Pregnancy and Fish May Not Mix

The health benefits offered by fish meat have long been praised. Low on harmful fats, but saturated with proteins and the much needed omega 3-fatty acids, health specialists have historically praised fish meat as a great way to receive much of the nutrition that a body needs. However, recent studies have also revealed a need for caution when consuming seafood products, as too much can also be harmful. While it has been a well known fact that consuming certain shellfish (clams, mussels, oysters, etc.) during certain seasons of the year could be harmful due to high levels of toxins, the dangers of consuming too much fish meat (regardless of the season of the year) has been a relatively new topic in the scientific world.

While some of the toxins (such as methylmercury) found in high levels in fish flesh is naturally occurring, other toxins are introduced to the marine ecosystem through toxic human waste in the water; these toxins can then enter humans after consumption of fish meat. While toxins such as mercury generally do not immediately reveal any ill effects on most of the adult population, the danger of such toxins is increased enormously in the body systems of children and fetuses. For this reason, pregnant women are advised to avoid consuming most sea foods, as the toxins could have a very harmful affect on their developing child.

A September of 2009 journal article titled "Maternal Levels of Xenobiotics that Affect Fetal Development and Childhood Health" points out that it is not only pregnant women who need to be concerned about possible toxins but also any woman who is of childbearing age, as the toxins tend to stay in a woman's body for an extended period of time; if such a toxins are left in a woman's body from consuming fish before she was even pregnant, they can still negatively affect her child. A 2003 Science Daily article states that it takes about one year for mercury to be cleansed from the body while it takes about six years to rid the body of polychlorinated biphenyls (PCBs), another common toxin in fish meat. The 2009 journal article lists "reduced cognitive and altered mood" as the adverse affects of offspring from women who tested positive for high levels of mercury in the merconium or cord blood. On the other hand, high levels of PCBs found in merconium or cord blood has been linked with the following: reduced infection fighting, recurrent infections, diminished IQ points, activity disorders, thyroid dysfunction, sexual changes, and hearing loss, according to the same journal article.

While the toxins found in fish are considered most harmful to developing fetuses (through pregnant or potentially pregnant women) and young children (who are also still developing), some fish are still considered dangerous for grown men as well. The Environmental Defense Fund (EDF) provides a helpful "seafood selector" on their website to help consumer's gauge the risks versus benefits for various sea foods. It is important to note that the location of the fish can be just as important as the type of fish itself. For example, while wild Alaskan salmon (which is full of long chain omega-3 fatty acids that are crucial for brain development in babies and cardiovascular health in adults) is considered safe to be a regular part of any adult's menu, farmed or Atlantic salmon is should only be eaten once a month. The relative cleanliness of the waters from which the fish are caught is the main contributor to this difference. Because of this, it is important for consumers to ask their grocers for the former location of the fish they are considering purchasing.

Sources consulted for this article:

Environmental Defense Fund: Seafood Selector Health Alerts

"Maternal Levels of Xenobiotics that Affect Fetal Development and Childhood Health" by Walter J. Crinnion, ND

Journal Subset: Alternative/Complementary Therapies; Double Blind Peer Reviewed; Editorial Board Reviewed; Expert Peer Reviewed; Peer Reviewed; USA

Source: Alternative Medicine Review (ALTERN MED REV), 2009 Sep; 14(3): 212-22

Science Daily: "Experts Say Consumers Can Eat Around Toxins in Fish" (Feb. 10, 2003)