It’s taken from the seeds of the Borago officinalis plant, which produces blue star-shaped flowers and is native to the UK, Europe and North Africa.
The oil extracted from the seeds is a potent source of gamma linolenic acid (GLA), which is an omega 6 fatty acid. Evening primrose oil supplements also contain GLA.
Dr Sarah Brewer says: ‘Starflower oil is a popular herbal remedy, and is particularly useful as a source of GLA which helps to reduce inflammation in the body. A starflower oil supplement may be especially beneficial for women’s health conditions such as PMS and to help improve the quality of skin.’
What does starflower oil do?
Starflower oil contains high levels of two types of polyunsaturated fatty acids, GLA and the essential omega 3 fatty acid, alpha-linolenic acid (ALA).
GLA produces prostaglandins, which are hormone-like substances that can affect the immune system, blood flow and the metabolism and hormonal system. GLA has beneficial anti-inflammatory effects, which may help protect against chronic diseases, including diabetes, heart disease, arthritis and Alzheimer’s disease.
Pre-menstrual syndrome (PMS)
Starflower oil may be helpful for PMS, a collection of physical and psychological symptoms some women experience in the fortnight before their periods. These include breast pain, mood swings, irritability and bloating. Five per cent of women are so badly affected they can’t live normal lives.
In a placebo-controlled study, published in Reproductive Health, polyunsaturated fatty acids including GLA, were given to 120 women suffering from PMS symptoms over a six-month period. The women who were given the fatty acids experienced an improvement in PMS symptoms.
Rheumatoid arthritis (RA)
RA is an autoimmune condition where the body produces antibodies which attack the joints, causing pain and swelling. Around 680,000 people have RA in the UK.
A review of 22 studies on herbal treatments for RA found there was moderate evidence that oils containing GLA could relieve symptoms.
In another study, 56 participants with RA either took a daily dose of supplements containing GLA or placebo capsules of sunflower seed oil for six months. Those taking the starflower supplements showed a statistically significant improvement and reduction in symptoms over those taking a placebo.
Getting starflower oil from your diet
The blue star-shaped flowers the oil is extracted from can be eaten in salads and soups. GLA is also found in the plant seed oils of evening primrose, blackcurrant, fungal oils and in spirulina, a type of algae. Alternatively, take starflower oil as a supplement.
Starflower oil can cause nausea, indigestion, headaches and rashes. It could also interact with certain medications. If you are taking blood-thinning medications contact your doctor before taking starflower oil. If you have liver or gastrointestinal issues, it is also advisable to speak to your doctor before taking the supplement.
Women who are pregnant or breastfeeding are advised not to take starflower oil because it may harm the foetus and induce early labour.
Starflower oil currently has no UK or EU recommended daily allowance or upper safe limit. A 1,000mg starflower capsule contains 205mg of GLA and 130mg of omega 9 fatty acids. One capsule a day is commonly taken.