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Seaweed Drink Suppresses Appetite, Says Obesity Journal Article

Tim Boyer's picture

Gel-forming extracts of seaweed have been used in the past in numerous weight loss products as a way to suppress appetite and lose weight. Controversy over false and misleading advertising by some sellers of weight loss pills—as well as pilot studies not detecting weight loss effects—has clouded the issue over whether or not alginates—a seaweed extract—can be beneficial toward fighting obesity. However, a recently reported online study tells us that the effectiveness of alginates toward appetite suppression is dependent upon the source of the alginates and the formulation of the seaweed drink.

One type of seaweed extract known more formally as “sodium alginate” is made from brown algae found in the ocean. The extract form of it is a mucilaginous polysaccharide carbohydrate isolated from the algae’s cell walls. Processed foods take advantage of alginate’s gel-like properties and is commonly used as a food additive in foods like ice cream and soy sauce to enhance flavor and taste, and as a thickener in gravy. When added to bread, studies have shown that alginate-containing bread scores higher in texture and richness than a typical standard loaf of white bread.

Its use in weight loss products has motivated nutritional researchers to see if the makers of supplements containing alginate can live up to their claims under scientific scrutiny. In one small pilot study published in the journal Appetite last year, researchers tested the weight loss effects of an alginate-containing drink in conjunction with a calorie-restricted diet. What they found was that drinking the alginate beverage was tolerable and acceptable by the majority of the test subjects, but it did not support previous claims made by the weight loss industry that alginate enhances weight loss. However, the researchers did note that a larger study was needed to be conclusive.

Another related study, published in the journal Obesity, may have found a reason why some studies do not reveal weight loss results with alginate. In their study the researchers believe that it is the specific alginate source—in particular its gel strength in the stomach—and the product’s chemical/physical matrix that appears to be crucial to its efficacy.

Their results in a study involving the drinking of a strongly-gelling alginate in a low-viscosity solution on 23 volunteers showed the researchers that the alginate needs to be in a fully hydrated form to be effective. Testing a range of various levels of alginate as a drink in place of a meal and looking at the effect the doses have on appetite suppression revealed that the subjects who had the highest level of alginate in their drink scored 20-30% lower in hunger in comparison to a control group.

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The researchers find that the appetite suppressing ability of their seaweed drink to be promising, but do note that additional studies are needed to establish its implications for food intake, compliance to weight loss programs, and long-term effects on weight loss or weight maintenance.

In fact, one of the concerns of taking an alginate extract is that its sodium form may be contraindicated for people with high blood pressure. In addition, because calcium is excreted with excess sodium in your urine, over time it could deplete calcium levels needed for bones, leading to a calcium deficiency and placing some individuals at risk for bone fractures and osteoporosis.

It appears then that extracts of seaweed as an appetite suppressant may be beneficial after all—if it is derived from the right source of algae and in the correct chemical/physical formulation. However, as always follow your physician’s advice before taking any supplement to ensure that there are no contraindications. For more information about seaweed and health, follow this link to a Dr. Oz-related article linking seaweeds to weight loss.

Image Source: Courtesy of MorgueFile


“Can alginate-based preloads increase weight loss beyond calorie restriction? A pilot study in obese individuals” Appetite 2011 Dec; 57(3):601-4; Georg Jensen M. et al.

“Dose-Dependent Suppression of Hunger by a Specific Alginate in a Low-Viscosity Drink Formulation” Obesity 19, 1171-1176; Harry P.F. Peters et al.