Algae Benefits, Nutrition, Types, Dosage and Side Effects - Dr. Axe

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Top 10 Algae Benefits that May Surprise You


Algae benefits - Dr. Axe

Algae are some of the most primitive life forms found on Earth and have been consumed for centuries due to the range of algae benefits for health.

Human consumption of the blue-green algae called spirulina (or blue spirulina) actually goes back to the Aztec civilization of the 14th century, and this type, including chlorella, is the edible variety most commonly used in supplements.

In fact, algae benefits are so pronounced — due to their high concentrations of vitamins, minerals, antioxidants and proteins — that they are commonly referred to as superfoods.

Brown algae, for example, have been used for weight loss, cancer, fibromyalgia, arthritis, stress, heart disease, high cholesterol and an array of other serious health conditions.

The blue-green variety is high in nutrients and also a very powerful energy booster. It’s used to naturally aid weight loss, hay fever, diabetes, stress, fatigue, anxiety, depression and premenstrual syndrome.


Blue-green algae have also been used to treat precancerous growths inside the mouth, improve memory and improve overall digestive health. Studies have indicated that the blue-green type has antiviral, antitumor, antioxidant, anti-inflammatory, antiallergic, antidiabetic and antibacterial properties as well.

It’s time we dive in to the world of algae benefits and talk about exactly what some of the scientific findings have been to date and why you might want to consider adding this primordial health aid to your daily routine.

What Are Algae?

What are algae (plural) or alga (singular)? Definitions vary, but they’re often thought of as simple aquatic plants that just aren’t very plant-like because they don’t have roots, stems or leaves while having primitive methods of reproduction.

Algae are members of a group of mainly aquatic photosynthetic organisms belonging to the kingdom Protista.

Some experts refer to algae as plants while others say they’re plant-like, but the cells have features that aren’t found among plants or animals.

The ecological role of algae is to produce oxygen along with providing a base for the ocean’s food pyramid.

Algae come in all different sizes, shapes, colors and growth forms. They can be single-celled or multi-celled and found in saltwater as well as freshwater.

Filamentous algae typically exist on the bottom of ponds where sunlight penetrates to the bottom. There are single-celled, protozoan-like algae mostly occurring in freshwater called euglenoids.

Then you have many named according to their colors, like blue-green, green, brown, golden-brown, fire, red and yellow-green algae.

Aphanizomenon flos-aquae (AFA) are one of the more commonly consumed edible species of blue-green algae. Aphanizomenon flos-aquae, also known as Klamath Blue Green Algae, flourish in the natural ecosystem of the Klamath Lake in the northwestern United States.

AFA is also sometimes called wild blue green algae, wild-crafted blue green algae and Klamath Lake blue green algae.

There are edible sea vegetables as well, also known as seaweeds, that are technically algae while phytoplankton are micro-algae and a type of plankton.

Algae contain chlorophyll, which is one of the reasons why they can be so beneficial to our health. Like plants, they use chlorophyll to trap the sunlight necessary for them to undergo photosynthesis, which is why chlorophyll is considered a “chelate.”

During photosynthesis, the energy absorbed by chlorophyll transforms carbon dioxide and water into carbohydrates and oxygen. A chelate is a chemical compound composed of a metal ion and a chelating agent that plays a vital role in oxygen transport and photosynthesis.

The chlorophyll found in algae is actually considered the single most important chelator found in nature, since it gives plants energy, which then give us energy. The very best sources of chlorophyll found on the planet are algae and green vegetables.


Nutrition Facts

Algae nutritional information varies by product, but here is a general idea of the typical nutrient profile.

In general, algae nutrition is as follows:

  • Protein and amino acids, up to 60 percent protein by dry weight
  • Vitamins A (beta-carotene), C (ascorbic acid), E and K
  • Many of the B-complex vitamins, including B1 (thiamine), B2 (riboflavin), B6 (pyridoxine), choline, biotin, niacin, folic acid, pantothenic acid and B12 (cobalamin)
  • Minerals and trace minerals, including iodine, calcium, chloride, chromium, copper, iron, magnesium, manganese, potassium, phosphorus, sodium and zinc
  • Omega-3 fatty acids, including EPA, DHA, GLA and ALA
  • Active enzymes
  • Phytochemicals like chlorophyll, fucoxanthin and other plant pigments

Here are a few of the most common types of seaweeds and algae that are used as foods and/or supplements:

The first land plants might have evolved from shallow freshwater algae almost 500 million years ago. Since that time, algae have continued to flourish, and their categorization continues to change as new molecular information is revealed by researchers.

The study of algae is called phycology, and a person who studies it is called a phycologist.

Back in the 1830s, the types began to be categorized according to their colors, like brown, red or green.

How do these types even get their colors? The colors are the result of various chloroplast pigments being reflected, including chlorophylls, carotenoids and phycobiliproteins.

There are many more groups of pigments in addition to brown, red and green.

Algae can also differ greatly in their cellular makeup. Many are only made up of one cell, while the largest varieties contain millions of cells.

It’s estimated that the term “algae” includes anywhere from 30,000 to over 1 million species.

Health Benefits

1. Weight loss

Algae benefits begins with weight loss. They’ve been shown to aid weight loss efforts, particularly the brown type that contains fucoxanthin.

What is fucoxanthin? It’s a naturally occurring carotenoid (pigment) found in brown algae that’s been shown to promote fat burning by increasing the expression of thermogenin.

Russian researchers published a double-blind, randomized, placebo-controlled study that used fucoxanthin for the first time in humans. This study looked at the effects of a supplement containing brown marine algae fucoxathin and pomegranate seed oil.

The subjects were 151 non-diabetic, obese, premenopausal women who took 600 milligrams of an extract that contained 2.4 milligrams fucoxanthin, which resulted in a significant weight loss compared with placebo by the end of the study.

Not only did the women taking the brown algae supplement lose an average of about 14.5 pounds in only 16 weeks, but the women taking fucoxanthin also experienced increases in resting energy expenditure, which also encourages fat burning and weight loss.

Meanwhile, they had positive reductions in many health markers, including liver fat, blood pressure, triglycerides and C-reactive protein.

2. Potential cancer fighter

Studies have shown that many types of algae may slow cancer cell growth in both animal and laboratory research, making them potential natural cancer treatments. Hopefully, there will be more human studies to confirm this potential cancer-killing ability.

Experimental animal studies have shown the inhibitory effect of algae on oral cancer, while a human study has shown its ability to fight precancerous mouth sores known as oral leukoplakia. These research findings published in Nutrition and Cancer show that taking one gram of spirulina (Spirulina fusiformis) daily by mouth for 12 months reduced oral leukoplakia in people who chewed tobacco.

This was the first human study showing the potential of Spirulina fusiformis to prevent cancer formation.

According to Memorial Sloan Kettering, animal studies suggest that spirulina has chemo- and radioprotective effects.

One study published in 2001 found that the polysaccharide of the Spirulina platensis acted as a chemo-protective agent with animal subjects, which means that it appears to have the ability to protect the body from or minimize the side effects of chemotherapy.

In addition, it also appears to possess a radio-protective capability, which means it can protect against the health-hazardous effects of radiation treatment. The study suggests its use as a potential add-on to cancer therapy.

Furthermore, antioxidants found in algal sources have been shown to help with the following cancers:

  • prostate
  • breast
  • melanoma
  • liver
  • colon
  • leukemia
  • and more

3. Heart health

A scientific review published in 2013 confirmed that blue-green algae can protect against cardiovascular disease and nonalcoholic fatty liver disease, which are two of the most significant threats to health in developed countries.

Overall, studies in cells, animals and humans have shown that dietary intake of blue-green algae can be “an effective natural product for improving blood lipid profiles and for preventing inflammation and oxidative stress,” which are all well-known contributing factors to the development of heart disease.

Specifically, the carotenoids, gamma linolenic acid (GLA), phycocyanin, fibers and plant sterols can be helpful in preventing heart disease as well as nonalcoholic fatty liver disease.

Algae have also been shown in animal studies to decrease the development of atherosclerotic lesions or plaques, another way it may likely be cardio-protective.

4. Inflammation and pain reducer

Algae benefits also extend to inflammation and pain relief. In general, algae contain anti-inflammatory compounds like omega-3 fatty acids and chlorophyll.

A 2016 study took a more specific look at the red variety, which is known for being “a rich natural source of compounds possessing interesting biological and pharmacological activities,” including anti-inflammatory, analgesic and gastroprotective activities.

The results of the in vitro study published in Pharmaceutical Biology confirmed that crude extracts from the Mediterranean red algae Laurencia obtusa exhibited significant anti-inflammatory and pain-killing activity. In addition, it was found to have a gastroprotective effect, specifically a gastric ulcer inhibition of up to 81.3 percent at a dose of 50 milligrams per kilogram.

An earlier study in 2015 showed that another type of marine algae called Pyropia yezoensis has a high protein count, which makes it an excellent source of biologically active peptides. In addition, it’s demonstrated the ability to act as a potent anti-inflammatory agent.

All about algae - Dr. Axe

5. Cholesterol-lowering

A 2016 study published in the Journal of the Science of Food and Agriculture revealed that fucosterol is a sterol that can be isolated from algae. Fucosterol has exhibited an ability to lower cholesterol naturally, among many other health-promoting qualities.

In general, algae are a rich source of phytosterols, which have the ability reduce blood cholesterol levels, specifically by effectively decreasing LDL (“bad”) cholesterol when given in supplements form.

How so? Phytosterols help lower intestinal cholesterol absorption.

Spirulina is rich in fatty acids like GLA, amino acids as well as antioxidants. A human study published in the Journal of Medicinal Food showed how spirulina can help to reduce the increased levels of blood lipids (fats) in people with hyperlipidemia nephrotic syndrome.

6. Heavy metal detox

Chlorella is a type of algae that acts as a natural chelator to remove heavy metals from the body.

High levels of exposure to environmental metals considered “heavy metals,” such as lead, mercury, aluminum and arsenic, can cause acute or chronic toxicity. This can result in damaged or reduced mental and central nervous function, along with damage to vital organs.

Long-term exposure may lead to more serious physical, muscular and neurological degenerative processes.

It’s important for your overall health and wellness to be proactive in detoxing heavy metals and toxins.

One of chlorella’s most significant health benefits is that it can wrap itself around stubborn toxins residing in our bodies, such as lead, cadmium, mercury and uranium, and keep them from being reabsorbed. Regular consumption of chlorella has been shown to keep heavy metals from accumulating in our bodies’ soft tissues and organs in the first place.

A study published in 2009 specifically showed the effects of chlorella intake on cadmium metabolism in animal subjects. Researchers found that when the subjects were exposed to the heavy metal cadmium, chlorella was able to counteract heavy metal poisoning and decrease tissue damage by decreasing cadmium absorption.

7. Stem cell proliferation promoter

In adults, stem cells are found throughout the body. They divide to replenish dying cells and also repair damaged cells.

As we age, stem cells age too and have a decreased regenerative capacity, which contributes to the aging process.

Based on prior studies showing that blue-green algae can modulate immune function in animals, the Department of Neurosurgery at USF investigated the effects of blue-green algae extracts on human stem cells in cultures. The preliminary findings showed that an ethanol extract of Aphanizomenon flos-aquae may help promote human stem cell proliferation.

8. Allergy relief

Algae benefits include helping relieve the effects of allergies, at least for some varieties. For instance, spirulina “significantly improved the symptoms and physical findings compared with placebo … including nasal discharge, sneezing, nasal congestion and itching,” in a 2008 study.

Brown algae have also displayed immune-supporting effects that can have benefits related to allergies, though certain allergies may not react well to incorporating these marine compounds.

9. Skin booster

If you’re looking for an anti-aging supplement, algae may do the trick.

As research published in 2023 notes: “Amino acids and peptides from macroalgae stimulate collagen production in the skin. Mycosporine-like amino acids act as antioxidants, antiinflammatories, UV-absorbing agents, and down-regulate the protein-glycation and collagenase activity. Ascorbyl palmitate antioxidant effect is used in anti-aging and anti-wrinkle formulations.”

The skin-boosting algae benefits are so great that carbohydrates from marine algae are commonly used in cosmetics to help with moisturizing, thickening and protecting skin.

10. Sustainable source of food and energy

Algae is increasingly recognized as a sustainable source of both food and energy due to its numerous environmental, nutritional and economic benefits. Here’s an overview of why algae is considered a sustainable resource in these areas:

As a sustainable food source, algae benefits include:

  • High in nutrition: Algae are packed with essential nutrients, including proteins, vitamins, minerals and omega-3 fatty acids. For example, spirulina and chlorella are popular microalgae consumed as dietary supplements. In addition, algae can contain up to 70 percent protein by dry weight, making alga an excellent alternative protein source for humans and animals.
  • Sustainable production: Algae can grow at astonishing rates, often doubling in mass within a day under optimal conditions. Plus, algae cultivation does not require arable land, reducing the pressure on agricultural lands needed for traditional crops. They can be grown in a variety of water conditions as well, including freshwater, saltwater and even wastewater, making them less reliant on freshwater resources.
  • Environmentally friendly: Algae photosynthesize, absorbing carbon dioxide (CO2) from the atmosphere, which helps mitigate climate change. Algae also can be used to treat wastewater by absorbing nutrients and contaminants, effectively cleaning the water while producing biomass.

There is also experimentation underway for algae benefits as a biofuel, with promising findings:

  • Biofuel production: Algae can be converted into various types of biofuels, such as biodiesel, bioethanol and biogas. Algal biofuels have a higher energy content compared to traditional biofuels derived from crops like corn and soybeans. They can be harvested year-round as well, providing a consistent and renewable source of biomass for energy production.
  • Sustainable and efficient: Algae have a higher oil yield per acre compared to traditional oilseed crops. Since algae can be grown on non-arable land and in non-potable water, they do not compete with food crops for land and water resources either.
  • Environmental impact: The cultivation and harvesting of algae for biofuels can result in lower greenhouse gas emissions compared to fossil fuels and some traditional biofuels. Algal biofuel production systems often incorporate CO2 capture from industrial emissions, enhancing their environmental benefits by reducing overall CO2 levels.


Depending on your health concern, there are so many algae supplements to choose from online or in your local health food store. You can get algae benefits in capsule, tablet and powder form.

Dosages vary by product and person. An appropriate dose also depends upon the user’s age and health concerns.

At this time, there is not enough scientific information to determine an appropriate range of doses for blue-green algae and other algae products supplements — though typical doses used have ranged from one to 10 grams daily for up to six months.

Algal oil is a health supplement derived from algae that’s often used as a vegan alternative to fish oils. Research suggests that supplementing between one to two grams of algal oil per day can significantly elevate blood levels of DHA and EPA.

Algal oil is a particularly good choice if you’re aiming to increase your intake of those important omega-3 fatty acids. DHA from algae has also been found to be bio-equivalent to fish oil’s DHA.

Make sure to read labels carefully and consult a professional if you feel unsure about an ideal daily dosage.

Risks, Side Effects and Drug Interactions

Algae products are typically safe for most people as long as they’re free of contaminants, like harmful bacteria and toxic metals. Consuming contaminated algae can lead nausea, stomach pain, vomiting, liver damage, weakness, rapid heartbeat, shock and even death.

Make sure you only use products that have undergone thorough testing to ensure that they’re free of microcystins and other unwanted contaminants.

Algae supplements can interact with medications that decrease the immune system (immunosuppressants) and medications that slow blood clotting (anticoagulant and antiplatelet drugs). Since some supplements can slow blood clotting, taking them along with herbs that also slow clotting might increase the chances of bruising and bleeding.

If you’re pregnant, breastfeeding or have any ongoing health condition, speak with your doctor before taking algae products.

Final Thoughts

  • Algae of one kind or another have been around for over 2 billion years, and they’ve been used in human diets for centuries.
  • To receive algae benefits, many people use algae supplements to fulfill their needs for essential fatty acids when they want to avoid animal supplements or are concerned about overfishing.
  • There is a great deal of scientific research to support the use for so many chronic health concerns from weight loss to cancer and high cholesterol.
  • Other algae benefits include helping protect heart health, reduce pain and inflammation, detox heavy metals from the body, relieve allergies, and boost skin health.
  • Algae benefits the environment as well since it’s a sustainable food source and has great promise as a sustainable biofuel.
  • If you’re going to give algae benefits a try, there are a few options with blue-green, chlorella and spirulina being some of the most popular choices.
  • Whatever product you choose, make sure it’s from a reputable source and has clearly undergone testing to ensure that it’s free of dangerous contaminants and that you get the most algae benefits possible.

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