Genes May Affect Nutrients in Breast Milk
A woman's genes could affect the nutrients in her breast milk, say researchers.
The Tip of the Iceberg?
It's too soon to base dietary recommendations for pregnant and nursing women on the findings; more research is needed first, says Weinberg.
An expanded study is planned to examine the clinical impact of additional genes and their effects on prenatal storage of DHA and other omega-3 fatty acids in body fat, says the news release.
Dietary Sources of DHA
DHA is found in cold-water fish such as salmon and mackerel. It's also been studied for its effects on heart health, depression, and other conditions.
However, cautions have been raised about mercury levels in some fish. The U.S. government says that while fish have health benefits, high mercury levels make
The FDA and the Environmental Protection Agency offer these guidelines for those women:
- Do not eat shark, swordfish, king mackerel, or tilefish because they contain high levels of mercury.
- Eat up to 12 ounces (two average meals) a week of a variety of fish and shellfish that are lower in mercury.
- Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.
- Another commonly eaten fish, albacore ("white") tuna, has more mercury than canned light tuna. So when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.
- Check local advisories about the safety of fish caught by family and friends in local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't eat any other fish during that week.
The same recommendations -- with smaller portions -- apply to young children.
DHA is also found in fish oil supplements and in some infant formulas.