Omega-7 fatty acids
Most people have heard of omega-3 and omega-6 essential fatty acids but few will have heard of omega-7 fatty acids. The family of omega-7 fatty acids is relatively rare, with palmitoleic and vaccenic acids comprising the more commonly found fatty acids.
Although omega-7 fatty acids are not “essential” fatty acids, as they can be made in the body, their list of demonstrated beneficial health attributes is impressive. A survey of data from both the traditional applications and modern research reveals mucous membrane benefits, cardiovascular benefits and potential applications for some forms of cancer.
The main dietary sources of omega-7 include tropical oils, especially coconut and palm kernel oil, macadamia nuts and milk. As the reputation of omega-7 fatty acids rapidly increases, commercial nutraceuticals offer oral and topical omega-7 products sourced primarily from the herb sea-buckthorn.
Sea-buckthorn is not a seaweed as the name may lead you to believe but rather a hardy, berry-bearing bush from the Elaeagnaceae family. It includes several species of which Hippophae rhamnoides is the most medicinally significant. This hardy bush is found in many Asian and European countries in both coastal and mountainous areas and has a long tradition of use.
Since the ancient Tibetans started using sea-buckthorn more than one thousand years ago, the nutritional and medicinal properties of this berry have been passed on in hundreds of traditional recipes. The traditional knowledge of sea-buckthorn’s applications include wound healing, reduction of inflammation and applications for mucous membrane health where it was considered useful in the treatment of cough, gastric and gynaecological problems.
The oils in sea-buckthorn are rich in both the seeds and in the fruit’s flesh and peel (pulp oil). While vaccenic acids are present in the seed oil, it is the pulp oil that contains the highest omega-7 fatty acid profile with palmitoleic acid comprising up to 50 per cent of the oil fraction.
Skin, stomach, and eyes
The potential for sea-buckthorn oil to positively influence mucous membrane health has attracted a significant amount of scientific interest.
Mucous membranes cover the digestive, respiratory and urogenital tracts as well as the surface of the eyes. As mucous membranes form a shield between us and our environment, mucous membrane health is a significant aspect of health and wellbeing. Modern research validates the long tradition of use of sea-buckthorn berries for mucous membrane health in the promotion of tissue regeneration, improvement of immune function and reduction of oxidative degradation of fats.
One placebo-controlled double-blind study found sea-buckthorn pulp oil given as five grams (10 capsules) daily for four months improved atopic dermatitis significantly. Another double-blind randomised trial found two grams of sea-buckthorn oil given orally for three months improved dry eye symptoms including redness and burning.
Further studies have found sea-buckthorn oil successful in treating and preventing gastric ulcer formation as well as chronic cervicitis where anti-inflammatory and analgesic properties were reported. As an external dressing for burns, it has been found to be valuable in the reduction of pain and for increasing skin growth and wound healing.
Cardiovascular disease is of huge significance in the Western world and research to date suggests the oils of sea-buckthorn may well have a role to play in this area of health care.
Results of animal experiments show that sea-buckthorn oils taken orally may lower the risk of cardiovascular disease. This includes decreasing the plasma total and LDL cholesterol levels, increasing HDL cholesterol, inhibiting thrombus formation and atherosclerosis and reducing oxidation of LDL.
It is interesting to note that a diet high in macadamia nuts, another good source of omega-7 oils, has been shown to lower serum cholesterol and LDL cholesterol as well as serum triglycerides without affecting HDL cholesterol levels.
Promise for cancer
The effect of sea-buckthorn oil on some forms of cancer is under preliminary investigation with promising results. One animal study found the seed oil suppressed growth of S180 and B16 tumours in mice while another found it elongated the living period of mice with S180 tumours. Yet another study suggested a cytotoxic effect of the oil on human leukaemia cell line K562 in in-vitro testing.
With so much positive evidence surrounding omega-7 oils in the form of sea-buckthorn, it’s reassuring to know that the addition of this oil to the diet is also considered quite safe. This is due to both the long history of use of sea-buckthorn as an edible berry and food throughout Asia and Europe as well as reviewed toxicological animal studies on the extracted oils. These studies investigated potential for acute and chronic toxicity in blood, liver and heart as well as potential for genetic mutation on a cellular level.
As omega-7 oils are not essential, there is no set recommended daily allowance for this fatty acid family. Studies show the use of omega-7 fatty acids in supplement form from two to five grams per day depending on the condition being treated. See your health practitioner for advice specific to your needs.
Topical use, while also being very safe, may lead to “old people smell”. This can be avoided by wiping over the area with another oil such as jojoba or by using commercially available products which have overcome this issue.
References available on request.
Kate Mirow is a naturopath, nutritionist, herbalist and homoeopath practising at Your Health in Manly, NSW. She specialises in fertility and weight loss while also seeing a myriad of other health conditions. T: 02 9977 7888