Dietary restriction of lycopene for a period of one month resulted in significantly increased biomarkers of oxidative stress and bone resorption in postmenopausal women.

BACKGROUND AND OBJECTIVES: Lycopene is a carotenoid commonly found in tomatoes and tomato products which acts as an antioxidant to decrease oxidative stress and osteoporosis risk. We wanted to determine the effects of a lycopene-restricted diet on oxidative stress parameters and bone turnover markers in postmenopausal women. SETTING: St. Michael 's Hospital, Toronto, ON, Canada. PARTICIPANTS AND STUDY DESIGN: 23 healthy postmenopausal women, 50-60 years old, provided blood samples at baseline and following a one-month lycopene-depletion period. MEASUREMENTS: Serum samples were analyzed for carotenoids; the oxidative stress parameters protein thiols and thiobarbituric-malondialdehyde reactive substances; the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and the bone turnover markers bone alkaline phosphatase and crosslinked N-telopeptide of type I collagen (NTx). A paired t-test was used to test for significant differences in bone turnover markers, oxidative stress parameters and antioxidant status after lycopene restriction. RESULTS: Dietary lycopene restriction resulted in significantly decreased serum lycopene (p < 0.0001), lutein/zeaxanthin (p < 0.01), and α -/ß -carotene (p < 0.05). GPx (p < 0.01), lipid and protein oxidation increased (not significant), while CAT and SOD were significantly depressed (p < 0.05 and p < 0.005, respectively). These changes coincided with significantly increased NTx (p < 0.05). CONCLUSIONS: These findings suggest that the daily consumption of lycopene may be important as it acts as an antioxidant to decrease bone resorption in postmenopausal women and may therefore be beneficial in reducing the risk of osteoporosis.

Supplementation with the antioxidant lycopene significantly decreases oxidative stress parameters and the bone resorption marker N-telopeptide of type I collagen in postmenopausal women.

UNLABELLED: To date, no intervention studies have been published demonstrating the effect of the antioxidant lycopene on bone. Postmenopausal women supplemented with lycopene had significantly increased antioxidant capacity and decreased oxidative stress and the bone resorption marker N-telopeptide (NTx). Lycopene decreases bone resorption markers and may reduce the risk of osteoporosis. INTRODUCTION: We have previously shown in vitro and in vivo that lycopene from tomato is associated with a protective effect on bone, but lycopene intervention studies have not been reported. Our aim was to carry out a randomized controlled intervention study to determine whether lycopene would act as an antioxidant to decrease oxidative stress parameters, resulting in decreased bone turnover markers, thus reducing the risk of osteoporosis in postmenopausal women. METHODS: Sixty postmenopausal women, 50-60 years old, were recruited. Following a 1-month washout without lycopene consumption, participants consumed either (N = 15/group): (1) regular tomato juice, (2) lycopene-rich tomato juice, (3) tomato Lyc-O-Mato lycopene capsules, or (4) placebo capsules, twice daily for total lycopene intakes of 30, 70, 30, and 0 mg/day respectively for 4 months. Serum collected after the washout, 2 and 4 months of supplementation, was assayed for cross-linked aminoterminal N-telopeptide, carotenoid content, total antioxidant capacity (TAC), lipid, and protein oxidation. RESULTS: Participants who consumed juice or lycopene capsules were analyzed in one group designated "LYCOPENE-supplemented". Repeated measures ANOVA showed that LYCOPENE-supplementation for 4 months significantly increased serum lycopene compared to placebo (p < 0.001). LYCOPENE-supplementation for 4 months resulted in significantly increased TAC (p < 0.05) and decreased lipid peroxidation (p < 0.001), protein oxidation (p < 0.001), and NTx (p < 0.001). These decreases in lipid peroxidation, protein oxidation, and NTx were significantly different from the corresponding changes resulting from placebo supplementation (p < 0.05, p < 0.005, and p < 0.02, respectively). CONCLUSIONS: Our findings suggest that the antioxidant lycopene is beneficial in reducing oxidative stress parameters and the bone resorption marker NTx.

Paraoxonase 1 polymorphisms 172T→A and 584A→G modify the association between serum concentrations of the antioxidant lycopene and bone turnover markers and oxidative stress parameters in women 25-70 years of age.

BACKGROUND/AIMS: Polymorphisms of the paraoxonase 1 (PON1) enzyme affect the ability to protect LDL from oxidation. Oxidative stress is a risk factor for osteoporosis and antioxidants may be beneficial for prevention. The aim of this study was to determine whether PON1 genotypes modified the association between lycopene and bone turnover markers and oxidative stress parameters. METHODS: Blood samples from 107 women 25-70 years of age were analyzed for serum carotenoid concentrations, bone-specific alkaline phosphatase (BAP), N-telopeptide of type I collagen (NTx) and oxidative stress parameters. Subjects were genotyped for the 172T→A and 584A→G polymorphisms of PON1. RESULTS: The 172T→A polymorphism modified the association between lycopene and NTx (p < 0.05 for interaction). In the 172TT genotype, high serum lycopene was associated with decreased NTx (p < 0.05). The 584A→G polymorphism modified the association between lycopene and BAP (p < 0.05 for interaction). Additionally, in participants with the 584GG genotype, high serum lycopene was associated with high TBA-reactive substances (p < 0.05). CONCLUSIONS: These findings show that PON1 polymorphisms modify the association between serum concentrations of lycopene and oxidative stress parameters and bone turnover markers and may, therefore, moderate the risk of osteoporosis.

Lycopene intake by Canadian women is variable, similar among different ages, but greater than that reported for women in other countries.

Lycopene is an antioxidant associated with a reduced risk of chronic diseases common in women such as osteoporosis and cancer; however, no official recommendation for lycopene consumption exists, and intake data from Canadian women are limited. This study was designed to generate information about average lycopene intake in Canadian women of different ages. A cross-sectional study was conducted at St. Michael's Hospital in Toronto, Ontario, Canada. One hundred one women, between the ages of 25 and 70 years, who were not on any medications, were recruited to record their diet for 7 days. Statistical analyses were performed to compare the types of lycopene-containing foods consumed, associations between intake of lycopene and macro/micronutrients, and whether participant characteristics, such as body mass index, could predict lycopene intake. Average lycopene intake was 6.14 +/- 5.35 mg/day, which is higher than reported in other countries. Intake was similar among age groups but was highly variable. Raw tomatoes were the most frequently consumed source of lycopene, while participants with the highest lycopene intake consumed more cooked/processed tomato products than those with lower intake (P < .005). Participants 25-49 years old consumed more dried/powdered tomatoes (P < .05), pizza (P < .002), and ketchup (P < .10) than 50-70 year olds. Lycopene intake could not be predicted by any participant characteristics. In older participants, lycopene intake was positively correlated with intake of calcium, niacin, and vitamins A, D, and K (P < or = .05). These findings are significant to women's health and may contribute to the establishment of nutritional and health recommendations regarding consumption of lycopene by Canadian women to prevent chronic diseases.

Lycopene consumption decreases oxidative stress and bone resorption markers in postmenopausal women.

INTRODUCTION: Oxidative stress induced by reactive oxygen species (ROS) is associated with the risk of osteoporosis, and can be reduced by certain dietary antioxidants. Lycopene is an antioxidant known to decrease the risk of age-related chronic diseases, such as cancer. However, the role of lycopene in osteoporosis has not yet been investigated. MATERIALS AND METHODS: In a cross-sectional study, 33 postmenopausal women aged 50-60 years provided seven-day dietary records and blood samples. Serum samples were used to measure serum lycopene, lipid peroxidation, protein thiols, bone alkaline phosphatase (BAP), and cross-linked N-telopeptides of type I collagen (NTx). The serum lycopene per kilogram body weight of the participants was grouped into quartiles and associated with the above serum parameters using one-way ANOVA and the Newman-Keuls post-test. RESULTS: The results showed that groups with higher lycopene intake, as determined from the dietary records, had higher serum lycopene (p<0.02). A higher serum lycopene was found to be associated with a low NTx (p<0.005). Similarly, groups with higher serum lycopene had lower protein oxidation (p<0.05). DISCUSSION: In conclusion, these results suggest that the dietary antioxidant lycopene reduces oxidative stress and the levels of bone turnover markers in postmenopausal women, and may be beneficial in reducing the risk of osteoporosis.