More Evidence on Side Effects of a High-Protein Diet 33547

More Evidence on Side Effects of a High-Protein Diet

WAGENINGEN, The Netherlands--Research conducted at Wageningen Centerfor Food Sciences and Wageningen University concluded a diet high in protein canincrease postprandial levels of homocysteine, which may contribute tocardiovascular disease. Published in the September issue of the AmericanJournal of Clinical Nutrition www.ajcn.org(82, 3:553-8, 2005), the randomized, dietarycontrolled, crossover trial involved 20 healthy men, aged 18 to 44, who consumeda low-protein controlled diet along with either a protein supplement (21 percentof energy from protein) or an isocaloric amount of short-chain glucose polymers(9 percent of energy from protein).

Following eight days of the diet treatment, as well as a 13-day washoutperiod, the treatments were reversed. Researchers took blood samples from eachman on days one and eight, before breakfast (fasting) and throughout the day.Blood tests revealed fasting total homocysteine (tHcy) levels did not differbetween the high-protein and low-protein diets after one week of treatment.However, the daily homocysteine levels were higher from the high-protein diet onboth day one and eight. The scientists concluded a high-protein diet raisedhomocysteine levels postprandially, but did not increase fasting homocysteinelevels. They noted the extent of tHcy increase was modified by the amino acidcomposition of the diet. Furthermore, they conceded the relevance of the resultsdepends on whether high concentrations of homocysteine, especially postprandiallevels, contribute to cardiovascular disease.