August 20, 2015

Although the body readily makes most of the fat that it needs from dietary starch or sugar, humans lack the ability to make essential fatty acids (EFAs) and must get them from food or dietary supplements.

Essential fatty acids come in two distinct families, based upon their chemical structure. The two EFA families are not interchangeable and, in fact, tend to compete with one another in the body’s metabolic pathways.

The larger family, called "omega-six" EFAs, is abundant in many vegetable seed oils, including corn, sunflower and safflower. Deficiency of omega-six EFAs can cause impairment of growth and fertility, hormonal disturbances and immunologic abnormalities. But an excess of omega-six EFAs may promote the development of cancer. People living in North America and Europe often have relatively high levels of omega-six EFAs in their diets, because of the increased consumption of vegetable oil.

The smaller family, called "omega-three" EFAs, is most concentrated in fish oils and in flax seed oil. It is also found in green leafy vegetables. The human brain is rich in omega-three EFAs; their deficiency causes abnormalities in the development and function of the nervous system as well as immune defects. Consumption of fish, flaxseed meal and soy beans supplied omega-three’s for our ancestors.

There has been a systematic depletion of omega-three EFAs from the typical modern diet because of changes in food choices and in techniques of food processing. Some theorists have traced the origins of numerous different diseases to a lifetime depletion of omega-three EFAs.

Fish oils, the other concentrated source of omega-three’s, have made front page news because of their potential ability to help prevent disorders as apparently unrelated to one another as cancer, heart attacks, and migraine headaches, and to help reverse the effects of conditions as different as psoriasis, ulcerative colitis, rheumatoid arthritis and cystic fibrosis.

Some indications that an EFA deficiency or imbalance are present are: dry skin; the need to use moisturizing creams and lotions; "chicken skin", the presence of tiny rough bumps, usually on the back of the arms; dry hair; dandruff; fraying or brittle nails; menstrual cramps; premenstrual breast tenderness. Many people in the United States and Europe are short on omega-three EFAs and could benefit from having omega-three rich foods such as flaxseed, walnuts or salmon.