In infancy and early childhood, fats are especially important, giving concentrated energy needed for rapid growth. Fat also provides essential fatty acids, it is necessary for the absorption of fat soluble vitamins such as A, D, E and K, and for fat-soluble antioxidants.
Not all fats are the same however, and not all are equally useful. Fats are usually divided into three types according to the chemical structure of their fatty acids – saturated, monounsaturated and polyunsaturated.
Polyunsaturated fats include two major families of essential fatty acids: Omega-3’s and Omega-6’s. Like minerals and vitamins, the Omega fats are essential to health. Our body cannot make them and relies on food to obtain them.
The Omega-3 family
- Alpha-linolenic acid (ALA) – occurs in oils such as canola, linseed, walnut and soybean as well as green vegetables.
- Eicosapentaenoic acid (EPA) – can be produced in the body from alpha linolenic acid. Found in fish oils, fish and seafood (and in small amounts in lean red meat).
- Docosahexaenoic acid (DHA) – high levels in tuna oil, smaller amounts in other fish oils, fish and seafood. Breast milk is rich in DHA.
Omega-3 fatty acids are incorporated into every cell in the body. They have many important functions, including development of the brain, eye and nerve tissues, promoting healthy blood flow and reducing inflammation.
The Omega-6 family
- Linoleic acid (LA) – a major component of oils (safflower, sunflower, corn, soybean, peanut, grapeseed) and present in grains, many nuts, seeds and wheatgerm.
- Gamma-linolenic acid (GLA) – can be made in the body from the parent compound LA. GLA is the active component of evening primrose oil.
- Arachidonic acid (AA) – made from GLA. Like DHA, AA is found in breast milk.
Omega-6’s, although chemically similar to the Omega-3’s, act differently, and generally in opposite ways to the Omega-3 fats. The body needs both of these nutrients in the right balance to function effectively.
I am pregnant and am not sure about Omega fats – can you tell me more?
During pregnancy, Omega-3 DHA and Omega-6 AA, are vital for formation and growth of the brain. (the baby’s brain grows rapidly in the last trimester and doubles in size in the first year of life). These essential Omega fats are supplied first from the mother’s blood, then from breast milk.
Your dietary intake of Omega-3 DHA in particular, during pregnancy and lactation, affects both your own and your baby’s health and nutritional status.
Foods that provide Omega-3 Fatty Acids
- Oily fish e.g. canned sardines, mackerel, fresh tuna and salmon.
- Listeria Food Safety Warning – during pregnancy avoid uncooked fish and chilled, precooked seafood products.
- Fresh gurnard, kahawai, mullet, trevally.
- Most white fish (e.g. hapuku, ling, orange roughy, snapper) have an Omega-3 content less than a quarter of that of oily fish.
- The NZ Food Safety Authority advise that while mercury levels in fish are very low, some fish types should be limited, especially by pregnant woman. See NZFSA booklet, Food Safety in Pregnancy, for more details.
- Omega-enriched eggs, Omega-enriched milk, lean beef and lamb also provide small amounts.
- Linseed (oil or ground), canola oil and canola- based spreads, soy, wheat germ, baked beans.
- Omega-3’s from plants are not as efficiently used by the body as Omega-3’s from fish.