Find out all about chlorella, including what it does, the benefits to taking it and how much you might need
What is chlorella and what does it do?
Chlorella is a tiny green algae that grows in freshwater ponds and lakes in south east Asia and Australia.1 The name comes from the Greek word for ‘green’, a reference to its vivid colour. Chlorella is also highly nutritious. It’s a source of:2,3,
- protein – it contains 50-60% protein and all nine essential amino acids
- vitamin C
- lutein, a carotenoid needed for healthy eyes
- vitamin K
In fact, it could be considered the first superfood: in the 1940s, scientists investigated whether chlorella could become a cheap, nutritious source of protein in times of scarcity, although it proved too expensive to grow in bulk.4
Traditionally used as a food supplement in Japan, studies have found various health benefits from taking chlorella, including:
- reduced cholesterol levels and improved fat metabolism5
- immune system support6
- a detoxifying effect, removing heavy metals from the body7
Chlorella is available as a powder, capsules, or tablets from Holland & Barrett.
Benefits of chlorella
What does chlorella do in the body?
It’s thought that chlorella has a few key jobs:
1. Improved cholesterol and fat metabolism
Chlorella may help lower cholesterol levels and improve fat metabolism in people with raised blood cholesterol, according to a 2014 study from Korea. Chlorella is a likely source of fat-soluble carotenoids – orange, yellow and red plant pigments – and scientists think these compete with fats for transportation in the blood, reducing the amount of fat in cells.8
2. Immune support
Scientists think chlorella has a stimulatory effect on the immune system. A Korean study published in 2012 in Nutrition Journal found that when healthy adults were given 5g of chlorella a day for eight weeks, their bodies increased levels of immune cells known to fight bacteria.9
3. Toxin removal
Chlorella may have a detoxifying effect, binding with heavy metals – like copper, lead and cadmium – which are then flushed out of the body as waste, although human studies are needed to confirm its effects.10 It’s not usual to be exposed to heavy metals but pollution or certain jobs, like mining, can increase this possibility.
4. Reduced blood sugar levels
A 2008 Japanese study on 17 healthy people with high-risk factors for lifestyle-related disease reported that chlorella helped reduce blood sugar.11
Read more: Benefits of chlorella
How much chlorella is safe to take?
There are no dietary recommendations for taking chlorella, but some studies use 1.2g a day, and others 5-10g daily.12 If you want to take chlorella, read the label carefully and avoid taking more than advised.
Do not take chlorella if you:
- are pregnant – it has not been proven safe during pregnancy
- have an immune deficiency disorder – chlorella has been shown to stimulate the immune system13
- are taking the anticoagulant medicine warfarin – chlorella is a source of vitamin K, which is important for blood-clotting14
Chlorella is freshwater algae, which are low in iodine, unlike marine algae. This means you don’t need to worry about consuming too much idodine.15
If you’re interested in taking chlorella, talk to your GP or an experienced medical herbalist first.
What are the side-effects of taking chlorella?
The following side-effects have been reported from taking chlorella:16
- stomach discomfort
Always consult your doctor before taking supplements if you are under medical supervision, pregnant or breast-feeding. Always read the label and check dosage instructions. If you are taking blood thinning drugs such as warfarin, chlorella should be avoided as it can interfere with blood clotting due to its vitamin K content.Advice is for information only and should not replace medical care.
1. Victoria Lambert. The Telegraph. Chlorella: the superfood that helps fight disease. Available from: https://www.telegraph.co.uk/lifestyle/wellbeing/6028408/Chlorella-the-superfood-that-helps-fight-disease.html
2. Keri-Ann Jennings. Healthline. 9 Impressive Health Benefit of Chlorella. Available from: https://www.healthline.com/nutrition/benefits-of-chlorella
3. Ryu NH, et al. Impact of daily Chlorella consumption on serum lipid and carotenoid profiles in mildly hypercholesterolemic adults: a double-blinded, randomized, placebo-controlled study. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4066283/
4. As Source 1
5. As Source 3
6. Kwak JH, et al. Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of Natural Killer cell activity and early inflammatory response (Randomized, double-blinded, placebo-controlled trial). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3511195/
7. Zhai Q, Narbad A, Chen W. Dietary Strategies for the Treatment of Cadmium and Lead Toxicity. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4303853/
8. As Source 3
9. As Source 6
10. As Source 7
11. Mizoguchi T, et al. Nutrigenomic studies of effects of Chlorella on subjects with high-risk factors for lifestyle-related disease. Available from: https://www.ncbi.nlm.nih.gov/pubmed/18800884
12. As Source 2
13. As Source 2
14. As Source 1
15. Algomed. Chlorella. Available from: https://www.algomed.de/en/chlorella-4/#1511512127095-38f0f3f6-6f6b
16. Halperin S, et al. Safety and immunoenhancing effect of a Chlorella-derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC164975/