Also called sea vegetables or seaweed, sea greens are a new superfood landing on the wellness scene. And they may be a boon to your heart, your gut, and more.
If you keep tabs on the latest food trends, you’ve probably noticed an uptick in the popularity of sea greens. These days, you can pick up dried seaweed snacks at your local grocery store, snag a sea vegetable salad at certain restaurants, or try a sea greens powder in your daily fruit smoothie. And although sea greens, sea vegetables, and seaweed may each sound like unique foods, the terms are often used interchangeably. “Sea greens, sea vegetables, and seaweed are all terms that typically refer to a variety of edible plants that grow in the ocean or other bodies of water,” says Kayley Myers, RDN, who practices in in Springfield, Missouri.
Some common examples of sea greens include:
Culinary seaweed may be a relatively new idea for many Westerners, but greens from the sea have long been a staple in East Asian diets. According to a BBC News story, coastal-dwelling people have eaten these plants since prehistoric times — and for good reason. They’re packed with antioxidants, vitamins, fiber, and omega-3 fatty acids. “Their mainstream popularity is most likely due to their versatility in use, the health benefits they offer, and the environmental impacts supporting sea greens has,” says Kelsey Kunik, RDN, of Saginaw, Michigan, the founder of Graciously Nourished and a nutrition adviser for Fin vs. Fin.
Here are seven reasons why you might want to include sea greens in your diet.
1. Sea Greens May Support Heart Health
Fatty fish tend to hog the credit for their high levels of heart-healthy omega-3 fatty acids — but when it comes to these nutrients, salmon and tuna aren’t the only fish in the sea (so to speak). “Sea greens are one of the few plant sources of omega-3 fatty acids,” says Kunik.
A study published in the September 2019 Phycologia found that the majority of fats in seaweed are omega-3s, and other research, published in the International Journal of Environmental Research and Public Health in May 2021, notes that some red and brown seaweed varieties might provide omega-3s for dietary supplements. Higher omega-3 levels could support heart health by lowering triglycerides and reducing resting blood pressure, among other mechanisms, scientific evidence shows.
Still, more studies are needed to determine exactly how effective sea greens might be for achieving these effects. “Because of the small amount of sea greens we usually eat at one time, it’s not likely to be a significant source in the diet,” says Kunik. “It’s easier to get more sea greens in the diet when we eat them in dried form. One tablespoon of dried spirulina has .146 gram (g) of polyunsaturated fatty acids, an omega-3 fatty acid, per the U.S. Department of Agriculture (USDA).
2. Sea Greens May Improve Digestive Health
It’s well established that adequate fiber supports healthy digestion, feeding healthy bacteria in the microbiome and regulating bowel movements. The fiber in seaweed can help you reach your daily target. Ounce for ounce, seaweed is a higher source of fiber than many fruits and vegetables. According to a previous study, microalgae (yet another name for sea greens) is made up of 25–75 percent fiber by dry weight.
Even if you eat only small amounts of seaweed, it could still make a difference to digestive health. One study published in the International Journal of Biological Macromolecules in June 2018 found that sugars called sulfated polysaccharides in some brown seaweed positively altered the composition of gut microbiota. They also increased short-chain fatty acid production, which could have an anti-inflammatory effect in the gut, per research.
3. Sea Greens Could Promote Thyroid Health
If an underactive thyroid is a concern for you, you may want to consider using sea greens in your soups, salads, or smoothies. “Adequate intake of iodine is essential to produce thyroid hormones, and kelp, nori, arame, sea palm, and dulse are all sources of iodine,” as Myers and research note.
That said, Myers cautions it’s possible to overdo it on iodine from sea greens. “It’s important to note that more iodine isn’t always better,” she says. “Excess iodine intake can negatively impact thyroid health and lead to issues like hypothyroidism, hyperthyroidism, and goiter.” If you know your thyroid hormone levels are outside the normal range, talk to your doctor or a registered dietitian about the quantity of sea greens you can incorporate into your diet.
4. Sea Greens Could Fight Seasonal and Food Allergies
Future medications for the dreaded runny nose and watery eyes of springtime might include substances from sea greens. “There is some evidence that spirulina may help people with seasonal allergies,” says Myers. She points to a previous study published in the Journal of Medicinal Food, in which people with allergic rhinitis received a spirulina-based dietary supplement for 12 weeks. (Allergic rhinitis is another name for seasonal allergies that affect the nasal passages.) Afterward, they had reduced levels of interleukin-4, the cytokines involved in the development of seasonal allergies. In theory, this could mean that consuming sea greens — especially in supplement form — could reduce the severity of symptoms of seasonal allergies. Still, more studies are needed before firm conclusions can be drawn about how eating sea greens in their whole form might affect springtime hay fever.
Meanwhile, some animal research suggests seaweed may influence food allergies as well. In one study, researchers fed polysaccharides from a red seaweed known as G. lemaneiformis to a group of shellfish-allergic mice. Compared to a control group, the mice who received the seaweed extract ended up having reduced allergy symptoms. Research on the effects of sea greens on human food allergies is lacking, however, so it’s impossible to know for certain whether the same results hold true for people.
5. Sea Greens Could Help Manage Diabetes
According to a previous review, sea greens might be a tool in the treatment of type 2 diabetes because of their high levels of antioxidants, fiber, and unsaturated fatty acids. The review found that bioactive compounds in seaweed were effective at reducing inflammation and inhibiting enzymes that raise blood sugar after a meal. Though the research didn’t make clear how much seaweed would be necessary to achieve these effects, the results may pave the way for future studies that explore this potential link — and for people with diabetes, it certainly can’t hurt to incorporate sea greens into meals and snacks. Per the USDA, 1 cup of raw seaweed contains 33 calories, 2.8 g of protein, 0.4 g of fat, and 6.3 g of carbohydrates, making it a low-carb, diabetes-friendly food.
6. Sea Greens Help Detoxify the Body of Heavy Metals
There’s plenty of misinformation out there surrounding “detox” regimens, but it can sometimes be beneficial to cleanse the body of harmful substances. There’s some evidence that sea greens could do just that — when it comes to clearing the body of heavy metals, that is.
One review in a 2020 issue of the Journal of Environmental Pathology, Toxicology, and Oncology found that spirulina consumption alleviated the effects of arsenic, cadmium, mercury, and lead. And in one April 2019 Antioxidants study, 90 days of supplementing chlorella and another seaweed named Fucus spiralis helped decrease heavy metal levels in patients with long-term dental titanium implants.
“For people who are routinely exposed to heavy metals, providing a way to safely remove these from the body could improve various health outcomes, including improved bone health and reduced risk of certain autoimmune diseases,” says Kunik.
7. Sea Greens Are a Weight Loss–Friendly Food
On a weight loss diet, sea greens can be a convenient go-to food. At under 5 calories per 2 tablespoon serving, options like raw wakame, kelp, and spirulina certainly qualify as low-calorie, as USDA data attest. And because fiber makes up about 75 percent of their dry weight, they can be especially satiating. According to the Mayo Clinic, higher-fiber foods tend to be more filling than lower-fiber ones, keeping you satisfied longer.
The antioxidants in seaweed could also pave the way for weight loss. In a large study published in the June 2017 Obesity and that was conducted for eight years, people who had higher levels of inflammation were more likely to have higher weight gain and new-onset overweight or obesity. Adding sea greens to your diet could help quell the inflammation associated with these weight issues.
Are you looking to try sea greens for weight loss? You can experiment with them either dried or fresh. “If you are able to find fresh sea greens, add them to salads, soups, and ramen,” Kunik recommends. Or incorporate them into sushi or miso soup, suggests Myers. “You can also eat sea vegetables as part of a salad or sprinkled as a salty topping over your favorite dishes,” she says. When it comes to these versatile greens, there are as many varieties as there are ways to eat them.
The watching, interacting, and participation of any kind with anything on this page does not constitute or initiate a doctor-patient relationship with Dr. Farrah™. None of the statements here have been evaluated by the Food and Drug Administration (FDA). The products of Dr. Farrah™ are not intended to diagnose, treat, cure, or prevent any disease. The information being provided should only be considered for education and entertainment purposes only. If you feel that anything you see or hear may be of value to you on this page or on any other medium of any kind associated with, showing, or quoting anything relating to Dr. Farrah™ in any way at any time, you are encouraged to and agree to consult with a licensed healthcare professional in your area to discuss it. If you feel that you’re having a healthcare emergency, seek medical attention immediately. The views expressed here are simply either the views and opinions of Dr. Farrah™ or others appearing and are protected under the first amendment.
Dr. Farrah™ is a highly experienced Licensed Medical Doctor certified in evidence-based clinical nutrition, not some enthusiast, formulator, or medium promoting the wild and unrestrained use of nutrition products for health issues without clinical experience and scientific evidence of therapeutic benefit. Dr. Farrah™ has personally and keenly studied everything she recommends, and more importantly, she’s closely observed the reactions and results in a clinical setting countless times over the course of her career involving the treatment of over 150,000 patients.
Dr. Farrah™ promotes evidence-based natural approaches to health, which means integrating her individual scientific and clinical expertise with the best available external clinical evidence from systematic research. By individual clinical expertise, I refer to the proficiency and judgment that individual clinicians acquire through clinical experience and clinical practice.
Dr. Farrah™ does not make any representation or warranties with respect to the accuracy, applicability, fitness, or completeness of any multimedia content provided. Dr. Farrah™ does not warrant the performance, effectiveness, or applicability of any sites listed, linked, or referenced to, in, or by any multimedia content.
To be clear, the multimedia content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any website, video, image, or media of any kind. Dr. Farrah™ hereby disclaims any and all liability to any party for any direct, indirect, implied, punitive, special, incidental, or other consequential damages arising directly or indirectly from any use of the content, which is provided as is, and without warranties.