Elsevier

Redox Biology

Volume 11, April 2017, Pages 384-389
Redox Biology

Research Paper
Hydroxytyrosol supplementation increases vitamin C levels in vivo. A human volunteer trial

https://doi.org/10.1016/j.redox.2016.12.014Get rights and content
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Abstract

Hydroxytyrosol (HT) is a main phenolic component of olive oil. In this study, we investigated the safety and effects produced by HT purified (99.5%) from olive mill waste. HT was administered at a daily dosage of 45 mg for 8 weeks to volunteers with mild hyperlipidemia (n=14). We measured markers of cardiovascular disease risk, enzyme markers of several clinical conditions, hematology, antioxidant parameters, vitamins and minerals at baseline (T0), 4 weeks (T4) and 8 weeks (T8). The values obtained at T4 and T8 were compared with baseline. We found that the HT dose administered was safe and mostly did not influence markers of cardiovascular disease, blood lipids, inflammatory markers, liver or kidney functions and the electrolyte balance. Serum iron levels remained constant but a significant (P<0.05) decrease in ferritin at T4 and T8 was found. Serum folate and red blood cell folate levels were also reduced at T4 and T8. Finally, vitamin C increased by two-fold at T4 and T8 compared with levels at baseline. These results indicate a physiologically relevant antioxidant function for HT through increasing endogenous vitamin C levels.

Abbreviations

ALT
alanine aminotransferase
AST
aspartate aminotransferase
ALP
alkaline phosphatase
CPK
creatine phosphokinase
CRP
ultrasensitive C-reactive protein
GGT
Gamma glutamyl transferase
HDL-C
high-density lipoprotein cholesterol
HCT
hematocrit
Hcy
homocysteine
ICAM
intercellular cell adhesion molecule 1
LD
lactate dehydrogenase
LDL-C
low-density lipoprotein cholesterol
Lpa
lipoprotein a
MCH
mean corpuscular hemoglobin
MCV
mean corpuscular volume
MCHC
mean corpuscular hemoglobin concentration
MDA
malondialdehyde
ox-LDL
oxidized LDL
TAC
total antioxidant capacity
TC
total cholesterol
TG
triacylglycerols
VCAM
vascular cell adhesion molecule 1

Keywords

Hydroxytyrosol
Polyphenolics
Olive oil
Antioxidant
Human study
Vitamin c

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