(OR18-03-25) A DGA-Style Diet Featuring Pulses as the Primary Protein Improves Iron Storage, Reduces Inflammation and Body Weight: A Randomized Controlled Feeding Trial

Objectives: Pulses are naturally low in sulfur amino acids, and robust research links reduced sulfur amino acid intake to significant chronic health benefits. Despite promotion of pulse consumption by healthy eating patterns such as the Dietary Guidelines for Americans (DGA), its consumption remains low in the U.S., potentially due to concerns about the lower bioavailability of non-heme iron. This study evaluated the effects of a DGA-style lacto-ovo-vegetarian diet, with pulses as the primary protein source, on key factors related to healthy aging, including body weight and biomarkers of iron storage and inflammation.

Methods: This 18-week PRODMED1 feeding study used a protein-distinct, macronutrient-equivalent design with two arms (pulse and meat) and included 47 healthy Midwestern adults aged ≥60 years. All foods were provided, with primary proteins contributing >45% of total protein intake. Biomarkers were assessed via serum multiplex immunoassays, and body composition via dual-energy X-ray absorptiometry, before and after intervention. Data analysis utilized R packages, paired t-tests, and linear mixed models for within- and between-group comparisons.

Results: The DGA-style diet, irrespective of protein sources, significantly improved health-related outcomes from baseline to post for both pulse and meat diets (all p< 0.05), however, greater improvements were observed after pulse consumption for ferritin (+24.6% pulse vs. +12.15% meat, p=0.047), CRP (-32.5% pulse vs. -22.7% meat, p=0.29), body weight (-4.5% pulse vs. -3.1% meat, p=0.04) and body fat (-9.9% pulse vs. -9.6% meat, p=0.91). Self-reported survey data indicated that satisfaction levels for the pulse diet were similar to those for the meat diet among Midwestern participants.

Conclusions: This RCT is among the first to demonstrate that pulses are an acceptable and healthful primary protein source for Midwestern older adults in a feeding study. A healthy lacto-ovo-vegetarian DGA-style diet with pulses—a non-heme iron source—improves anti-inflammatory outcomes, supports weight and fat loss, and maintains iron status, making it a viable option for promoting healthy aging.

Funding Sources: United States Department of Agriculture (PCHI, Hatch). The trial is registered as NCT #NCT05577858.