If parents want to help their teens stay away from drugs, the solution may be as simple as sitting down to a family dinner, a new study shows.

The Importance of Family Dinners VII report was released by the National Center on Addiction and Substance Abuse at Columbia University (CASA Columbia).

Parental engagement in children's lives is key to raising healthy, drug-free kids and one of the simplest acts of parental engagement is sitting down to the family dinner, CASA chairperson and founder Joseph A. Califano, Jr. said in a statement. Seventeen years of surveying teens has taught us that the more often children have dinner with their families the less likely they are to smoke, drink or use drugs.

The study compared teens who spend 21 hours or more per week with their parents to teens who spent seven hours or less per week with their parents.

Research found that 58 percent of teenagers in the U.S. sit down for family dinners at least five times a week. Research also found that teens who spend more time with their parents at the dinner table also spent more time with their parents in general.

On the flip side, teenagers who reported infrequent dinners also reported spending less time in general with their parents, and even when the family did sit down, dinners tended to be short.

Overall, teens who spend less time with their parents are more likely to have used alcohol and to have at least one friend or classmate who has access to and engages in drug abuse, whereas teens who spend more time with their parents are less likely to abuse illegal substances.

How parents agree to teach their children about drug and alcohol use also mattered.

Research showed that children of parents who did not completely agree on these issues were more likely to experiment with illegal substances, such as drugs and alcohol.