In a recent study published in the journal Brain Sciencesscientists are investigating the role of β-carotene in supporting cognitive abilities and mental health, alone or in combination with other dietary components.
study: The effect of beta-carotene on cognitive function: a systematic review. Image credit: Daniela Maksimović / Shutterstock.com
About the research
All relevant studies were retrieved from multiple databases, including Scopus, PubMed, and Web of Science. The MySLR digital platform was used to select and assess the quality of articles obtained from various sources. MySLR is a digital tool equipped with the Latent Dirichlet Algorithm (LDA) for analyzing large data sets by text mining.
The present study included all adult participants without psychiatric disorders. Several types of studies were considered for the analysis, including randomized clinical trials, prospective or cross-over studies, and longitudinal studies.
A total of 168 studies were identified after the initial search. However, after consideration of eligibility criteria and removal of duplicates, 16 studies were included in the final review.
The importance of optimal cognitive function in maintaining daily life
Cognitive behavior is vital to an individual’s overall health and well-being. Cognitive functions include learning, language, memory, attention, perceptual-motor function, and social cognition, as well as receiving, processing, and interpreting information. Disequilibrium in brain structure and disorientation at the molecular/cellular level, neuronal interactions and protein-protein interaction networks lead to cognitive dysfunction.
Importantly, cognitive function is not stable, as it is constantly evolving throughout life. Aging is associated with cognitive impairment, with one recent study estimating that 19% of people under the age of 75 suffer from some degree of cognitive dysfunction, compared to about 29% among people over the age of 85.
About 30% of the world’s population over the age of 65 has been diagnosed with Alzheimer’s, a brain disease that affects memory and thinking skills. Cancer patients treated with chemotherapy often develop cognitive impairment called “hemobrain” after or during treatment. The ongoing coronavirus disease 2019 (COVID-19) pandemic has also caused brain fog, which is a type of temporary cognitive impairment.
Thus, the development of effective strategies related to dietary interventions is imperative to prevent cognitive decline.
Use of β-carotene to combat cognitive dysfunction in adults
Carotenoids are common antioxidants and anti-inflammatory agents that can effectively improve cognitive health. To date, there are no guidelines or recommendations regarding the optimal dose of carotenoid intake for beneficial results.
β-Carotene is a major natural carotenoid and a dietary source of provitamin A. In addition, β-carotene possesses significant antioxidant and free radical scavenging properties due to the presence of abundant unsaturated bonds in its molecule. β-Carotene is present in fruits, vegetables, soups/broths and food colorings.
Vitamin A is essential for many functions related to vision, immunity and fertility. Few studies have examined the relationship between β-carotene and cognitive function. Some epidemiological studies have presented inconclusive results regarding how β-carotene affects cognitive function.
A recent study showed that dietary intake of β-carotene was inversely related to decline in cognitive function. A linear dose-response relationship between dietary intake of β-carotene and Alzheimer’s Disease Registry Consortium results of a word learning test (CERAD WL), alpha-fetoprotein test, and standardized subject defense test (DSST) were observed; however, these results varied by gender.
A positive correlation was observed between high blood β-carotene levels and improved semantic memory. Thus, serum β-carotene levels appear to be an important predictor of semantic memory performance.
The Rotterdam study reported that lower β-carotene consumption caused reduced cognitive performance. Comparatively, long-term dietary consumption of β-carotene at a higher concentration was associated with a lower likelihood of poor cognitive function.
Many randomized clinical trials support the protective role of β-carotene against cognitive impairment. For example, the Physicians Health Study (PHS) recommended that 50 mg of β-carotene every alternate day can improve verbal and cognitive memory in adults.
Greater episodic memory and semantic fluency were reported when β-carotene was supplemented with vitamins C and E. In particular, cognitive improvement was more significant among nonsmokers.
Mechanistically, β-carotene and vitamin E act synergistically to prevent lipid peroxidation. However, in some cases, high antioxidant intake may increase lipid peroxidation and oxidative DNA damage. Recent studies have shown that β-carotene intake alleviates brain fog through the calcium/calmodulin-dependent protein kinase IV (CAMKIV) pathway.
The present study summarizes the clinical evidence regarding the benefits of using β-carotene as a nutritional intervention for cognitive support. Most epidemiological and randomized control studies support the beneficial role of β-carotene in improving cognitive function.
The combination of β-carotene with other nutrients with higher antioxidant properties, such as zinc, vitamin C and vitamin E, has been shown to significantly affect cognitive function.
- Abrego-Guandique, DM, Bonet, ML, Caroleo, MC, and others. (2023) The effect of beta-carotene on cognitive function: a systematic review. Brain Sciences 13(10); 1468. doi:10.3390/brainsci13101468