A study by the a group of scientists from the USA and Sweden reports that consuming a single concentrated dose of thylakoids (present in spinach) increased the levels of the satiety hormone and reduced food cravings over a two-hour period in a gender-specific manner.
Spinach is known to be a leafy vegetable of good nutritional value and is rich in antioxidants, positively influencing eye, skin, hair, and bone health. A 100g serving of spinach provides 3g of protein, 4g of carbohydrates, and 2g of fiber. Spinach is considered to possess anti-inflammatory and anti-cancer properties. The folate in spinach is known to improve cognitive functioning.
The new study, published in the Journal of the American College of Nutrition, adds to the qualities mentioned above of spinach. Thylakoids, which are membrane-bound chambers inside the chloroplasts (which make the food for the plant), are sites where photosynthesis takes place in plants. It has previously been shown with mice and rats that thylakoid supplementation was useful in suppressing appetite and weight gain, as well as a reduction in body fat percentage.
In the study being discussed here, 60 overweight and obese volunteers, aged 18-65 years, were recruited. Each participant was tested for two days, with spinach extract being served one day and placebo on the other, in a random manner. Blood samples were collected from participants before a standard breakfast and later following a standard lunch and 5g dose of the extract four hours later. Blood was also drawn two hours after lunch. A pizza dinner was served as well, with free access.
The results of the study show that:
- Those on spinach extract showed increased satiety over a two-hour period when compared to individuals who consumed placebo extract.
- This satiety coincided with increased postprandial plasma glucose response.
- Thylakoid consumption resulted in reduced cravings for salty food and savory food and decreased thirst when compared to the placebo group.
- No significant differences were observed in craving for sweet food between the groups.
- The thylakoid group also expressed increased fullness after a meal and a decreased longing for food.
- There were no significant differences in dinner intake between the two groups.
- However, men showed a tendency toward decreased energy intake during dinner, following thylakoid extract consumption.
One of the co-authors of the article, Dr. Frank L. Greenway, says in the Taylor and Francis News Release, “The reduction in hunger and the desire for salty food that we saw in this study might make thylakoids particularly useful for people with high blood pressure and associated weight problems.”
The authors state in the article, “thylakoids supplementation may influence food cravings by acting on the reward system, thereby offering a novel way to address a positive energy balance in a manner that is minimally burdensome on the consumer.”
Written by Mangala Sarkar Ph.D.
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