By Matt Ntinos, PhD

Obesity is increasing worldwide at an alarming rate, giving rise to major health problems such as heart disease, type 2 diabetes, stroke and cancer. Obesity is the result of an imbalance between energy intake and energy expenditure. Diet and exercise, pharmacological therapy and surgical interventions are common ways to treat obesity.

While increase in energy expenditure and reduction of calorie intake is of enormous importance and has to be followed religiously for one’s good health, common treatment approaches that are based on physical activity and food restriction alone often fail due to poor compliance.

Pharmacological options, such as sibutramine, orlistat and phentermine, are commonly prescribed to assist weight loss efforts. However, despite the initial benefits, drug treatment is often associated with rebound weight, side effects and potential drug abuse.

Similarly, surgical interventions involve dramatic permanent changes in a person's ability to digest food and are not always appropriate.

When conventional medicine fails to treat obesity successfully and without adverse events, many people seek therapies in herbal medicine. Natural products with anti-obesity properties are receiving a lot of attention in light of the alarming upward obesity trend and the often serious side effects posed by medicinal drugs of chemical origin.

Proactol – A Natural Medicinal Product

Proactol is a revolutionary patented fiber complex that is 100% natural, made from the dried leaves of Opuntia ficus indica, a species of cactus (prickly pear cactus) known for its large, sweet fruits called tunas or nopal. Traditionally, the leaves and fruits of the cactus Opuntia ficus indica have been used in the medicinal and cosmetic industry [1].

Early studies performed in animals that consumed fresh or dehydrated leaves of the plant showed that tunas lowered the levels of LDL—the bad cholesterol—by 34% without changing HDL—the good cholesterol—levels [2].

A medicinal herb made from the dehydrated leaves of the prickly pear cactus has been patented under the name NeOpuntia, which is the basis of the commercially known diet pill Proactol. NeOpuntia binds and prevents absorption of lipids from the intestine, thus minimizing the caloric contribution of fat to the overall energy content of food. What sets NeOpuntia apart from other herbal diet supplements is the clinical studies that have demonstrated its efficacy and safety.

The fat binding capacity of NeOpuntia has been tested in a number of clinical studies conducted by InQpharm, as well as other independent laboratories.

Study 1. Fat-Binding Properties of Proactol in a Gastrointestinal Model

When NeOpuntia was first patented, it was hypothesized that it binds the ingested lipids and prevents their absorption as the food bolus moves through the gastrointestinal tract.

How are lipids absorbed in humans? Nutrients—carbohydrates, proteins and lipids—can be absorbed only if they are in a water-soluble (hydrophilic) form. Of course, lipids are not soluble in water, unlike carbohydrates and protein. In order for lipids to be absorbed after a meal, the gallbladder contracts and discharges bile salts. The salts bind the fat molecules and convert them to water-soluble structures known as micelles. A micelle has the shape of a sphere where the water-soluble bile salts are on the surface and the water-insoluble lipids are enclosed within. The process is called emulsification of lipids. Unlike the free lipids, the micelles are hydrophilic—they can be dispersed in water—and therefore the intestinal wall can easily absorb them. NeOpuntia is supposed to bind lipids and prevent the emulcification process—the coating of lipids by the bile salts.

In order to test the hypothesis that NeOpuntia binds lipids in the digestive system, a device known as TNO-intestinal model was used. This unique in-vitro system is an accurate simulator of the digestive processes that take place in the human stomach and small intestine. In this study, the TNO system was used to simulate the digestive process of a typical American breakfast. The food was inserted in the device and was left to digest for 4 hours. The lipids in the food were "absorbed" in a way that mimics the normal digestive process, which involves the formation of micelles. The experiment showed that the addition of 2 grams of NeOpuntia to the system prevented the absorption of 23% of the fats contained in a typical American breakfast, as compared to a control condition where no NeOpuntia was added.

Study 2: Effect of Proactol on Fat Excretion in Humans

NeOpuntia's lipid binding effect has been tested in humans. This study examined the effect of NeOpuntia in the meal digestion process of ten healthy volunteers. The hypothesis was that if the patented Opuntia ficus indica binds the fat component of food when consumed with a meal, it should prevent absorption of lipids from the small intestine. This inhibition of fat absorption from the intestinal wall would manifest itself as excess fat in feces (steatorrhea).

The participants, 5 men and 5 women with a BMI of 23.3 kg/m2, were randomly divided into two groups. The experimental group was administered the patented fiber complex of Opuntia ficus indica material (NeOpuntia group) whereas the control group received an inactive material (placebo group). Both groups consumed 1.6 grams of the encapsulated test material with a meal rich in fat content. In order to make sure that the dietary intake of lipids was the same in both groups, all participants followed a carefully designed diet with standardized meals that contained the same amount of fat.

A mean increase of 27.4% of the amount of excreted fat was observed in the feces of the NeOpuntia group, while none of the participants experienced any adverse reactions. These results suggested that NeOpuntia binds and therefore prevents the absorption of fat in the gastrointestinal tract of human subjects.

Study 3: Proactol Does Not Cause Vitamin Deficiency

The energy equivalent of 1 gram of fat is 9 calories, whereas the energy load of 1 gram of protein or carbs is only 4 calories. Fat blockers can be a great anti-obesity tool because they inhibit absorption of lipids, which are the most calorie dense nutrient. However, lipids are necessary for the absorption of fat-soluble vitamins A and E. These vitamins are absorbed together with the fat in the small intestine. That means that substances that block absorption of fat, usually block the absorption of fat-soluble vitamins as well, posing the risk of vitamin deficiency. A good example is Alli, a popular over the counter fat blocker, which inhibits vitamin E absorption by 60%.

In order to examine the effect of the patented fiber complex of Opuntia ficus indica on the fat-soluble vitamins A and E, the following simple test was performed: NeOpuntia was added to a mixture of sunflower oil containing amounts of vitamin A and E that are typically consumed by a person in a day. The experiment was carried out in a gastrointestinal model that simulates the physiological conditions of the digestive tract. Interestingly, NeOpuntia did not bind to fat-soluble vitamins A and E. Therefore, it is clear that the fat binding action of NeOpuntia does not interfere with the absorption of fat-soluble vitamins, and thus it does not have an impact on the physiological levels of these vitamins.

Study 4. Weight Loss and Satiety Effect Of Proactol

A study conducted in Berlin, Germany, aimed at assessing the effect of NeOpuntia—the patented ingredient of Proactol—on body weight and appetite in human subjects. For the purpose of this study, Caucasian subjects were randomized in two groups: the NeOpuntia and the placebo group. In order to eliminate individual food intake variations the participants were instructed to adhere to a specified diet plan, which consisted of 2500 calories daily intake.

After consumption of the patent fiber complex for 3 days, the average body weight decreased significantly by 0.72kg (1.7lbs). The reduction in body weight reflected the observed increase in fecal fat excretion—an effect of NeOpuntia that has been observed in other studies as well. Eighty percent of the subjects in the NeOpuntia group reported moderate to strong feelings of satiety. In contrast, the members of the placebo arm did not report similar feelings. These results were achieved with very good tolerance.

Study 5. Effect of NeOpuntia on Metabolic Syndrome

The International Diabetes Federation defines Metabolic Syndrome a cluster of abnormalities that include elevated fasting glucose, abdominal obesity (waist circumference greater than 80cm), high blood pressure and triglycerides, as well as lower than normal HDL, the good cholesterol.

A double-blind placebo-controlled study that was conducted in France in the summer 2006 tested whether the Opuntia patented fiber complex can improve the conditions that are risk factors for Metabolic Syndrome.

Of the 68 women that were recruited in the study, 35 consumed 1 capsule containing 1.6g of NeOpuntia 3 times a day, 30-60min after each meal with a glass of water. The remaining 33 women followed the same protocol but took placebo capsules, instead. During the course of the study, the participants in both groups followed a 2000-calorie balanced diet combined with a minimum 30min of exercise per day. After forty-two days on the experiment, blood lipid parameters (LDL, HDL, total cholesterol and triglycerides) were measured.

In the placebo group, LDL, the bad cholesterol, decreased, but so did HDL, the good cholesterol. The decrease in the LDL observed in the placebo group was attributed to the exercise and balanced diet that was part of the experiment. However, at the end of the study, Metabolic Syndrome was still present in 92% of the placebo group.

Unlike the placebo group, the NeOpuntia group showed a significant increase in HDL, the good cholesterol. This is of particular importance because elevated HDL is associated with lower cardiovascular risk. In addition to the cardioprotective effect, triglycerides, blood pressure, and waist circumference also improved in the NeOpuntia group. When the study was over, only 61% of the NeOpuntia group had Metabolic Syndrome.

Although the biological mechanisms by which NeOpuntia protects against Metabolic Syndrome are not yet known, it is possible that the high fiber content of the leaves and antioxidant components, such as carotenoids and lutein, play a significant role [4].

Closing Thoughts

Popular weight management programs in the US, such as Medifast and Nutrisystem—also known for their sought after Nutrisystem promotion coupons and Medifast coupon codes—cannot boast the simplicity, cost effectiveness and herbal nature of Proactol. Based on the proven lipophilic properties of the fiber from Opuntia ficus indica cactus, Proactol represents a breakthrough in the world of natural weight loss. Backed by strong scientific research Proactol is being used world-wide and is considered one of the best diet pills on the market.

References
1. Stintzing FC, Carle R. Cactus stems (Opuntia spp.): a review on their chemistry, technology, and uses. Mol Nutr Food Res. 2005;49:175-194.
2. Cárdenas Medellin ML, Serna Saldívar SO, Velazco de la Garza J. Effect of raw and cooked nopal (Opuntia ficus indica) ingestion on growth and profile of total cholesterol, lipoproteins, and blood glucose in rats [in Spanish]. Arch Latinoam Nutr. 1998;48:316-323.
3. Wolfram RM, Kritz H, Efthimiou Y, Stamotopoulos J, Sinzinger H. Effect of prickly pear (Opuntia robusta) on glucose- and lipid-metabolism in non-diabetics with hyperlipidemia — A pilot study. Wien Klin Wochenschr. 2002;114:840-846.
4. Jaramillo-Flores ME, González-Cruz L, Cornejo-Mazón M, Dorantes-Alvarez L, Gutiérrez- López GF, Hernández-Sánchez H. Effect of thermal treatment on the antoxidant activity and content of carotenoids and phenolic compounds of cactus pear cladodes (Opuntia ficus-indica). Food Sci Technol Int. 2003;9:271-278.