High protein-high red meat versus high carbohydrate weight loss diets do not differ in effect on genome stability and cell death in lymphocytes of overweight men

The importance of diet in DNA damage prevention is well established; however, the comparison of weight loss diets with different micronutrient and macronutrient profiles on genome stability in peripheral blood lymphocytes (PBLs) has not been studied. This study tested the hypothesis that genome stability in PBLs of overweight men who consume a high protein-high red meat (HP) weight loss diet is different from that of overweight men who consume a high carbohydrate (HC) weight loss diet. Thirty-three male subjects were randomly assigned to an HP or HC isocaloric energy-restricted dietary intervention for 12 weeks intensive weight loss and weight maintenance up to 52 weeks. Blood samples were collected at 0, 12 and 52 weeks. DNA damage in PBLs was assessed using the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay. Average weight loss after 12 weeks was 9.3 +/- 0.7 kg for both diets, with no further change at 52 weeks. Two-way analysis of variance showed no time or diet effect on micronucleus frequency (chromosome loss/breaks). There was a significant trend with time (P = 0.03) but not diet, for reduction of nuclear buds (gene amplification). There was a positive trend with time for increased nucleoplasmic bridges (chromosome rearrangement) (P = 0.051). Necrosis and apoptosis both significantly decreased with time (P = 0.037 and P = 0.007, respectively) with no diet effect. There was no significant effect of time or diet for nuclear division index, a biomarker of immune response. The results suggest that the effect of the HP weight loss diet on DNA damage measured using the CBMN-Cyt assay in PBLs was not different from that observed for the HC weight loss diet.