Alpha-Carotene
Research reviewed: Up until 03/2026
Alpha-Carotene (Alpha-carotene) is a dietary supplement with 23 published peer-reviewed studies involving 30,122 participants, researched for Mortality & Longevity, Cancer Prevention, Antioxidant Properties & Inflammation and 2 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Mortality & Longevity
ModerateCancer Prevention
ModerateAntioxidant Properties & Inflammation
ModerateClinical trials
ModerateSystematic reviews
WeakResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Mortality & Longevity
To evaluate the association between serum alpha-carotene concentration and risk of death.
Study Type
Prospective cohort (NHANES III follow-up)
Purpose
To evaluate the association between serum alpha-carotene concentration and risk of death.
Dose
Observational
Participants
15,318 adults in NHANES III cohort
Duration
14 years follow-up
Results
Serum alpha-carotene inversely associated with all-cause mortality; highest serum levels associated with 39% lower risk of death.
How They Measured It
Serum alpha-carotene by HPLC; death certificate linkage over 14 years
To investigate whether serum alpha-carotene predicts cardiovascular disease mortality.
Study Type
Prospective cohort
Purpose
To investigate whether serum alpha-carotene predicts cardiovascular disease mortality.
Dose
Observational
Participants
6000 adults in prospective study
Duration
15 years
Results
Highest alpha-carotene quartile associated with 42% lower CVD mortality compared to lowest quartile; independent of other carotenoids.
How They Measured It
Serum alpha-carotene quartile; CVD-specific mortality over 15 years
Cancer Prevention
To evaluate serum alpha-carotene and lung cancer risk.
Study Type
Case-control study
Purpose
To evaluate serum alpha-carotene and lung cancer risk.
Dose
Observational (serum quartile analysis)
Participants
400 lung cancer cases, 600 controls
Duration
Case-control
Results
Low serum alpha-carotene significantly associated with lung cancer risk; OR 0.60 for highest vs lowest quartile.
How They Measured It
Serum carotenoid panel; pathologically confirmed lung cancer
To compare the anti-tumour potency of alpha-carotene vs beta-carotene in cancer cell lines and rodent models.
Study Type
Animal and in vitro study
Purpose
To compare the anti-tumour potency of alpha-carotene vs beta-carotene in cancer cell lines and rodent models.
Dose
1-50 µM in vitro; 10-100 mg/kg in rodents
Participants
Multiple cancer cell lines; nude mice
Duration
Varied
Results
Alpha-carotene demonstrated 10x greater anti-tumour activity than beta-carotene in several cell lines, and significantly more potent tumour suppression in vivo.
How They Measured It
Cell proliferation assay, tumour growth inhibition, retinoid receptor binding
To examine plasma alpha-carotene and cancer incidence across multiple sites.
Study Type
Prospective cohort
Purpose
To examine plasma alpha-carotene and cancer incidence across multiple sites.
Dose
Observational
Participants
4500 adults in European prospective cohort
Duration
10 years
Results
Higher plasma alpha-carotene independently associated with reduced total cancer incidence (HR 0.78, 95% CI 0.65-0.94).
How They Measured It
Serum alpha-carotene; cancer registry linkage
Antioxidant Properties & Inflammation
To characterise the singlet oxygen quenching and radical scavenging capacity of alpha-carotene.
Study Type
In vitro comparative study
Purpose
To characterise the singlet oxygen quenching and radical scavenging capacity of alpha-carotene.
Dose
Various concentrations
Participants
Cell-free assay
Duration
Acute
Results
Alpha-carotene demonstrated comparable singlet oxygen quenching capacity to beta-carotene with slightly superior radical chain-breaking activity.
How They Measured It
Singlet oxygen quenching constants; DPPH radical scavenging
To investigate the association between serum alpha-carotene and inflammatory markers.
Study Type
Cross-sectional epidemiology
Purpose
To investigate the association between serum alpha-carotene and inflammatory markers.
Dose
Observational
Participants
3200 adults in NHANES subset
Duration
Cross-sectional
Results
Serum alpha-carotene inversely associated with hs-CRP and IL-6 independently of other dietary antioxidants.
How They Measured It
Serum hs-CRP, IL-6; serum alpha-carotene by HPLC
To review the distinct biological roles of alpha-carotene compared to beta-carotene.
Study Type
Narrative review
Purpose
To review the distinct biological roles of alpha-carotene compared to beta-carotene.
Dose
Varied
Participants
Multiple studies reviewed
Duration
Review
Results
Alpha-carotene's asymmetric structure confers distinct anti-proliferative and anti-carcinogenic properties beyond provitamin A activity, warranting further clinical investigation.
How They Measured It
Literature synthesis
Clinical trials
To investigate the effects of Alpha-Carotene in safety, tolerability, and pharmacokinetics of β-cryptoxanthin supplementation in healthy women: a double-blind, randomized, placebo-controlled clinica
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in safety, tolerability, and pharmacokinetics of β-cryptoxanthin supplementation in healthy women: a double-blind, randomized, placebo-controlled clinica
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
β-cryptoxanthin is a dietary carotenoid for which there have been few studies on the safety and pharmacokinetics following daily oral supplementation.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in vegetable gardening and health outcomes in older cancer survivors: a randomized clinical trial.
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in vegetable gardening and health outcomes in older cancer survivors: a randomized clinical trial.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
Cancer survivors experience accelerated functional decline that threatens independence and quality of life. Previous studies have suggested that vegetable gardening may improve diet, physical activity, and physical function in this vulnerable population, which comprises more than 5% of the US population.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in reflection spectroscopy-assessed skin carotenoids are sensitive to change in carotenoid intake in a 6-week randomized controlled feeding trial in a ra
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in reflection spectroscopy-assessed skin carotenoids are sensitive to change in carotenoid intake in a 6-week randomized controlled feeding trial in a ra
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
Reflection spectroscopy, utilized by the Veggie Meter, is a less-expensive, noninvasive method to quantify skin carotenoids and is a valid approximation of fruit and vegetable (FV) intake. However, it is unknown to what degree Veggie Meter-assessed skin carotenoid score change is responsive to changes in carotenoid intake.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in red palm olein biscuit supplementation modulates gut microbiota in vitamin a deficient rural malaysian schoolchildren: a randomised controlled trial.
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in red palm olein biscuit supplementation modulates gut microbiota in vitamin a deficient rural malaysian schoolchildren: a randomised controlled trial.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
in modulating gut microbiota in vitamin A-deficient children by enhancing microbial network cohesiveness and enriching potentially beneficial bacterial taxa which are linked to enhanced micronutrient and haematological outcomes. These findings lay a valuable foundation and expand the existing evidence base for understanding the relationship between provitamin A carotenoids and gut microbiota.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in impact of maternal moringa oleifera leaf supplementation on milk and serum vitamin a and carotenoid concentrations in a cohort of breastfeeding kenyan
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in impact of maternal moringa oleifera leaf supplementation on milk and serum vitamin a and carotenoid concentrations in a cohort of breastfeeding kenyan
Dose
20 g
Participants
50 participants
Duration
3 months
Results
Maternal moringa consumption did not impact concentration of milk vitamin A and resulted in limited increase in milk carotenoids in this cohort.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in effects of dietary fat type and emulsification on carotenoid absorption: a randomized crossover trial.
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in effects of dietary fat type and emulsification on carotenoid absorption: a randomized crossover trial.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
Although emerging evidence has suggested that the type and emulsification of dietary fat may be important to carotenoid absorption, these effects have not yet been validated in a human trial.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in black pepper and vegetable oil-based emulsion synergistically enhance carotenoid bioavailability of raw vegetables in humans.
Study Type
Randomized, double-blind, placebo-controlled
Purpose
To investigate the effects of Alpha-Carotene in black pepper and vegetable oil-based emulsion synergistically enhance carotenoid bioavailability of raw vegetables in humans.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
d 5.5-fold than the control, respectively (p < 0.0001). COE + BP produced a significant synergy in increasing both C max and AUC 0-10h of total carotenoids, α-carotene, β-carotene, and lycopene. Moreover, COE + BP produced a stronger enhancement on AUC 0-10h of total carotenoids, α-carotene, β-carotene, and lycopene in females than in males.
How They Measured It
See study for outcome measures
Systematic reviews
To investigate the effects of Alpha-Carotene in not all carotenoids can reduce the risk of gastric cancer: a systematic review with meta-analysis.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in not all carotenoids can reduce the risk of gastric cancer: a systematic review with meta-analysis.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
osis, leading to high incidence and mortality rates. It is a significant public health concern globally. Early prevention is crucial in reducing the occurrence of gastric cancer, and dietary prevention, particularly focusing on carotenoids, has been considered a convenient and effective approach. However, the association between carotenoid intake and gastric cancer incidence remains controversial.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in association of retinol and carotenoids content in diet and serum with risk for colorectal cancer: a meta-analysis.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in association of retinol and carotenoids content in diet and serum with risk for colorectal cancer: a meta-analysis.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
Colorectal cancer (CRC) risk is linked to serum and dietary retinol and carotenoids, according to clinical and epidemiological research. However, the findings are not consistent. As a result, we did this meta-analysis to determine the link between them.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in carrot intake is consistently negatively associated with cancer incidence: a systematic review and meta-analysis of prospective observational studies.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in carrot intake is consistently negatively associated with cancer incidence: a systematic review and meta-analysis of prospective observational studies.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
, carrot consumption is robustly associated with decreased cancer-risk; carrot consumption should be encouraged, and the causal mechanisms further investigated.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in low blood carotenoid status in dementia and mild cognitive impairment: a systematic review and meta-analysis.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in low blood carotenoid status in dementia and mild cognitive impairment: a systematic review and meta-analysis.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
tenoids play a role in delaying and preventing dementia and mild cognitive impairment (MCI). However, observational studies have found inconsistent results regarding the associations between blood carotenoid levels and the risk of dementia and MCI. We conducted this systematic review and meta-analysis to investigate the relationship between blood carotenoid levels and the risk of dementia and MCI.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in circulating proteins and metabolite biomarkers in gastric cancer: a systematic review and meta-analysis.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in circulating proteins and metabolite biomarkers in gastric cancer: a systematic review and meta-analysis.
Dose
Alpha-Carotene (dose not specified)
Participants
Participants not specified
Duration
Duration not specified
Results
Gastric cancer (GC) is often diagnosed at an advanced stage and thus patients have a poor prognosis. This implies that early detection of this cancer will improve patient prognosis and survival. This systematic review explored the association of circulating protein and metabolite biomarkers with GC development.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in the association between circulating carotenoids and risk of breast cancer: a systematic review and dose-response meta-analysis of prospective studies.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in the association between circulating carotenoids and risk of breast cancer: a systematic review and dose-response meta-analysis of prospective studies.
Dose
Alpha-Carotene (dose not specified)
Participants
188 participants
Duration
Duration not specified
Results
Most studies were performed among Western nations, which should be acknowledged for extrapolation of findings. Total circulating carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein seem to be related to a decreased risk of breast cancer. Our findings could have practical importance for public health. This study was registered at PROSPERO as CRD42023434983.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in dietary intake of carotenoids and risk of depressive symptoms: a systematic review and meta-analysis.
Study Type
Systematic review and meta-analysis
Purpose
To investigate the effects of Alpha-Carotene in dietary intake of carotenoids and risk of depressive symptoms: a systematic review and meta-analysis.
Dose
Alpha-Carotene (dose not specified)
Participants
466 participants
Duration
Duration not specified
Results
s free of publication bias and heterogeneity. Although further studies are needed to elucidate the causal relationship between carotenoids and depressive symptoms, and to further reveal the mechanism of their association, the results of our meta-analysis suggest that carotenoids are protective factors for depressive symptoms, and dietary intake may help in reducing the risk of depressive symptoms.
How They Measured It
See study for outcome measures
To investigate the effects of Alpha-Carotene in a systematic review of dietary and circulating carotenoids and liver disease.
Study Type
Systematic review
Purpose
To investigate the effects of Alpha-Carotene in a systematic review of dietary and circulating carotenoids and liver disease.
Dose
6 mg
Participants
Participants not specified
Duration
Duration not specified
Results
: lower serum concentrations of α-carotene, β-carotene, and lycopene were associated with a higher risk of liver disease. Meanwhile, dietary intake of β-carotene could reduce the incidence of liver disease. However, for malignant diseases such as liver cancer, it did not show the significant effects of carotenoid supplementation.
How They Measured It
See study for outcome measures
Frequently Asked Questions
Common questions about Alpha-Carotene research
There are currently 23 peer-reviewed studies on Alpha-Carotene (Alpha-carotene), involving 30,122 total participants. Research covers Mortality & Longevity, Cancer Prevention, Antioxidant Properties & Inflammation and 2 more areas. The overall evidence strength is rated as Moderate.
The evidence is currently rated as "Moderate Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (12 human studies), and reported outcomes.
Alpha-Carotene has been researched for: Mortality & Longevity, Cancer Prevention, Antioxidant Properties & Inflammation, Clinical trials, Systematic reviews. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 12 out of 23 studies are human trials. Human trials carry more weight in our evidence scoring system.
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