In 1998's "The Big Lebowski," Jeff Bridges' "Dude" character takes his car for a spin with a beer in one hand and a joint in the other — all for comic effect. But in real life, the combined effects are no laughing matter.

Crash deaths involving the combination of cannabis and alcohol more than doubled from 2000 to 2018, accounting for more than 10% of all traffic deaths.

What's going on?

For people of all ages, there are troubling immediate and long-term effects. Two lab studies out of the University of Illinois found that when developing brains (in humans that goes on into your 20s) are exposed to the combination of alcohol and cannabis, there are measurable changes in neurological and chemical functions that damage memory and learning — which turns immediate hazards, like driving under the double influence, into long-term risks.

Other studies indicate that exposure to cannabis and alcohol is damaging to older people’s brains because aging alone can cause loss of neurons in the hippocampus and cannabis use may add to the problem, lowering IQ in your middle years.

About 12% of people ages 50 to 80 years old say they have used cannabis at least once in the past year and 4% use it multiple times a week. Seniors who drink alcohol have a much higher rate of cannabis use than those who don't. 

Our recommendation: Use topical CBD to aid sleep and medical marijuana when under supervision; don't smoke anything (think gummies); adopt moderate to scant or no alcohol intake; and never drive under the influence.