Scientists have discovered that the removal of Earth's magnetic field influences the lifespans of fruit flies in complex ways, a finding that sheds light on the aging process as well as the risks of future human space travel, according to a study published in the journal Aging on Wednesday.
All life on Earth has evolved under the planet’s geomagnetic field, a vast bubble lined with electrical currents that is generated in the core and extends out into space. This protective magnetic shield is a major factor in Earth’s habitability, as it wards off harmful radiation from space, allowing life to flourish on the surface.
Many migratory animals—including fish, birds, and insects—can clearly sense Earth’s magnetism and use it for navigation. But much less is known about how the field interacts with living cells and their components, such as mitochondria, the famous “powerhouses” that generate most of the energy that fuels life.
To better understand this mystery, scientists observed two populations of fruit flies in a “hypomagnetic” shield system, a cylindrical benchtop apparatus that essentially blocks the influence of Earth’s magnetic field. One group contained “wild-type” healthy flies, while the other was made up of “mutant” flies carrying a gene defect called Pink1, which is associated with early-onset Parkinson’s disease in humans and specifically involves mitochondrial dysfunction.
The removal of the magnetic field’s effect extended the lifespan of the Pink1 group by 20 percent but reduced their mobility, whereas the healthy flies experienced just the opposite—reduced lifespan, but improved mobility.
“We had an idea that there would be a difference just based on the fact that we know that every organism has developed under a magnetic field,” said Jacob Reed, a PhD student in bioscience at the University of Nottingham who co-led the study, in a call with 404 Media. “But we didn't really plan that there would be this difference in the experiment.”
“I think we're the first to show that there's an effect in an organism that has a disease phenotype,” added co-lead Lisa Chakrabarti, a professor of biochemistry at the University of Nottingham, in the same call. “We're really drilling into what the differences are between having that applied pressure or relieving it.”
While there is a lot of research into the effects of hypermagnetic fields on life—meaning magnetic fields that are stronger than Earth’s—the “biological consequences of hypomagnetic fields remain poorly understood,” according to the new study.
To fill in this research gap, Reed developed an initial pilot study of diseased and healthy flies using the magnetic shielding apparatus, and was surprised to find that the Pink1 population of flies seemed to live longer.
“I was really confused at first,” Reed recalled. “I was thinking: ‘Why are these Parkinson's flies living longer than some of the wild-type flies?’ I had to double-check all of my data. From that, we realized that was what's happening and developed the experiment.”
The team observed dozens of diseased and healthy flies living in these hypomagnetic spaces over the course of their lives, which normally last about two months. In particular, they monitored shifts in the energy metabolisms and chemical outputs of mitochondria using quantum diamond sensors.
The experiment showed that the absence of Earth’s magnetic field changes how cells age and produce energy, producing clear and measurable effects on longevity. The researchers also saw shifts in locomotion by tracking how far flies climbed upward against gravity in their containers. However, it will take more research to unravel the complex mechanisms that underlie these observable changes.
“This is the early stage, where we can say there is a very real effect,” Chakrabarti said. “As soon as you take off the geomagnetic field, there are physiological effects that we can measure in the mitochondria, in the cellular physiology, and in big things like lifespan and climbing as well. It's a definite interaction between Earth's magnetic field and physiology.”
The researchers plan to build on their work by studying different organisms in hypomagnetic fields to see if they experience similar mitochondrial and behavioral changes. This work could eventually inspire therapeutic treatments for humans with various conditions, and could also help prepare astronauts for deep space missions beyond Earth’s magnetic field. It is already well-known that astronauts are exposed to harmful radiation outside of the magnetic field, but little is known about the specific impact of the absence of the field itself on human physiology.
“The link with interplanetary space travel is absolutely key,” said Chakrabarti. “There could be subtle differences that we don't really notice while we're on Earth. Unless we know what those parameters are to measure, we're going to be sending astronauts up there that are potentially going to really suffer over the short, or even or the longer, term.”
“All of this is out there at the moment, but what we're saying is that we definitely see a really reproducible and startling effect of removing the geomagnetic field,” she concluded.