Spinach Leaf Extract Found to Suppress Appetite, Increase Meal Satisfaction

Study Published in Journal of the American College of Nutrition
August 5, 2015, CLEARWATER, FL––The nutritional value of spinach is well documented.  The vegetable is rich in crucial vitamins A, C, E, and this versatile food that can be sauteed, used as the foundation for a salad, or be an essential ingredient in a festive party dip. 

A key element of spinach is thylakoids, a photosynthetic membrane of chloroplasts. In a new study (http://bit.ly/1Da1ONr), a team of medical and nutritional researchers measured subjective satiety (the feeling of being full after eating) ratings and food intake after a single dose of thylakoids from a patented spinach leaf extract, and measured them against participants who consumed a placebo. They found that a single supplement of five grams of the extract increased satiety measured subjectively over two hours. Adding the extract to the diet may influence food cravings by acting on the brain’s reward system thereby offering a unique way to address the issue of weight gain in a manner that is convenient for the public.  

The Study
The study, “Acute Effects of a Spinach Extract Rich in Thylakoids on Satiety:  A Randomized Controlled Crossover Trial,” is published online in the Journal of the American College of Nutrition. Sixty overweight volunteers (30 male and 30 female) were enrolled in a double-blind randomized crossover study who consumed the spinach extract or placebo in random order for at least a week apart. The spinach extract was mixed with standard beverages but not with the placebo. 

Hunger, fullness, desire to eat, satisfaction, thirst and an appetite for sweet, salty and savory foods were assessed. Blood was drawn to assess baseline fats and sugars before a standard breakfast meal, which was followed four hours later by a five gram dose of the spinach extract and a standard lunch. Other measurements were taken to assess appetite satisfaction before lunch and at regular intervals until a dinner was served four hours later. 

The researchers found that when compared to a placebo, a single dose of five grams of thylakoids increased appetite satisfaction measured subjectively over two hours.  That satisfaction was accompanied by a greater increase in the after-dinner blood sugar response.   

The spinach extract contained concentrated thylakoids extracted from spinach leaves. By interacting with fats and retarding fat digestion, thylakoids membranes are believed to promote the release of satiety hormones and reduce the hunger-stimulating hormone ghrelin. This may lead to a release of a mechanism for increasing appetite suppression. 

The study also suggests that thylakoids supplementation may influence food cravings by acting on the reward system of the brain.  “As obesity remains a critical impediment to good health for millions of Americans, these findings might offer one solution to over-eating, a critical cause of unwanted weight gain,” according to the authors. “Reducing the desire for salt may be particularly helpful for those with high blood pressure,” they add.

Research Team
The research team was composed of Candida J. Rebello, Robbie Beyl and Frank L. Greenway, all of the Pennington Biomedical Research Center, School of Nutrition and Food Sciences, Louisiana State University System, Baton Rouge, La.; Jessica Chu, Louisiana State University School of Medicine, New Orleans, La.; Dan Edwall, Greenleaf Medical AB, Stockholm, Sweden; and Charlotte Erlanson-Albertsson, Department of Experimental Medical Science, Appetite Regulation Unit, Faculty of Medicine, Lund University, Lund, Sweden. 

The study was funded in part by a grant from Greenleaf Medical AB, Stockholm, Sweden.


About the Journal of the American College of Nutrition
The Journal of the American College of Nutrition (JACN) publishes original and innovative research articles, commentaries, and other data about nutrition which is useful for researchers, physicians, and other health care professionals. The journal is published six times per year and is the flagship publication of the American College of Nutrition.

NOTE TO EDITORS: The article is available online at no charge at http://bit.ly/1Da1ONr. 
To schedule an interview with a member of the research team please contact the American College of Nutrition’s Media Relations Department at Media@AmericanCollegeofNutrition.org.

Keywords:  Spinach, spinach extract, thylakoids, satiety, nutrition, Journal of the American College of Nutrition, weight management, functional foods