Are dietary amino acids prospectively predicts changes in serum lipid profile?

Besides of dietary fat and carbohydrate, amino acids(AAs), as constituent components of dietary protein have been related with serum lipid levels. This study aims to examine the association between dietary AAs and prospective changes in serum lipid profile in adults.

Analyses were conducted on 3881 participants aged, 18-75 years of Tehran lipid and Glucose study, at baseline (2008-2011) and were followed for 3 years (2011-2014) to ascertain serum lipid profile changes. Dietary intakes of AAs were collected at baseline using food frequency questionnaire. Multiple linear regression adjusted for age, sex, body mass index, physical activity, smoking and daily intakes of energy, total fat, and fiber were used.

The median(IQR) changes in triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were 6.0(-19.0, -35.5), 9.0(7.0, -24.0), 1.0(-3.0, -6.0), and 5.2(-8.0, -18.6) mg/dl, respectively. Higher intakes of isoleucine, lysine, tyrosine, alanine, threonine, methionine, valine, histidine, aspartic acid, and branched chain, alkaline, and alcoholic AAs were positively associated with TGs-changes in the final adjusted model, whereas tryptophan, glutamic acid, and acidic AAs were negatively related to TG-changes. Alanine and tryptophan were associated with higher and lower LDL-C-changes, respectively. Lysine, alanine, methionine, aspartic acid, and alkaline AAs showed positive association with changes in TC, whereas tryptophan and glutamic acid had a negative association with TC-changes.

Our findings showed that some dietary amino acids have the potential to increase or decrease serum lipid profile.