Does Chewing Gum Help Concentration? Briefly, Maybe - and a Gum Company Founded an Institute to Find Out

This is a small question with an unusually clean structure: a modest, plausible effect; a mechanism that predicts exactly how long it should last; a null replication; and an industry that stood up a research institute to study it.

What the positive studies found

The strongest recent evidence uses realistic learning material rather than laboratory tasks. Ginns, Kim and Zervos (2019), in Applied Cognitive Psychology 33, 214-224, ran two experiments.

Experiment 1 (n = 40) gave adults a 20-minute physiology lesson followed by terminology and comprehension tests. Experiment 2 (n = 39, one outlier excluded) used a 9-minute mental-arithmetic lesson followed by a problem-solving test. Both compared chewing gum against not chewing, between subjects.

Outcome	Effect
Terminology (Exp 1)	d = 0.99, p = 0.004
Comprehension (Exp 1)	d = 0.65, p = 0.053
Combined test score (Exp 1)	d = 1.06, p = 0.003
Problem-solving accuracy (Exp 2)	d = 0.87, p = 0.001
Errors (Exp 2)	d = 0.93, p = 0.006
Alertness (Exp 1)	no difference, p = 0.944
Alertness (Exp 2)	d = 0.65, p = 0.049

Those are large effect sizes. They are also from samples of forty and thirty-nine, and the authors say so first among their limitations: “relatively small sample sizes with wide confidence intervals”, no delayed post-test, and mixed evidence that the alertness gains explain the performance gains.

The alertness result is the interesting inconsistency. If gum works by raising arousal, alertness should have moved in both experiments. It moved in one.

The finding that constrains everything else

The most useful paper in this literature has the most honest title. Onyper and colleagues (2011) published “Cognitive advantages of chewing gum. Now you see them, now you don’t” in Appetite - and the title is the finding.

We could not retrieve that paper directly; every route to it was blocked. What we can report is how the cognitive scientist Daniel Willingham characterised it and the surrounding literature in April 2012, reviewing the field on his own blog. His reading of Onyper: “the act of mastication offers a brief - perhaps ten or twenty minute - boost to cognitive function due to increased arousal.”

That is a mechanism with a stopwatch attached, and it explains the pattern. If gum raises arousal for roughly a quarter of an hour, then studies that test immediately after chewing find effects and studies that test later do not. It also means the practical claim - chew gum to concentrate through a long study session - does not follow from the evidence even if the evidence is real.

Willingham’s survey of the rest is worth having, because it is less flattering than the headlines:

• Wilkinson et al. (2002) ran about a dozen tasks including vigilance and memory, and found positive effects on four - but, Willingham notes, apparently without correcting the statistics for multiple comparisons. Run twelve tests and four significant results is close to what chance produces.
• Smith (2010) found positive effects on some tasks, especially subjective alertness, but used sugared gum, so mastication and glucose cannot be separated.
• Kozlov, Hughes and Jones (2012), using a standard short-term memory paradigm, found no benefit.
• One study found gum chewing harmed vigilance in children with ADHD.

Willingham’s summary: “There is not much evidence to allow it for a significant cognitive advantage.”

Who paid for the research

This is the part that belongs next to every result above.

Reporting by Shayla Love in National Geographic (December 2025) records that “in 2006, the Wrigley Company created the Wrigley Science Institute to fund experiments and PhD positions to investigate the benefits of chewing gum.”

The same piece states the general finding plainly - “studies that are funded by industry tend to have more favorable results” - and quotes Andrew Smith of Cardiff University, one of the most published researchers in this area, saying his own team’s findings were mixed.

Smith’s own summary of the effect is narrower than the coverage: chewing “consistently increased alertness and sustained attention, by around 10 percent”, and it is conditional on the task - “If you’re doing a fairly boring task for a long time, chewing seems to be able to help with concentration.” Crystal Haskell-Ramsay of Northumbria University adds the second condition: “If you’re already feeling very awake and focused, it might not add on too much benefit.”

None of that is an accusation. Industry funding does not make a result wrong, and Smith’s public characterisation of his own work is more restrained than the popular version of it. But a commercial body was created specifically to fund research into whether its product has cognitive benefits, and a reader assessing this literature should know that before weighing the count of positive studies.

What to conclude

There is a defensible small claim: for a boring, sustained task, when you are not already alert, chewing something may lift performance for a short period, probably through arousal.

There is no support for the larger claim the search implies - that gum is a study aid you can rely on across an afternoon. The effect is short by its own proposed mechanism, one standard memory paradigm found nothing, the most-cited early study appears not to have corrected for multiple comparisons, and the field’s principal funder has a product to sell.

The boundary against the neighbouring articles is worth stating because the same reader asks all four questions. Unstructured background noise is a different intervention with a different answer that depends on the listener. Music turns on whether it has lyrics. Caffeine has a much larger evidence base and an unresolved argument about what it is actually doing. And the decay this is all meant to counteract is measured directly elsewhere - where the one intervention Mackworth found effective was an interruption, and the one he found useless was being told to try harder.

Limitations and disputes

• Onyper et al. (2011) could not be read in the original. Its finding is reported here as characterised by a named cognitive scientist reviewing the literature, and is labelled as such.
• Kozlov et al. (2012) and Wilkinson et al. (2002) are likewise reported through that review, not read directly.
• The positive experiments are small - n = 40 and n = 39 - with effect sizes that would be unusual in a large trial.
• No meta-analysis of gum and attention was located that we could read in full; the 2015 review in BioMed Research International was not accessible.
• The 10% figure is Andrew Smith’s characterisation of his own body of work as quoted in a magazine, not a pooled estimate from a review.
• Industry funding is a disclosure, not a verdict. We have not established that any particular study’s result was affected by it.
• The ADHD finding is reported as it appears in the review and is not a claim about clinical populations, which this article does not address.
• Nothing here is dental or dietary advice.