When you grill a piece of fish for dinner, you'll benefit from a good source of vitamins, healthy fats and important protein. And, if you're pregnant or nursing, that fish contains nutrition essential for the growth and development of your baby's brain and nervous system.
But you need to pay attention to the particular kind of fish you are eating. Eating the wrong type of mackerel in pregnancy could cause harm to yourself and your child because of the potential of mercury poisoning.
Yes, you can eat mackerel during pregnancy, but only certain types. For you and your baby's health, you can safely consume up to three servings of Atlantic or Pacific mackerel a week.
What Is Mackerel?
Mackerel, from the Scombridae family of fish, is found in both temperate and tropical seas. Mackerel has a strong, rich flavor and is popular in Japan, where it is used for sushi.
Among the most common types of mackerel, the Spanish mackerel is a tasty fish that is caught off the south coast of Florida. The Pacific mackerel is an abundant sport fish from the coast of California. Atlantic mackerel is the smallest and the healthiest fish for consumption and can be found from Labrador to North Carolina.
King mackerel, or kingfish, prefer the warm water of the Western Atlantic Ocean and Gulf of Mexico. Kingfish is the largest type, with an average weight of 10 pounds, and should be avoided due to contamination concerns.
How Much Should I Eat?
The Food and Drug Administration recognizes fish as beneficial to the health of pregnant women and young children. But it advises following the guidelines in accordance with consuming only certain species, due to the risk of mercury content in fish.
For women of childbearing age (16 to 49 years old), especially pregnant and breastfeeding mothers, the recommendation is to eat two to three servings of fish each week from the "best choices" list. Pacific mackerel and Atlantic mackerel are on this list as fish that are safe to eat. Children over 2 years of age can also eat one to two servings of fish from this list per week.
The FDA "good choices" list, which limits the recommendation to one serving a week, includes Spanish mackerel. _King m_ackerel is reported as "choices to avoid," due to the highest level of mercury that it may contain. The FDA advises women who may become pregnant, who are pregnant or nursing should not eat king mackerel.
Swim Away From King Mackerel
Mercury not only occurs naturally in the environment, industrial pollution can be a contributing factor. Mercury accumulates in streams and oceans and is turned into methylmercury in the water. Fish absorb the methylmercury as they feed and it builds up in their flesh. Species of large predator fish that are closest to the top of the food chain, such as king mackerel, have the highest level of mercury.
Although eating most mackerel fish can be a healthy addition to your diet, avoid king mackerel. King mackerel contains high levels of the toxic mercury. The U.S. Environmental Protection Agency reports that about 75,000 babies are born every year with an increased risk of learning disabilities because of mercury exposure from their mothers.
Negative Health Effects of Mercury
Mercury levels in fish may not affect everyone in the same way but are especially threatening to women who are pregnant or planning to become pregnant. Consuming toxic fish prior to pregnancy is as critical as exposure during pregnancy because mercury remains in the body for many months. Infants may ingest mercury through breast milk in addition to diet.
Methylmercury is a neurotoxin that can damage or impair functions of the brain and nervous system, according to a report by PEW on "Mercury and the Developing Brain." Unborn and young children are most vulnerable to mercury exposure. Mercury affects the developing brain, and can cause neurological problems that can affect vision, hearing, delays in motor-skill development, language acquisition and a wide range of learning difficulties once children attend school.
- Problems with peripheral vision
- Impaired sensation, especially on the hands, feet and mouth
- Difficulty with coordination and walking
- Impeded speech and hearing
- Reduction in muscle strength
Nutrition of Atlantic Mackerel in Pregnancy
If you stick to Atlantic mackerel, you will benefit from a good protein source in addition to a wealth of micronutrients and omega-3s with a safe mercury level. Atlantic mackerel is rich in niacin, phosphorus, vitamin B12 and selenium. These nutrients are essential, particularly for pregnant mothers, as they contribute to healthy fetal, infant and childhood development.
A review published in Nutrients in 2015 says the benefits of eating moderate amounts of fish during pregnancy outweigh any potential harmful effects to the neurodevelopment of infants. But the report emphasizes the importance of the type of fish consumed being low in mercury.
Go Fish For Omega-3s
Two key omega-3 fatty acids are EPA and DHA, which work in unison. EPA maintains heart health, inflammatory response and the immune system, while DHA is important for the brain, eyes and nervous system. Omega-3s may also prevent preterm labor and delivery, lower the risk of preeclampsia and increase birth weight.
All types of mackerel are fatty fish, which makes them a superior source of healthful polyunsaturated fats known as long-chain omega-3s. Just 3 ounces, or 85 grams, of cooked Atlantic mackerel contains 1,209 milligrams of omega-3 fatty acids. Omega-3s have been shown to reduce the risk of heart disease.
Preterm birth is a major cause of disability or death in the first 5 years of life. Because omega-3 in fish has been associated with longer pregnancies, a 2018 review analysed the effect of polyunsaturated fatty acids as a dietary benefit in relation to healthy outcomes for babies and mothers. The study, published in Cochrane Database of Systematic Reviews, involving almost 20,000 women, assessed the intervention of omega-3 from supplements and food. Researchers found the women who received omega-3 had a lower rate of preterm birth, longer length of pregnancy, reduced risk of low birthweight and a possible reduced risk of perinatal death.
Importance of Vitamin B12
Atlantic mackerel is exceptionally high in vitamin B12, supplying 16.2 micrograms or 269 percent of your daily value. A study, published in the American Journal of Epidemiology in 2017, showed evidence that a deficiency in vitamin B12 during pregnancy is also associated with increased risk of preterm birth and low birth weight.
If pregnant women or breastfeeding moms don't get enough vitamin B12 in their diet, their babies may suffer from a deficiency. NIH warns that infants with a B12 deficiency may fail to thrive, have problems with movement and experience delays in typical developmental milestones.
Riboflavin for Baby's Development
Atlantic mackerel contains 21 percent of the DV for riboflavin in a 3-ounce serving. Riboflavin, or vitamin B2, is an essential vitamin that helps your body produce energy which will be needed for delivering your baby. Riboflavin promotes your baby's bone, muscle and nerve development as well as giving your baby the benefit of good vision and healthy skin.
Phosphorus for Strong Bones
In addition to building strong bones in you and your developing baby, phosphorus aids in muscle contractions, blood clotting, proper kidney function and nerve conduction. In addition, phosphorus helps maintain and repair tissue and cells. Atlantic mackerel is an excellent source of phosphorus, supplying 236 milligrams or 24 percent of the daily value.
Selenium to Reduce Birth Complications
A mini-review from the Journal of Nutrition and Food Sciences in 2016 reports that a deficiency of selenium during pregnancy can lead to complications, including spontaneous abortion, preeclampsia and low birth weight. Atlantic mackerel is a good source of selenium and a 3-ounce piece of fish provides 44 micrograms, or 63 percent of your recommended daily intake.
- Food and Drug Administration: Eating Fish: What Pregnant Women and Parents Should Know
- NRDC: Mercury Guide
- Department of Environmental Conservation: Mercury in Fish
- PEW: Mercury and the Developing Brain
- Better Health: Mercury Exposure and Poisoning: Symptoms of Methylmercury Poisoning From Fish
- Nutrients: Fish Intake During Pregnancy and Foetal Neurodevelopment--a Systematic Review of the Evidence
- American Pregnancy Association: Omega-3 Fish Oil and Pregnancy
- SELFNutritionData: Fish, Mackerel, Atlantic, Cooked, Dry Heat
- Clinical Nutrition: Effects of Maternal Omega-3 Fatty Acids Supplementation During Pregnancy/Lactation on Body Composition of the Offspring: A Systematic Review and Meta-Analysis.
- Cochrane Database of Systematic Reviews: Omega‐3 Fatty Acid Addition During Pregnancy
- National Institutes of Health: Vitamin B12
- American Journal of Epidemiology: Maternal Vitamin B12 in Pregnancy and Risk of Preterm Birth and Low Birth Weight: A Systematic Review and Individual Participant Data Meta-Analysis
- NutritionalValue: Fish, Dry Heat, Cooked, Atlantic, Mackerel
- National Institutes of Health: Riboflavin
- Baby Center: Riboflavin in Your Pregnancy Diet
- Baby Center: Phosphorus in Your Pregnancy Diet
- Journal of Nutrition & Food Sciences: Selenium in Pregnant Women: Mini Review
- EPA: Mercury Emissions: The Global Context