Only 54% of U.S. adults say they drink alcohol, a record low. A new poll shows what's behind the decline.

Fewer Americans are reporting that they drink alcohol amid a growing belief that even moderate alcohol consumption is a health risk, according to a Gallup poll released Wednesday.

The survey finds that 54% of U.S. adults say they drink alcoholic beverages such as liquor, wine or beer — "the lowest by one percentage point in Gallup's nearly 90-year trend," the analytics company says.

And a record high percentage of U.S. adults, 53%, now say moderate drinking is bad for their health, up from 28% in 2015. The uptick in doubt about alcohol's benefits is largely driven by young adults — the age group that is most likely to believe drinking "one or two drinks a day" can cause health hazards — but older adults are also now increasingly likely to think moderate drinking carries risks.