Writing in Osteoporosis International, calcium researchers at the University of Toronto (UT) claim that 30mg of lycopene found in tomatoes – the equivalent to two glasses of tomato juice – is enough to help prevent the brittle-bone disease.
The study was funded by the Canadian Institutes of Health Research (CIHR), the Research and Development Departments of Genuine Health, Heinz, Millenium Biologix, Kagome (Japan), and LycoRed.
Osteoporosis is characterised by low bone mass, which leads to an increase risk of fractures, especially the hips, spine and wrists. An estimated 75 million people suffer from it in Europe, the US and Japan.
Women are four times more likely to develop osteoporosis than men and previous research indicates that diabetes decreases bone turnover that is associated with impaired osteoblastic maturation and function.
According to the International Osteoporosis Foundation, the total direct cost of osteoporotic fractures in Europe is €31.7bn so boosting bone density in high-risk and post-menopausal women could ease the burden of osteoporosis.
Lycopene is the red pigment in tomatoes and several fruits. According to the UT scientists, it is a potent carotenoid – a group of naturally occurring pigments essential for plant growth – with a high ability to quench singlet oxygen.
Due to this ability to decrease oxidative stress, lycopene has been associated with a decreased risk of chronic diseases.
The researchers claims that to date, no intervention studies have been published demonstrating the effect of the antioxidant lycopene on bone, and that the aim of the study thus was to determine whether lycopene would act as an antioxidant to decrease oxidative stress parameters that result in decreased bone turnover markers.
Methodology and results
Post-menopausal women aged 50 to 60 were restricted from consuming anything containing lycopene for a month.
The participants were split into four groups over four months. Each group of participants either consumed a 15mg lycopene supplement, a glass of tomato juice naturally containing 15mg of lycopene, a gourmet Japanese tomato juice with 35mg of lycopene or a placebo.
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, added the authors.
By the end of the initial lycopene-free month, in every participant, "There was an increased reobsorption of bone. In other words, within a month, the participants were more prone to the risk of osteoporosis," says Leticia Rao, director of the Calcium Research Laboratory who conducted the study.
After four months, results showed that lycopene-supplementation had significantly increased serum lycopene compared to the placebo group.
The lycopene groups had significantly increased antioxidant capacity, decreased oxidative stress parameters and decreased bone reobsorption markers.
The results of the study, concluded the researchers, showed a significant increase in serum lycopene after supplementation with juice or lycopene based capsules, which resulted in a decrease in the bone resorption marker NTx in postmenopausal women:
“This reduction in NTx may be due to the ability of the absorbed lycopene to reduce the oxidative stress parameters in these women. Our findings are the first to show that lycopene intervention, given in capsule or juice form, supplying at least 30 mg/day, may decrease the risk of osteoporosis by decreasing oxidative stress and bone resorption.”
Source: Osteoporosis International
Published online ahead of print: 10.1007/s00198-010-1308-0
Title: Supplementation with the antioxidant lycopene significantly decreases oxidative stress parameters and the bone resorption marker N-telopeptide of type I collagen in postmenopausal women
Authors: E. S. Mackinnon, A. V. Rao, R. G. Josse and L. G. Rao