Dr. Oz and Dr. Sharon Moalem
It would seem that in an ideal world, there would be no disease. According to Dr. Sharon Moalem, some disease is necessary to keep human evolution on the move. He talks to Dr. Oz about evolutionary medicine, the value of the sun and what honeybees can tell us about antibiotics.

Dr. Moalem says his interest in genetic medicine began with his grandfather, who claimed that giving blood made him physically feel better. As a medical student, Dr. Moalem realized his grandfather likely was affected by hemochromatosis, a condition that causes the body to over-absorb iron. It was considered a rare disease, but now it's more likely that it's an under-diagnosed condition in many people. In his research, Dr. Moalem found that one-third of people of western European descent are likely to carry the gene for the disease. Looking at European history, he thinks it's likely that they are descendents of survivors of the bubonic plague, which was caused by an organism that fed off iron. Rather than being taken by the plague, people with this gene survived because their bodies had created a surplus of iron.

Dr. Moalem takes evolutionary issues into account when looking at our complicated relationship with the sun as well. One of the benefits of being in the sun is the absorption of vitamin D, which is good for our bones, our immune system and our cholesterol levels. "In areas of the world where there's not enough sun, the body creates more cholesterol to compensate," Dr. Moalem says, explaining that some cultures make up for their lack of sun by getting more vitamin D through their diet. In sunnier climates, moderation is the key. Dr. Moalem cites an Australian study that found when women there greatly restricted their sun exposure, children were born with vitamin D deficiency and rickets. "We need to find creative ways of compromise," he says. "By letting kids have some sun every day, we have a chance of improving their health."

Honeybees proved to be a valuable area of study for Dr. Moalem. By studying how they deal with infection, he was able to find correlations that we can learn from. One of the most fascinating things he discovered was that bees don't produce antibodies because they don't live long enough to need immunity. Instead, they create antibiotics specific to the bacteria that are affecting them, and continually change those antibiotics to prevent the bacteria from becoming resistant. "We knew this many years ago, but never applied it," Dr. Moalem says. "[With this knowledge] we could have been able to avert or delay the formation of superbugs through the over-prescription of antibiotics."