Haemochromatosis pathobiology
Hereditary haemochromatosis (HH) is primarily caused by mutations in the HFE gene (chromosome 6) — most commonly C282Y homozygosity (present in ~1 in 200 individuals of Northern European descent) and compound heterozygosity C282Y/H63D. HFE protein normally modulates hepcidin signalling — the master regulator of iron absorption in the duodenum.
- Mechanism:Mutated HFE protein fails to upregulate hepcidin appropriately. Without adequate hepcidin, duodenal ferroportin remains constitutively active — iron absorption continues regardless of body iron stores. The body has no efficient iron excretion mechanism; excess iron accumulates over decades.
- Tissue damage:Iron deposits in hepatocytes (hepatic fibrosis → cirrhosis → hepatocellular carcinoma), cardiac myocytes (cardiomyopathy, arrhythmia), pancreatic islet cells (diabetes mellitus), pituitary gland (hypogonadism), and joints (arthropathy).
- Fenton chemistry:Excess non-transferrin-bound iron catalyses the Fenton reaction (Fe²+ + H⊂2;O⊂2; → Fe³+ + OH• + OH−) — generating hydroxyl radicals that drive lipid peroxidation, DNA oxidation, and mitochondrial damage in affected organs.
Spirulina iron: directly contraindicated
This is unambiguous:
- Diagnosed C282Y homozygous haemochromatosis with elevated ferritin (>200 µg/L in women, >300 µg/L in men) or elevated transferrin saturation (>45%): do not use spirulina as an iron source. Any additional dietary iron accelerates the accumulation driving organ damage.
- Spirulina provides 3–8 mg iron per 10 g — a meaningful contribution to daily iron intake that actively counteracts the phlebotomy (venesection) programme used to deplete iron stores.
- Even in maintenance phase after iron normalisation, HH patients typically remain on low dietary iron intake to prevent re-accumulation. Spirulina iron is inconsistent with this management.
HFE heterozygotes: different picture
C282Y heterozygotes (one copy) and H63D homozygotes have variable clinical significance:
- The majority of C282Y heterozygotes do not develop clinical iron overload — penetrance is incomplete, with full haemochromatosis developing in perhaps 28% of C282Y homozygous men and <1% of C282Y homozygous women (menstrual iron losses are protective through reproductive years)
- For HFE heterozygotes with normal ferritin and transferrin saturation: the iron concern is theoretical and monitoring-based. Discuss with the managing physician — some are not restricting dietary iron in heterozygotes with normal iron studies.
Phycocyanobilin and iron-driven oxidative stress
This is the nuanced part: in patients who have completed phlebotomy and normalised iron stores, the residual tissue oxidative damage from prior iron accumulation may be addressed by phycocyanobilin:
- Phycocyanobilin is a potent inhibitor of NADPH oxidase (NOX2/NOX4) — which is activated by both iron-driven ROS and the hepatic inflammatory response to iron deposition
- It directly scavenges hydroxyl radicals and superoxide — the products of Fenton chemistry from excess iron
- In patients with normalised ferritin post-phlebotomy: spirulina without its iron content would be ideal. This is not commercially available — but ultra-low-dose spirulina (1–2 g/day, providing 0.3–0.8 mg iron from food matrix, well below therapeutic concern) may provide phycocyanin with minimal iron contribution. Discuss dose and monitoring with haematologist.
Practical guidance
- Diagnosed HH with elevated ferritin: spirulina iron is contraindicated — do not use
- Diagnosed HH with normalised ferritin (post-phlebotomy maintenance): very low-dose spirulina may provide phycocyanin benefit with minimal iron; requires haematologist discussion and regular iron monitoring
- HFE heterozygote with normal iron studies: discuss with managing physician; monitoring iron studies every 6–12 months is appropriate if using spirulina
- Always check serum ferritin and transferrin saturation before starting spirulina if you have a family history of haemochromatosis or known HFE carrier status