Vaping may damage the brain: Inhaling high levels of nicotine can destroy stem cells that turn to neurons, study suggests
- Millions of teenagers and adults in the US use e-cigarettes under the impression the devices are ‘safer’ than combustible nicotine
- New University of California, Riverside, research shows how the high nicotine content of c-cigs can flood brain cells’ predecessors with harmful compounds
- Breaking down these stem cells can prevent new, specialized brain cells from forming
- The researchers say their findings should serve as a warning, particularly to pregnant women and adolescents that e-cigs may be harmful
Trendy e-cigarettes may be damaging users’ brains, including those of the millions of teenagers that vape, a new study suggests.
Exposure to nicotine from e-cigs breaks down brain cells, according to new research from the University of California, Riverside.
The same likely applies to any nicotine product, but is particularly worrisome in light of the teen vaping epidemic, because young people’s brains are still developing and the damage done by e-cigs may limit their cognitive growth for life.
The study authors are warning that young people and pregnant women should be particularly wary of vaping as it may not only be addicting by damaging to their minds and the minds of developing babies.
A single Juul pod contains as much nicotine as an entire pack of cigarettes. High concentrations of nicotine may kill off stem cells that would otherwise become neurons
E-cigarettes may be less carcinogenic than combustible ones, according to research thus far, but the more scientists learn about them, the more clear it becomes that ‘safer’ is not the same as safe.
Vaping appears to have the same effects on the cardiovascular system that smoking does and popular devices like the Juul use e-liquids with higher concentrations of nicotine than a cigarette contains, making them more addictive.
But its not just the brain’s dependency that the vapor gets to, the UC Riverside team explained.
Nicotine starts to damage cells at a much earlier stage, according to their new study in the journal Cell Press.
E-liquid compounds seem to break and enter into the energy centers of stem cells that precede neurons.
To demonstrate this, the UC Riverside researchers used stem cells from mice and exposed them to e-liquids in the lab.
They focused on mitochondria, the ‘powerhouses’ of our cells.
Mitochondria serve a second function, too.
They help to repair stem cells and give them many self-protective mechanisms, ensuring the stem cells will go on to become healthy, functional, fully-fledged cells.
Among their defense mechanisms is a process called stress-induced mitochondrial hyperfusion (SIMH).
When mitochondria detect an overload of oxidative stress – which happens when free radicals set loose by normal metabolism are attacking cells – they link up to one another, finding safety in numbers and closed ranks that keep the rogue molecules from entering the cells.
Nicotine creates this oxidative stress, forcing mitochondrial into this ‘survival mode.’
But particularly high concentrations of nicotine – such as the contents of one Juul pod, which equates to a whole pack of cigarettes – can overwhelm the chain defense by binding to and ‘opening’ receptors for the addictive chemical.
This lets in not only nicotine but calcium, an ionic (or charged) molecule.
Cells need calcium, and mitochondria capture and store it, but with the flood gates – in the form of nicotine receptors – flung wide open, the defensive chain of cell power stations can get overwhelmed.
That may cause abnormal changes in them and even rupture and kill the mitochondria and the stem cells they fuel.
‘If the nicotine stress persists, SIMH collapses, the neural stem cells get damaged and could eventually die,’ before they ever get a chance to become fully-fledged brain cells, explained lead study author and UC Riverside postdoc, Dr Atena Zahedi explained.
‘If that happens, no more specialized cells – astrocytes and neurons, for example – can be produced from stem cells.’
While nicotine could have this effect on stem cells for any tissue, the study authors note that inhalation gives nicotine relatively easy access to the brain.
Humans continue to grow new brain cells throughout their lives, recent research has shown, so disruption to their predecessors, stem cells, at any age is bad news.
But the earlier in development a person is – whether that’s in the womb or as a child – the more rapid and fundamental this cell growth is.
‘Their brains are in a critical developmental stage,’ said Dr Prue Talbot, the director of the UCR Stem Cell Center.
‘Nicotine exposure during prenatal or adolescent development can affect the brain in multiple ways that may impair memory, learning, and cognition.
‘Furthermore, addiction and dependence on nicotine in youth are pressing concerns. It’s worth stressing that it is nicotine that is doing damage to neural stem cells and their mitochondria. We should be concerned about this, given that nicotine is now widely available in ECs and their refill fluids.’
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