Hypo- and Hyperresponse to Egg Cholesterol Predicts Plasma Lutein and β-Carotene Concentrations in Men and Women

Abstract

The purpose of this study was to determine whether the plasma response to dietary cholesterol from eggs is associated with the plasma carotenoid response and whether gender influences the carotenoid response. Using a crossover design, 40 subjects classified as either hyper- (10 men and 10 women) or hyporesponders (10 men and 10 women) to dietary cholesterol consumed an egg (EGG, 640 mg/d additional dietary cholesterol and 600 microg lutein + zeaxanthin) or placebo (SUB, 0 mg/d cholesterol, 0 microg lutein + zeaxanthin and 568 microg beta-carotene) diet for 30 d, followed by a 3-wk washout period and the alternate diet. Plasma concentrations of lutein and beta-carotene after each dietary period were then examined to determine whether the response to carotenoid intake was similar to that seen for dietary cholesterol. After the EGG period, the increase in plasma lutein in female hyperresponders (mean increase +/- SD; 0.32 +/- 0.19 micromol/L) and male hyperresponders (0.26 +/- 0.11 micromol/L) was significantly greater than that of their hyporesponsive counterparts (0.16 +/- 0.18 micromol/L for women and 0.14 +/- 0.11 micromol/L men). Gender was not a significant factor influencing lutein response. Both men and women classified as hyperresponders significantly increased plasma beta-carotene after the SUB period, whereas their hyporesponsive counterparts were not affected. The increase in plasma beta-carotene in female hyperresponders (0.29 +/- 0.48 micromol/L) was significantly greater than that in male hyperresponders (0.07 +/- 0.07 micromol/L). We conclude that plasma responses to cholesterol and carotenoids are related and that gender influences the beta-carotene response to a greater degree than the lutein response.

Eggs distinctly modulate plasma carotenoid and lipoprotein subclasses in adult men following a carbohydrate-restricted diet

“…To determine carotenoid content of egg and egg substitute, a 100-μl aliquot was placed in a screw-top test tube with 1 ml pyrogallol in reagent alcohol and 5 ml 15% potassium hidroxyde (KOH) in methanol, as previously described [13]. An internal standard (ethyl-β-apo-8′-carotenoate) was added to the sample and reconstitute with 2-propanol in preparation for high-performance liquid chromatography (HPLC) analysis.…”

“…Plasma samples were prepared for HPLC analysis as previously described [13]. Briefly, 200 μl of serum was mixed with an equal volume of absolute ethanol containing butylated hydroxytoluene and ethyl-β-apo-8′-carotenoate (internal standard).…”

“…Carotenoids and cholesterol share common pathways in absorption and transport in the plasma compartment and the definitions of hypo-and hyper-responders exist for both [13,14]. Since carotenoids are transported in plasma by lipoproteins, changes in the concentrations of different lipoprotein subclasses are expected to affect carotenoid transport.…”

Carotenoids from Rhodotorula and Phaffia: yeasts of biotechnological importance

“…Epidemiological evidence and experimental results suggest that dietary carotenoids inhibit the onset of many diseases in which free radicals are thought to play a role in initiation, such as arteriosclerosis, cataracts, multiple sclerosis and cancer [34,[39][40][41][42][43][44].…”

Macular zeaxanthins and lutein – a review of dietary sources and bioavailability and some relationships with macular pigment optical density and age-related macular disease

“…0·3 mmol/l per mg, and only in one study where one of the lutein treatments provided 826 mg/d for 12 weeks was a lower response of 0·136 mmol/l per mg obtained 40 . It could be argued that it might take longer for the plasma concentration to reach its plateau in response to large doses but Clark et al 39 gave 600 mg egg lutein per d for only 3 weeks and the total response (lutein and zeaxanthin combined) was 0·367 mmol/l per mg. So the reason for the relatively poor response to the high-xanthophyll-containing eggs used by Wenzel et al 40 is not immediately apparent.…”