Microalgae, a health solution

Article published in Vitality Quebec magazine, March 2015
By Viviane Bélair,
Marine biologist (B.Sc.) and chemist (M.Sc.)
Doctoral candidate in Bioresource Engineering at McGill University

Whether you're an athlete or sedentary, vegetarian or in search of a dietary supplement, microalgae are an ideal source of vitality [1]. Most people have heard of microalgae supplements, mainly chlorella and spirulina, but without knowing the reasons why they're considered energizing, anti-aging, anticancer, hepatoprotective, neuroprotective, and cardioprotective. Discover these different species of microalgae on the market and their health benefits.

What is a microalgae?

Microalgae, including cyanobacteria (blue-green algae), are considered the earliest form of life on Earth, appearing respectively around 2 and 3.8 billion years ago. Microalgae are microscopic aquatic cells ranging in size from 2-30 μm that, through photosynthesis, can convert solar energy into chemical energy, essential for synthesizing compounds [2]. Rich and balanced foods, microalgae form the basis of the aquatic food chain and produce, among other things, omega-3 and omega-6 oils, which accumulate in fish, and astaxanthin (red pigment), which gives fish flesh its pink coloration. Microalgae have been known for centuries, and over the past 40 years, commercial production has focused on a few species for applications in the food, pharmaceutical, and cosmetic industries: Arthrospira (spirulina), Chlorella (chlorella), Dunaliella, Haematococcus, and Aphanizomenon, reaching thousands of tons per year [2,4]. Bishop (2012) provides an interesting critical review of global production of these five microalgae species, with spirulina and chlorella being the most cultivated [5]. Microalgae have not yet received the attention they deserve, but today, as consumers demand more natural foods with health claims (under Natural Product Numbers (NPN) regulated by Health Canada), they are poised to play a significant role in the food industry [2].

Balance: An Essential for Vegetarians

A vegetarian diet or deficient diets can be compensated for by the proteins, iron, zinc, calcium, omega-3 and omega-6 fatty acids, and vitamins (B12, D, and A) contained in microalgae. The protein content of spirulina and chlorella represents 50 to 70% of dry weight, surpassing that of meat, milk, eggs, or soy, with an excellent profile of essential amino acids [2]. For example, 10 grams of spirulina contain as much protein as an egg, as much iron as 300 grams of calf liver, as much β-carotene as 200 grams of carrots, as much calcium as a yogurt, and as much magnesium as three squares of dark chocolate [6].

Check: an aid for weight loss and digestion

Microalgae are an ally for people undertaking a weight loss diet. In a hypocaloric diet, nutrition is often unbalanced, leading to deficiencies in essential fatty acids and vitamins (A, D, E, K), causing fatigue. In addition to being natural and balanced, spirulina and chlorella contain phenylalanine, an amino acid that suppresses appetite by triggering the secretion of a hormone (cholecystokinin) that signals satiety to the brain. Taking five to ten grams of spirulina 30 minutes before meals facilitates following a diet [1,7]. Microalgae also aid in digestion because their pH is basic, which helps restore the stomach's pH, typically disrupted by our overly acidic diet, while stimulating the growth of beneficial bacteria for the digestive system [2].

Performance: an ally for athletes

Athletes, including Olympic athletes, consume microalgae to enhance their endurance, performance, and achieve quicker recovery after intense efforts. Iron deficiency is common among athletes, reducing the oxygen-carrying capacity through hemoglobin. The high iron content in microalgae serves as a natural supplement, with absorption being 60% more effective than other supplements. Moreover, the high oxygen consumption in athletes leads to an overproduction of free radicals that accumulate, exacerbating muscle soreness, cramps, and the risk of tissue rupture. Consuming microalgae containing β-carotene acts as an antioxidant [1].

Anticancer: Antioxidants

Oxidative stress levels (from tobacco, alcohol, pollution) generate free radicals in the body, which are normally eliminated by the production of antioxidants (such as superoxide dismutase (SOD)), but in excess, they attack tissues and cause oxidative damage that can lead to cancer. The pigments in microalgae are a source of antioxidants, including β-carotene (a precursor of vitamin A) found in spirulina and chlorella. The National Institutes of Health and the American National Cancer Institute recommend a dietary source rich in natural β-carotene, which is absorbed ten times more easily than the synthetic form and, importantly, without any risk. The pigment phycocyanin, found only in blue-green algae, including spirulina, also helps prevent or inhibit cancer [1,8]. Consuming foods rich in antioxidants like carotenoids, phycocyanin, SOD, and vitamins (C and E) from microalgae is a way to prevent cancer [1,7].

Hepatoprotective: A detoxification regimen

Chlorophyll, the primary pigment present in all microalgae, is known to help detoxify the body from pollution-related aggressions. Chlorella has the highest chlorophyll content found in nature (2 to 3%), followed by spirulina (1%) [1].

Maintaining good vision

Zeaxanthin and lutein are concentrated in the human eye's retina and promote good vision. Zeaxanthin and lutein from microalgae increase their concentration in the serum, reducing the risk of cataracts and age-related macular degeneration [3]. Moreover, the ß-carotene in microalgae transforms into vitamin A, essential in the vision mechanism and without the risk of hypervitaminosis A [1].

Essential fatty acids: cardioprotective and good for the skin

Polyunsaturated fatty acids have favorable effects on cardiovascular diseases [9]. Chlorella contains a short-chain omega-3 fatty acid, alpha-linolenic acid (ALA, 18:3, omega-3), and an omega-6, linoleic acid (LA, 18:2, omega-6). Spirulina, on the other hand, contains omega-6 fatty acids, namely gamma-linolenic acid (GLA, 18:3, omega-6), and linoleic acid (LA, 18:2, omega-6) [10]. GLA found in spirulina is readily assimilated and one of the best sources (1 to 1.5%) after breast milk. GLA is a precursor fatty acid of anti-inflammatory metabolites (prostaglandins), which helps combat cardiovascular diseases [11,12]. GLA has also demonstrated significant efficacy in improving skin quality and reducing symptoms associated with skin conditions such as eczema and psoriasis.

How to choose and use microalgae?

Microalgae are available in the form of tablets and powder, which can be incorporated into beverages or dishes to increase their nutritional value. Spirulina, among others, is a source of β-carotene (provitamin A), phycocyanin, chlorophyll, zeaxanthin, lutein, gamma-linolenic acid (GLA), and superoxide dismutase (SOD) [5,8]. Chlorella is recognized as a source of chlorophyll, β-carotene, lutein, alpha-linolenic acid (ALA), vitamin B12, and dietary fiber [3]. Health Canada suggests consuming up to 5 to 6 grams per day, starting with 1 gram per day and gradually increasing to the desired dose. Pregnant or breastfeeding women and individuals with specific health conditions should consult their doctor before consuming them. Spirulina is not allergenic, and chlorella is considered a weak allergen for certain types of individuals [1]. Not all microalgae offered on the market are exactly the same, so it is important as a consumer to make certain checks on the quality of the product.

A choice of purity: water and air quality

Environmental conditions and the microalgae cultivation system play a crucial role in the quality of the final product. Microalgae are highly absorbent of heavy metals, which is beneficial for their detoxifying properties, but they also absorb impurities from the cultivation environment. For instance, some farms located near polluted areas use river water, which increases the presence of heavy metal traces and contaminants [2, 5, 13], compared to the farm in Hawaii, which uses ocean water pumped from 600 meters deep (which has not been at the surface for over 2,000 years) and aquifer water [1]. Guidelines for heavy metals in microalgae have been issued by farms in California and Hawaii, which, during a five-year testing program with 120 independent laboratories, demonstrated that heavy metals were either undetectable or extremely low in their products. Strict standards for heavy metals are established for arsenic (<0.5 ppm), cadmium (<0.05 ppm), lead (<0.2 ppm), and mercury (<0.025 ppm) [14]. These standards comply with California Proposition 65 on levels of daily exposure accumulation without significant risk of cancer or reproductive disorders.

A choice of assurance: producer certification

Industrial microalgae production facilities must adhere to sanitary standards. This approach includes implementing good agricultural practices (GAP), hygiene (GHP), and manufacturing (GMP), as well as hazard analysis critical control point (HACCP) systems [1]. The only farms to qualify for Generally Recognized as Safe (GRAS) certification by the U.S. Food and Drug Administration (FDA) are those in California and Hawaii [4]. Furthermore, organic certification for microalgae is not necessarily an assurance of product quality because the nutrients required for their cultivation come from compost teas derived from plant or animal materials. After three years of research into alternative nutrient sources, California and Hawaii farms decided not to integrate organic standards into their facilities due to higher levels of heavy metal contamination and bacteria, as well as higher production costs, in order to focus on producing a superior-quality product [7].

A quality choice: drying and packaging process

The manufacturing process directly influences the quality of the product. For example, chlorella has a cell wall composed of indigestible cellulose, so the producer must ensure cell wall disruption (by Dyno-Mill or jet pulverizer) to increase its digestibility, from 47% for intact cells to 80%. In the case of spirulina, which lacks a cell wall, it is easy to digest at 85-90% [5]. Additionally, many compounds in microalgae are destroyed by improper drying or prolonged exposure to light. Drying in a few seconds by atomizer limits the degradation of nutritional compounds and produces a fine powder that is easy to assimilate, virtually without aroma or taste. The farm in Hawaii has an innovative drying process called "Ocean Chill" with low oxygen levels (<1%) that preserves 90 to 95% of carotenoids. Packaging in a sealable multilayer aluminum sachet is recommended to remove residual oxygen. A well-sealed package, protected from moisture and light, helps preserve the nutritional qualities of the powder for up to five years [1].

Investment in health

Microalgae, considering their multiple benefits, are a health solution. They are whole, natural, minimally processed supplements available in various forms (powder and capsules) that provide vitality, energy, and support improved metabolism. The products on the market are diverse, so it's important to make an informed choice based on the desired application and consider the quality of the product.

Viviane Bélair is a marine biologist (B.Sc.) and chemist (M.Sc.)
Doctoral degree in Bioresource Engineering at McGill University.

References:

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