrial function (1).

Key findings from the study include:

Decreased ATP production:

• “Specifically, mouse ISS data, astronaut studies, and the NASA Twin Study data all strongly support an alteration in the electron transport chain reaction and ATP production in the mitochondria. Taken as a body of evidence, this suggests spaceflight induces mitochondrial stress in multiple organisms” (1).

Increased Oxidative Stress and Decreased Antioxidant Production:

• “The existence of spaceflight-induced mitochondrial stress is further supported by metabolite studies reporting increased urinary 8-OHdG and PDGF2-alpha. 8-OHdG is a biomarker of cellular oxidative stress related to DNA repair. Increased PDGF2-alpha levels in urine are associated with oxidative stress and cyclooxygenase-independent synthesis. These markers are consistent with our analysis suggesting mitochondrial stress and dysfunction due to oxidative stress during spaceflight. Oxidative stress is critical to mitochondria-mediated disease processes. The longitudinal decrease in antioxidant capacity observed in astronauts during spaceflight agrees with the development of mitochondrial and metabolic impairment dependent on space exposure” (1).

• “Spaceflight reduced astronauts’ antioxidant capacity (Figure 3F), coupled with an increase in urinary markers of oxidative stress including 8OHdG and prostaglandin F2 alpha (PDGF2-alpha) (Table S4; Figure 3F). Urinary 8-OHdG is a biomarker of generalized cellular oxidative stress, a marker of oxidized DNA that signals that DNA repair is occurring, and a risk factor for cancer, atherosclerosis, and diabetes (Wu et al., 2004). These data suggest that spaceflight increases oxidative stress as indicated by both blood and urinary markers” (1).

Innate Immune Response:

• “Cell culture models found an overall upregulation in immune-related pathways during spaceflight (Figure 4A). In the internal organs, there was also a high presence of activated innate immune system pathways” (1).

Lowered Vitamin D Levels:

• “We found decreased 1,25 vitamin D levels and increased levels of VEGF-1, IGF-1, IL-1a, IL-1b, and IL-1ra during spaceflight in astronauts that again resolved to baseline levels upon returning to Earth” (1).
• “This enrichment agrees with our findings of reduced 1,25 (OH)2 vitamin D during spaceflight (Figure 5B) and also with increased urinary 8-OHdG excretion” (1).

Altered Lipid Metabolism:

• “The lipid profile in astronauts changed with spaceflight. We found higher levels of total cholesterol and low-density lipoprotein (LDL) cholesterol accompanied by decreased levels of highdensity lipoprotein (HDL) cholesterol” (1).

Circadian Rhythm Disruption:

• “Circadian rhythm pathways were upregulated at the transcriptional level in all internal organs but the liver (Figure 7C), suggesting that spaceflight impacts diurnal patterns of gene expression. Also, circadian rhythm pathways for the methylated genes were upregulated in the Quad and adrenal gland” (1).

• “Renin, an enzyme linked to vitamin D and calcium levels, was significantly increased in 59 astronauts and increases in renin impact circadian rhythm activity” (1).

While mitochondria have been implicated as the source of dysfunction among space travelers in previous research, the depth of analysis in the most recent study is novel.

What the researchers have demonstrated are the downstream effects of mitochondrial dysfunction and just how quickly the whole system can break down. Put simply—when energy production is broken, the rest will follow. And the consequences for overall health are severe.

Why Are Space And Mitochondria Seemingly Incompatible?

Space is clearly a tough environment for mitochondria to operate in, resulting in major alterations to their function. But, why?

A human traveling into space is subject to an environment of harsh extremes and foreign influence, including:

• Exposure to high levels of radiation from space and equipment (2). 
• Microgravity (3)
• Circadian rhythm desynchronization as astronauts see a sunrise or sunset every 45 minutes (4).
• Sleep disruption from “noise and uncomfortable temperatures” (4).
• Limited diet, composed largely of artificial food (5).
• Intense exposure to artificial light

Human biology is the result of millions of years of evolution on earth and we are optimized to the rhythms of nature to create function and energy. We were shaped by the diurnal patterns of light and dark, seasonal food, and quality water, influenced only by naturally occurring radiation and the earth’s magnetic field. Despite technologic advancement around us, nothing’s really changed.

Space is an example of extreme disconnection from our evolutionary nature—the antithesis of optimal human function. It’s an environment characterized by incorrect circadian messaging, unnatural influence, low-quality sleep, lack of cellular repair and artificial exposures.

In essence, a recipe for mitochondrial disaster.

When we disconnect from nature, our mitochondria can’t function optimally. The result will always be cellular chaos, loss of energy production and eventually disease.

The Question: How Do Space And Creating Optimal Health On Earth Intersect?

If you’ve made it this far, I am certain you are wondering why you should care about the effects of space on mitochondrial health. Sure, it’s interesting to some, but it’s unlikely most will ever need to worry about experiencing it firsthand—at least for now. 

But, the unfortunate reality is that our current environment is not that far off from what an astronaut would experience by leaving the planet. Maybe it’s not as extreme, but it also isn’t ideal.

Think of dysfunction as a spectrum mediated by two factors: intensity of exposure and time. When exposure to toxic influences is intense, the time required for dysfunction to arise is rather short—i.e. space travel. When exposure to toxic influence is lower, the time required for dysfunction to manifest is longer—i.e. the modern world.

The modern world lives completely disconnected from nature and is moving farther away from it each day. The toxic inputs present during space travel are now a regular part of lives—albeit not as intensely. This includes:

• Constant exposure to increasing levels of electromagnetic radiation from phones, wifi and other technology.
• Chronic circadian desynchronization from exposure to artificial light at all hours.
• Low quality sleep
• Artificial food
• Low energy
• Widespread vitamin D deficiency
• Chronic inflammation

Sound familiar?

Space offers a unique look at disconnection in the most extreme form—a proverbial soup of artificial and unnatural influence. A recipe for absolute mitochondrial disaster in a short period of time.

But, it also offers the solution: optimal mitochondrial function is achieved only by reconnecting with nature and avoiding/eliminating unnatural influences and toxic exposures—day in and day out.

Check out the rest of our blog for great strategies to help you reconnect with your inner function!

See you in the field.

Cites:

1. https://www.cell.com/action/showPdf?pii=S0092-8674%2820%2931461-6

2. https://www.nasa.gov/analogs/nsrl/why-space-radiation-matters

3. https://www.nature.com/articles/s41598-018-32965-3

4. https://www.nasa.gov/feature/ames/nasa-research-reveals-biological-clock-misalignment-effects-on-sleep-for-astronauts

5. https://ntrs.nasa.gov/citations/20160011582

 

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