Is It Safe To Eat Seaweed During Pregnancy?

✔ Research-backed

In recent years, seaweed has emerged as a superfood and has gained importance as a dietary supplement. But, you may not be sure of the safety of seaweed during pregnancy. Pregnant women should exercise caution while consuming it because it can have adverse effects on the growth of the fetus if taken in excess.

Although the right amount of seaweed is believed to be beneficial during pregnancy, you should consult a doctor before deciding to consume it.

Read on the types of seaweed, their health benefits during pregnancy, and the possible risks associated.

In This Article

Types Of Seaweed

Edible seaweed is of three types – the green, brown and red varieties. Green seaweed, also known as ulva or sea lettuce, is usually used in soups and salads. Brown seaweed again includes many varieties like wakame, kelp, arame and hijiki. Red type includes the variety nori that is used in making sushi and dulse. Dulse is a chewy reddish brown form used to make stews and soups.

Health Benefits Of Seaweed During Pregnancy

Seaweed is a part of Asian cuisine

Image: Shutterstock

Seaweed is a member of the algae family, and is a part of Asian cuisine. Just 2 tablespoons worth of serving seaweed could actually give your body a good dose of many important vitamins and minerals.

  • It has been found that seaweed is a rich source of antioxidants as well, which can protect the body against a wide range of illnesses, particularly arthritisiAn inflammatory condition characterized by swelling, stiffness, and pain in the joints. , celiac diseaseiAn autoimmune condition where the consumption of gluten causes health issues such as diarrhea, stomach pain, and fatigue. , obesity, asthma and even depression.
  • A few studies have also found that seaweed could be potentially useful in promoting the normal development of the sexual organs, thereby reducing the risk of breast cancer.
  • Seaweed has also been found effective in reducing the severity of PMSiA period before the menstrual cycle in females, marked by symptoms such as mood swings, irritation, and bloating symptoms, and is thought to improve female fertility as well (1).
Seaweed is good vitamin and fibre content

Image: IStock

  • Iron is also highly available in seaweed because of major vitamin C content in marine vegetables. Vitamin C helps to absorb and use more iron in the body. It is also rich in calcium, magnesium, folic acid, carotenoids, and DHA. The polysaccharides present in seaweeds also contribute significantly to their health-benefiting characteristics.
  • Seaweed is also a good source of omega-3 fatty acids which helps in a baby’s brain development.
  • The high fiber content helps treat constipation and also improves digestion ability.

Nutritional Content Of Dried Seaweed

Seaweed is rich in minerals such as calcium, potassium, magnesium, and sodium. These minerals are essential during pregnancy. The following table presents the nutritional value of 100 grams of dried seaweed (2).

NutrientsAmount (per 100g)
Water6.68g
Energy298Kcal
Protein31.84g
Total lipid (fat)4.01g
Carbohydrate, by difference52.39g
Fiber, total dietary5.6g
Sugars, total including NLEA3.04g
Calcium, Ca372mg
Iron, Fe24.95mg
Magnesium, Mg482mg
Phosphorus, P85mg
Potassium, K1244mg
Sodium, Na575mg
Zinc, Zn3.9mg
Copper, Cu3.355mg
Selenium, Se7.3µg
Vitamin C, total ascorbic acid5mg
Thiamin1.195mg
Riboflavin1.946mg
Niacin6.511mg
Vitamin B-60.334mg
Folate, total337µg
Folate, food337µg
Folate, DFE337µg
Choline, total64.6mg
Vitamin A, RAE14µg
Carotene, beta171µg
Vitamin E (alpha-tocopherol)5mg
Vitamin K (phylloquinone)25µg

Source: U.S. Department of Agriculture

protip_icon Nutrition fact
Seaweeds offer all the essential amino acids, including some that our bodies cannot synthesize (3).

Can Pregnant Women Eat Seaweed?

Take a physician’s advice before eating seaweed during pregnancy

Image: IStock

With its tempting health benefits, seaweed may sound like an ideal food to be consumed during pregnancy, considering the amount of nutrients that it has to offer. However, it is best to limit its consumption during pregnancy, and have a talk with your healthcare provider regarding the ideal dosage to be followed for the same.

According to the Food Standards Australia New Zealand, pregnant women must limit their consumption of seaweed to not more than one serving per week. This is because seaweed tends to contain unnaturally high amounts of iodine, which could be potentially dangerous if consumed during pregnancy.

Iodine is an important nutrient that the body needs to function properly, but if taken in excess, it could have a negative impact on the functioning of the thyroid gland. It has been found that pregnant women who consumed excess seaweed during pregnancy had babies that were ill.

Also, there is a possibility of contamination due to the presence of heavy metals. So be cautious! Take your nutritionist’s or your physician’s advice.

It is therefore best to stick to moderate consumption of seaweed in pregnancy, so that the excess iodine can be rapidly excreted from the body (4). Seaweed, when consumed in the right amount, could actually be helpful during pregnancy. Thanks to its high iodine content, seaweed could prove to be extremely helpful in preventing neurological impairment in the developing baby, and could positively affect the baby’s reading ability later in life.

An anonymous mother and blogger shares how consuming seaweed during pregnancy helped her maintain her iodine levels. She says, “My doctor insisted on checking my iodine level during pregnancy #3, as he had attended a seminar on the importance of sufficient iodine for pregnant women a few months previously. And every single one of his patients tested since had been extremely deficient.

“I assured him mine would be fine because I eat kombu (a kelp seaweed) all the time, but told him to go ahead and check anyway. When the results came back, he raised his eyebrows and laughed, ‘What did you say you were eating?’ ‘Kombu. Comb-oo.’ ‘OK, well, keep eating it! Your iodine levels are as high as a Japanese woman’s.’ Kombui is probably the easiest sea vegetable (seaweed) to use (i).”

Infact, a study conducted on Japanese women has revealed that the consumption of seaweed when pregnant could reduce the risk of depressive symptoms in women to a considerable extent (5).

protip_icon Quick fact
Green seaweed, nori, contains less iodine than brown seaweed. Since it has safer levels of iodine, it may be consumed more often than brown seaweed during pregnancy (4).

Possible Health Risks Associated With Seaweed

Seaweed may lead to thyroid disorders in pregnancy

Image: Shutterstock

Seaweed is a package of nutrient-dense food in small sizes, containing some nutrients in quantities that exceed our daily recommended intake. This is why consumption of seaweed on a regular basis could prove to be harmful, particularly for pregnant women.

According to Medline Plus, seaweed, owing to its high concentration of iodine, could be harmful for pregnant women. (6)

Seaweed is often used as a supplement and is believed to improve breast milk supply in lactating women, but daily intake could cause abnormally high levels of iodine in the body, which may in turn, affect the thyroid gland of both the mother and the baby, possibly even causing hypothyroidismiFailure of thyroid glands to produce sufficient thyroid hormones, leading to weight gain, tiredness, skin, and other body changes. in newborn babies. (7)

What’s more, a study has also pointed out to a strong association between the consumption of seaweed and a risk of thyroid cancer in women. (8)

A Delicious Seaweed Recipe

It is best to stick to minimal consumption of seaweed during pregnancy, if at all. Also, rather than taking vitamin or mineral supplements and buying risk to your health, you can get minimal necessary iodine from seaweed consumption.

Here is a great tasting seaweed salad recipe from epicurious that offers you a healthy iodine boost. Give it a try.

Ingredients to use:

  • Dried wakame seaweed – 3/4 ounce
  • Rice vinegar – 3 tbsp
  • Soy sauce – 3 tbsp
  • Asian sesame oil – 2 tbsp
  • Sugar – 1 tsp
  • Finely grated fresh ginger – 1 tsp
  • Minced garlic – 1/2 tsp
  • Tart apple – 1 small one (Granny Smith variety)
  • Thinly sliced scallion – 2
  • Chopped fresh cilantro – 2 tbsp
  • Toasted sesame seeds – 1 tbsp

Preparation Method:

  1. Soak dried seaweed in warm water for 5 minutes.
  2. Drain and squeeze out excess water and cut the seaweed into 1/2 wide inch strips.
  3. Stir all the ingredients mentioned above from vinegar to minced apple in a separate bowl.
  4. Dice tart apple into 1/4 inch and add to the above dressing along with the seaweed, scallions and cilantro.
  5. Toss the salad and top it with some sesame seeds.
Seaweed recipe to try when pregnant

Image: Shutterstock

Frequently Asked Questions

1. Is seaweed high in mercury?

The limited data that is available suggests that seaweed may have moderate amounts of mercury, depending on the location it is sourced from (9).

2. Why does seaweed have a lead warning?

Seaweed has a high concentration of lead, cadmium, and arsenic which are known as toxic metals. Lead is often associated with causing cancer and reproductive harm and hence, contains a warning sign (10).

Seaweed is a good source of antioxidantsiNatural or synthetic substances that may prevent or slow down cell damage caused due to harmful molecules called free radicals. , vitamin C, omega-3 fatty acids, and fiber. You may consider eating seaweed during pregnancy due to its nutritional value and beneficial effects on digestion and fetal brain development. However, due to its high iodine content and potential adverse effects on the thyroid gland, moderation is advisable to consume seaweed. But, one cannot rule out heavy metal contamination in seaweed, so it is best to include it in your pregnancy diet after consulting a doctor or a nutritionist.

Infographic: Seaweed Types And Why You Should Consume Them In Pregnancy

Seaweeds are a great source of nutrients essential for the mother and the growing baby when consumed in moderation. In this infographic, we shed light on the most common types of edible seaweeds and the various benefits they offer.

different types of seaweeds and their benefits in pregnancy (infographic)

Illustration: Momjunction Design Team

Key Pointers

  • Seaweed is a nutritious supplement, but pregnant women should be cautious due to potential fetal risks.
  • It is high in antioxidants, vitamins, minerals, fiber, and omega-3 fatty acids, and may aid PMS symptoms and fertility.
  • Pregnant women should limit seaweed consumption to one serving per week and consult a doctor.
  • Excessive consumption can be dangerous due to high iodine levels and potential heavy metal content.
  • Consuming seaweed in moderation during pregnancy can prevent neurological damage and enhance reading skills.
Seaweed During Pregnancy_illustration

Image: Stable Diffusion/MomJunction Design Team

Personal Experience: Source

References

MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
  1. The effect of Fucus vesiculosus an edible brown seaweed upon menstrual cycle length and hormonal status in three pre-menopausal women: a case report.
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC514561/
  2. Seaweed dried.
    https://fdc.nal.usda.gov/fdc-app.html#/food-details/2345512/nutrients
  3. The Science of Seaweeds.
    https://www.americanscientist.org/article/the-science-of-seaweeds#
  4. Seaweed.
    https://www.foodsafety.asn.au/topic/seaweed/
  5. Seaweed consumption and prevalence of depressive symptoms during pregnancy in Japan: Baseline data from the Kyushu Okinawa Maternal and Child Health Study.
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4161851/
  6. Fucus Vesiculosus.
    https://medlineplus.gov/druginfo/natural/726.html
  7. Warning to Pregnant and Breastfeeding Women: Seaweed Soup.
    https://www.mhcs.health.nsw.gov.au/publications/9120?collectionfilter=1
  8. Seaweed consumption and the risk of thyroid cancer in women: the Japan Public Health Center-based Prospective Study.
    https://pubmed.ncbi.nlm.nih.gov/22414981/
  9. Report Of The Expert Meeting On Food Safety For Seaweed.
    https://www.fao.org/3/cc0846en/cc0846en.pdf
  10. Sixty-day Notice Of Intent To Sue For Violation Of The Safe Drinking Water And Toxic Enforcement Act Of 1986
    https://oag.ca.gov/system/files/prop65/notices/2019-01265.pdf
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Shivani Sikri

Shivani SikriPublic health and Clinical Nutrition & Dietetics

Shivani Sikri is the chief nutritionist and co-founder of Nutri4Verve and holds about 13 years of experience in the field of nutrition. After completing her Masters, Shivani Sikri did a postgraduate in nutrition and health education, a postgraduate diploma in public health and nutrition (PGDPHN), and a postgraduate diploma in nutrition and clinical dietetics. She has also completed her certification...read full bio