Japanese Chlorella (algae)

1. Very Nutritious
Chlorella's impressive nutritional profile has led some to call it a "super food." While its exact nutrient content depends on growing conditions, the species used and how supplements are processed, it's clear it packs several beneficial nutrients.

They include:

Protein: Chlorella is 50–60% protein. What's more, it's a complete protein source, meaning it contains all nine essential amino acids (3, 5Trusted Source).
Vitamin B12: Some chlorella varieties may also contain vitamin B12, but more studies are needed (6Trusted Source).
Iron and vitamin C: Chlorella can be a good source of iron. Depending on the supplement, it may provide anywhere from 6–40% of your daily need. It's also an excellent source of vitamin C, which helps you absorb iron (1Trusted Source, 3, 7).
Other antioxidants: These tiny green cells provide a wide range of antioxidants (1Trusted Source, 3).
Other vitamins and minerals: Chlorella provides small amounts of magnesium, zinc, copper, potassium, calcium, folic acid and other B vitamins (1Trusted Source, 3, 8).
Omega-3s: As with other algae, chlorella contains some omega-3s. Just 3 grams of chlorella delivers 100 mg of omega-3s (8).
Fiber: In large quantities, chlorella can be a good source of fiber. However, most supplements don't provide even 1 gram of fiber per dose (1Trusted Source, 8).
SUMMARY:
Chlorella contains many nutrients, including vitamins, minerals, antioxidants and omega-3 fats. Exact quantities may differ among brands.

2. Binds to Heavy Metals, Aiding Detox
Chlorella has gotten some buzz for its ability to help the body "detox." In fact, animal studies indicate that it's effective at helping remove heavy metals and other harmful compounds from the body (9Trusted Source, 10Trusted Source, 11Trusted Source).

Heavy metals include some elements that are essential in small amounts, such as iron and copper, but these and other heavy metals like cadmium and lead can be toxic in larger amounts.

While it's rare for people to have dangerous levels of heavy metals in their system, people can get exposed to heavy metals through pollution or certain jobs such as mining (12Trusted Source).

In animals, algae, including chlorella, has been found to weaken the heavy metal toxicity of the liver, brain and kidneys (13Trusted Source).

Furthermore, chlorella has been shown to help lower the amount of other harmful chemicals that are sometimes found in food. One of these is dioxin, a hormone disruptor that can contaminate animals in the food supply (14Trusted Source, 15Trusted Source).

Based on this evidence, it seems that chlorella could help enhance your body's natural ability to clear toxins.

SUMMARY:
Chlorella may help the body detox by binding to heavy metals and other toxins.

3. Could Enhance Your Immune System
Your immune system helps keep you healthy by fighting off infections.

It's a complex system made up of multiple mechanisms and cells that get into gear when an invader enters your body.

Chlorella has been found to enhance the immune response in both animal and human studies, although the evidence so far is limited.

In one small study, men produced more antibodies when taking chlorella than when they took a placebo. Antibodies help fight foreign invaders in your body, meaning this finding is quite promising (16Trusted Source).

In another small, eight-week study, healthy adults who took chlorella showed markers of increased immune activity (17Trusted Source).

Nevertheless, findings have been mixed, with some studies showing little to no effect.

For instance, one study found that chlorella supplements enhanced immune function in participants aged 50–55, but not those over 55 (18Trusted Source).

So it's possible that chlorella may have immune-boosting effects in some populations and age groups, but not in all. More and larger-scale studies are needed.

SUMMARY:
Chlorella may bolster immune function by increasing the activity of various parts of the immune system.

4. May Help Improve Cholesterol
Several studies have suggested that chlorella supplements may help lower cholesterol (5Trusted Source, 19Trusted Source, 20Trusted Source).

Specifically, several studies have shown that taking 5–10 grams of chlorella daily lowered total and LDL cholesterol and triglycerides in people with high blood pressure and/or slightly elevated cholesterol (5Trusted Source, 19Trusted Source).

Chlorella's content of the following may help improve blood lipid levels:

Niacin: A B vitamin known to lower cholesterol (1Trusted Source, 21).
Fiber: A cholesterol-lowering agent (1Trusted Source, 22Trusted Source).
Carotenoids: Have been shown to naturally lower cholesterol (19Trusted Source, 23Trusted Source, 24Trusted Source).
Antioxidants: Help prevent the oxidation of LDL cholesterol, which is known to contribute to heart disease (25Trusted Source).
SUMMARY:
The nutrients found in chlorella, including niacin, fiber, carotenoids and antioxidants, may help lower your cholesterol levels.

5. Acts as an Antioxidant
Chlorella contains several compounds that are considered antioxidants, including chlorophyll, vitamin C, beta-carotene, lycopene and lutein (26Trusted Source).

These antioxidants can help fight many chronic diseases (26Trusted Source).

Some of these antioxidants seem to reduce the production of advanced glycation end products (AGEs), which drive many of the complications of diabetes (1Trusted Source, 27Trusted Source).

In animals and lab studies, chlorella has interfered with the way genes age (1Trusted Source, 28Trusted Source).

Also, a human study showed chlorella supplements increased antioxidant levels in chronic cigarette smokers, a population at a higher risk of oxidative damage (29Trusted Source, 30Trusted Source).

Although much of this research is promising, it is still preliminary.

SUMMARY:
Chlorella's antioxidant content may provide some protection against chronic disease, but more human studies are needed to confirm this.

6. Helps Keep Blood Pressure in Check
Chlorella supplements could help promote heart and kidney health, which is essential for normal blood pressure.

In one study, people with mildly high blood pressure took four grams of chlorella daily for 12 weeks.

By the end, these people had lower blood pressure readings than participants who took the placebo (31Trusted Source).

Another small study in healthy men showed that taking chlorella supplements was linked to less stiffness of the arteries, a factor that affects blood pressure (32Trusted Source).

One theory to explain this is that some of chlorella's nutrients, including arginine, potassium, calcium and omega-3s, help protect arteries from hardening (32Trusted Source, 33Trusted Source).

SUMMARY:
Some research on chlorella has pointed to a blood pressure-lowering effect. Many of its nutrients have been shown to prevent arteries from hardening.
7. Could Improve Blood Sugar Levels
Some research shows that chlorella may help lower blood sugar levels (1Trusted Source).

One study found that taking chlorella for 12 weeks lowered fasting blood sugar levels in both healthy individuals and those at high risk of lifestyle-related diseases (20Trusted Source).

Other studies have shown that supplementing with chlorella improves blood sugar control and increases insulin sensitivity in patients with non-alcoholic fatty liver disease (34Trusted Source, 35Trusted Source, 36Trusted Source).

There isn't enough research yet to say that you should take chlorella to manage blood sugar, but it may help when combined with other therapies.

SUMMARY:
Taking chlorella supplements may help lower blood sugar levels and increase insulin sensitivity.
8. May Help Manage Respiratory Diseases
Managing respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD) often requires controlling inflammation (37Trusted Source, 38Trusted Source).

Chlorella has some components that can help reduce inflammation, including its many antioxidants (1Trusted Source, 39Trusted Source).

One study found that chlorella supplements improved antioxidant status in COPD patients, but that didn't translate into any improvements in breathing capability (40Trusted Source).

More studies are needed to determine its true effect on respiratory conditions, but chlorella might help with inflammation.

SUMMARY:
The antioxidants in chlorella may have anti-inflammatory effects, which can possibly improve asthma and other respiratory diseases.
9. May Enhance Aerobic Endurance
Only one study has looked at chlorella's effect on aerobic endurance, but it showed a positive effect.

Researchers gave a group of young adults six grams of chlorella or a placebo daily for four weeks.

At the end of the study, the chlorella group showed a significantly improved ability to saturate their lungs with oxygen, which is a measure of endurance. The placebo group did not experience any changes in endurance (41Trusted Source).

This effect may be due to chlorella's branched-chain amino acid content.

Branched-chain amino acids are a collection of three amino acids that have been found to improve aerobic performance in various studies (42Trusted Source, 43Trusted Source).
SUMMARY:
Chlorella may improve your aerobic performance, although scientific support for this benefit is limited.
Other Potential Benefits
Many other possible benefits have been proposed, but there's little research to support these claims.

Here are some of the main health claims:

Promotes eye health: Chlorella contains lutein and zeaxanthin, two carotenoids that protect the eye and lower the risk of macular degeneration (44Trusted Source, 45Trusted Source, 46Trusted Source).
Supports liver health: Chlorella supplements have been shown to improve markers of liver health in people with liver disease. However, it's not clear whether there's a benefit for healthy people (34Trusted Source, 35Trusted Source, 36Trusted Source, 47Trusted Source).
Improved digestion: Many sources claim chlorella eases digestion and reduces bloating. However, no studies have assessed these proposed benefits.
Relieves PMS: Anecdotal evidence says that chlorella can relieve symptoms of premenstrual syndrome (PMS). It could be a stretch, but chlorella contains calcium and B-vitamins, both of which have been shown to reduce PMS (48Trusted Source, 49Trusted Source).
While there's no specific research to back up these claims, chlorella's nutrient content could, in theory, have these benefits (8).
SUMMARY:
Chlorella has been claimed to improve energy levels, liver health, digestion and symptoms of PMS.