Wakame Nutrition Facts and Health Benefits

Wakame (Undaria pinnatifida) is a bright green, edible seaweed with a distinctive flavor and texture. The sea vegetable is one of the three most common seaweed varieties in Japan and is commonly grown in Japan and Korea. Wakame can be eaten on its own but is often added to miso soup, stir fry dishes, and salads.

Like most seaweed, wakame is considered to be good for your body and good for the environment. It's versatile, easy to add to your diet, and low in calories, carbohydrates, and fat.

Wakame Nutrition Facts

One serving of wakame (2 tablespoons or 10g) provides 4.5 calories, 0.3g of protein, 0.9g of carbohydrates, and 0.1g of fat. Wakame is an excellent source of iodine, manganese, magnesium, and calcium. This nutrition information is provided by the USDA.

Carbs

Wakame, like all seaweed, is very low in carbohydrates. A typical serving measuring 2 tablespoons provides less than 1 gram of carbs. But even a more substantial 1/2 cup (100-gram) serving provides only about 9 grams of carbs. Most of the carbohydrate is starch. There is less than 1 gram of fiber and less than 1 gram of sugar in a serving of wakame.

The estimated glycemic load of wakame is zero if your serving size is 2 tablespoons. The 100-gram serving has a glycemic load of 4, making it a low glycemic food.

Fats

There is almost no fat in wakame seaweed. Even the larger serving has less than 1 gram of fat, and most of that is healthy polyunsaturated fat.

Protein

Wakame can boost the protein content of your favorite soup, salad or entree, depending on how much you use. A small serving has less than 1 gram of protein, but the larger 100-gram serving provides 3 grams of protein.

Vitamins and Minerals

Wakame is a good source of iodine, providing about 42 micrograms per gram of seaweed. A 2-tablespoon serving would provide 420 micrograms of iodine, or nearly three times the recommended daily intake for adults. Other minerals in wakame include manganese, magnesium, and calcium.

Wakame also provides vitamins. Each 2-tablespoon serving of wakame provides 5% of your recommended daily intake of folate. It also provides smaller amounts of vitamin C, vitamin K, vitamin A, vitamin E, and pantothenic acid.

Calories

One 10-gram serving of wakame provides 4.5 calories, making wakame a low-calorie food.

Health Benefits

Wakame is often promoted as a weight loss aid and even as a potential treatment for obesity, diabetes, cancer, cardiovascular disease, and other chronic conditions. There is some research to support these claims.

Delivers Antioxidant Properties

Fucoxanthin, a compound found in wakame, is the subject of several research studies investigating potential health benefits. Fucoxanthin is a carotenoid that provides antioxidant benefits and is believed to provide other advantages as well.

However, research investigating these benefits is still in the early stages. While scientists point out that there are no side effects to wakame consumption and fucoxanthin can be easily extracted from sea vegetables, there are not enough human studies to confirm these benefits.

Regulates Thyroid Hormones

The iodine in wakame can boost your health. Your body needs iodine to make thyroid hormones, which help regulate metabolism and are essential for bone and brain development during pregnancy and infancy. If you don’t get enough iodine, a goiter—or enlarged thyroid gland—may develop. It is often the first sign of hypothyroidism.

It is also possible, however, to get too much iodine. If you consume too much iodine on a regular basis, thyroid hormone synthesis is inhibited. Too much iodine can cause the same symptoms as iodine deficiency, including goiter, elevated TSH levels, and hypothyroidism.

May Increase Longevity

Studies have shown that iodine levels among Japanese people who consume nori, wakame, and kelp (all types of seaweed) average 1,000 to 3,000 micrograms per day. Some health experts associate the higher iodine intake with health benefits seen in Japanese populations, including a longer average life expectancy, a lower risk for certain types of cancer, and fewer heart-related deaths in people ages 35 to 74.

Supports Digestive Health

Seaweed varieties, including wakame, boast essential amino acids, as well as a host of vitamins. A 2011 scientific review examined the potential gut benefits of seaweed and found that regular consumption may improve digestive health in humans.

May Prevent Diabetes

Studies from 2019 have shown that consuming wakame can help in balancing postprandial (post-eating) blood glucose and insulin levels. The 26-subject study found that subjects' levels of blood glucose were much lower when consuming a meal of rice and wakame rather than a meal of only rice. Consuming wakame regularly may have a positive effect on preventing prediabetes.

Allergies

According to the American Academy of Allergy, Asthma, and Immunology, there are rare cases of seaweed allergy. However, there have been published reports of iodine-rich foods such as wakame causing skin rash or other reactions in sensitized individuals.

Those with seafood allergies may be concerned about consuming seaweed or other sea vegetables like kelp or kombu. These foods do not contain fish protein, which is what generally causes an allergic reaction. But experts still advise caution when trying seaweed for the first time.

Adverse Effects

While wakame is overall healthy and packed with nutrients, you should beware consuming large amounts of this, and other, seaweed because of its iodine content. U.S. health officials have established the upper limit for adults at 1,100 micrograms of iodine per day (it would take about 26 grams of wakame to reach that amount).

Seaweed supplements are available. However, there isn't strong evidence to show any benefit. And there may be cause for concern. There is little legislation requiring food or supplement companies to disclose mineral, heavy metal, or iodine content of seaweed products or to provide guidance on a safe portion size to prevent excessive intakes.

If you are interested in the potential health benefits of wakame, it's best to eat the food in its whole form, rather than as a supplement. This allows you to consume the fiber and protein it provides along with the vitamins and minerals.

Varieties

Wakame is often compared to another seaweed called alaria. These two seaweeds can be used interchangeably in recipes. Wakame has a softer taste and texture as compared to nori and is much more mild and sweet than kombu.

In terms of nutrition, kombu has the highest iodine content. But even among these three popular varieties, the nutritional content including the iodine content can vary depending on species, harvest location, and preparation.

When It's Best

Wakame is available year-round in many supermarkets and specialty grocery stores. While you might be able to eat seaweed that you harvest on the beach, it is not recommended simply because there is no way of knowing if the sea vegetable has been exposed to pollutants or other contaminants.

Storage and Food Safety

Dried wakame should be stored in an air-tight container in a cool and dry place (like a pantry or cabinet) and can last up to a year.

How to Prepare

Cooking with wakame or any seaweed is relatively simple. You'll find seaweed sold in sheets or dried and packaged in many grocery stores. If you buy it fresh, you'll need to clip the blades and hang them to dry yourself. You can keep the blades whole or process with a spice grinder to toss into soups or salads.

In general, cooking seaweed reduces its iodine content. You may also eat more seaweed after it has been boiled as the texture softens, making it easier to consume. 

Some cooks combine wakame with other ingredients that provide flavor and texture, such as shrimp, cucumbers, cabbage, or sauerkraut. You can also eat it alone as a salad topper with sesame seeds or crushed peanuts.