Satiety - Appetite Control
In a study just published in the Journal of the American Medical Association (JAMA), the effects of caloric restriction were measured in a group of overweight adults over a six-month period.1 The findings were nothing short of astounding!
The most exciting finding of this study was the amount of weight lost in the groups that restricted their calorie intake. The moderate caloric-restriction group experienced a 24% reduction in body fat mass, while the very low-calorie group achieved a 32% reduction in fat mass.1
You may be wondering how these findings pertain to you, since hunger is the factor that precludes most people from even considering a low-calorie diet.
The remarkable news is that pinolenic acid – a natural plant extract discovered in Europe has been shown to suppress appetite dramatically without causing any stimulatory effect. Pinolenic acid attacks the underlying mechanisms involved in hunger so effectively that study participants reduced their food intake by 36%.7
How Satiety Hormones Affect Appetite
Satiety is the sense of food satisfaction and fullness experienced after eating. Hunger and satiety both depend on a complex feedback loop involving many hormones and other substances secreted by the gut that interact with control centers in the brain The gut participates in the hunger-satiety circuit by secreting two important hormones, cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), among others.
Cholecystokinin is recognized to suppress appetite in humans. When a partially digested meal rich in fats or proteins leaves the stomach to enter the duodenum (the first portion of the small intestine), the duodenal mucosa cells secrete CCK. In turn, CCK stimulates the pancreas to secrete numerous enzymes to help digest food. CCK also acts on the gallbladder to stimulate the release of bile into the small intestine, which helps to emulsify and break down fats. Most important to appetite control, CCK acts to slow gastric emptying and to promote a feeling of fullness, thus suppressing further food intake.19
Glucagon-like peptide-1 is another hormone that is intimately connected with fullness and satiety. Produced in the small intestine in response to fat and carbohydrates, GLP-1 works in part by activating the "ileal brake" mechanism. This slows down the absorption of food in the gut, promoting feelings of fullness and satiety, and therefore limits the desire for further food intake.20
GLP-1 also helps to control the health of pancreatic beta cells, which serve the crucial function of manufacturing insulin in the body. Abnormal beta-cell function plays a key role in the development of insulin resistance, and scientists believe that therapies that boost GLP-1 levels could help to favorably alter the course of diabetes.21
CCK and GLP-1 are key hormones for appetite control and satiety, and scientific studies show that these two hormones exert effects in combination that are more powerful than either alone (synergistic effects). 15, 22-27 Studies of normal-weight and obese subjects have shown that GLP-1 and CCK reduce feelings of hunger and decrease voluntary food intake at meals.28-31
Recent findings demonstrate that pinolic acid, a polyunsaturated fatty acid derived from pine nuts, stimulates the secretion of the hunger-suppressing hormones CCK and GLP-1.7 This exciting finding suggests that pinolenic acid may have powerful effects in reducing appetite and increasing food satisfaction and fullness.
Pinolenic Acid: Effective Appetite Suppressant
In early 2006, scientists reported on the health benefits of Korean pine nut extract at a meeting of the American Chemical Society. They described the results of a randomized, double-blind, placebo-controlled trial to determine how supplementing with pine nut-derived pinolenic acid, brand name PinnoThin, affected feelings of satiety and hunger.7 The researchers discovered that the pine nut extract stimulates production of the two important hunger suppressing hormones CCK and GLP-1.
In this study, overweight women were given either 3 grams of pinolenic acid or inactive placebo (olive oil) immediately before eating a modest breakfast consisting of carbohydrates. Scientists drew blood and measured for hormones associated with hunger, satiety, and eating behavior, at baseline and thereafter at regular intervals for four hours following the initial dose. The women also provided assessments of their perceived hunger at each interval.7
The women were asked to rate their "desire to eat" and "prospective food intake." Those who received pinolenic acid reported significantly decreased hunger compared to subjects who had taken placebo. Subjects who received pinolic acid rated their "desire to eat" an impressive 29% lower than placebo subjects, while they rated their "prospective food intake" 36% lower than those who received placebo.7
Furthermore, the lab tests in this study showed that pinolenic acid increased satiety hormones like CCK in the participants' bloodstreams. Specifically, four hours after taking pinolenic acid, test subjects had 60% more CCK circulating in their bloodstreams than did placebo subjects.7
Hormonal Effects of Pinolenic Acid
Among the pinolenic acid subjects, levels of GLP-1 initially climbed in both the placebo and pinolic acid subjects. In the placebo group, however, GLP-1 values began to drop after 30 minutes and continued to decline steadily for the remainder of the four-hour test period. In the women supplemented with pinolenic acid, GLP-1 levels continued to rise, peaking at one hour and reaching a level well above that achieved by placebo subjects. GLP-1 levels remained comfortably above those of placebo subjects throughout the trial, peaking again at three hours post-dose, and this time achieving an even greater increase in levels of this satiety-enhancing hormone over placebo subjects. In total, over four hours, GLP-1 increased 25% more in subjects who took pinolenic acid than in those who took the placebo.7
Appetite Control at Mealtime
The benefit of appetite control at mealtime is critical to anyone interested in cutting calories and losing weight, especially those who have struggled to overcome feelings of hunger and deprivation while dieting. Pinolenic acid, a natural fatty acid derived from the Korean pine nut, offers an effective tool to help enhance satiety and appetite control. Promoting satiety and thus curbing the impulse to over-indulge at mealtime is just one of the beneficial effects of pinolenic acid, brand name PinnoThin.
Recent research has demonstrated that when subjects are given GLP-1 before a meal, their blood sugar remains lower and their blood cholesterol levels are reduced compared to subjects given placebo. Since elevated blood sugar and high cholesterol after meals are associated with diabetes and cardiovascular disease, researchers speculate that therapies that boost GLP-1 levels (such as pinolenic acid) may be helpful in preventing cardiovascular disease.12
Other Benefits of Pinolenic Acid
In another study, Japanese researchers fed pinolenic acid to animals bred to develop high blood pressure, a known risk factor for cardiovascular diseases like stroke and heart attack. After five weeks of feeding, the animals' blood pressure readings were substantially lowered. Decreased cholesterol levels also were noted in the pinolenic acid-fed animals.33
Scientists have investigated the mechanism by which pinolenic acid lowers cholesterol. They found that after adding concentrated pinolenic acid extracted from pine nuts, enhanced uptake of detrimental LDL by liver cells was observed. The scientists suggest that the pinolenic acid concentrate may have LDL-lowering properties by enhancing liver LDL uptake.34
Reprinted with exclusive permission of Life Extension.