Allergic Rhinitis and Essential Fatty Acids (EFAs)

Essential fatty acids--EFAs for short--include the famous omega-3 and omega-6 fatty acids. EFAs are called "essential" because our bodies need them but cannot make them, so they must be obtained from our diet. Some health practitioners recommend increasing your intake of EFAs, through diet and/or supplements, as a treatment for allergic rhinitis and other conditions that involve the body's inflammatory response.

The body uses essential fatty acids (EFAs) to make various prostaglandins and leukotrienes. These substances influence inflammation and pain; some of them increase symptoms, while others decrease them. Taking EFAs may swing the balance over to the more favorable prostaglandins and leukotrienes, making it helpful for diseases that involve inflammation, including allergic rhinitis. (The body's inflammatory response is the basis for many of the bothersome symptoms of allergic rhinitis.)

Read more details about Essential Fatty Acids (EFAs).

Although many people experience positive results by supplementing with EFAs, especially omega-3s, there is not much research evidence supporting the use of EFAs to treat allergic rhinitis.

A 2009 review of 6 high-quality trials with over 1,000 children found that neither omega-3 nor omega-6 oil consumption prevented allergic diseases in high-risk children. Allergic diseases included eczema, asthma, allergic rhinitis or food allergy; and omega-3 and omega-6 sources included gamma-linolenic acid (GLA), fish oil, canola oil, and borage oil.⁷¹

Food sources of EFAs include:

• fish (especially cold-water fish) and shellfish
• meat, dairy and eggs from grass-fed and pastured animals
• flax, hemp and chia seeds (and their oils)
• pumpkin and sunflower seeds (and their oils)
• walnuts (and walnut oil)
• leafy vegetables
• soy

Supplement sources of EFAs include:

• fish oil
• borage oil
• evening primrose oil
• black currant oil

The body probably absorbs the EFAs from animal sources (such as fish) more readily because plant-based sources contain fatty acids that require extra metabolic processes before they become the long-chain fatty acids DHA and EPA.

Also, many experts suggest that most Americans already get plenty of omega-6 fatty acids in their diet and instead need to focus on increasing their intake of omega-3's, especially from fatty, cold-water fish (like salmon) and fish oil.

Nutritionists and health practitioners who specialize in nutrition, such as some naturopathic doctors, would be good sources of information on using EFAs to treat allergic rhinitis.

EFAs and their sources are generally regarded as harmless, except when there might be a food allergy involved (such as an allergy to shellfish). One concern with fish and fish-oil supplements involves the accumulation of mercury, PCBs, and other environmental toxins. For information that can help you make safe fish choices, see the Environmental Working Group's "Fish List." For fish oil supplements, look for products that are certified to not contain high levels of environmental toxins.

Fish oil has a mild blood-thinning effect;² in one case report, it increased the effect of the blood-thinning medication warfarin (Coumadin).³ Fish oil does not seem to cause bleeding problems when it is taken by itself⁴ or with aspirin.⁵ Nonetheless, people who are at risk of bleeding complications for any reason should consult a physician before taking fish oil.

Fish oil does not appear to raise blood sugar levels in people with diabetes.⁶ Nonetheless, if you have diabetes, you should not take any supplement except on the advice of a physician.

Fish oil may modestly increase weight and lower total cholesterol and HDL (“good”) cholesterol levels.⁷ It may also raise the level of LDL ("bad") cholesterol; however, this effect may be short-lived.⁸ If you decide to use cod liver oil as your fish oil supplement, make sure you do not exceed the safe maximum intake of vitamin A and vitamin D . These vitamins are fat soluble, which means that excess amounts tend to build up in your body, possibly reaching toxic levels. The official maximum daily intake of vitamin A is 3,000 mcg for pregnant women as well as other adults. Look at the bottle label to determine how much vitamin A you are receiving. (It is less likely that you will get enough vitamin D to produce toxic effects.)

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