This single center, double-blinded, cross-over, placebo controlled clinical trial was performed in 2016 by the US National Institutes of Health, and investigated the effect of oral α-cyclodextrin (ACD^®), a soluble dietary fiber, on blood lipid and lipoprotein levels in healthy human subjects. ACD^® forms a hydrophobic central cavity that binds lipids and has been shown in animal studies and in previous clinical trials to alter plasma lipid levels. ACD^® is a cyclical polymer containing 6 glucose subunits and is currently sold as a food supplement known as AlphaFibe.

In the present study, we examined in a randomized cross-over placebo-control design the effect of oral ACD^® in a relatively healthy control population without diabetes and or obesity to determine if ACD^® supplementation could have broader health benefits in the general population. The primary outcome variable was plasma total cholesterol but other measures related to lipid and glucose control were also assessed.

Healthy subjects, males and females between ages 18 to 75 were screened. Out of total 103 subjects interviewed, 75 subjects completed the study. Qualified individuals in each gender group were randomized into two groups in terms of which treatment arm they received first (placebo vs. ACD^®, receiving 6 grams P.O. a day, for 12–14 weeks with a 7 day wash out between arms). The primary outcome variable plasma total cholesterol, as well as other tests related to lipids and lipoprotein and glucose metabolism was measured at baseline and at the end of each arm of the study.

ACD^® was well tolerated; no serious adverse events related to ACD^® were observed. Approximately 8 % of the subjects on ACD^® complained of minor gastrointestinal symptoms versus 3 % on placebo (p=0.2). Small-LDL particle number decreased 10 % (p<0.045) for subjects on ACD^® versus placebo. Fasting plasma glucose (1.6 %, p<0.05) and Insulin resistance index (11 %, p<0.04) were also decreased when on ACD^® versus placebo.

ACD^® supplementation appears to be safe and well tolerated in healthy individuals and showed a reduction in small LDL particles, and an improvement in glucose related parameters.

Healthy adults consumed an egg and sausage breakfast muffin, then hade their blood tested with and without supplementing with alpha-cyclodextrin (ACD^®) fiber. This study tested healthy adults at a range of weights and ages, and for the first time documented postmeal responses to a common, commercially available fat-containing meal.

In a double blind, placebo-controlled, crossover trial conducted in 2013, 34 healthy adults (28 female, 6 male) were given a commercially available breakfast sandwich as their first meal of the day, along with 8oz. of bottled water. The sandwich contains 26g of fat. They consumed the meal within 10 minutes, followed by immediate ingestion of ACD^® tablets. Blood triglyceride levels, which ordinarily rise after highfat meals, remained in the normal range in the post-meal blood profiles for the ACD^® group with triglyceride levels falling 15-20% at the 1 and 2 hour marks, and nearly 50% lower at the 3 hour mark. Furthermore, ACD^® ingestion was associated with the positive effects of increasing insulin and leptin sensit ivities. The placebo group showed no such reduction in blood triglyceride levels after 3 hours.

This human clinical study showed that taking 2g of ACD^® with a fat-containing meal supported healthy postmeal blood triglycerides. ACD^® was shown to be effective in decreasing the absorption of triglycerides into the bloodstream in the 3 hours following the meal. The effectiveness of ACD^® in supporting healthy blood triglycerides and glycemic response confirms its beneficial effects in adult men & women.

A 2012 study, conducted on the effects of Green Coffee Bean Extract was performed by Dr. Joseph Vinson, a Chemistry Professor at The University of Scranton, Pennsylvania. He studied the effects of Green Coffee Bean Extract on 16 overweight subjects over a 22 week period.

The World Health Organization predicts there will be 2.3 billion overweight adults in the world by 2017, and more than 700 million of them will be obese. Worldwide obesity has more than doubled since 1980. In 2008, 1.5 billion adults, 20 years of age and older, were overweight. Of these, over 200 million men and nearly 300 million women were obese. Adult weight gain and obesity have become worldwide problems. Issues of cost and potential side effects of prescription weight loss drugs have led overweight and obese adults to try nutraceuticals that may aid weight loss. One promising nutraceutical is green coffee extract, which contains high concentrations of chlorogenic acids that are known to have health benefits and to influence glucose and fat metabolism. A 22-week crossover study was conducted to examine the efficacy and safety of green coffee extract (GCB) at reducing weight and body mass in 16 overweight adults.

Subjects received GCB (Green Coffee Bean Extract) or placebo in separate six-week treatment periods followed by two-week washout periods to reduce any influence of preceding treatment. Treatments were counterbalanced between subjects. Primary measurements were body weight, body mass index, and percent body fat. Heart rate and blood pressure were also measured.

Significant reductions were observed in body weight (−8.04 ± 2.31 kg), body mass index (−2.92 ± 0.85 kg/m2), and percent body fat (−4.44% ± 2.00%), as well as a small decrease in heart rate (−2.56 ± 2.85 beats per minute), but with no significant changes to diet over the course of the study. Importantly, the decreases occurred when subjects were taking GCB [Green Coffee Bean Extract]. Body mass index for six subjects shifted from pre-obesity to the normal weight range (<25.00 kg/m2).

The results are consistent with human and animal studies and a meta-analysis of the efficacy of green coffee extract in weight loss. The results suggest that GCB [Green Coffee Bean Extract] may be an effective nutraceutical in reducing weight in pre-obese adults, and may be an inexpensive means of preventing obesity in overweight adults.

All subjects completed the study and there were no side effects of using GCB [Green Coffee Bean Extract]. Regarding nutrient intake, there were no significant changes in calories, percentage carbohydrates, percentage fat, or percentage proteins at any time during the study.

In looking at the individual effects of the GCB [Green Coffee Bean Extract]; 16 of 16 lost weight, 16/16 had decreased percent body fat 16/16 had a reduction in BMI, 3/13 experienced a decrease in systolic blood pressure, and 5/16 a reduction in diastolic blood pressure.

At the completion of the study, results were 16 subjects lost an average of 17 pounds and 16% of their body fat, with ZERO changes to their diet or exercise over a 22 week period.

The recently completed double-blind clinical study, conducted at the University of California in 2010, involved healthy but overweight, non-obese non-diabetic individuals. This investigation intended to confirm the effects of AlphaFibe^® on weight management and blood lipid levels, implicated in the development and pathogenesis of numerous disease states--including type 2 diabetes and cardiovascular disease in otherwise healthy individuals. Twenty-nine healthy adults (age: 43.9+/-13.3 yrs, 8 males) with a stable body weight in the previous month participated in this study. The mean BMI was 27.1 +/-2.1kg/m2 at the beginning of this double-blind, 1 month crossover study.

Unlike any other studied weight loss product, the participants did not follow a low-fat or low calorie diet. The study data showed significantly more weight loss with those using the active tablets compared to those using the placebo tablets. Levels of blood cholesterol, LDL (bad) cholesterol, and the atherogenic Apolipoprotein B level s showed significant reduction using the active tablets while HDL (good) cholesterol levels remained unchanged. Participants with high triglyceride levels reduced their blood cholesterol levels more than twice as much compared to participants with normal triglyceride levels. In addition, the higher the cholesterol levels, the greater the cholesterol reduction when using the active tablets. Using the active tablets showed significant reduction of blood insulin levels compared to those using the placebo tablets, which suggests a reduced risk of developing type 2 diabetes.

In 2008, the US Government National Institutes of Health found that high dietary intake of saturated fat and cholesterol, and elevated low-density lipoprotein cholesterol levels are some of the modifiable risk factors for cardiovascular disease. Alpha-Cyclodextrin (ACD^®), when given orally, has been shown in rats to increase fecal saturated fat excretion and to reduce blood total cholesterol levels in obese hypertriglyceridemic subjects with type 2 diabetes mellitus.

In this study, the effects of dietary ACD^® on lipid metabolism in low-density lipoprotein receptor knockout mice were investigated. Low-density lipoprotein receptor knockout mice were fed a “Western diet” (21% milk fat) with or without 2.1% of ACD^® (10% of dietary fat content) for 14 weeks. At sacrifice, there was no difference in body weight; but significant decreases were observed in plasma cholesterol (15.3%), free cholesterol (20%), cholesterol esters (14%), and phospholipid (17.5%) levels in mice treated with ACD^® compared with control mice. The decrease in total cholesterol was primarily in the proatherogenic apolipoprotein B-containing lipoprotein in fractions, with no significant change in the high-density lipoprotein fraction. Furthermore, ACD^® improved the bloody fatty acid profile, reducing the saturated fatty acids (4.5%) and trans-isomers (11%), while increasing (2.5%) unsaturated fatty acids

In summary, the addition of ACD^® improved the lipid profile by lowering proatherogenic lipoproteins and trans-fatty acids and by decreasing the ratio of saturated and trans-fatty acids to polyunsaturated fatty acids (-5.8%), thus suggesting that it may be useful as a dietary supplement for reducing cardiovascular disease.

Obesity and diabetes have become an epidemic in US. Dietary fibers have been reported to reduce the absorption of dietary fat, prevent weight gain and reduce blood lipid levels. In the current double-blind study, obese patients with type 2 diabetes were recruited for a 3 month study to examine the health effects of a new dietary fiber AlphaFibe^®.

In 2006, 66 participants were recruited and were randomized into AlphaFibe^® or placebo groups. They were instructed to take two 1-g tablets per fat-containing meal and not to change their eating patterns or daily routine. Three-day dietary records and fasting blood samples were collected prior to enrollment in the study and at the end of months 1, 2 and 3.

Dietary records showed that some participants changed their eating patterns; therefore body weight data were adjusted according to energy intake. As a group, in the 30 days leading into the study, all participants experienced an average weight gain of 1.0 ± 0.4 k. While those in the placebo group continued to gain weight during the study, those in the AlphaFibe^® group maintained their weight. Those in the AlphaFibe^® group required more energy to maintain their body weight, while those in the placebo group required less (p<0.05). Participants with hypertriglyceridemia showed a reduction (-0.48 ± 0.24 mmol/L, -8.2%) in total cholesterol with AlphaFibe, while those with the placebo group had an increase (0.24 ± 0.21 mmol/L, 5.2%, p<0.05). Adiponectin, the key weight loss hormone, was increased in the AlphaFibe^® group but reduced in the placebo group (p<0.05).

AlphaFibe^® has thus shown promising benefits in weight maintenance, a reduction of blood lipids and an increase in adiponectin levels. Therefore, AlphaFibe^® can easily be incorporated into any diabetic management regimen.

This study was performed in 2005, at the Ehime University School of Medicine, Department of Medical Biochemistry in Japan, and showed that raspberry ketones helps prevent obesity and activate lipid metabolism.

Raspberry ketone (RK) is a major aromatic compound of red raspberry (Rubus idaeus). The structure of RK is similar to the structures of capsaicin and synephrine, compounds known to exert anti-obese actions and alter the lipid metabolism. To test the effect on obesity, our group designed the following in vivo experiments: 1) mice were fed a high-fat diet including 0.5, 1, or 2% of RK for 10 weeks; 2) mice were given a high-fat diet for 6 weeks and subsequently fed the same high-fat diet containing1% RK for the next 5 weeks. RK prevented the high-fat-diet-induced elevations in body weight and the weights of the liver and visceral adipose tissues (epididymal, retroperitoneal, and mesenteric). RK also decreased these weights and hepatic triacylglycerol content after they had been increased by a high-fat diet. RK significantly increased norepinephrine-induced lipolysis associated with the translocation of hormone-sensitive lipase from the cytosol to lipid droplets in rat epididymal fat cells.

RK prevents obesity and fatty liver. These effects appear to stem from the action of RK in altering fat metabolism, or more specifically, in increasing norepinephrine-induced lipolysis in white adipocytes.

In 2004, a human clinical study was performed at the Nutritional Physiology Research Center in Adelaide, Australia. This study evaluated the dose-response effects of Alpha-Cyclodextrin, a cyclic oligosaccharide, on the glycemic and insulinemic responses to the consumption of a standard carbohydrate meal.

In a double-blind, randomized, cross-over design, 10 healthy subjects consumed boiled white rice containing 50g of digestible carbohydrate to which 0 (control). 2. 5 or 10g of a-Cyclodextrin was added. Plasma glucose and insulin concentrations were determined prior to and for 2 hours after consumption of each meal.

The area under the plasma glucose curve was negatively related to the dose of a-Cyclodextrin (r2 = 0.97, p = 0.02), with the areas being significantly reduced at the 5- and 10-gram doses compared with the control (p < 0.05). a-Cyclodextrin did not affect the area under the plasma insulin curve (p = 0.39). Higher doses of a-Cyclodextrin resulted in greater satiety, but were associated with reduced palatability and an increased incidence of minor gastrointestinal complaints (stomach ache, nausea, bloating).

a-Cyclodextrin reduces the glycemic response to a standard carbohydrate meal in a dose-dependent manner and may be useful as an ingredient for reducing the glycemic impact of such foods.