Months after the city of Berkeley, California, passed a soda tax in 2014, consumption of sugar-filled drinks–from Coke and Pepsi to energy drinks and sweetened coffee or tea–dropped 21%. Three years later, it dropped even more: Residents report drinking 52% fewer sugary drinks than they did before the tax passed.
The study, published in the American Journal of Public Health today, is the first to look at the long-term impacts of a soda tax. Researchers polled 2,500 people about their sugary drink habits each year in Berkeley and in nearby Oakland and San Francisco. The other cities, which passed taxes later, helped researchers compare the effects of the tax to overall changes in diets; in Oakland and San Francisco, people drank more soda and other sweet drinks.
California is now considering several statewide soda bills, including one that would ban Big Gulp-style drinks and another that would ban soda displays near checkout counters. The bills come a year after the soda industry essentially extorted state lawmakers into banning cities from enacting more local soda taxes; Coca-Cola, Pepsi, and others funded an initiative that would have made it difficult for cities to raise any taxes at all via ballot measures, and then withdrew it from the statewide ballot only when lawmakers agreed to ban city soda taxes. The new study, though, could help provide evidence for a statewide tax.
It could also help convince cities and countries elsewhere to pass similar laws. “What’s really interesting is the United States is actually pretty far behind,” says Kristine Madsen, faculty director of the Berkeley Food Institute in UC Berkeley’s School of Public Health and senior author of the new study. “Britain has a tax now, Ireland has a tax, Australia has a tax, many Middle Eastern countries now have a tax, some as high as 100%–they’re doubling the price of sugar-sweetened beverages. They all see the link between the health of their economy and the health of their population and recognize that obesity is killing their people and they need to do something about it. And they’ve been far more proactive than we have.”
One large part of the challenge is the strength of the beverage industry. “They’re really a powerful force,” says Madsen. “Pepsi and Coke alone spend over $3 billion each annually on advertising. I’m a pediatrician. How do I possibly counsel patients as effectively as the really slick advertising they see everywhere?”