who had higher consumption of soft drinks (two or more a day) were associated with mortality, artificially sweetened drinks with cardiovascular diseases and sugar-sweetened drinks with digestive diseases. Government regulation Schools Since at least 2006, debate on whether high-calorie soft drink vending machines should be allowed in schools has been on the rise. Opponents of the soft drink vending machines believe that soft drinks are a significant contributor to childhood obesity and tooth decay, and that allowing soft drink sales in schools encourages children to believe they are safe to consume in moderate to large quantities. Opponents also argue that schools have a responsibility to look after the health of the children in their care, and that allowing children easy access to soft drinks violates that responsibility. Vending machine proponents believe that obesity is a complex issue and soft drinks are not the only cause. A 2011 bill to tax soft drinks in California failed, with some opposing lawmakers arguing that parents—not the government—should be responsible for children's drink choices. On May 3, 2006, the Alliance for a Healthier Generation, Cadbury Schweppes, the Coca-Cola Company, PepsiCo, and the American Beverage Association announced new guidelines that will voluntarily remove high-calorie soft drinks from all U.S. schools. On May 19, 2006, the British education secretary, Alan Johnson, announced new minimum nutrition standards for school food. Among a wide range of measures, from September 2006, school lunches will be free from carbonated drinks. Schools will also end the sale of junk food (including carbonated drinks) in vending machines and tuck shops. In 2008, Samantha K Graff published an article in the Annals of the American Academy of Political and Social Science regarding the "First Amendment Implications of Restricting Food and Beverages Marketing in Schools". The article examines a school district's policy regarding limiting the sale and marketing of soda in public schools, and how certain policies can invoke a violation of the First Amendment. Due to district budget cuts and loss in state funding, many school districts allow commercial businesses to market and advertise their product (including junk food and soda) to public school students for additional revenue. Junk food and soda companies have acquired exclusive rights to vending machines throughout many public school campuses. Opponents of corporate marketing and advertising on school grounds urge school officials to restrict or limit a corporation's power to promote, market, and sell their product to school