Annatto carotenoids and red blood cell resistance to hemolysis
What it found
In lab tests and in a small group of healthy people, annatto carotenoids made red blood cells more resistant to breaking apart.
Bixin worked better than norbixin.
What they found
Studies in people
Supplementation in people
After 7 days of taking bixin or norbixin, red blood cell membranes were more resistant to breaking. Bixin was more effective than norbixin.
Animal and lab studies
Lab tests on cells
In lab tests, bixin and norbixin reduced red blood cell membrane fragility caused by AAPH, glucose, or sodium nitrite. They also improved the cells' natural resistance to breaking.
Studies in people and animals
Oxidative damage
Both bixin and norbixin protected red blood cells from lipid peroxidation and improved the cells' redox environment.
What the authors conclude
“These results support the hypothesis that annatto carotenoids supplementation exerts antihemolytic properties by preventing the oxidative damage of human erythrocytes.”
Also in their conclusions
- They say the results support the idea that annatto carotenoid supplements have antihemolytic properties by preventing oxidative damage to human red blood cells.
How it was done
Red blood cells are easily damaged by oxidation in several diseases. The authors thought annatto carotenoids might protect red blood cell membranes and make them harder to break.
In lab tests, red blood cells from healthy volunteers were mixed with bixin or norbixin and substances that cause hemolysis. In a second part, healthy volunteers took a capsule of bixin or norbixin (0.05 mg/kg body weight per day) or a placebo for 7 days, then their red blood cells were tested.
What it can’t tell you
- We summarised it from the abstract only.
- The people in the study were healthy, so the results may not apply to people with conditions that cause red blood cell breakdown.
- The study was small and lasted only 7 days, so it cannot show long-term effects.
Who paid
- Authors work at
- Federal University of Santa Maria, Brazil
The paper
- Title
- Dietary supplementation with annatto food-coloring extracts increases the resistance of human erythrocytes to hemolysis
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Beni AA, Rodrigues RF, Conte L, et al (2020). Dietary supplementation with annatto food-coloring extracts increases the resistance of human erythrocytes to hemolysis. Nutrition research (New York, N.Y.). doi:10.1016/j.nutres.2020.02.003PubMed 32217378DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error