Review supports white bean extract’s weight management potential

A white bean extract that inhibits the action of the enzyme alpha-amylase is effective for glucose control and weight management, says a new review of the literature.

According to data in the literature, the alpha-amylase inhibitor called Phase 2 produced by Pharmachem may reduce the rate of carbohydrate absorption, which effectively decreases the glycemic index (GI) of the food.

“Experiments conducted with the Phase 2 alpha-amylase inhibitor indicate that it reduces the rate of absorption of carbohydrates, thereby reducing the GI of foods,” wrote Marilyn Barrett from Pharmacognosy Consulting and Jay Udani from Medicus Research LLC in Nutrition Research, an open-access journal.

“The evidence also indicates that Phase 2 promotes weight loss when taken concurrently with meals containing carbohydrates,” they added.

Phase 2

A proprietary extract from the common white bean (Phaseolus vulgaris), Phase 2 was first introduced in the US in 2001, and has since been made available internationally.

Phase 2 is marketed for reducing the calories gained from eating starchy food such as potatoes, bread, pasta or rice. The ingredient is said to function by neutralizing the digestive enzyme alpha amylase before it can convert starch into glucose and then into fat. As such, Pharmachem claims consuming Phase 2 permits carbohydrate to pass through the system with potentially less caloric intake.

Medicus Research has received research grants from Pharmachem Laboratories.

Review details

According to the review, the weight loss potential of the product has been reported in ten clinical trials, with three studies demonstrating efficacy compared to placebo. Doses used in these studies ranged from 445 mg over 4 weeks to 3000 mg over 12 weeks.

In addition, studies have found that the white bean extract may reduce the spike in blood sugar levels after a meal, and that the ingredient can be formulated into foods and beverages “without losing activity or altering the appearance, texture or taste of the food”.

In terms of safety, the reviewers report no serious side effects following consumption of the ingredient.

“The importance of reducing the GI of foods in weight management and type 2 diabetic control is indicated by an emerging body of evidence,” wrote the researchers. “Reducing the post-prandial spikes of glucose and insulin following a high GI meal may also reduce the risks of developing insulin resistance, which can lead to cardiovascular disease.”

An expanding market for expanding waist lines

The slimming ingredients market can be divided into six groups based on the mechanisms of action – boosting fat burning/ thermogenesis, inhibiting protein breakdown, suppressing appetite/boosting satiety (feeling of fullness), blocking fat absorption, carbohydrate blockers, and regulating mood (linked to food consumption).

At last year’s SupplySide West Expo in Las Vegas, Tom Vierhile from Datamonitor told attendees that the big growth area for supplements regarding claims is for calorie or fat burning. In 2007, calorie/fat burning was experiencing 1 percent growth, while in 2010 this had increased to 3 per cent, he said.

Satiety continues to receive a lot of attention from consumers, said Vierhile, however such interest does not necessarily translate into product sales, he said. Indeed, according to a recent survey of global consumers by Datamonitor, “consumers talk around satiety, and not about it”.

“Hunger control will potentially resonate more effectively with consumers than satiety,” he advised.

Source: Nutrition Research

2011, 10:24 doi:10.1186/1475-2891-10-24

“A proprietary alpha-amylase inhibitor from white bean (Phaseolus vulgaris): A review of clinical studies on weight loss and glycemic control”

Authros: M.L. Barrett1, J.K. Udani