In an exclusive interview with Caroline Scott-Thomas, professor of nutrition Dr Barry Popkin said that he was wrong to single out high fructose corn syrup as largely responsible for obesity. Now he’s taking on another contentious issue: Soda tax.
High fructose corn syrup has had a vast amount of bad press in recent years. Consumers are shunning the sweetener en masse, and manufacturers are taking their cue, removing it from products, often to replace it with sugar.
The demonization of high fructose corn syrup (HFCS) was sparked in 2004 when Popkin, along with Dr George Bray of the Pennington Biomedical Research Center in Baton Rouge, published a widely read and much-quoted study in the American Journal of Clinical Nutrition. It noted the parallel between obesity and the rise in high fructose corn syrup consumption, and hypothesized that the two could be related. The study prompted a massive reaction – but Popkin maintains he was just putting forward a theory that was intended to instigate further research.
“We showed later that fructose from sugar has the same effect,” Popkin said. “We were wrong in our speculations on high fructose corn syrup about their link to weight.
“…People are always looking for enemies. We said it needs to be studied more, that there need to be further studies. Anybody who talks about foods gets demonized or glamorized…You can’t stop doing what you think is right when science backs you up.”
Taxing all sugary beverages
This is not to say that Popkin is letting high fructose corn syrup off the hook – just that he is also eyeing other fructose-containing sweeteners, like sugar.
He says that there is an extremely clear link between consumption of beverages sweetened with nutritive sweeteners, like HFCS and sugar, and health problems – including obesity, heart disease and diabetes.
“The idea is very simple, that essentially in America – and the rest of the world – when you consume any caloric beverage, particularly sugar-sweetened beverage, [including corn-based sugar] you don’t reduce your food intake.”
Popkin has done a huge amount of research in this area and his work has demonstrated that the proportion of energy that Americans obtain from soft drinks has more than doubled from the late seventies to the early part of this decade.
Meanwhile, the obesity rate has increased from 15 percent of the population in 1980 to 34 percent this year, while another 33 percent are overweight.
He says that part of the solution is heavy taxation.
This is a highly controversial idea that has been floated – and quashed – several times, most infamously when the governor of New York proposed an 18 percent tax on sweetened beverages last December.
“The taxes have been rejected but we’re not ready yet. It will take a state or two to do it, but I think it will come in other countries first. There are a lot of people who say we should leave everything unfettered, but we’re getting close.”
The ‘soda tax’ idea routinely makes headlines and has prompted impassioned opposition from those who say, for example, that such a tax would be regressive, or that it unfairly penalizes responsible consumers, as well as the beverage industry. But Popkin does not shy away from controversy.
“We know that if you increase the price of sugar-sweetened beverages, you will reduce their impact,” he said. “Much like cigarette taxes have worked grandly in the US and elsewhere to reduce smoking…These are one of the only foods and beverages with no health benefits and clearly defined health cost.”
If Popkin thinks that beverages sweetened with sugar carry a health cost equal to that of those with high fructose corn syrup, then what does he make of sugar benefiting from the backlash against HFCS? After all, many consumers have started to look at sugar as an ingredient they can trust, with a pure, natural image.
“The sugar industry won’t have that for long,” said Popkin. “We’re working on that. We’re trying to reach out and say it’s a sugar problem – any sugar.”
And when he says ‘any sugar’, he means it.
“I would like to do this on other things,” he said. “…We don’t have enough research on fruit juice. I can’t get the world yet to be ready on fruit juice.”
Soft drinks don’t come with a much healthier image than fruit juice. Other drinks have suffered from image problems, including those sweetened with sugar, before they became eclipsed by the furore surrounding high fructose corn syrup – but for fruit juice, what about the five-a-day recommendation? Doesn’t juice count?
“The five-a-day pushed it originally and then it got holy,” said Popkin. “I would love, down the road, to be able to move to a tax on fruit juice too.”
He added: “There is a consensus that we should not have large portions of fruit juice anymore, but there isn’t enough evidence available at the moment. And the public’s not ready for that.”
This consensus, he says, means drinking no more than about 4oz or just over 100ml of fruit juice each day.
Of course, alcoholic drinks fall into a similar bracket, according to diverse research including Popkin’s, in that they too provide little nutritive value and are high in calories. But even this outspoken proponent of low- and no-calorie beverages has to have a vice.
So what does he drink?
“I drink a ton of wine,” says Popkin. “And I like Coke Zero.”