Alcohol consumption trends have been on the decline for years, even before the US Surgeon General said alcohol is a leading cause of cancer.semenovp/Getty ImagesThe US Surgeon General released a report directly linking alcohol to cancer.A BI analysis found that spending on most kinds of alcohol has declined — especially among young adults.It's reflective of Gen Z's shifting habits when it comes to alcohol consumption.By the time the US Surgeon General dropped its report linking alcohol to cancer on Friday, Americans had already been curbing their spending on booze over the last several decades — especially young people.Surgeon General Vivek Murthy said in his latest advisory that alcohol consumption is the third leading preventable cause of cancer in the US, following tobacco usage and obesity.