Daily supplements of the oil for three months also produced improvements in symptoms for contact lens wearers, according to findings published in the Journal of Nutrition.
Keratoconjunctivitis sicca, or dry eye syndrome, is a condition where the eyes do not make enough tears, or the tears evaporate too quickly. This produces dry eyes and increases the risk of inflammation. According to the Finnish researchers behind the new study, the prevalence of dry eye can be up to 30 per cent in people aged 50 y and older.
“The results of this study suggest that sea buckthorn oil consumption can attenuate the increase in tear film osmolarity occurring during the cold season,” wrote the researchers, led by Riikka Jarvinen. “It may also influence the maximum intensity of redness and burning symptoms in participants with dry eye.
“Further studies should investigate the effects of sea buckthorn oil on more defined populations and aim to determine the mechanisms of a positive sea buckthorn oil effect,” they added.
Sea buckthorn oil has been reported to have a number of other health applications, including atopic eczema, other skin problems related to deficient regeneration, UV radiation stressed skin, mouth dryness, mouth ulcers, gastric ulcers, urinary tract inflammations, cervicitis, genital ulcers, sinus inflammation and eye dryness.
Dr Jarvinen and her co-workers recruited 86 people aged between 20 and 70 to participate in their double-blind, randomized, parallel trial. The participants were randomly assigned to receive either two grams of sea buckthorn oil (Aromtech, Finland) or placebo oil ever day for 3 months from fall to winter. People with both types of dry eye syndrome were included – people who can’t make enough tears, and people whose tears evaporate too quickly.
Results showed that all the people in the study experienced an increase in the concentration of water evaporation from the eye, but people receiving the sea buckthorn supplement experience a significantly smaller increase in this measure. Furthermore, people who complied well with the regime and took at least 80 per cent of their supplements experienced greater reductions in this increase.
“The maximum intensities of redness and burning tended to be lower in the sea buckthorn group,” added the researchers.
Commenting on the potential mechanism and the bioactives involved, the researchers note that the linolenic acid contained in the oil is a basis for anti-inflammatory compounds, which could reduce inflammation. The researchers also note that sea buckthorn oil is a rich source of vitamin E and that antioxidants “may protect the eye from oxidative damage leading to activation of inflammatory cascades”.
Source: Journal of Nutrition
Published online ahead of print, doi: 10.3945/jn.109.118901
“Oral Sea Buckthorn Oil Attenuates Tear Film Osmolarity and Symptoms in Individuals with Dry Eye”
Authors: P.S. Larmo, R.L. Jarvinen, N.L. Setala, B. Yang, M.H. Viitanen, J.R. K. Engblom, R.L. Tahvonen, H.P. Kallio