What is the difference between chlorella and spirulina? Why would you use one over the other? How do you choose which brand to buy? These are all the questions that sprung to mind when I began researching these superfoods upon finding out about my high mercury levels last year. Being geeky old “moi”, I researched, read articles, scoured through studies and listened to a bunch of podcasts on the matter to try and understand it better. But as often is the case, I found too many contradictive findings and was confused. In the end, I bought an expensive powdered variety, tried it in a few smoothies, was put off by the taste and forgot about it. Until a few months ago, when a friend of ours told us how so many of his ailments disappeared when he started taking chlorella. A few weeks later, as luck would have it, I met Dr Charlotte Zoeller, a family practitionner and certified acupuncturist who also happens to be a real connoisseur when it comes to these two supplements. She debunked so many myths and actually gave me information I wouldn’t have been able to easily find online. After spending the afternoon with her I knew I’d have to share her knowledge with you. So here it is.

WM: What is the difference between chlorella and spirulina?

CZ: Both supplements are great immune system boosters, rich in minerals, chlorophyll and cartenoids, as well as powerful antioxydants. They have an alkalizing effect on the body and rich in amino acids, protein and fiber.

That being said, they are different. Chlorella is a single-cell dark green microalgae that thrives grows in fresh water. Spirulina is often described as a blue-green algae but it’s actually a cyanobacteria. So they are “genetically” distinct.

Chorella is:

• Recommended for heavy metal detoxification. The reason for this is because it has a multilayer cell wall which effectively absorbs polluting substances and binds to harmful organic toxins and metals like mercury or cadium. There are a few other ways of getting rid of heavy metals (cilantro, zeolites, DMPS, e.g.), they are part of a medical protocol to address specific cases.
• A powerful cleanser thanks to its exceptionally high chlorophyll content
• Excellent for tissue repair and cell regeneration
• Great for the brain and nervous system because it is exceptionally rich in bio-available Vitamin b12.

Spirulina is:

• A very good source of protein and good fats
• Known to have a positive impact on insulin resistance and lipid metabolism. Chlorella and Spirulina have health benefits in preventing hypercholesterolemia, hyperglycerolemia, obesity, inflammation, cardiovascular diseases
• Has been proven to be effective at preventing allergies
• Great for skin and nails
• Is easier to digest for people with sensitive guts

WM: What should you look for when buying chlorella or spirulina?

CZ: Read the labels. A few tips:

• When Country of origin, the used specie and cultivation method are absent form the labels, these are good indicators about the seriousness and ethics convey by the brand. It’s about evidencing respect to the customer vs. marketing hype claims.
• Organic doesn’t mean metals-free. At the very maximum, they’re screened for pesticides or chemicals added. Contamination by the cultivation water used, by the rain pollution, microorganisms form birds-insects, microcystines are inevitable in open air ponds. Then Chlorella and Spirulina are sterilised after harvest…how natural can this be? Try to opt for the kind that has grown in glass tubes and that used optimal photosynthesis, ie. CO2 and sunlight. Do your research.
• Spirulina should be a blueish green and chlorella is dark green. They should have a fresh grass smell.
• Don’t buy spirulina that boasts its vitamin b12 content: spirulina contains b12 but it is not bioavailable. If you want to get a boost in b12, get chlorella.
• Be careful about marketing claims that the cell walls of chlorella should be broken in order for it to be digestible and effective. That’s actually incorrect. You have to understand that over 95% of the chlorella and spirulina production in the world is made using old fashioned, standardized, inexpensive drying and cultivation techniques designed for mass production. These lead to breaking the cell walls. When cell walls are broken, the nutrients get damaged through oxydization. The digestibility of Chlorella is not significantly increased by breaking up its cell walls. Factors such as the drying process or the species (strain) of Chlorella used, have a greater impact.
  Again, the label needs to specify the species, it can either be C. vulgaris, C. sorokiniana or C. lobophora. The C. pyrenoidosa no longer is classified as a Chlorella species.

WM: Could you take these supplements on a daily basis or is it just to do a heavy metal detox or to get rid of a bout of allergies?

CZ: You can absolutely take chlorella or spirulina every day, they are a great source of so many nutrients. Just make sure you get one that is well sourced and keep in mind that no supplement will replace healthy, fresh, sustainably grown foods.

WM: Are there any side effects to taking chlorella or spirulina?

CZ: Some people have gastrointestinal effects for a few days, feel tired or even a little nauseous. It is actually a good sign because it means your body is ridding itself of toxins. Chlorella is slightly harder to digest than spirulina so people with sensitive intestinal systems, like I mentioned, might prefer the latter.

Obviously, like with any supplement or food, some people may have an intolerance to it but it isn’t common.

WM: Are there any contra-indications to take either of these?

CZ: People with auto-immune diseases like Hashimoto’s or Crohns at an acute stage might react to their immune-enhancing effects so best to check with their doctor first. As chlorella and spirulina contain the amino acid phenylalanine, people with phenylketonuria should not use these supplements.

Dr Charlotte Zoeller
Dr Charlotte Zoeller is an M.D. and German Board Family Physician. She graduated in Medicine at Goethe University Frankfurt. Specialist in Family Medicine (Bavarian Medical Council, Munich). She is also an Acupuncture Medicine Practitioner, and trained at the China Beijing International Acupuncture Training Center. She later got an Additional Designation in Acupuncture (Bavarian Medical Council, Munich).

She practices at Synergy Clinic Al Wasl and Top Medical Centre in Dubai