Beta-carotene and cognitive function across 16 human studies
What it found
In people, diets rich in beta-carotene and higher blood levels of it were linked to better scores on some thinking and memory tests in most of the studies looked at.
When beta-carotene was given alone as a supplement, it did not help thinking in the short term, but one long study found a benefit.
What they found
Studies in people
Diet and blood levels
In 7 out of 10 epidemiological studies, eating more beta-carotene or having higher blood levels of it was linked to better scores on tests of thinking and memory. The other 3 studies did not show this link.
Supplements alone, short term
When beta-carotene was taken alone as a supplement, it did not improve thinking in the short term. Only one long study, lasting about 18 years, found a benefit when beta-carotene was taken alone.
Supplements with other nutrients
Almost all the supplement studies that combined beta-carotene with other nutrients such as vitamin E, vitamin C, zinc, or selenium found better thinking scores. Doses ranged from 6 mg to 50 mg per day, and studies lasted from 16 weeks to 20 years.
Mixed results
Some studies found no effect or even a worse effect on thinking. For example, one study linked higher beta-carotene intake to poorer executive function, and another linked it to faster cognitive decline.
Other findings
Possible synergy
The authors suggest that beta-carotene may work best together with other nutrients rather than on its own. They note that in some conditions, such as high doses or in smokers, beta-carotene can act as a pro-oxidant.
What the authors conclude
“The β-carotene most probably does not act alone but in synergy with other micronutrients.”
Also in their conclusions
- They conclude that most epidemiological evidence supports a positive effect of beta-carotene from diet and from vegetables and fruit.
- They suggest that combining beta-carotene with other nutrients with antioxidant properties, such as vitamin E, vitamin C, zinc, or selenium, may have a greater impact on cognitive function when serum levels of beta-carotene are not depleted.
- They call for further randomized clinical trials, especially in adults aged 60 to 70 years, with measurements of serum beta-carotene at baseline and a battery of cognitive tests.
How it was done
The authors wanted to see whether beta-carotene, an antioxidant and a source of vitamin A, could help maintain thinking and memory as people age, since oxidative damage is thought to play a role in age-related cognitive decline.
They searched three databases for studies published before 31 May 2023 and found 16 eligible studies in adults aged 30 to 100. These included 4 prospective studies, 5 cross-sectional studies, and 7 randomized intervention studies from seven countries.
What it can’t tell you
- Most of the evidence comes from studies that follow people over time or survey them, so they can show a link but not prove that beta-carotene causes better thinking.
- The studies used different doses, durations, and cognitive tests, so the results cannot be combined to give one clear answer.
- The questionnaires used to estimate beta-carotene intake may not reflect long-term habits, and blood levels only capture part of the body's beta-carotene.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- University of Magna Graecia Catanzaro, Italy; University of Calabria, Italy; Universitat de les Illes Balears, Spain
The paper
- Title
- The Effect of Beta-Carotene on Cognitive Function: A Systematic Review
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Abrego-Guandique DM, Bonet ML, Caroleo MC, et al (2023). The Effect of Beta-Carotene on Cognitive Function: A Systematic Review. Brain sciences. doi:10.3390/brainsci13101468Free full textPubMed 37891835DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error