by Dr. Mark Edwards
n energy imbalance causes children and adults to be overweight. The body needs a certain amount of energy, which comes from the caloric energy in food to sustain basic life functions. Body weight tends to remain the same when the number of calories eaten equals the number of calories the body uses or “burns.” When people eat and drink more calories than they burn, the energy balance tips toward weight gain, overweight, and obesity.
Children need to balance their energy too, but differently. Children tend to burn more calories than adults because their bodies are growing, which takes energy and good nutrition. Energy balance in children happens when the amount of energy taken in from food or drink and the energy used by the body to support natural growth without promoting excess weight gain.
The 2010 National Health and Nutrition Examination Survey reports that more than 2 in 3 adults are considered to be overweight or obese. About one-third of children and adolescents ages 6 to 19 are considered to be overweight or obese.
Algae offer a set of solutions to moderate obesity, including satiety, fat and nutrient bioavailability.
Satiation and satiety are central to understanding appetite control and inhibition of eating. Satiation is the feeling of fullness during an eating episode that slows, and then stops the eater. Satiety starts after the end of eating and prevents further eating before the return of hunger. Enhancing satiation and satiety derived from food assists with weight control. Many studies have examined the various sensory, cognitive, postingestive, and postabsorptive factors that can potentially contribute to the inhibition of eating.
The comparative satiety levels of these foods can be measured with the satiety index developed by Susanna Holt. A bowl of oatmeal creates a full feeling but the typical eater must munch three doughnuts before feeling satisfied. The satiety index takes 240-calorie portions of popular foods and ranks them according to how they compare with a slice of white bread, which carries a rank of 100. Oatmeal has a high satiety level at 209, while a doughnut’s rank is 68. A 240-calorie serving of boiled potatoes rank highest at 323, but French-fries score 116. Algae foods have not been added to the index yet but they will probably rank higher than oatmeal since algae offer over twice the fibers per ounce than oats.
Algae offer a rich set 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.
The fibrous bulk in algae foods delivers compounds that create a feeling of satiation. Research at the University of Copenhagen found dietary fiber from brown algae boosts satiety and promotes weight loss and weight maintenance. The researchers demonstrated that healthy subjects who took alginates and were allowed to eat as much as they wanted felt less hungry and ate less than the subjects not drinking fiber drinks with alginates. The 80 subjects who completed the study achieved a far larger weight loss with alginate treatment than those drinking a similar drink without alginates. Subjects in the seaweed fiber drink group lost 1.7 kg more body fat than those in the placebo group. The weight loss occurs because the alginates form a gel in the stomach, which strengthens the gastrointestinal satiety signals to the brain. The gel takes up space in the stomach and gives an artificial feeling of fullness. When subjects feel full, they eat less than usual.
Several patents are pending claiming original discovery of algae-based methods of inducing satiety by providing algae-based foods. These patent applications note that macro or microalgal biomass contains high levels of dietary fiber and/or digestible crude protein and/or low saturation triglyceride oil. Homogenization methods to liberate free oil and fiber enhance the feeling of satiety in a human, thereby reducing caloric intake. These patents also note that algae-based foods have the further benefit of providing heart-healthy microalgae-based ingredients while achieving levels of satiety sufficient to reduce further caloric intake.
These patents will be difficult to defend since this author intentionally described algae’s natural ability to create a feeling of satiety in the public domain. Prior Algae 101 posts describe algae-based food satiety effects before these patents were filed.
Recent studies suggest that saffron extract creates a similar feeling of satiety and assists both weight loss and avoidance of weight gain. Saffron, the dried stigmata of Crocus sativus L., is used in traditional medicine for a wide range of conditions including cramps, asthma, and depression. Saffron extract contains water-soluble glycosidic carotenoids, which act as metabolites. Metabolites are tiny compounds that facilitate metabolism as fuel, structure, signaling as well as stimulatory and inhibitory effects on enzymes.
Saffron is the most expensive natural spice and the best saffron from Iran contains only about 8% saffron glycosidic carotenoids. Several algae species contain glycosidic carotenoids, which can be grown and extracted far faster and more cheaply from algae than saffron.
Algae metabolites probably trigger the release of serotonin in the brain that occurs when people snack or overeat. By modulating the serotonin receptors, people feel calmer, have fewer urges to eat, and are less prone to overeat.
Less fat and cholesterol
Fats carry delightful flavors to the pallet but too much fat causes obesity. Food processors have tried to trim fat from junk foods by raising the salts and using sugars. Chemists have created proteins to try to mimic the smooth flavor release of fat and engineered fake fat particles so big they pass through the intestinal tract undigested. Other products have used an array of artificial sweeteners. These strategies have fooled neither the pallet nor the brain. Reduced fat chips, cookies and ice cream do not attract consumers.
Solazyme to grow algae began in 2003 with the strategy to convert sugars into ethanol for fuel. The scientists found that some algae are also adept at converting sugars into fat. Solazyme’s new culinary division, Solazyme Roquette Nutritionals now grows algae in large industrial vats using fermentation rather than photosynthesis. When stressed slightly, the algae naturally react to produce more fats than proteins. A chlorella strain produced a healthy fat similar to olive oil but with a consistency fit for use in cookies and ice creams.
The commercial product, Almagine, is a bright yellow powder made from dried algae ground up into tiny one-micron pieces. Almagine is a lipid substitute for some of the butter, eggs and flour in a chocolate chip cookie, bread, pasta or cake. The product can be used for any recipe to gain the buttery, chewy feel of the original with 40% less fat and cholesterol. Several large food processors will be testing new product lines containing Almagin in 2013.
Most algae species offer low fat, low cholesterol source of macro and micronutrients, antioxidants, vitamins, minerals and trace elements. Algae foods will play a major role in fighting obesity and all the diseases associated with extra weight.
Contemporary young people as well as adults have become less active and more sedentary. Sedentary life styles have reduced caloric intake needs with decreased energy demands. This places greater emphasis on the bioavailability of nutrients in foods because the total intake of total caloric intake largely determines ingested nutrients.
The adequacy of dietary intakes of nutrients requires not only knowledge of the nutrient content of the foods ingested but also the extent to which the nutrient present in the diet is available for absorption and utilization. Nutrients ingested but not released during the digestive process for absorption are of no nutritional value.
Bioavailability represents the relative absorption of a nutrient from food. A bioavailability index describes the relative accumulation of a nutrient into various tissues. Various nutrients and dietary components interfere with the bioavailability of vitamins. Requirements for vitamins cannot be considered independently, but must be evaluated in relationship to other nutrients and compounds consumed.
Several lines of research have studied the bioavailability trace elements, minerals and vitamins from algae such as calcium, iron, magnesium, zinc and vitamins A, B, C, D and E. Algae provide highly bioavailable micronutrients except that some studies question vitamin B12.
Algae provide the source for omega-3 fatty acids, which decrease the risk of obesity and are recommended for weight management. The beneficial effect from omega-3s for obese, at-risk children may come from the oil’s ability to alter the lipid composition of membranes.
Algae polysaccharides are gums derived from brown seaweeds, such as alginates, and red seaweeds, such as agar and carrageenan, which is also known as Irish moss. Alginates form insoluble gels that are used as emulsifiers, thickeners, and binders in food production. Polysaccharides 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 effect of algae polysaccharides, 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).
Today, algae polysaccharides are currently integrated through the modern food supply as sub-ingredients, primarily to make food more appealing or have longer shelf life. Soon, many other companies will follow Solazyme Roquette Nutritionals’ lead and produce foods that headline algae nutralence and polysaccharides to make healthier, tastier foods.