Scientists at Georgia Tech last week published research in the journal Medical Hypotheses (abstract only) that suggests a link between intelligence and cancer risk. Specifically, the researchers believe that the increased brain capacity in humans, compared to chimpanzees, may explain why we get cancer more often than our primate relatives. Cancer results from errors in apoptosis, or programmed cell death, which is when a cell commits suicide. If a cell acquires a mutation it can't fix, or encounters other serious damage, apoptosis is critical to prevent a damaged cell from replicating and potentially affecting the rest of the body. Apoptosis is also a normal, healthy part of the life cycle - a classic example is during frog development; tadpole cells undergo apoptosis to get rid of the tail and make a mature frog. (See the super-short, but helpful apoptosis video below).
When apoptosis this process goes awry, damaged cells can divide uncontrollably, leading to cancerous tumors. The scientists behind this new study argue that since human brains are larger (and therefore require more cells), the increased brain size may have required the cell-death process to be less efficient. As a result, the authors of the study suggest that cancer could be an unfortunate side effect of our increased intelligence.
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