If it is raised, the brain is further in development, and it would be harder for legally aged kids at parties and in college to supply alcohol to minors. Also, the more it is raised, the more likely the consumer would have a family, which lowers the chance for binge drinking.
The age for legally consuming alcohol should be kept the same and not raised. 21 is the highest age in the world for legally consuming alcohol. It would not make sense to raise it higher than 21. People are already adults by that age, and they must be responsible for their action.
Depending upon where one is that age for drinking is either 18 or 21. Raising the age would do nothing because young people who want to get alcohol have always and will always manage to get it. So really what we need are laws that penalize one for drinking and driving more than they do now.