Thylakoid, a compound hidden away in spinach and other green leaves, slows down food digestion and therefore makes us feel fuller, according to research at Lund University in Sweden. A spinach extract high in thylakoids triggered a release of satiety hormones in the intestine, the researchers found.
Eating spinach isn't enough, however. It has to be crushed, filtrated and centrifuged, freeing the thylakoids from the plant's cells, since our bodies can’t break it down from fresh spinach directly. The final product, a natural water extract, is different from many plant-based extracts that use organic solvents.
Thylakoids are believed to slow down fat digestion, meaning the whole intestine has time to get involved. Once food enters the distal intestine, satiety hormones are released and sent up to the brain, telling us we are full. Modern, processed foods tend to only utilize the upper intestine, so the key hormones are not released.
“I like to say our intestines are unemployed”, says Professor Charlotte Erlanson-Albertsson at Lund University, the researcher behind the findings.
Professor Erlanson-Albertsson knew that if she found a way to slow down fat digestion, she could put our intestines back to work. Since she only dealt with synthetic molecules, she asked her husband, a scientist researching the photosynthesis, if there was a natural molecule that could trigger satiety. He steered her in the direction of thylakoids in green leaves, as they are high in galactolipids.
She found that if human test subjects were given a shot of the spinach extract in the morning, they felt less hungry and had fewer cravings during the day. They subsequently found it easier to stick to three meals a day, compared to the control group that was given a shot without the active substance. The thylakoid group also had had higher levels of satiety hormones in their blood, and had more stable blood glucose levels.
Professor Erlanson-Albertsson believes that the powerful effect of thylakoids can’t be traced to just one active ingredient.
“It contains hundreds of substances - galactolipids, proteins, vitamin A, E, K, antioxidants, beta-carotene, lutein, and so on”, she concludes.
A full list of Professor Erlanson-Albertsson’s published research (several publications relating to thylakoids)
Charlotte Erlanson-Albertsson, Professor in Appetite Regulation, Lund University