I’m traveling with Mikael Knip, a short, energetic Finnish physician and University of Helsinki researcher with a perpetual smile under his bushy mustache. He has come to Petrozavodsk—an impoverished Russian city of 270,000 on the shores of Lake Onega and the capital of the Republic of Karelia—to solve a medical mystery, and perhaps help explain a scourge increasingly afflicting the developed world, the United States included. For reasons that no one has been able to identify, Finland has the world’s highest rate of Type 1 diabetes among children. Out of every 100,000 Finnish kids, 64 are diagnosed annually with the disease, in which the body’s immune system declares war on the cells that produce insulin. Type 1 diabetes is usually diagnosed in children, adolescents and young adults. The disease rate wasn’t always so high. In the 1950s, Finland had less than a quarter of the Type 1 diabetes it has today. Over the past half-century, much of the industrialized world has also seen a proliferation of the once rare disease, along with other autoimmune disorders such as rheumatoid arthritis and celiac disease. Meanwhile, such afflictions remain relatively rare in poorer, less-developed nations.
Petrozavodsk, only about 175 miles from the Finland border, may be the perfect place to investigate the question: The rate of childhood Type 1 diabetes in Russian Karelia is one-sixth that of Finland. That stark difference intrigues Knip and others because the two populations for the most part are genetically similar, even sharing risk factors for Type 1 diabetes. They also live in the same subarctic environment of pine forests and pristine lakes, dark, bitter winters and long summer days. Still, the 500-mile boundary between Finland and this Russian republic marks one of the steepest standard-of-living gradients in the world: Finns are seven times richer than their neighbors across the border. “The difference is even greater than between Mexico and the U.S.,” Knip tells me.