Iron status in association with cardiovascular disease risk in 3 controlled feeding studies.
BACKGROUND
The role of body iron stores in free radical-induced peroxidation and cardiovascular disease risk has been debated, but controlled feeding studies using measurements of non-transferrin-bound iron (NTBI) and LDL oxidation have not been conducted.


OBJECTIVE
We tested the hypothesis that NTBI and other measures of iron status do not affect oxidative susceptibility in healthy subjects with normal iron status.


METHODS
Plasma samples were analyzed from 77 healthy men and women aged 20-65 y who participated in 3 controlled feeding studies in which the type and amount of dietary fat were controlled. Iron status and in vitro LDL oxidation were assessed at baseline and at the end of each feeding period (4-8 wk).


RESULTS
No significant relations were found between any measure of iron status (ferritin: 83 +/- 8.9 micro g/L; iron: 20.9 +/- 5.4 micro mol/L; TIBC: 74.4 +/- 11.0 micro mol/L; NTBI: 0.184 +/- 0.15 micro mol/L) and the in vitro measures of LDL oxidation (total dienes: 485 +/- 55 micro mol/mg LDL protein; lag time: 51.7 +/- 15.9 min; and rate of oxidation: 25.4 +/- 6.8 micro mol dienes.min(-1).g LDL protein(-1)). Equal-iron peanut butter-based diets were associated with higher plasma iron in men (22.4 +/- 3.8 micro mol/L) than was the olive oil diet (17.7 +/- 4.5 micro mol/L) (P = 0.02), but this slight elevation did not alter LDL oxidation.


CONCLUSIONS
Diet composition may affect plasma iron in men, but LDL oxidative susceptibility is unaffected by the subtle variation in iron status. Thus, the results do not support a relation between iron status and LDL oxidative susceptibility, a possible risk factor for cardiovascular disease.
Derstine
Jessica L
JL
Department of Nutrition, The Pennsylvania State University, University Park 16802, USA.
Murray-Kolb
Laura E
LE
Yu-Poth
Shaomei
S
Hargrove
Rebecca L
RL
Kris-Etherton
Penny M
PM
Beard
John L
JL
D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000209:etiology*; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010084:Oxidation-Reduction; D012307:Risk Factors
D004041:Dietary Fats; D005293:Ferritins; D007501:Iron