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 also are 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.
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.
According to an analysis of several studies conducted by researchers at Harvard School of Public Health and published in the journal Pediatrics, the authors found that healthy pre-term infants who were fed DHA-supplemented formula showed significantly better visual acuity at 2 and 4 months of age, compared with similar pre-term infants who were fed formula that did not contain the omega-3 supplement.
Adequate amounts of DHA and other omega-3 fatty acids in the diet of pregnant women also appear to be important in normal infant vision development.
In a study published in the American Journal of Clinical Nutrition, Canadian researchers found that infant girls whose mothers received DHA supplements from their fourth month of pregnancy until delivery were less likely to have below-average visual acuity at 2 months of age than infant girls whose mothers did not receive the omega-3 supplements.
DHA (docosahexaenoic acid, 22:6n-3) is a physiologically-essential essential nutrient and a key omega-3 fatty acid needed in high levels in the brain and retina (eye) for optimal neuronal functioning (learning ability, memory) and visual acuity, respectively.
For breast-fed infants, their only source of nutrition (incl. DHA) for growth and development is their mother’s milk. The amount of DHA in the diet is a major factor determining how much DHA appears in breast milk for the baby to consume for health. Since fish is by far the predominant food source of dietary DHA, and since fish is consumed at a very low rate (approximately one serving every 10 days), the level of DHA in North American breast milk is very low. For example, Health Canada has reported that DHA represents an average of only 0.14% of the total fat in breast milk. This low level reflects the low dietary intake of DHA during lactation of approximately only 80 mg/day.
Dietary Sources of Omega-3 DHA
- Fish: Fish is the best dietary source for DHA. The amount of DHA you eat directly influences the level of DHA in breast milk and blood. “Fatty,” “oily,” and “cold-water” are terms used to describe fish with higher levels of EPA+DHA. Most fish are safe for you to eat; however, the FDA and EPA recommend that pregnant and lactating women avoid eating Swordfish, King Mackerel, Tilefish and limiting Albacore Tuna intake due to their higher mercury levels. A list of fish with high DHA and low mercury is included in the report you receive with your MM-DHA Test results.
- Supplements: Fish oil supplements are a safe and potent source of DHA. The source and form of the DHA in the supplements affect how well you absorb the omega-3s, as well as whether or not you take them with food. There are also vegan/vegetarian supplements in which DHA is produced by algae. It is also important to look at the label for the amount of DHA (rather than general “omega-3s”) that the supplement contains. For example, many supplements are 1,000 mg of fish oil but only contain 120 mg of DHA.
- Plant Omega-3s: Plant-sources of omega-3s, such as walnuts, flaxseed oil and chia or flaxseeds, contain the omega-3 ALA. To a small extent, this omega-3 can be converted into EPA (and to an even smaller extent, DHA). It is much more effective to consume pre-formed DHA to raise breast milk DHA levels. Plant-based omega-3 sources are still healthy food choices, but they will not raise your breast milk DHA or your Omega-3 Index.