by Mark Edwards
lgae are the oldest photosynthetic organisms on Earth, having survived 3.7 billion years. This tiny plant developed incredible survival strategies in order to flourish through climatic cycles, temperature spikes and fierce electrical storms. Marine algae also had to live with pounding ocean waves and violent currents. The plant may have evolved fibers to sustain itself in the littoral zone at the margins of estuaries and oceans.
Algae assumed its long-term role to provide food at the bottom of the food chain. Plants and animals that evolved later depended on algae to provide the essential nutrients, vitamins and trace elements for an active life.
Systemic obesity and diabetes would have ended animal evolution eons before early hominoids appeared. Therefore, algae had to offer dietary nutrients that moderated obesity and diabetes. Plant, animal and human fossils reveal that algae provided the essential nutrients for development and growth, while providing compounds that created a feeling of satiation—fullness—that moderated hunger pains and the desire to eat beyond basic needs.
Obesity and diabetes have become an epidemic globally. The Centers for Disease Control reported recently that one of three of our children born after the year 2000 will develop diabetes. Algae fibers may moderate the onset and provide treatment of diabetes.
Algae offer a source of bioactive agents that facilitate efficient and healthful metabolic processes. The fibrous components of algae add bulk to the digestive tract reducing hunger, transit time, and intestinal pathologies. Studies have revealed that the fibrous bulk reduces hunger pains by creating a feeling of satiety, which aids in avoiding weight gain and obesity. Avoiding hunger pains reduces the urge to find another bite to eat.
Algae polysaccharides also demonstrate anti-atherosclerotic functions, reducing blood LDL cholesterol concentrations and cardiovascular disease risk. These soluble polysaccharides may act as prebiotics, stimulating growth of beneficial bacteria in the colon.
The soluble dietary fibers in algae provide value for avoiding obesity and diabetes. The total fiber content of several algae species, (~6 g/100g), is greater than that of fruits and vegetables promoted today for their fiber content: prunes (2.4 g), cabbage (2.9 g), apples (2.0 g), and brown rice (3.8 g).
Research shows that the fibers attenuate the blood glucose response after a meal. In long-term studies, algae fibers improved control of diabetes. Sodium alginate induces significantly lower postprandial rises in blood glucose, serum insulin and plasma C-peptides. The diminished glucose response, after the addition of sodium alginate in the diet, may lead to the delayed gastric emptying rate, induced by the fiber.
The effect of soluble fiber on the blood glucose response seems related to its ability to increase the viscosity of a meal. Viscous fibers slow the gastric emptying rate of a meal in subjects with and without diabetes. Alginate fiber offers a source of viscous dietary fiber in algae-based foods. The main constituents of alginates are uronic acids (mannuronic and guluronic acids), which give the alginate characteristics similar to pectin (galacturonic acid).
Other research has investigated algae’s ability to moderate hypoglycemic effects through enhancement of glucose uptake in the liver and in soleus muscles. Improved insulin sensitivity after algae treatment could be also due to lower serum non-esterified fatty acid levels. Insulin sensitivity tends to blunt elevated non-esterified fatty acids in diabetes. Phenolic-rich extracts from four edible marine macroalgae—Ulva, Ascophyllum, Alaria, and Palmaria—were found to offer biological components that inhibit replication of cultured colon cancer cells. These studies confirmed that phenolic extracts inhibit digestive enzymes and achieve anti-diabetic effects.
Several studies have shown algae’s ability to decrease lipids, lower blood sugar and improve diabetic symptoms. Research confirms that algae reduce triglycerides and low-density proteins in blood cholesterol, which helps regulate lipids, and offers other health benefits.
Most algae offer low-fat proteins that often have nutrient profiles superior to land-based plants, dairy or meat. The next generation of food processing will incorporate more low fat, nutrient rich algal components throughout the food system to improve health and reduce obesity.
Food processors commonly use algae fiber as a texture modifier in the food industry. Alginates provide alginic acid from brown algae, which thicken liquid products and make them creamier and more stable over wide variations in temperature, acidity and time.
Kelp, Fucus and Sargassum seaweed produce alginic acid. Sargassum begins its life growing in the tropics near coral reefs. It breaks off, begins to drift, and yet continues to grow at both ends. Ocean currents such as the Gulfstream carry it across the oceans. Harvesters collect Sargassum from tropical waters all the way to the British coast.
Processors extract alginic acid from the algae cell walls. This alginate is a colloidal product used for thickening, suspending, stabilizing, emulsifying, gel forming or film forming. About half of the alginate produced goes into ice cream and other dairy products to make them smoother and to prevent ice crystals. Processors use the remainder in shaving cream, lotions, rubber and paint.
Manufacturers use alginates in textiles to thicken fiber-reactive dye pastes, which facilitate sharpness in printed lines and conserves dyes. Dentists use alginates to make dental impressions of teeth. Other products made with alginates include kelp shampoo, antacids, salad dressings, syrups, orange juice and Top Ramen noodles.
Although very low in fat, algae is an excellent source of the essential polyunsaturated fatty acids. The omega-6 and omega-3 fatty acids (ARA and EPA/DHA respectively) are necessary for normal metabolism, as they are the precursors to critical hormone-like, signaling molecules known as the eicosanoids. These short-lived messengers direct life-supporting functions such as blood clotting, inflammation, vasodilation, blood pressure and immune function.
Algae provide substantially higher levels of essential minerals than other food sources, especially iron, zinc, manganese and iodine. Algae are high in chlorophyll, which aids in tissue repair and may be useful in assimilating and chelating calcium and other heavy minerals. Algae components have proven to support the immune system and act as antiviral and antitumor agents. Research shows algae phycocyanin promotes healthy tissue growth and provides resistance to influenza viruses and intestinal virus. Other studies have found algae proteins stop the spread of SARS and H5N1 viruses.
Some algae such as the blue-green spirulina have no cell walls, which aid digestion and nutrient absorption. Studies have demonstrated digestion rates of 95% for essential amino acids. Algae provide higher quality protein than red meat. Unlike meat, algae contain all eight essential amino acids required for the human body. Algae also pack a variety of essential vitamins including a, c, e, b, and b-carotene, biotin, folic acid, pantothenic acid and creatine. The vitamin e and b-carotene content is the best antioxidant and helps the body stave off free radical damage.
Edible algae have played an important part of the diet in many Pacific Rim countries for eons. Chinese sources offer over 1,000 algae naturopathic remedies from both micro and macroalgae. Recent research in Western countries confirms the therapeutic value of algae components in providing satiety and moderating glucose uptake from foods. Algae polyphenol extracts have anti-diabetic effects through the modulation of glucose-induced oxidative stress. The extracts also slow starch-digestive enzymes such as alpha-amylase and alpha-glucosidase.
Algae polyphenol extracts are likely to become a universal health ingredient in thousands of food formulations in the future. Algae offer strategic solutions in the modern battles against obesity, diabetes, heart disease and cancers.