Microalgae meals: good for humans and the planet

People| Human Health

By Laura Butula, Kingfisher Writer

Published January 26th, 2022

Many food brands are introducing their customers to microalgae supplements and powders. Albeit with a few drawbacks, a microalgae diet offers a burst of proteins, vitamins, minerals and fibre, supporting the health of humans and benefitting the planet.

Recent years have seen countless superfoods conspicuously enter global food markets, causing people to either purchase the hyped product or uphold their scepticism. Many of these powerfoods, including chia, goji berries, turmeric and soybeans are often associated with vegetarian or vegan diets. In reality, they can be incorporated into any diet.

Different uses of microalgae. | Mota F.G. 2022 / Algal Research

The ideology surrounding superfoods has been around since the 1960s, but they were simply called ‘health foods’ back then. Their latest resurfacing has mainly been a result of searching for sustainable alternatives for food production and human health.

Food production currently accounts for approximately 30% of global greenhouse gas (GHG) emissions and contributes to 20% to 30% of the global environmental footprint. Notably, the quantity of produced food must double to meet the needs of the 10 billion people predicted to inhabit the planet by 2050.

‘The ideology surrounding superfoods has been around since the 1960s, but they were simply called ‘health foods’ back then.’

Some scientists argue that crop production is reaching an optimal point, beyond which, food security might depend on nourishment substitutes. This is where a particular type of environmentally-conscious superfood comes into play: microalgae.

One of the first life forms on the planet, microalgae are unicellular or simple-multicellular microorganisms that have evolved to comprise complex yet valuable constituents. It therefore comes to no surprise that the use of and application of microalgal species for food has been recognized for centuries. The Aztecs (circa A.D. 1300) consumed Spirulina species, which are a type of cyanobacteria, known commonly as blue-green algae.

All species of microalgae use solar energy to grow and produce a selection of bioactive compounds such as vitamins, proteins and antioxidants. Thus originates the frenzy about microalgae-based foods and their appeal to improve human health.

‘All species of microalgae use solar energy to grow and produce a selection of bioactive compounds such as vitamins, proteins, and antioxidants.’

Microalgal species have differing quantities of certain vitamins. For example, Euglena gracilis contains vitamin E, Eisenia arborea contains vitamin C, and Spirulina species are high in vitamin B12. From a nutritional perspective, these vitamin equivalents are found in almonds, citrus fruits, and eggs, respectively.

Additionally, many microalgal species are protein-rich, meaning they support development and cell repair. Chlorella vulgaris has an elevated protein content (58 grams per 100 grams) relative to chicken (24 grams per 100 grams) and fish (21 grams per 100 grams). Moreover, microalgae can provide humans with essential amino acids (protein building blocks) that are not naturally produced by the body, including leucine, methionine, valine and lysine.

Chlorella vulgaris dietary supplements. | Philipp Alexander / Flickr

Antioxidants, which protect the human body from free radicals, are also present in microalgae. Namely, Scytosiphon lomentaria, Papenfussiella kuromo, and Nemacystus decipiens all contain antioxidants, such as carotenoids.

Marketing the health benefits can attract a range of consumers to try microalgae, but especially vegetarians and vegans. Notably, one study used Golden Chlorella® powder, by Alver, to create meat-alternative products with increased nutritional value, which is a typical result associated with the use of microalgal species in foodstuffs.

The significance of this research lies in the fact that microalgae may account for 18% of all protein sources by the year 2050. Food companies, therefore, have a prominent opportunity to introduce potential customers to sustainable and natural microalgae meals. Blue Biotech, Soliance and BioReal are all already supplying microalgae dietary supplements.

Another start-up, a Swiss brand named Alver, discovered the aforementioned Golden Chlorella® microalgae powder. The product is made from naturally fermented and dried Chlorella vulgaris, and is rich in fibre, minerals, vitamins and proteins. One teaspoon (10 grams) of Golden Chlorella® powder has the protein quantity of half an egg, 100 millilitres of milk or 12 grams of a beefsteak.

‘One teaspoon (10 grams) of Golden Chlorella® powder has the protein quantity of half an egg, 100 millilitres of milk or 12 grams of a beefsteak.’

The species Chlorella vulgaris, which is in Golden Chlorella®, also contains the amino acids arginine and glutamic acid, which can support immune function and improve memory. Additionally, the microalgal cell wall absorbs localised toxins, leaving the body detoxified. Evidently, there seem to be countless bonuses of a microalgal snack.

Apart from the obvious health benefits of consuming microalgae and microalgae-based supplements or powders, this specific dietary choice is also known to be relatively environmentally friendly for several reasons.

First, research confirms that microalgae are ‘carbon hungry’, as they act as a carbon sink to trap carbon dioxide and other GHGs. In terms of simple science, they have the potential to slow global warming. This function could counterbalance the disastrous greenhouse effects linked to less climate-friendly diets, such as meat-heavy carnivorous or omnivorous diets, which account for 14.5% of all anthropogenic GHG emissions.

Microalgae cultivation through bioengineering techniques has allowed a variety of applications for both human and animal food. | Kusmayadi A. 2021 / Chemosphere

Second, there are low land-use requirements associated with the growth of microalgae. Specifically, microalgae-based proteins need less than 2.5 cubic metres of land per one kilogram of protein, compared with 47.0 cubic metres per kilogram for chicken, 55.5 cubic metres per kilogram for pork, and 201 cubic metres per kilogram for beef production. Some studies conclude that land use for microalgae is also less than some plant-based proteins, including soybean meal and pea protein powder.

Third, a microalgae-based diet helps conserve water. Microalgal species are not picky about water sources; they can thrive in seawater, freshwater, or even wastewater—drinkable water is not a prerequisite for development. Furthermore, microalgae have toxin-removing abilities, meaning they can maintain water balance. For example, Spirulina platens can absorb cadmium, a highly toxic metal, from water.

‘First, research confirms that microalgae are ‘carbon hungry’, as they act as a carbon sink to trap carbon dioxide and other GHGs.’

Fourth, a microalgae-based diet helps prevent deforestation, since microalgae are a sustainable alternative for energy production. Due to their high lipid content and speedy biomass maturation, microalgae are gaining attention as a potential biofuel. The associated production process is said to be carbon neutral and forest-friendly, which seems unimaginable when comparing it to that of other fuel sources (e.g. natural gas, coal, wood).

Finally, both habitats and ecosystems are protected and preserved by microalgae. Some microalgae, including Hapalosiphon and Nostoc species, can be supplemented and used as a biofertilizer in crop fields to stimulate development and maintain robustness.

Researchers performing studies on microalgae to develop plant-based products.| Nestlé / Flickr

It is incontestable that the commercial production and marketing of microalgae for food is advantageous for human health and relatively preferable for the health of the planet. Nonetheless, there are some drawbacks to a microalgae diet.

For example, although relatively harmless in contrast to other food production processes, the production of microalgae protein powders has a higher environmental impact compared to regular algal cultivation. Moreover, microalgae exploitation requires further optimization and development of technologies to make the process faultlessly environmental.

‘Due to their high lipid content and speedy biomass maturation, microalgae are gaining attention as a potential biofuel.’

So, where will the future take us? Will we all be drinking power-packed microalgae smoothies to boost our energy levels? Or will we reject the thought of yet another microorganism-infused meal? Is microalgae simply another food fad, or will it prove its sustainability in the long run?

Science tells us that ovo-lacto-vegetarian diets are climate-friendly and environmentally sound. A microalgae-added diet fits within this category. The final question is, would you be interested in a bite of a greener and healthier future?

Featured Image: CSIRO | Science Image

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