It is known that phospholipid hydroperoxides (PLOOH) build up in the red blood cells (RBCs) of dementia patients. (Phospholipids include phosphatidylcholine and phosphatidylethanolamine.) PLOOHs are the products of oxidation of the phospholipids of the cell wall membranes. These products of oxidation in the RBCs could impair the transport of oxygen to the brain and contribute to dementia.
Dietary xanthophylls, including carotenoids such as astaxanthin are deficient in the RBCs of dementia patients. This study was done to test that theory that xanthophylls such as astaxanthin can prevent the buildup of PLOOHs. Xanthophylls may be a functional food to help prevent dementia.
The study was a placebo controlled randomized, double-blind study. Human patients were studied with astaxanthin supplementation for 12 weeks. They were given either 6 or 12 mg daily. There were 30 subjects who were middle-aged or seniors. The blood levels of astaxanthin were higher in the treated subjects than in the placebo subjects who received none. PLOOH levels were lower in the treated patients than in the placebo patients.
The authors have previously developed the test of astaxanthin levels in RBCs and used that analysis in the current study. Before supplementation with astaxanthin, PLOOHs in all patient’s RBCs were similar to those in placebo RBCs. After supplementation with astaxanthin, the astaxanthin levels of RBCs went up and PLOOH levels went down. There was not a significant difference between the 6 mg and the 12 mg doses of astaxantin. The reduced PLOOHs were presumed to be due to the astaxanthin. Reducing the PLOOHs may be of benefit in dementia.
Lipid peroxidation has been found to be associated with arteriosclerosis, dementia, and aging. Food sources of antioxidants must be absorbable and digestible. In this regard, astaxanthin does digest, absorb, and distribute into the cells of the body, in this case to RBCs.
Astaxanthin is synthesized by plants and algae. The suggested daily dose is 1-12 mg/day. Lutein is another xanthophyll which has been shown to prevent the accumulation of PLOOHs in the RBCs of humans.
Additionally, the cell membranes are protected from oxidation by the antioxidants superoxide dismutase and glutathione peroxidase.
CONCLUSION: It is believed that astaxanthin supplementation could lower oxidation levels in RBCs and may be beneficial in dementia. The mechanism by which it might work is not defined at this time. Further study is needed to determine the most beneficial dose of astaxanthin.
NOTE: Peroxidation refers to the oxidation which degrades lipids.
Astaxanthin is found in krill.