Antioxidants = Bad?

Really interesting (but very early) research from Harvard Med School. Antioxidants, which we know of as ways to neutralize free radicals and possibly prevent cancer, might actually encourage pre-cancerous cells to become cancerous. The research press release is here, but I'll give a summary.


Antioxidants work by stopping a process called oxidation, which is part of a chain of events that can result in cell damage. Basically, when our cells need to create energy to keep going, they use oxygen, and part of what results from that process are "free radicals," which are molecules that can cause damage. Lots of substances (like, say vitamin C) act as antioxidants, sucking in free radicals so they aren't free to...be radical. And, you know, you eat your 5 servings of fruits and vegetables and drink your green tea every day and your wife calls you "The Antioxidant King," and you get cancer anyway.


(And when I say "you," I of course mean "me.")


So these researchers at Harvard were interested in why cancer cells don't die off on their own, which is what usually happens to abnormal cells. It's kind of a key question in cancer research -- what makes some abnormal cells take off and grow into tumors, while others just die off?


They knew that some cells have a particular gene that keeps them from dying a natural death. But these researchers discovered that, even when they have this cancer-allowing gene, they can still die, if they are dislodged from their natural environment. Sometimes that happens -- a cancer cell grows too big and gets pushed out of the place it was growing. So the researchers wanted to know what caused the mutated cell to die off anyway, even though it has this gene that should keep it alive. What was it about being out of their natural environment that caused these abnormal cells to die?


What they found was that when they left their natural environment, the cells had a hard time taking up glucose -- the simple sugar that all cells need to survive (and the sugar that gets measured in a PET scan -- more cells eating sugar quickly means possible cancer). But they also found that the cells had an accumulation of something called Reactive Oxygen Species. Together, these two things (not enough sugar and too much ROS) caused the cells to stop producing ATP, which is the "lifeblood that transports energy" in the cells. The cells were starving to death.


So the researchers decided to work backwards, asking What would allow the sugar to be taken in and the ROS to not accumulate? So they tried two things: giving the cells a gene that would allow sugar to be taken in, and giving antioxidants that would stop the ROS from accumulating.


Both of those things worked. In other words, both of them allowed the cancer cells to grow. The gene allowed the sugar to be taken in. But giving the antioxiodants allowed something else altogether: it allowed the cells to use fatty acids instead of sugar to get enough energy to grow.

It's kind of complicated science, but the point is, the antioxidants allowed cells that would have otherwise died off on their own to continue to grow into cancer cells.


The researchers warned that this was a different type of antioxidant than is normally taken in with food, but it certainly does raise some interesting questions for further research.


I will remain the Antioxidant King until further notice. Pass the green tea.