Why should you know the high fructose corn syrup (HFCS) story? Because it's an incredible parable that has it all; presidential politics, the unintended consequences of manipulating our foods, good guys and bad guys, the obesity epidemic, and the neuroscience of appetite control. If you think you're not a HFCS consumer, I'll bet you're wrong. It is added to practically all prepared food products, not just sodas and juices (breads, breakfast cereals, ketchup, cookies, ice cream, crackers, cough syrup, cottage cheeses, yogurts, applesauces, pickles, jams, fruit, salad dressings, sauces, soups, sports drinks... you get the picture).
The tale begins with president Nixon's War on Poverty in the early '70's. He feared that unstable food prices (especially sugar) could cost him the election. So he assigned his Secretary of Agriculture, Earl Butz, the task of exploring ways to produce cheap food. In 1966 a Japanese scientist had invented HFCS, a very inexpensive, very sweet, and very stable substitute for traditional sugar (sucrose). Bingo! HFCS was introduced to this country, stabilized the cost of sugar and quickly found its way into almost everything.
Generally speaking, the sweeter a food, the more people like it. If you want to increase sales, make the product sweeter. Once there was a very cheap way of doing that we were off to the races. Soda and juice led the way. Soft drink consumption has increased by 41% in the last 20 years. Fruit drinks have posted a 35% increase in the same period. But something curious happened. Somehow this increased sugar consumption did not translate into our feeling full. In fact, we started eating more. Our innate appetite feed-back system had been circumvented.
It is essential to understand that human physiology evolved over millions of years in an environment that provided very little sugar. In other words, we're not made to handle much of the stuff. A quick illustration of how that has changed: In the late 15th century when Columbus introduced sugar cane to the New World, most Europeans has never eaten sugar. By 1700 the average Englishman consumed 4 pounds of sugar per year, 1800 18 pounds, 1900 90 pounds. But the United States has surpassed all other nations in this arena. The average American now consumes more than 140 pounds of sugar per year (much of it in the form of HFCS). And it shows.
But why aren't we sated? How is it possible to knock back a 20 ounce soda that provides 240 calories and eat as much or more than we would have if we'd had 20 ounces of water? This is where HFCS distinguishes itself.
Our bodies control energy balance (the eating and burning or storage of calories) by a complex feedback system of hormones and neural connections where glucose is the primary indicator of global energy status. If there is an energy surplus, we store glucose as glycogen and make fat. If there is an energy shortage, we break down glycogen and make new glucose. When we eat, our blood glucose rises initiating a sequence of reactions that reach higher brain centers where this "information" is processed and a behavioral response (stop eating) is triggered. Fructose does none of this. Not only does increased fructose consumption not produce the experience of satiety, it increases appetite!
This is why the curves for HFCS and obesity track together. The food industry has found the perfect ingredient, sweeter than old-fashioned sugar and an appetite stimulant. We have outsmarted ourselves.
In my next post I will look at the medical advice that fueled the obesity epidemic.