Could microalgae be the secret weapon to ending global hunger and saving the planet?


Commercially grown microalgae not only provide vital nutrients to combat child, maternal, and elderly undernutrition but also offer a greener alternative to traditional farming, helping to reduce carbon emissions and wastewater pollution.

Study: Improving Undernutrition with Microalgae. Image Credit: Chokniti-Studio / ShutterstockStudy: Improving Undernutrition with Microalgae. Image Credit: Chokniti-Studio / Shutterstock

In a recent review article published in the journal Nutrition, researchers in Australia discussed the potential of commercially farmed microalgae to address global nutritional issues.

They concluded that microalgae consumption has various health benefits and that cultivation has several advantages, including the fact that it does not require pesticides or arable land.

Undernutrition: a global concern

Nutritional deficiencies are a pressing issue around the world, with experts suggesting that child and maternal undernutrition accounts for the greatest loss of life years due to poor health and disability. Undernutrition in older adults is also a significant issue, increasing their risks for chronic diseases, muscle mass loss, and diminished physical and mental functioning. Older adults also suffer undernutrition and are particularly deprived of energy and protein.

Estimates indicate that more than 20% of children under five years of age are too short for their age and that undernutrition is a cause of 45% of deaths among children of this age. Improving nutrition will improve health and lessen the burden of non-communicable illnesses while reducing hunger and poverty.

Microalgae in nature

Microalgae, like other phytoplankton, are microscopic organisms found in water. Green and marine algae are the ancestors of all existing land plants and evolved more than a billion years ago. In fact, microalgae played a significant role in Earth’s Great Oxidation Event over 2 billion years ago, contributing to the oxygenation of the atmosphere.

Today, microalgae are essential for photosynthesis even though they have no roots or leaves. They are found in marine and freshwater regions and grow rapidly. They have beneficial nutrients and improve soil fertility, filter out pollutants, and control crop diseases.

Some microalgae may have antibacterial properties against human pathogens, and their biosynthetic pathways have several uses. However, they form a small part of commercial algal production, with Spirulina accounting for nearly 97% of microalgae production worldwide.

Nutritional benefits

Depending on species, microalgae contain varying levels of proteins, carbohydrates, and lipids. For example, Chlorella and Spirulina are high in protein, while red microalgae like Porphyridium are rich in carbohydrates. For example, Nannochloropsis and Schizochytrium can produce high amounts of eicosapentaenoic acid (EPA), while Schizochytrium produces docosahexaenoic acid (DHA), both crucial for human health.

Microalgae can be used in foods and nutraceuticals to address global nutrient deficiencies and serve as a sustainable alternative to fish oil, which is the main source of omega-3 fatty acids but cannot meet global demand. Similarly, they are more sustainable sources of protein than animal-based sources and can also be used as prebiotics and for animal feed.

Products incorporating microalgae include developing and functional foods. While Spirulina has been used by indigenous people around the world for centuries, microalgae are now appearing in dishes at fine-dining restaurants. Sustainable methods for home production have been developed, and adding them to food products like soups or tomato puree can improve consumer acceptance, nutritional value, and antioxidant capacity.

Commercial cultivation

Microalgae are economical, sustainable, and renewable, making them valuable in biopharmaceuticals, nutraceuticals, and renewable energy industries. Biomass from wastewater treatment can produce biofertilizers, biostimulants, and biopesticides, offering sustainable alternatives to synthetic options.

In addition, microalgae can remove contaminants such as heavy metals and pesticides from water, providing a valuable environmental service.  They have shown potential for medical applications, including treatments for rheumatoid arthritis, cancers, brain disorders, and diabetic ulcers.

Microalgae ponds can produce 4.5-9 times more biomass per hectare than legumes without using fertile land, freshwater, or pesticides. They can remove pollutants from wastewater, creating clean water and biomass that can be used for biofuels, bioplastics, and biopesticides. This ability to treat wastewater while producing valuable biomass gives microalgae a dual environmental and economic role.

They can also remediate contaminated water and soils, remove pollutants from industrial and municipal wastewater, and help reduce carbon dioxide and nitrogen oxides. Large-scale microalgae farms could significantly reduce global carbon emissions, making them valuable for environmental sustainability.

However, successful commercialization depends on the selection of appropriate microalgal strains and growing conditions. Commercial microalgal production requires large-scale cultivation and involves factors like species selection, cultivation technology, lighting, and harvesting strategies.

Advancements in biotechnology and engineering are needed to drive industrial growth. Technologies like photobioreactors and immobilized microalgae biofilms help improve production efficiency, especially for biofuels and wastewater treatment.

Additionally, microalgae-based food products face regulatory challenges in regions like Europe, where approval processes are lengthy due to food safety regulations such as the Qualified Presumption of Safety (QPS) status.

Conclusions

Microalgae can provide essential nutrients like lipids, carbohydrates, proteins, vitamins, and minerals, offering a feasible solution to undernutrition, especially in vulnerable populations like children, mothers, and older adults. Their composition varies by species, allowing selective use for specific nutritional needs, such as omega-3 fatty acids, dietary fiber, or protein. Different types of microalgae offer a range of nutrients like omega-3 fatty acids, dietary fiber, proteins, and micronutrients, allowing for selective use based on nutritional needs.

These products offer a sustainable way to supply key nutrients and help reduce the global impact of undernutrition while also reducing environmental impacts associated with traditional food cultivation. However, a better understanding of microalgal species is needed to identify their potential as food ingredients while biotechnological improvements increase their production and expand their commercial viability. Intervention studies will also be crucial to identifying the specific health benefits of various microalgae species for undernutrition.



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