Clinical studies of sea buckthorn
- Effects of sea buckthorn oil intake on vaginal atrophy in postmenopausal women: A randomized, double-blind, placebo-controlled study.
Background: Vaginal atrophy, the thinning and drying of vaginal mucosa, is associated with menopause. The standard estrogen treatment is not suitable for all women. Objective: To investigate the effects of oral sea buckthorn (SB) oil supplementation on vaginal atrophy. Method: A total of 116 postmenopausal women experiencing symptoms of vaginal dryness, itching or burning were randomized to this placebo-controlled, double-blind study. Ninety-eight participants completed the intervention of three months, during which they consumed 3 g of SB or placebo oil daily. At the beginning and end, factors of vaginal health were scored by a gynecologist, vaginal pH and moisture were measured and vaginal health index was calculated. Symptoms of atrophy and menopause were evaluated at study visits and by daily logbooks. Serum samples were collected for the analysis of circulating lipids, liver enzymes and C-reactive protein. Results: Compared to placebo, there was a significantly better rate of improvement in the integrity of vaginal epithelium in the SB group when both compliant and noncompliant participants were included (odds ratio (OR) = 3.1, 95% CI 1.11–8.95). A beneficial trend was observed when only the compliant participants were included (OR = 2.9; 95% CI 0.99–8.35). There was a tendency (P = 0.08) toward better improvement of vaginal health index from baseline to the end in the SB group [(0.8 (SD 2.8)] compared to placebo [−0.1(SD 2.0)].Conclusions: SB oil showed beneficial effects on vaginal health, indicating it is a potential alternative for mucosal integrity for those women not able to use estrogen treatment for vaginal atrophy. [Larmo PS, Yang B, Hyssala J, Kallio HP, Erkkola R. Maturitas. Effects of sea buckthorn oil intake on vaginal atrophy in postmenopausal women: A randomized, double-blind, placebo-controlled study. 2014; Article in Press.]
- Different berries and berry fractions have various but slightly positive effects on the variables associated to metabolic diseases in overweight and obese women.
Dietary habits have a major role in obesity, type 2 diabetes and atherosclerotic cardiovascular diseases. In this study, we compared the effects of sea buckthorn (SB) and its fractions, and bilberries (BBs) on associated variables of metabolic diseases on overweight and obese women. In total, 110 female volunteers were recruited, and they followed four different berry diets (BB, SB, SB phenolic extract (SBe) and SB oil (SBo)) in a randomized order for 33-35 days. Each intervention was followed by a wash-out period of 30-39 days. Blood samples were drawn and physical measurements were performed after each period. Eighty volunteers completed the study. There was statistically significant decrease in waist circumference after BB (Δ, -1.2 cm; P = 0.041) and SB (Δ, -1.1 cm; P = 0.008) periods and also a small decrease in weight after BB diet (Δ, -0.2 kg; P = 0.028). Vascular cell adhesion molecule decreased after BB (Δ, -49.8 ng/ml; P = 0.002) and SBo (Δ, -66.1 ng/ml; P = 0.001) periods, and in intercellular adhesion molecule (ICAM) after SBe diet (Δ, -6.1 ng/ml; P = 0.028). Based on the results, it can be stated that different berries and berry fractions have various but slightly positive effects on the associated variables of metabolic diseases. [Lehtonen HM, Suomela JP, Tahvonen R, Yang B, Venojärvi M, Viikari J, Kallio H. Different berries and berry fractions have various but slightly positive effects on the variables associated to metabolic diseases in overweight and obese women. Eur J Clin Nutr. 2011;65:394–401.]
- Effects of oral sea buckthorn oil on tear film fatty acids in individuals with dry eye.
Evaporative dry eye is associated with meibomian gland dysfunction and abnormalities of the tear film lipids. Dry eye is known to be affected positively by intake of linoleic and γ-linolenic acids and n-3 fatty acids. Oral sea buckthorn (Hippophaë rhamnoides) (SB) oil, which contains linoleic and α-linolenic acids and antioxidants, has shown beneficial effects on dry eye. The objective was to investigate whether supplementation with SB oil affects the composition of the tear film fatty acids in individuals reporting dry eye. One hundred participants were randomized to this parallel, double-blind, placebo-controlled study, which 86 of them completed. The participants daily consumed 2 g of SB or placebo oil for 3 months. Tear film samples were collected at the beginning, during, and at the end of the intervention and 1 to 2 months later. Tear film fatty acids were analyzed as methyl esters by gas chromatography.There were no group differences in the changes in fatty acid proportions during the intervention (branched-chain fatty acids: P = 0.49, saturated fatty acids: P = 0.59, monounsaturated fatty acids: P = 0.53, and polyunsaturated fatty acids: P = 0.16). The results indicate that the positive effects of SB oil on dry eye are not mediated through direct effects on the tear film fatty acids. Carotenoids and tocopherols in the oil or eicosanoids produced from the fatty acids of the oil may have a positive effect on inflammation and differentiation of the meibomian gland cells. [Järvinen R, Larmo P, Setälä N, Yang B, Engblom J, Viitanen M, Kallio H. Effects of oral sea buckthorn oil on tear film fatty acids in individuals with dry eye. Cornea 2011;30:1013–1019 (Samples collected in the dry eye study of Larmo et al (2010) J Nutr).]
- Oral sea buckthorn oil attenuates tear film osmolarity and symptoms in individuals with dry eye.
Dry eye is a common condition that can severely impair the quality of life. We aimed to find out whether oral sea buckthorn (SB) oil, containing (n-3) and (n-6) fatty acids and antioxidants, affects dry eye. In this double-blind, randomized, parallel trial, 20- to 75-y-old women and men experiencing dry eye symptoms consumed 2 g of SB or placebo oil daily for 3 mo from fall to winter. One hundred participants were recruited and 86 completed the study. Clinical dry eye tests and symptom follow-ups were performed. Tear film hyperosmolarity is a focal factor in dry eye. There was a general increase in the osmolarity from baseline to the end of the intervention. Compared with the placebo group, the increase was significantly less in the SB group when all participants were included [intention to treat (ITT), P = 0.04] and when only participants consuming the study products for at least 80% of the intervention days were included [per protocol (PP), P = 0.02]. The maximum intensities of redness and burning tended to be lower in the SB group. In the ITT participants, the group difference was significant for redness (P = 0.04) but not for burning (P = 0.05). In the PP participants, the group difference was significant for burning (P = 0.04) but not for redness (P = 0.11). In conclusion, SB oil attenuated the increase in tear film osmolarity during the cold season and positively affected the dry eye symptoms. [Larmo P, Järvinen R, Setälä N, Yang B, Viitanen M, Engblom J, Tahvonen R, Kallio H. Oral sea buckthorn oil attenuates tear film osmolarity and symptoms in individuals with dry eye. J Nutr. 2010;140:1462-1468.]
- Berry meals and risk factors associated with metabolic syndrome.
Nonalcoholic fatty liver disease is commonly associated with obesity, insulin resistance, dyslipidemia and type 2 diabetes, and can thus be regarded as the hepatic manifestation of metabolic syndrome. In this study we compared the effects of lifestyle intervention with and without industrial berry products, on risk factors associated with metabolic syndrome on slightly overweight women. Sixty-one female volunteers (average age 42.9 years) were recruited and randomized for a 20-week dietary intervention trial with two parallel treatment groups, one lifestyle intervention group with berry products equaling with an average daily dose of 163 g of northern berries (berry group, diet 1, N=31, of which 28 completed the study) and the other group with lifestyle intervention only (control group, diet 2, N=30, of which 22 completed the study).Increased berry consumption as part of the normal daily diet was the only lifestyle difference between the two intervention groups. The major effects achieved by diet 1 were changes in the levels of alanine aminotransferase (ALAT) and adiponectin (at P-values <0.001 and 0.002, respectively). A statistically significant difference between the two intervention groups was the higher decrease in the ALAT value in the berry group (P=0.003). The 23% decrease in the ALAT value, from 20.29 to 15.66 U/l in the berry group may be regarded as nutritionally significant by enhancing the liver function. This may contribute positively to the low-grade systemic inflammation in body and decrease the risk of cardiovascular diseases. [Lehtonen HM, Suomela JP, Tahvonen R, Vaarno J, Venojärvi M, Viikari J, Kallio H. Berry meals and risk factors associated with metabolic syndrome. Eur J Clin Nutr. 2010;64:614-621]
- Effects of oral supplementation and topical application of supercritical CO2 extracted sea buckthorn oil on skin ageing of female subjects.
Sea buckthorn (Hippophaë rhamnoides) seed and pulp oil is known to promote skin regeneration, speed up wound healing and ease skin inflammation. The present study was carried out to investigate the anti-ageing effects of oral supplementation of a standardized supercritical CO2-extracted sea buckthorn oil and topical skin application of supercritical CO2-extracted sea buckthorn seed oil. Sixty female subjects of age 50-70 years were randomly divided into two groups, thirty subjects in each group. In one group, the subjects took sea buckthorn oil capsules, four capsules (4 x 0.5 g oil) per day, for three months. In the other group, the subjects applied topically sea buckthorn seed oil rejuvenating night cream on the face, twice per day, for three months. Skin hydration status, elasticity, surface roughness, luminosity and cutaneous thickness were determined using non-invasive instrumental measurements before, after one month and at the end of treatments. Both treatments significantly improved the skin hydration status and the overall skin elasticity of the subjects (P < 0.001). Oral supplementation with the sea buckthorn oil capsules resulted in decreases in the mean roughness (Ra) and maximum roughness (Rz) of the skin surface, indicating anti-wrinkle efficacy of the product. Topical application of the sea buckthorn oil cream increased cutaneous thickness, suggesting positive structural changes and improvement in collagen synthesis in the skin. This is the first study showing beneficial effects of orally used sea buckthorn oil in reducing the signs of skin ageing. This is also an important breakthrough demonstrating the great potential of sea buckthorn oil in supporting the health and well being of healthy skin through internal use. [Yang B, Bonfigli A, Pagani V, Isohanni T, von-Knorring Å, Jutila A, Judin V-P. Effects of oral supplementation and topical application of supercritical CO2 extracted sea buckthorn oil on skin ageing of female subjects. J. Appl. Cosmetol. 2009 Jan-Mar;27:1-13.]
- Sea buckthorn oils, mucous membranes and Sjögren’s syndrome with special reference to latest studies.
Source: Yang B, Erkkola R. (2008) In: Singh et al., editors. Seabuckthorn (Hippophae L.). A Multipurpose Wonder Plant. Vol. III: Advances in research and development. New Delhi, India: Dya Publishing House; p.254-267
- Absorption of flavonols derived from sea buckthorn (Hippophaë rhamnoides L.) and their effect on emerging risk factors for cardiovascular disease in humans.
Sea buckthorn (Hippophaë rhamnoides L.) is a rich source of flavonols, especially isorhamnetin. Most prospective cohort studies have indicated some degree of inverse association between flavonoid intake and coronary heart disease. Animal and human studies suggest that sea buckthorn flavonoids may scavenge free radicals, lower blood viscosity, and enhance cardiac function. The effects of flavonol aglycones derived from sea buckthorn on the risk factors of cardiovascular disease as well as their absorption were studied in humans. The flavonols, ingested with oatmeal porridge, did not have a significant effect on the levels of oxidized low-density lipoprotein, C-reactive protein, and homocysteine, on the plasma antioxidant potential, or on the paraoxonase activity. Flavonols at two dosages in oatmeal porridge were rapidly absorbed, and a relatively small amount of sea buckthorn oil added to the porridge seemed to have increased the bioavailability of sea buckthorn flavonols consumed at the higher dose. [Suomela JP, Ahotupa M, Yang B, Vasankari T, Kallio H. Absorption of flavonols derived from sea buckthorn (Hippophaë rhamnoides L.) and their effect on emerging risk factors for cardiovascular disease in humans. J Agric Food Chem. 2006;54:7364-7369.]
- Sea Buckthorn oils: towards healthy mucous membranes.
Topical application sea buckthorn oils and preparations containing sea buckthorn oil have been shown to improve the health of mucous membranes of urogenital tract. Therefore we decided to design a trial by using orally administered sea buckthorn oils for the treatment of patient who had suffered from conditions described above, and had experienced a multitude of treatments. The patients took orally capsules of Sea Buckthorn Oil (extracted by supercritical CO2, kindly provided by Aromtech Ltd, Finland), a mixture of oils from seeds and berry soft parts, 3 capsules twice a day (3 g sea buckthorn oil per day) for 12 weeks. The committee of ethics accepted the study plan. Significant improvement was seen in three severe cases after sea buckthorn oil treatment. The best improvement was seen in patient No.2 representing as much as 66% decrease of the total VAS score. The average total score value was decreased by 46%, from 185 to 100 by sea buckthorn oil treatment. Estrogen levels at the end of trial were equal to the pretreatment measurements. None of the subjects reported any side effects. [Erkkola R, Yang B. Sea Buckthorn oils: towards healthy mucous membranes. AgroFood Industry Hi-Tech. 2003;May-June.]
- Sea buckthorn berry oil inhibits platelet aggregation.
A small-scale preliminary cross-over study was conducted to investigate the effects of supercritical CO(2)-extracted sea buckthorn berry oil (SBO) on some risk factors of cardiovascular disease. Special features of the oil are high proportions of palmitic (16:0), oleic (18:1n-9), palmitoleic (16:1n-7), linoleic (18:2n-6), and alpha-linolenic (18:3n-3) acids as well as vitamin E, carotenoids, and sterols. Twelve healthy normolipidemic men were recruited and each volunteer consumed SBO and fractionated coconut oil (control) 5 g per day for a period of 4 weeks in a random order (wash-out 4-8 weeks). Phospholipid fatty acids, plasma lipids, and glucose were unaffected by SBO supplementation. Instead, a clear decrease in the rate of adenosine-5′-diphosphate-induced platelet aggregation and maximum aggregation were found. This suggested the beneficial effects of SBO on blood clotting, but further studies on the dose-response effects are needed to assess the practical use of SBO supplements. [Johansson AK, Korte H, Yang B, Stanley JC, Kallio HP. Sea buckthorn berry oil inhibits platelet aggregation. J Nutr Biochem. 2000;11:491-495.]