Atherosclerosis is a condition in most cardiovascular diseases, where the walls of the arteries become thick and stiff because of fatty deposit accumulation. In experimental and clinical studies, algae source 9-cis beta-carotene had positive effects on heart health. In arterial walls, it can inhibit the formation of foam cells from macrophages, which is a key process in atherosclerosis.
This was shown in an experimental study in mice using beta-carotene with 50 percent all-trans and 50 percent 9-cis isomers. Feeding algae extract increased beta-carotene levels in plasma and macrophages (both all-trans and 9-cis isomers) and it inhibited formation of pro-atherogenic foam cells.
In the same study, pure 9-cis beta-carotene as well as an extract of algae powder inhibited foam cell formation while pure all-trans beta-carotene failed to have an effect. Other carotenoids present in the algae extract including phytoene and phytofluene, lutein, zeaxanthin, and alpha-carotene were tested in comparison but were not as effective as 9-cis betacarotene or the algae extract.
In another mice study, researchers found that a diet containing natural carotenoids, rich in 9-cis beta-carotene, had the potential to inhibit atherosclerosis progression, particularly in a high-fat diet regime.
In patients with cardiovascular disease, 9-cis betacarotene in combination with drug therapy improved HDL-cholesterol levels. This was observed by Shaish et al. (2006) where 20 fibrate-treated men with plasma HDL-cholesterol levels below 40 mg/dl were given 60 mg beta-carotene/day, containing all-trans and 9-cis betacarotene at a one to one ratio. The results show that a combination treatment of fibrate plus 9-cis beta-carotene amplifies the effect of the drug on HDL-cholesterol levels.
Several studies have suggested that 9-cis beta-carotene, as a precursor of 9-cis-retinal and all-trans-retinal, could also have therapeutic applications in vision loss. In patients with retinitis pigmentosa, the leading cause of incurable inherited blindness in the developed world, algae source 9-cis beta-carotene improved eye (retina) function which was shown in a clinical trial by Rotenstreich et al. (2013).
The authors concluded that 9-cis beta-carotene may represent a new therapeutic approach for some patients with retinitis pigmentosa. This finding is consistent with recent reports of significant functional and structural improvements after treatment in mouse-model experimental studies.
For retinal dystrophy leading to night blindness, in another small human trial by Rotenstreich et al. (2010) there was an improvement in visual function and structure after supplementation of 60mg/day algae beta-carotene containing an equal ratio of trans to cis isomers for 90 days.
All of the subjects showed significant improvements in peripheral visual field and a highly significant improvement in rod cell recovery rates. While the precise mechanism of the observed beneficial effect has not yet been established, it indicates potential for algae beta-carotene therapy in yet another area of eye health.
