Back in my grad school days, I hesitated to tell new acquaintances I was working on a PhD in nutrition. Disclosing that information led people to unload their dietary woes, worry I was judging their every bite, or complain vociferously about their frustration that nutrition scientists couldn't seem to provide settled advice about what to eat.
Earlier today, when I read results of a University of Southern California study (.pdf) on the fructose content in soda, I was the one to grumble aloud about my former field.
A little background: My PhD supervisor, Peter Havel, DVM, PhD, professor of nutrition at the UC Davis, did much of the early research on negative health effects of fructose. He found that the sugar - a component of the high fructose corn syrup used to sweeten sodas and many other processed foods - raises levels of insulin, triglycerides and LDL cholesterol (a.k.a. "bad cholesterol"), and causes people to accumulate more fat around their abdomen than glucose (another, less-sweet sugar) if the two are fed in equal amounts.
When his work hit the news in the early 2000s, consumers worried that sodas sweetened with high fructose corn syrup were worse for their health than those sweetened with other sugars. Nutrition experts answered with a "not really" - the alternative sweetener, table sugar, is chemically similar enough to high fructose corn syrup to make the health difference negligible, they said.
The problem was that advice was based on a (faulty) assumption about the type of high fructose corn syrup that soda manufacturers were (supposedly) using. No one had actually tested sodas' fructose content.
Now someone has - and, as described in this study, it turns out that Coke, Pepsi, Sprite and several other popular soft drinks have quite a bit more fructose than anyone realized - or, indeed, than their labels stated. Fountain drinks served at fast food restaurants were the worst offenders.
This research doesn't change the general gist of nutrition wisdom: eat more vegetables, skip the soda, and so on. But it does make me want to alternately scream and hide under the covers in shame. Why hadn't this study been done earlier? Were the nutrition scientists just sitting around believing what food manufacturers claimed about soda ingredients? Perhaps some of the frustration with nutritionists is justified.