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When you consume alcohol, your body detoxifies it and then extracts calories from it. It's a complex process that involves many different enzymes and multiple organs, although most of the process takes place in the liver. First, an enzyme called alcohol dehydrogenase converts the alcohol into another chemical called acetaldehyde; another enzyme—cleverly called acetaldehyde dehydrogenase—converts the acetaldehyde into acetate. And a third enzyme converts that into fat, carbon dioxide, and water. (The calories synthesized from alcohol are generally stored as fat—beer bellies really do come from beer.) Many Asians have a genetic variation (labeled ALDH2*2) that causes them to produce a less powerful form of acetaldehyde dehydrogenase—one that isn't as effective in converting acetaledehyde, that first by-product of alcohol, into acetate. Acetaldehyde is thirty times as toxic as alcohol; even very small amounts can produce nasty reactions. And one of those reactions is the flushing response. That's not all it does, of course. After even one drink by people who have the ALDH2*2 variation, the acetaldehyde buildup causes them to appear drunk; blood rushes to their face, chest, and neck; dizziness and extreme nausea set in—and the drinker is on the road to a nasty hangover. Of course, there's a side benefit to all this—people who have ALDH2*2 are highly resistant to alcoholism. It's just too unpleasant for them to drink. |
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Quick thinkers are born not made: The speed at which we process new information is written in our genes
People with slower processing speed overall were found to have variants near a gene called CADM2. The CADM2 gene is linked to the communication process between brain cells - the gene is particularly active in the frontal and cingulate cortex in the brain, which are areas of the brain involved in thinking speed. |
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A copyediting error appears to be responsible for critical features of the human brain that distinguish us from our closest primate kin, new research finds. |
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UCP1, UCP3, ENPP7, PRKG1 Researchers have identified three genetic mutations that appear to have helped humans survive in the frigid climate of Siberia over the last 25,000 years. One helps the body's fat stores directly produce heat rather than producing chemical energy for muscle movements or brain functions, a process called 'nonshivering thermogenesis.' Another is involved in the contraction of smooth muscle, key to shivering and the constriction of blood vessels to avoid heat loss. And the third is implicated in the metabolism of fats, especially those in meat and dairy products—a staple of the fat-laden diets of Arctic peoples. |
Endogenous retroviruses such as HERV-W splice their RNA into host DNA where is it now transmitted into an further offspring. |