Borage is a herb that grows throughout the Mediterranean, Asia, Europe, and South America that is also known as starflower. It can grow to a height up to over 3 feet. Borage is cultivated as an oilseed that is high in gamma linolenic acid (GLA). The oil derived from the seed is often sold as "borage oil" used as a GLA supplement. Borage seed oil is derived from the seeds of Borage, and has many health benefits including:
treatment of rheumatoid arthritis 
borage oil (GLA) is shown to help relieve childhood eczema [2, 5]
borage oil helps improve skin conditions in women  and also helps enhance skin barrier function 
borage oil GLA is also found to help reduce weight regain in humans following major weight loss 
it also alters fatty acid metabolism and improves skin function in the elderly 
borage oil also reduces body fat accumulation 
it has also been found to have blood pressure lowering effects [10, 11]
studies have also found borage oil to improve stress reactivity and performance - attenuated blood pressure and heart rate responses to stress, increased skin temperature, and improved task performance 
Borage is the highest known plant source of GLA, and its seed oil content is between 26-38% and in addition to GLA contains the fatty acids palmitic acid (10-11%), stearic acid (3.5-4.5%), oleic acid (16-20%), linoleic acid (35-38%), eicosenoic acid (3.5-5.5%), erucic acid (1.5-3.5%), and nervonic acid (1.5%). 
Health Benefits of Borage Seed Oil GLA
As you can see from the list above, there are many health benefits of the gamma linolenic acid (GLA) in borage oil. It has many benefits for improving skin conditions, provides anti-inflammatory benefits, helps treat arthritis, can help lower blood pressure, has weight loss applications, and even improve human responses to stress. In a wide range of clinical studies and trials, borage seed oil has been found to benefit people across all age groups for men, women, children, and the elderly. It is a health supplement with numerous clinically proven health benefits. Below, we will discuss in a bit more detail on the three most important benefits of borage oil: 1) improving skin conditions, 2) weight loss and weight maintenance applications, and 3) improving response to stress and blood pressure lowering effects.
Borage Seed Oil Gamma Linoleic Acid and Skin Conditions
As we've mentioned, GLA offers a host of benefits for improving skin conditions in children, adults, and the elderly. It has been found to help relieve eczema in children, enhance skin condition in women, and improve skin function in the elderly. Gamma-linoleic acid preparations, borage oil, and evening primrose oil has shown efficacy in relieving childhood eczema. 
In a German flaxseed and borage oil study, 2 groups of women supplemented with flaxseed, borage oil, or a placebo for 12 weeks. The study found that for both flaxseed and borage oil groups, skin reddening was diminished, while skin hydration was significantly increased after the 12 week treatment period. They also found that the roughness and scaling of the skin was significantly decreased after 12 weeks - concluding that flaxseed and borage oil supplements significantly improved skin conditions in women.  Another study found that female volunteers with dry and sensitive skin supplementing Gamma-linolenic acid (GLA) had improved skin barrier function as early as 6 weeks of treatment, and the improvements continued through the 24 week trial period. 
Despite the overwhelming clinical evidence supporting the benefits of borage seed oil for improving skin conditions, I did run in to one study where it had contradictory results. In a randomized double blind, placebo controlled study, 151 patients (including 69 children) received borage oil twice daily (920mg GLA). Children received half doses. After the 12 week trial period, they did not report a significant difference between treatment group and the placebo group - showing that GLA did not improve atopic dermatitis (eczema).  Of course, this is just one borage oil study that did not find any benefits of supplementing GLA. There are dozens of other studies where GLA was found to have significant benefits for skin conditions. For example, a study of GLA effects on atopic dermatitis (eczema) was conducted on 32 children aged 1 to 10 years old. 16 children were given undershirts coated with borage oil for 2 weeks, and 16 children wore non-coated shirts as a placebo. The children who wore borage oil coated undershirts had significant improvements in their erythema (skin redness) and itch - providing further evidence that borage seed oil is effective for treating eczmea in children. 
Gamma Linoleic Acid (GLA) and Weight Loss
The GLA in Borage oil is more commonly known to help improve various skin conditions, so many may not know about its uses for weight control. Various studies have found GLA to help reduce weight gain and reduce body fat mass. One study done at the University of California found that GLA supplementation helps suppress weight regain after major weight loss.
In this study, 50 obese individuals were given either 890 mg/d GLA (5g borage oil) or 5g/d olive oil for one year. Body weight, body composition, and adipose fatty acids were assessed at 0, 3, 12, and 33 months. They found that weight regain was significantly less for the Borage oil group compared to the control group. The Borage oil group had average weight regain of just 2.17kg compared to 8.78kg weight regain for the control group.  Seeing that weight regain is an issue that many people face after losing much weight, its ability to minimize weight regain could put Borage seed oil as a potential supplement for weightloss programs.
Other studies involving elderly subjects found that consuming Borage oil had an effect on fatty acid metabolism, and at the same time improve skin functioning for the elderly. 29 healthy elderly subjects (average age 68.6 years) were given a daily dose of 360 or 720mg GLA for 2 months. About 34% of the participants who had an itch before treatment had no itch afterwards. Dry skin conditions were reduced from 42% to 14%. The fatty acid composition of erythrocyte membrane (outer structure of red blood cell) phospholipids demonstrated an increase of GLA and a reduction of saturated and monounsaturated fatty acids. 
Borage GLA and Hypertension
Borage GLA helps improve skin conditions, has weight management applications, and it also has blood pressure lowering benefits. In several studies involving hypertensive rats, researchers found that borage GLA works to lower blood pressure in hypertensive rats. [10, 11] In addition, it is worth mentioning that borage oil has been found to attenuate blood pressure and heart rate responses to stress. In a Canadian study, 30 men were supplemented with either borage oil, fish oil, or olive oil (placebo). Their reactivity to Stroop color word conflict test was assessed. The study found that borage oil reduced the blood pressure and heart rate response to stress in the subjects, and it also improved task performance - making a conclusion that borage oil maybe also help alter stress reactivity in man and help improve performance. 
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