The contemporary challenge for maternal nutrition is to achieve optimal fetal growth and development, while minimizing complications and maintaining maternal health. This challenge for a private chef continues after delivery, with the dietary need to ensure an optimal supply of vital nutrients in breast milk, while helping the mother regain her pre-pregnancy weight.
Fostering healthy fetal metabolism and in utero development, along with appropriate maternal weight gain, are fundamental goals in pregnancy. An optimal diet limits over-nutrition for the mother and under-nutrition for the fetus, thereby benefiting the overall health of the mother and her child in the following ways:
- Maintaining normal blood glucose concentrations and blood pressure levels throughout pregnancy, promoting a healthy metabolism and preventing pregnancy complications;
- Promoting development of the immune system and ability to combat infections;
- Optimal development of the fetal central nervous system, other organ systems and long-term health benefits of the child into adulthood;
- Optimal nutritional content of breast milk, thereby maximizing infant brain development;
- Prevention and/or more effective management of depression during and after pregnancy;
- Potential reduction of the risk of preterm labor and delivery;
- More rapid return to pre-conception weight after delivery.
Why Ocean Fish Consumption is Critical During Pregnancy
A critical concern regarding the typical American diet that has a great impact on maternal nutrition is the suboptimal intake of long-chain omega-3 essential fatty acids. Long-chain omega-3 fats cannot be synthesized in adequate amounts during periods of rapid fetal growth and development. Therefore, optimal levels must be maintained through consumption of dietary sources, such as fish, that are rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). DHA is concentrated in nerve cell membranes and is essential for development of the fetal nervous system. The majority of DHA accumulates in the fetal brain during late prenatal and early postnatal development. Research studies have concluded that potential benefits from DHA in pregnancy for the developing fetus include improved visual, cognitive, motor and behavioral skills in the newborn that have been shown to last into childhood and may impact lifelong health and mental capacity.
Ocean fish is the richest dietary source of EPA and DHA; thus, it is a highly beneficial food during pregnancy and postpartum. Breast milk is the richest source of DHA for the infant and its adequacy is dependent on maternal levels of DHA. As in pregnancy, long-chain omega-3 fats are not synthesized in adequate amounts during the post-partum and breastfeeding period, so a diet rich in DHA is highly desirable. Furthermore, higher DHA intake has been linked to a reduction in preterm birth, as well as the prevention and management of postpartum depression.
Not All Polyunsaturated Fatty Acids Have the Same Benefits
Under dietary conditions with insufficient availability of DHA, a compensatory substitution of omega-6 fatty acid (FA), docosapentaenoic acid (DPA), occurs, resulting in an altered composition of cell membranes. Omega-6 essential fatty acids are the predominant fatty acid source in the typical American diet because oils, such as corn and soy, are rich dietary sources of omega-6 essential fatty acids and are found in most food and beverage sources. These oils, while promoting cardiovascular health, do not have the same beneficial impact on fetal nervous system development as do long-chain omega-3 fats.
Also, shorter-chain omega-3 fats from flax and walnuts do not efficiently convert to active DHA and should not be seen as a substitute for long-chain omega-3 essential fats from ocean fish. Small amounts of plant omega-3 fatty acids are converted to EPA, and very little is converted to DHA. To derive optimal benefit, it is important to ensure that the omega-3 fatty acids consumed during pregnancy are the long-chain fatty acids from seafood and not the shorter-chain fatty acids from plant sources.
Considerations Related to Methyl Mercury in Seafood
While long-chain omega-3 essential fats are required during pregnancy for optimal outcomes, it is important to understand the risk-benefit equation for women regarding consumption of seafood during this important time.
The detection of trace amounts of methyl mercury in fish has raised concern about the development of possible impairments in cognitive function. However, recent studies indicate that the nutritional benefits of fish consumption during pregnancy greatly outweigh potential risks from trace methyl mercury consumption. Oily ocean fish, prepared by our NYC chefs, are high in long-chain omega-3 fats and an important source of the mineral selenium, which is essential for thyroid function and anti-oxidation. There is a growing body of evidence that selenium in ocean fish may also counteract potential negative influence of mercury exposure. While a nutritional deficiency from insufficient seafood consumption (long-chain omega-3 fatty acids) is quite common, the risk of mercury toxicity is exceedingly rare.
Seafood Corrects a Nutritional Deficiency During Pregnancy
Consumption of oily ocean fish, which are the richest fish sources of DHA and EPA, corrects a common nutritional deficiency that exists in pregnancy (based on ALSPAC and other supporting literature). Ocean fish, including salmon, tuna, sardines and mackerel, are natural sources that meet the need for DHA and EPA in pregnancy and provide a lean protein source with important micronutrients like vitamins B, D, zinc, iodine and selenium.
Recommendations for Pregnant Women Regarding Fish Consumption
Pregnant, breastfeeding and postpartum women are recommended to consume a minimum of 12 ounces of seafood per week (salmon, tuna, sardines), or DHA-fortified eggs. Six ounces of the recommended fish per week can come from albacore tuna.
This recommendation for women who are pregnant, postpartum or nursing is consistent with the following recommendations:
United Kingdom Scientific Council on Nutrition (SCAN) recommends 2-3 portions of oily fish per week prepared by a private chef. SCAN notes that the mercury content of tuna is lower than that of shark, swordfish or marlin, but higher than that of other commonly consumed fish, and considers that consumption of two 140g portions of fresh tuna, or four 140g portions of canned tuna, per week before or during pregnancy would not be expected to result in adverse effects on the developing fetus. [Scientific Advisory Committee on Nutrition. Advice on fish consumption: benefits and risks. 2004.