6 Surprising Health Benefits of Seaweed

Updated: Apr. 19, 2021

Step aside, kale. Seaweed has health—and possibly weight loss—benefits that may have you craving sushi.

woman with measuring tape around her waist

Seaweed absorbs fat

Eating seaweed, which is not actually a vegetable at all but an algae, could help shrink your waistline. According to a 2016 study, algae can reduce the rate of fat absorption by 75 percent, by inhibiting the effect of the digestive enzyme lipase. The researchers believe that if the alginates can block the enzyme, the body will absorb less fat. “This is very exciting for people who struggle with managing their weight,” says Maria E. Rodriguez, RD, of Mount Sinai Diabetes Alliance in New York City.

woman doing yoga pose

Seaweed may strengthen bones

Seaweed is a non-dairy source of calcium. Two tablespoons of wakame seaweed, for example, provides 15 milligrams of calcium. Calcium is essential to increase bone growth and bone repair. As we age, our bone density decreases. For men, this generally happens around age 55 and for women, at the time of menopause, usually around age 51. Bone loss can lead to increased risks of fractures. Shoot for 1,000 to 1,200 milligrams of calcium a day. Here are the signs you could need more calcium.

seaweed on a plate

Seaweed contains iron

If you’re seeking more dietary sources of iron, kelp may be for you. “Kelp can be especially helpful for people following a diet with low or no animal proteins, as animal protein is a rich source of iron,” says board-certified sports dietitian Kylene Bogden. Kelp, a popular form of seaweed, contains 0.28 milligrams in a two-tablespoon serving. Devin Alexander, celebrity chef and weight loss coach, suggests using seaweed as a crunchy snack. “I’ve used it toasted and finely crumbled as a seasoning for popcorn along with a bit of cayenne.” He also enjoys toasting seaweed with seasonings to make DIY seaweed chips.

chopsticks taking vegetables out of a boiling pot

Seaweed may help with thyroid regulation

Seaweed, particularly wakame, provides about 164 micrograms of iodine, which is essential for a healthy thyroid. Our body depends on healthy thyroid function to manage metabolism. “Our bodies do not make iodine, so it’s important that we consume it through food,” says Bogden. One way to take advantage of the iodine in wakame is to add it to soup, suggests author and chef Matthew Robinson of culinaryexhange.com. Find out if your thyroid is out of whack.

doctor checking blood pressure of patient

Seaweed may help with blood pressure regulation

Uncontrolled high blood pressure hikes up your risk of heart attack or stroke. Consider stocking up on seaweed to keep yours in check. “One study in hypertensive patients found that 1.5 grams of pure chlorella per day resulted in decreased blood pressure over a six-month period, as well as lowered hypertension-related symptoms,” says Cassandra Suarez, RDN,  of Boston. Add chlorella, another type of seaweed, to a vinaigrette dressing to get the healthy benefits while masking its strong fishy taste. Adding a half-teaspoon to a serving of bottled dressing. Whisk, and add more powder if desired. These other foods can also help lower high blood pressure.

smiling woman with to-go coffee and phone

Seaweed may boost mood

The typical treatment for depression is antidepressant medication, but a 2015 study found chlorella might boost their effectiveness. The researchers found chlorella to have an effect on symptoms of depression and anxiety in patients who were taking antidepressants for major depressive disorder.