Green Superfoods: Barley Grass, Wheatgrass & Algae

Green Superfoods: Between Tradition and Science

Barley grass, wheatgrass, spirulina and chlorella are often marketed as “green superfoods.” But what does the research actually say? What nutrients do they contain, and how does science evaluate their health effects?

Chlorophyll: The Green Plant Pigment

Structure and Function

Chlorophyll is the pigment that gives plants and algae their green colour. Chemically, its structure is strikingly similar to haemoglobin in human blood. Both molecules share a ring-shaped framework (porphyrin ring). In haemoglobin, iron sits at the centre. In chlorophyll, it is magnesium.

Current Research

Studies suggest that chlorophyll may possess antioxidant properties. In laboratory settings, chlorophyllin (a water-soluble form of chlorophyll) has demonstrated the ability to neutralise free radicals. However, the transferability of these findings to the human body has not been conclusively established. Most evidence comes from in vitro studies or animal models.

Barley Grass vs. Wheatgrass

Both grasses are harvested young and sold as powder or juice. Their nutrient profiles are remarkably similar.

Nutrient Comparison

Nutrient (per 10 g powder)	Barley Grass	Wheatgrass
Chlorophyll	40-60 mg	50-70 mg
Iron	2-4 mg	2-3 mg
Vitamin C	5-15 mg	3-10 mg
Fibre	2-3 g	2-3 g
Protein	2-3 g	2-3 g

What Does the Research Say?

The body of research on barley grass is somewhat larger than that on wheatgrass. Animal models and smaller human studies suggest that barley grass extracts may exhibit antioxidant capacity. However, large-scale, randomised controlled trials in humans are still lacking.

Similar indications of antioxidant properties exist for wheatgrass. The evidence remains limited, though. Both grasses provide a broad spectrum of micronutrients but are no substitute for a balanced diet rich in varied fruits and vegetables.

Spirulina: The Cyanobacterium

Spirulina (Arthrospira platensis) is technically not an alga but a cyanobacterium. It has been used as a food source for centuries.

An Impressive Nutrient Profile

• Protein: 60-70% of dry weight. This makes spirulina one of the most protein-dense natural food sources.
• Phycocyanin: A blue-green pigment found exclusively in cyanobacteria. Chaiklahan et al. (2022) investigated the antioxidant mechanisms of phycocyanin and found that it may act as a potent antioxidant by directly neutralising reactive oxygen species.
• Iron: Approximately 28 mg per 100 g. Studies suggest spirulina may support iron status.
• B vitamins: Contains various B vitamins, including B1, B2 and B3.

Vitamin B12: An Important Caveat

Spirulina predominantly contains pseudovitamin B12 (analogues) that are not usable by human metabolism. Bito & Watanabe (2016) demonstrated that plant-based sources such as spirulina are not reliable B12 suppliers. Those following a plant-based diet should supplement B12 separately.

Chlorella: The Microalga

Chlorella (Chlorella vulgaris) is a single-celled green alga with several distinctive characteristics.

Cell Wall Structure

The triple-layered cellulose cell wall makes chlorella difficult to digest if not broken down. This is why high-quality chlorella products use “broken cell wall” processing. Only then do the nutrients become bioavailable.

Chlorella Growth Factor (CGF)

CGF is a complex of nucleic acids, amino acids and peptides produced during chlorella’s rapid cell division. Research has associated CGF with supportive effects on cellular processes. However, the data remain sparse and largely preclinical.

Panahi et al. (2016): Chlorella and Blood Lipids

A randomised, double-blind study by Panahi et al. (2016) examined the effect of chlorella supplementation on blood lipid levels. The results suggest that chlorella may have positive effects on triglycerides and total cholesterol. However, the study was relatively small, and the authors recommend larger follow-up studies.

Nutrient Density Compared

How do green superfoods compare to common vegetables?

Nutrient (per 100 g)	Spirulina (dried)	Spinach (raw)	Broccoli (raw)
Protein	57 g	2.9 g	2.8 g
Iron	28 mg	2.7 mg	0.7 mg
Beta-carotene	342 mcg	5,626 mcg	361 mcg
Vitamin C	10 mg	28 mg	89 mg
Calcium	120 mg	99 mg	47 mg

Important: Direct comparison is limited. Nobody eats 100 g of dried spirulina per day. Typical servings range from 3 to 10 g. At these amounts, superfoods complement the diet but do not replace fresh vegetables.

Critical Assessment: Hype vs. Evidence

What is well supported

• Spirulina has an exceptionally dense nutrient profile with high protein content
• Phycocyanin demonstrates antioxidant properties in studies
• Chlorella can serve as a nutrient source when its cell wall is broken
• Barley grass and wheatgrass deliver chlorophyll and micronutrients

What is overstated

• “Detoxification” through green superfoods is not scientifically supported
• Spirulina is not a reliable B12 source
• Most impressive study results come from cell culture or animal experiments
• Green superfoods do not replace a varied diet of fruits and vegetables

What still needs further research

• Long-term effects of regular consumption
• Optimal dosages for specific effects
• Interactions with medications at higher doses

Conclusion

Green superfoods such as spirulina, chlorella, barley grass and wheatgrass are nutrient-rich supplements. Research provides promising indications of antioxidant and nutritional benefits. At the same time, one should be aware of the limits of current evidence. Green superfoods can meaningfully complement a daily diet but are no substitute for a balanced, vegetable-rich nutrition.

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Sources:

• Chaiklahan R et al. (2022). Phycocyanin: A potential antioxidant and bioactive compound. Journal of Applied Phycology.
• Bito T & Watanabe F (2016). Vitamin B12 sources and bioavailability. Experimental Biology and Medicine.
• Panahi Y et al. (2016). Impact of adjunctive therapy with Chlorella vulgaris extract on antioxidant status, lipid profiles, and quality of life. Complementary Therapies in Medicine.
• Kulshreshtha A et al. (2008). Spirulina in health care management. Current Pharmaceutical Biotechnology.
• Zeng Z et al. (2020). Chlorella as a potential functional food. Food & Function.