Canthaxanthin and lipid membranes in the eye
What it found
In lab models, canthaxanthin changed the physical properties of lipid membranes at very low concentrations.
This may help explain how the pigment forms crystals in the eye, but the work was not done in people.
What they found
Animal and lab studies
Membrane changes at low doses
In model DPPC lipid membranes, canthaxanthin changed membrane properties at concentrations below 1 mol%, and in some cases at levels as low as 0.05 mol%.
Ordering of lipid chains
Canthaxanthin ordered the lipid alkyl chains, most likely through strong van der Waals interactions with its rigid polyene chain. This made the hydrophobic core of the membrane thicker.
Surface and fluidity effects
Canthaxanthin modified the polar head zone of the membrane, caused liposomes to clump together, and changed the membrane's thermotropic properties. Its effect was much stronger than that of lutein or zeaxanthin.
Hydrogen bonds
Canthaxanthin formed hydrogen bonds through its keto groups, either directly with the lipid ester carbonyl group or indirectly through water molecules. This may be important for forming the aggregates that lead to retinopathy.
Studies in people and animals
Crystals in the eye
Canthaxanthin intake is linked to golden yellow or red crystalline deposits in the retina around the macula. These deposits are thought to be a canthaxanthin-lipoprotein complex rather than pure canthaxanthin.
Blood vessel damage
Canthaxanthin retinopathy is strongly connected with damage to the blood vessels around the place where crystals are deposited, and with the growth of new, abnormal vessels.
What the authors conclude
“Canthaxanthin toxicity towards the macula lutea lipid membranes could be due to its very strong molecular interactions with the lipid molecules.”
Also in their conclusions
- They conclude that canthaxanthin toxicity towards the macula lutea lipid membranes could be due to its very strong molecular interactions with lipid molecules.
- They say these effects are seen at much lower concentrations of canthaxanthin than of other xanthophylls such as lutein or zeaxanthin.
- They list five molecular mechanisms, including aggregation of canthaxanthin in the lipid phase and the formation of hydrogen bonds, and say the last may be crucial for the aggregates that lead to canthaxanthin retinopathy.
How it was done
Canthaxanthin is used as a drug and as a food and cosmetic colorant, but it can cause crystals to form in the macula of the retina, a condition called canthaxanthin retinopathy. The author wanted to see whether the way canthaxanthin interacts with lipid membranes could help explain this.
The author reviewed experiments done on model membrane systems, including monolayers of pure canthaxanthin, mixtures of canthaxanthin and lipids, oriented bilayers and liposomes. The review also draws on animal and human observations of canthaxanthin in the eye.
What it can’t tell you
- Most of the evidence comes from model membrane systems in the lab, not from people.
- The exact way canthaxanthin is delivered to the retina and how it acts there is still unclear.
- No data on the canthaxanthin concentration in the macula lutea in humans is available.
Who paid
- Authors work at
- University of Life Sciences, Poland
The paper
- Title
- Interactions between canthaxanthin and lipid membranes--possible mechanisms of canthaxanthin toxicity
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Sujak A (2009). Interactions between canthaxanthin and lipid membranes--possible mechanisms of canthaxanthin toxicity. Cellular & molecular biology letters. doi:10.2478/s11658-009-0010-8Free full textPubMed 19214394DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error