A daily 70 gram portion of tomato paste containing 33.3 mg of lycopene was associated with a 3.3% improvement in flow-mediated dilation (FMD), a measure of a blood vessel's healthy ability to relax, report researchers from Athens Medical School in the journal Nutrition Research.
However, such benefits were only observed after medium term consumption of the tomato product, with no benefits observed over the short term, reported the researchers.
“Multiple mechanisms contribute to the effect of tomato products,” wrote the authors, led by Panagiotis Xaplanteris.
“The antioxidant properties of carotenoids, mainly lycopene, are central to their beneficial properties. The processing of tomatoes and cooking them with olive oil increases the carotenoid bioavailability.
“Carotenoids prevent the oxidation of LDL-cholesterol, and some studies report a mild LDL-cholesterol reduction effect after tomato juice supplementation.”
Tomatoes beyond lycopene
The health benefits of tomatoes have been linked to its lycopene content, an antioxidantreported to have heart, blood pressure, prostate, osteoporosis, skin and other benefits in both natural and synthetic form.
The Greek researchers explained that they chose to use a whole tomato product and not lycopene in order to directly extrapolate their findings to everyday culinary practices.
“The amount of lycopene contained in a serving of tomato paste exceeds the average dietary intake; nonetheless, it represents a physiologically relevant dose that compares favorably to doses used in similar human studies in the past.
“The beneficial effect of tomato products may be attributed to an additive/synergistic effect of lycopene with other micronutrients, including alpha-tocopherol, vitamin C, and rutin.”
Xaplanteris and his co-workers recruited 19 people with an average age of 39 to participate in their randomized, single-blind, crossover study.
Participants continued to consume their regular with or without 70 grams of supplemental tomato paste for two weeks.
Results showed that no significant changes in FMD were observed after one day of supplementation, but a 3.3% improvement was observed after 15 days. On the other hand, no supplementation was associated with a 0.5% decline in FMD.
“This is the first study to investigate the endothelial effects of tomato paste administration after a short-term and midterm (1 and 14 days, respectively) period of dietary supplementation in young, healthy volunteers,” wrote Xaplanteris and his co-workers.
“As hypothesized, tomato paste exerted a beneficial effect on the endothelium as demonstrated by the rise in FMD.”
Source: Nutrition Research
Published online ahead of print, doi: 10.1016/j.nutres.2012.03.011
“Tomato paste supplementation improves endothelial dynamics and reduces plasma total oxidative status in healthy subjects”
Authors: P. Xaplanteris, C. Vlachopoulos, P. Pietri, et al.