Funded by Swedish Oat Fiber, which owns a patent for liposomes from fractionated oat oil (LOO) and satiety, the clinical trial found that LOO significantly increased the appetite regulating hormones PYY, GLP-1 and CCK as well as the feeling of satiety.
“Our results suggest that the oat oil preparation could be an effective dietary supplement that supports reduced energy intake in a healthy way. However, more studies are needed to confirm our results and further chart the mechanisms,” said Lena Ohlsson, a medical researcher at Lund University.
Two blinded randomised studies with crossover design were performed. In the first study 19 healthy men and women consumed 35g lipids from LOO or yogurt as part of a normal breakfast. In a follow-up study 15 women consumed 14 or 1.8g lipids from LOO mixed in yoghurt. Blood samples were analysed for plasma lipids, insulin, glucose and intestinal hormones CCK, PYY, GLP-1 and GLP-2 before and at intervals of one, three, five and seven hours after the meal. Satiety was measured via a questionnaire.
The main finding was that intake of 14g and 35g lipids from LOO significantly increased blood concentrations of the satiety hormones CCK, GLP-1 and PYY, as well as levels of GLP-2 – a hormone that promotes the growth of intestinal cells.
“The levels of PYY, GLP-1 and CCK were surprisingly high five hours after consumption of LOO containing more than 14g lipids. The trend we found between PYY concentration and total energy intake during the rest of the day indicates a reduction of energy intake during the rest of the day after a breakfast with LOO,” wrote the researchers.
The oat oil preparation used in the study was developed by Magnus Härröd, who invented a method of creating oat oil with extra high levels of polar lipids. Polar lipids are building blocks in the cell membranes and act as signal substances. The main components of polar lipids in oats are galactolipids.
The researchers hypothesised that after consuming galactolipid-rich oils dispersed into very small liposomes, the amount of lipids in the distal small intestine would increase. This would stimulate the release of gastric hormones, slow down gastric emptying and pancreatic secretion and induce satiety.
“An increasing amount of lipids in the ileum will thereby stimulate hormone signals or satiety and affect postprandial lipemia at a relative low energy intake,” wrote the researchers.
Comparison with Fabuless
The researchers compared the oat oil preparation in the study to DSM’s Fabuless, a fat emulsion containing 40% palm oil, 2.5% fractionated oat oil and 57.5% water. Early intervention studies showed a significant decrease in energy intake after eating Fabuless, but these results have since been rendered inconclusive.
The researchers pointed out that the lipids used in the present study do not contain palm oil, and that the concentration of polar lipids in LOO was considerably higher than in Fabuless (56% vs 2%).
“A consequence of this is that the structure of the particles is different; the core of liposomes is water, while the core of the particles in an emulsion (Fabuless) is oil,” they wrote.
They added that this meant LOO was digested differently than the dairy emulsion and said: “The positive postprandial effects are more obvious with LOO than with Fabuless.”
The researchers said a well-controlled, long-term study aimed at satiety, weight control and gut health was warranted as a next step.
Food & Nutrition Research, volume 58, 6 October 2014
“Postprandial effects on plasma lipids and satiety hormones from intake of liposomes made from fractionated oat oil: two randomized crossover studies”
Authors: Lena Ohlsson, Anna Rosenquist, Jens F. Rehfeld and Magnus Härröd