By Anthony Almada, MS
"Starch blockers," among the many ineffective diet fads of the 1980s, are trying to make a comeback—this time gaining legitimacy through scientific studies in humans. Their marketers claim they work by reducing the ability of carbohydrate-digesting enzymes to break down more complex carbs into absorbable sugars. Prescription starch blockers are already being used to manage blood sugar in diabetics, yet weight loss is not a notable side effect for these patients. Of the starch blockers that are currently available on the market as dietary supplements, one ingredient called Phase 2, or Phaseolamin 2250, has been the subject of a modest amount of research. In the only study presented at a scientific meeting, 11 subjects ate four slices of white bread with 42 grams of margarine and either Phase 2 or a placebo. Tested four hours later, those who took the starch blockers (vs. placebo) appeared to absorb two-thirds less of the digested sugars from the bread. Results from another study did show evidence that starch blockers could promote weight loss, although it appears that an appreciable amount of the weight lost may be water. Blocking carbs may work without side effects, but long-term studies need to prove this.
Nutrition and exercise biochemist Anthony Almada, MS, has collaborated on more than 45 university-based studies and is cofounder of Experimental and Applied Sciences (EAS) and founder and chief scientific officer of IMAGINutrition.