The Claim

Among employed adults aged 19–50, daily caffeine intake averaging 262.5 mg is significantly associated with poorer sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI), with higher intake linked to reduced sleep duration and increased nighttime disturbances.

Source: Caffeine intake from different dietary sources and its association with sleep quality in employed adults

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
44score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

Adults aged 19–50 who consume about 262.5 mg of caffeine daily have worse sleep quality, shorter sleep duration, and more nighttime awakenings compared to those with lower intake.

See the scientific wording

Among employed adults aged 19–50, daily caffeine intake averaging 262.5 mg is significantly associated with poorer sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI), with higher intake specifically linked to reduced sleep duration and increased nighttime disturbances, suggesting that caffeine consumption patterns may contribute to widespread sleep disruption in working populations.

Why this might work

Caffeine enters the brain and sticks to sleep-signaling receptors, stopping the natural buildup of sleep pressure. This keeps the brain alert, prevents deep sleep from starting, and causes frequent awakenings during the night, leading to less total sleep.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Caffeine intake from different dietary sources and its association with sleep quality in employed adults

    This study found that adults who drink about 260 mg of caffeine a day—like from coffee or tea—tend to sleep worse, getting less sleep and waking up more at night. It directly links caffeine to poor sleep in working people.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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