7 Common Foods That Contain Algae (and Whether You Should Avoid Them)

Algae is a type of seaweed commonly added to foods to help thicken and color them, as well as add some nutrients. Though it sounds questionable, algae is found in many different foods.

Some supplements can also contain algae or can be cross-contaminated with it. Fish oil and algae-based supplements are rich in omega-3 fatty acids. And because fish get their fatty acids from algae, seaweed can be present in fish oil supplements, according to the Seafood Nutrition Partnership.

Algae can also be eaten on its own. It is a natural source of many nutrients and is often sold in powdered form and used in green juices and smoothies.

When reading an ingredients list, you likely won't spot the word "algae." Instead, you'll have to look for ingredients that are extracted from sources of algae or the name of a type of algae.

Here's a list of the different names of algae, so you can easily spot algae on food labels:

• Carrageenan
• Algin
• Spirulina
• Chlorella
• Beta carotene
• Alginate
• Agar (or agar-agar)
• Kelp
• Seaweed

Carrageenan and algin are food additives extracted from sea algae, according to the U.S. Department of Energy. These are commonly used to thicken food products, including yogurt, baby formula and ice cream.

Although generally regarded as safe to eat, there are some concerns about the side effects of carrageenan, and some people choose to avoid it. Carrageenan is commonly found in dairy and non-dairy products like various milks, cheeses and creamers.

Other words to look out for include spirulina and chlorella. These are types of algae commonly used to make algae powders, capsules and other algae food products. Spirulina is a great source of protein, B vitamins, iron and beta-carotene, according to the Cleveland Clinic. Add it to smoothies and dips for extra nutrients.

While some foods obviously contain algae, such as dried seaweed snacks, it can be challenging to spot algae on all food labels. Familiarize yourself with the names of algae derivatives and food products that commonly contain them.

Some foods that contain algae include the following. Note that not all foods in these categories are guaranteed to contain algae — you still have to look at ingredient lists to confirm.

Dairy products are a common source of carrageenan, a thickening ingredient derived from red seaweed. You might find carrageenan in dairy products like yogurt, whipped cream, chocolate milk, cottage cheese, ice cream and coffee creamers.

Like dairy products, non-dairy alternatives may contain hidden sources of algae. Carrageenan and agar are also used to thicken foods such as almond milk, vegan cheese and non-dairy creamers.

Supplements like spirulina and chlorella powders are potent sources of algae. These supplements can be used to fill nutritional gaps.

"A 2-teaspoon serving of chlorella can pack in 60 percent of our daily needs for vitamin A and 70 percent of our daily needs for iron," says Mackenzie Burgess, RDN. "Although we shouldn't rely on chlorella to meet our daily needs for these nutrients, it can be an easy way to help fill in any gaps."

If you've had sushi, you've had algae. Sushi is made with nori sheets, a common algae product.

"Nori is made from red algae, which is a great source of B vitamins and calcium," Burgess says. "You can add it to sushi bowls, soup or hummus."

Nori is also the main ingredient in seaweed snacks. "By definition, seaweed is algae. You can buy ready-to-eat seaweed snacks. They're very low in calories, contain protein and are bursting with immunity-helping vitamin C," says Amy Gorin, RDN.

Some spices intended for seafood may contain algae. Because sea vegetables are a great source of iodine, many vegans eat algae food products like dulse flakes, agar powder and kelp granules. These can add flavor to food or be used for other purposes like thickening.

Kelp granules and dulse flakes are types of seaweed that can be sprinkled onto food to add salty, umami flavors and trace minerals.

Meat and fish products may also be a source of algae. Steaks, sausages and fish sometimes contain algae to improve their quality, according to a November 2018 review in ​Critical Reviews in Food Science and Nutrition​.

Baby food, Ranch dressing, packaged danishes and smoothies may contain sources of algae, like carrageenan, alginate and agar, according to the Cheadle Center for Biodiversity and Ecological Restoration.

The November 2018 review in ​Critical Reviews in Food Science and Nutrition​ also states that some cereal food products like pasta, flour and bread are enriched with algae.

Algae food products have both their advantages and disadvantages. Algae is a natural source of many nutrients, though more research is needed to determine the safety of various types of algae.

One limitation of foods that contain algae is their bioavailability in the digestive tract, according to an April 2017 study in the ​Journal of Applied Phycology​. Some people report having digestive discomfort after eating algae food products, and researchers call for more studies in this area.

If you have digestive issues after eating foods with algae, try avoiding them for a bit. Algae like spirulina may have side effects or contaminants, according to Columbia University.