Essential Fatty Acids for Eye Health

You may find it hard to believe that fat is essential to your health, but it's true. Without fat, our bodies can't function properly. And without the proper kinds of fats in our diet, our eye health also may suffer.

Fatty acids are the "building blocks" of fat. These important nutrients are critical for the normal production and functioning of cells, muscles, nerves, and organs. Fatty acids are also required for the production of hormone-like compounds that help regulate blood pressure, heart rate, and blood clotting.

Some fatty acids — called essential fatty acids (EFAs) — are necessary to our diet, because our body can't produce them. To stay healthy, we must obtain these fatty acids from our food.

The two types of EFAs are omega-3 fatty acids and omega-6 fatty acids. Studies have found that omega-3 fatty acids, in particular, may benefit eye health.

Essential fatty acids are critical for proper visual development in infants. Also, deficiencies of omega-3 fatty acids in adults (particularly omega-3) can lead to impaired vision. Studies suggest that prolonged deficiencies may increase the risk of damage to the retina. EFAs also play a role in helping eye fluids (aqueous) drain, which helps regulate intraocular pressure.

In 2007, a large multi-site study found that people who eat at least two servings of fish weekly are less likely to develop age-related macular degeneration (AMD), the leading cause of irreversible vision loss among people over 65 in the United States.

Those in the study who consumed the highest levels of omega-3 fatty acids, primarily from fish, had a 39 percent lower risk of AMD compared with those who ate the least fish (Archives of Ophthalmology, May 2007).

In a 2005 study, researchers found that the amount, type, and ratio of essential fatty acids in the diet may play a key role in the prevention of dry eye syndrome in women. Among other findings, the study, conducted at Brigham and Women's Hospital in Boston (a teaching affiliate of Harvard Medical School), showed:

• Women with the highest levels of omega-3 fatty acids in their diets reduced their risk of dry eye syndrome (DES) by 20 percent, compared with women with the lowest levels of omega-3 in their diet.
   
• A dietary ratio of omega-6 to omega-3 fatty acids greater than 15:1 was associated with a 2.5-fold increased risk of DES in women.
   
• Women who reported eating at least five servings of tuna per week had a 68 percent reduced risk of DES, compared with women who consumed one serving per week.
   
• Other fish types that have lower levels of omega-3 fatty acids did not appear to protect against dry eye syndrome.
   

What amount of fatty acids do you need?

While both omega-3 and omega-6 fatty acids are important to health, the balance of these two types of EFAs in our diet is extremely important.

Most experts believe the ratio of omega-6 to omega-3 fatty acids we consume should be 4:1 or lower. Unfortunately, the typical American diet, characterized by significant amounts of meat and processed foods, tends to contain 10 to 30 times more omega-6 than omega-3 fatty acids.

This imbalance of omega-6 ("bad") fatty acids to omega-3 ("good") fatty acids appears to be a contributing cause of a number of serious health problems, including heart disease, cancer, asthma, arthritis, and depression.

Page 2 of 2: Foods that contain each type of essential fatty acid