With all the attention paid to omega-3 fish oils, it's easy to overlook gamma-linolenic acid, an omega-6 fatty acid with impressive anti-inflammatory properties.
What is GLA?
GLA is synergistic with omega-3s. It is a precursor to prostaglandin E1, which is an anti-inflammatory hormone-like compound. Production of GLA depends on the enzyme delta-6-desaturase. Unfortunately, D6D activity is inhibited by trans fats, alcohol and nutrient deficiencies and often appears weak in the best of circumstances. Supplemental GLA bypasses this bottleneck and increases production of dihomo-gamma-linolenic acid, the precursor to prostaglandin E1.
Why is GLA synergistic with omega-3s? Both substances increase production of prostaglandin E1, creating a two-pronged anti-inflammatory effect.
The research on GLA
GLA has broad-spectrum anti-inflammatory benefits and can help restore normal fatty-acid metabolism.
- Rheumatoid arthritis. GLA supplements significantly reduce symptoms of rheumatoid arthritis. Studies at the University of Massachusetts, Worcester, found that 1.4 and 2.8 grams of GLA daily led to a 25 percent to 45 percent reductions in symptoms.
- Overuse injuries. The Danish Olympic team uses a combination of GLA and omega-3 fish oils to treat inflammatory overuse injuries among athletes. The regimen—approximately 600 to 700 milligrams of each fatty acid—enables athletes to keep training as they heal.
- Psoriasis and eczema. GLA supplements may reduce symptoms of eczema and psoriasis. The beneficial amount appears to be between 275 and 345 milligrams daily. Adding 5,000 IU of vitamin D and 1,000 to 2,000 milligrams of omega-3 fish oils may enhance the benefits.
- Asthma. In a study at the University of Moncton, Canada, researchers gave GLA and EPA supplements to 35 people with mild-to-moderate asthma. After four weeks, the supplements led to a 54 percent improvement in symptoms, as well as a 54 percent reduction in the use of inhalant medications.
- Weight maintenance. Being overweight suggests disturbed fat metabolism. Just as trans fats promote weight gain, GLA can help people keep weight off. In a small study of people who lost weight, those who took GLA for one year regained only four pounds. In contrast, people taking placebos regained 17 pounds.
- Cancer. The most promising—and most experimental—use of GLA may be in the treatment of cancer. In an article in Medical Science Monitor, Dr. Undurti Das described cell, animal and human studies in which GLA was used to treat different types of brain cancer. In the three human studies, GLA was injected directly into the brain tumors, with individual dosages of 0.5 to 1 milligram and total dosages of GLA ranging from 4.5 to 20 milligrams over periods up to 20 days. The GLA led to significant reductions in tumor size without significant side effects, and most of the patients were alive and well at least three years after diagnosis. GLA also reduces the activity of HER2, a gene involved in aggressive breast cancers.
How to use GLA
GLA supplements are derived from borage seed oil, black currant seed oil and evening primrose seed oil. However, the amount of GLA is more important than the source. Read supplement labels carefully.
Tips for retailers
It is important to convey these two points to customers:
- Using GLA and omega-3 fish oils together will yield more impressive anti-inflammatory benefits than either supplement alone.
- Large amounts of GLA—several hundred milligrams daily—may be needed in cases of severe inflammation. It may be possible to reduce the dose after a month or two to save money. Jack Challem is a personal nutrition coach in Tucson, Ariz. E-mail him with "NFM" in the subject line at firstname.lastname@example.org.