Glucagon: a 29-amino-acid polypeptide secreted by the alpha cells of the pancreas in response to hypoglycemia or starvation.
Insulin: a 51-amino-acid polypeptide secreted by the beta cells of the pancreas in response to nutrient consumption.
It’s December 13th, 1932, Camden, New Jersey. You are playing alto sax and clarinet in the reed section of Bennie Moten’s Kansas City Orchestra. It’s the low point of the Depression, and your boss is feeling it: the financial challenges of running a big band in the setting of a national unemployment rate of 24%. The band spent all of its money on partying and hotels during its triumphant weeklong engagement at the Pearl Theater in Philadelphia, and now it is starving. A rabbit stew cooked up on a pool table and four loaves of bread is dinner for the 15 of you. You then go to the RCA Victor recording studio in Camden and cut the classic “Moten Swing”–3 minutes and 24 seconds of exultation.1 The Moten band, at its creative peak with Ben Webster on tenor sax and Count Basie on piano, is running on glucagon.
It’s Thanksgiving evening, 2011, and you’re at your aunt’s house. You and your family have just consumed, on average, 4700 calories each. Dinner was a 24-pound turkey, Brussels sprouts, mashed potatoes with gravy, yams with marshmallows on top, cranberry sauce in the shape of a cylinder bearing the impression of the ribs on the can, and pumpkin cannolis for dessert. Uncle Jack’s parasympathetic nervous system is totally kicked in; he has just nodded out on the sofa in front of the television. The Detroit Lions are losing to the Green Bay Packers 24-0 in the fourth quarter. Aunt Mary Anne gasps and says, “Oh my God! I forgot to put out the blueberry pies!” They are sitting in the oven, untouched.
You and your family are running on insulin. The 1430 base pairs that make up the insulin gene on the short arm of everybody’s chromosome 11 are being transcribed and translated to pre-proinsulin billions of times per second. And insulin, the end product, is socking away all that excess glucose as glycogen and fat, as everyone will discover tomorrow morning when they step on the scale.
Think of glucose as cash and your body as a bank. Insulin is the deposit slip that allows you to put excess glucose into your carbohydrate and fat accounts. The carbohydrate account– glycogen in your muscles and liver–is small. A man on a hunger strike goes through his glycogen in a couple of days before starting to burn his fat stores. Adipose accounts, on the other hand, can be vast.
Insulin is the good-times hormone, the hormone of plenty. Glucagon is the pawnshop hormone, the withdrawal slip.
You are an 18-year-old woman living in the countryside of Malawi, the poorest nation in the world, with a per-capita income of $272 per year. Protein-energy malnutrition is the fourth leading cause of years-of-life-lost in your country, after AIDS, pneumonia, and diarrhea.2 Your one-year-old daughter is stunted, not having been adequately breastfed. She is showing signs of delayed cognitive development, and is deficient in iodine and zinc. You are sharing your dinner of cassava and plantains with dozens of roundworms (Ascaris lumbricoides) that have made a home for themselves in your small intestine. You have iron-deficiency anemia so severe that you could benefit from a blood transfusion. You are 4 feet, 10 inches tall and weigh 86 pounds.
It’s July 4th, 2016, Coney Island. You are the legendary pancreas of Joey Chestnut. “Jaws” has just set the all-time record in the Annual Fourth of July Nathan’s Hot Dog Eating Contest, consuming 70 hot dogs with buns (19,600 calories) in 10 minutes, a glucose deposit unprecedented in human history. Thanks to your ability to secrete amazing amounts of insulin, at no time did your boy’s blood-sugar level get above 200.
In 1968, Paul Ehrlich began The Population Bomb with this prediction: “The battle to feed all of humanity is over. In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.”3 The global famine never materialized because a “crash program”–the Green Revolution brought about by Norman Borlaug and others–actually worked. High-yield strains of wheat and other agricultural innovations vastly increased the planet’s food supply. There is now enough food in the world to feed all 7.4 billion of us, and maybe even the 11 billion of us projected to be around in 2100. The problem is inequality.
And, paradoxically, obesity. The nutritional status of the world is at a fulcrum. The Global Nutrition Report, published in June, identified 72 countries with high rates of stunted children under five, 71 countries with high rates of overweight and obese adults, and 22 countries with both problems.4 The challenge of the century is for glucagon countries like Malawi and the Central African Republic to become insulin countries like ours, without overshooting the mark and incurring the terrible side effects of the American diet.
Michael Tanner, MD is the Executive Editor for Clinical Correlations
References
- https://www.youtube.com/watch?v=hr42hm6GvkQ
- Global Burden of Disease 2013 Mortality and Causes of Death Collaborators. Global, regional, and national age–sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet.
- Ehrlich PR. The Population Bomb. New York, NY: Ballantine Books; 1968: xi.
- International Food Policy Research Institute. 2016. Global Nutrition Report 2016: From Promise to Impact: Ending Malnutrition by 2030. Washington, DC: 116