Is Diabetes an Adaptation?

Written by Anonomous Contributor

Though widely disputed, evidence does suggest that diabetes may be an adaptation to cold tolerance. Careful observation of the way other organisms react to extremely cold temperatures, patterns between diabetic people and cold weather, and speculation based on the human body’s reaction to cold suggests that our ancestors who lived in extremely cold environments could have benefited from the symptoms of diabetes. Animals resistant to the harmful effects of freezing, like the wood frog, exploit their high blood sugar levels in order to survive the winter. Because sugar decreases the freezing point of water, it would benefit living organisms to have higher sugar levels to avoid the harmful effects of freezing. When frosted, grapes undergo a drastic rise in sugar concentration. The sugar in the grapes’ water and the frogs’ blood acts as an antifreeze, preventing the formation of damaging ice crystals. In addition, rats in extremely cold temperatures exhibit a diabetic response: they “become resistant to their own insulin”, mirroring the lack of insulin in someone diagnosed with diabetes (Moalem 45). The reactions these organisms have to cold temperatures suggest that diabetics may have persisted through natural selection because of their condition. With a higher percentage of blood sugar (prompted by the lack of insulin), the freezing point of the water in their blood would decrease, allowing them to survive in colder temperatures. Accordingly, more diabetics are diagnosed during the colder times of the year. A study consisting of over 200,000 American diabetic veterans revealed that the veterans’ blood sugar would spike during colder seasons, and level during warmer ones. This suggests that there is a correlation between diabetics and cold weather. The human body reacts to cold temperatures by first shivering, then thinning the arteries in the fingertips and toes in order to keep the torso (where many vital organs are located) as warm as possible. Those with lower blood sugar levels would have been more susceptible to frostbite, making it difficult to gather food and survive. Though a high blood sugar could lead to a myriad of health complications today, it could have actually been beneficial for ancestors who had to survive the ice age. Food for diabetics trying to survive such a harsh environment must have been scarce, meaning their blood sugar levels may never have become high enough to be life-threatening. This theory is supplemented by the fact that these diabetics could have had great amounts of brown fat (anyone living in extremely cold temperatures would develop brown fat), furthering their likelihood of surviving the cold temperatures to reproduce and pass on their genes.

This article was written by an anonomous contrubutor of the Elysian Muse Literary Magazine!