Use of the dietary supplement 5-aminiolevulinic acid (5-ALA) and its relationship with glucose levels and hemoglobin A1C among individuals with prediabetes.

Objective: This study examined the association between 5-aminolevulinic acid (5-ALA) and glucose tolerance.

Design: A double blinded, randomized prospective parallel-group comparison study.

Setting: Participants were recruited from the community in Honolulu, Hawaii, using radio and TV ads, and at community events.

Participants: One hundred fifty-four males and females ages 40-70 years, with evidence of prediabetes: hemoglobin A1c (HbA1c) 5.8%-7.0% at the screening visit.

Intervention: Participants were randomized equally to one of three study groups: (1) low dose 5-ALA supplement (15 mg capsule); (2) high dose 5-ALA (50 mg capsule); and (3) control (placebo capsule of identical size and color).

Main Outcome Measures: HbA1c and 2 hours post-oral glucose tolerance test (OGTT) glucose levels.

Results: Among individuals taking 5-ALA supplements for 12 weeks, 2 hours post-OGTT glucose levels declined significantly compared to those not taking the supplement (p= 0.02). The relationships were stronger among those with baseline glucose intolerance, or 2 hours post-OGTT glucose measurements greater than 140 mg/dL (p= 0.005 and p= 0.02 for the low and high dose group, respectively). Similar trends were observed for HbA1c but results were of borderline significance (p= 0.07). No untoward effects were reported.

Conclusions: Further studies are indicated. The potential benefits of 5-ALA dietary supplementation are affirmed by this investigation.