June 10, 2014
Ketchup And Other Tomato Products May Help Stave Off Heart Disease
Lawrence LeBlond for redOrbit.com - Your Universe Online
A Mediterranean diet has long been touted as a surefire way to improve cardiac health, but it has been a mystery as to what the underlying mechanism of the diet was that helped keep the heart healthy. Now, researchers from University of Cambridge say tomatoes may be the answer.The researchers, publishing a paper in the journal PLOS ONE, have found that a daily supplement of an extract found in tomatoes may improve blood vessel function in patients with cardiovascular disease (CVD).
The incidence of cardiovascular disease varies around the world, but is noticeably lessened in southern Europe, where people largely subsist on ‘Mediterranean diet’ foods, such as fruit, vegetables and olive oils. Recent studies suggest that this type of diet reduces the incidence of events related to CVD, including heart attack and stroke. As well, it has been suggested that this type of diet reduces incidences of heart attack and stroke in patients who are at high cardiovascular risk or in those who have previously had the disease.
One fruit that is widespread in Mediterranean dishes is the tomato. Tomatoes, as well as other fruits, contain a powerful antioxidant called lycopene, which has been previously thought to play a role in reducing cardiovascular disease risk. Lycopene is ten times more potent than vitamin E and its potency appears to be enhanced when it is consumed pureed, as is done in ketchup or in the presence of olive oil. While there is strong evidence that supports the role of lycopene in reducing cardiovascular risk, the mechanism by which it does so has remained unclear.
Dr Joseph Cheriyan, of Addenbrooke’s Hospital and Associate Lecturer at Cambridge, worked with researchers at the Cambridge University Hospitals National Health Service Foundation Trust to demonstrate one mechanism by which lycopene is believed to reduce cardiovascular risk.
“There’s a wealth of research that suggests that the Mediterranean diet – which includes lycopene found in tomatoes and other fruit as a component – is good for our cardiovascular health. But so far, it’s been a mystery what the underlying mechanisms could be,” Cheriyan said in a statement.
Cheriyan and colleagues carried out a randomized, placebo-controlled trial investigating the effects of lycopene using a gold standard method of measuring the function of blood vessels called forearm blood flow, which is predictive of future cardiovascular risk. The study included 36 CVD patients and 36 healthy volunteers. The participants were randomly given either Ateronon – an off-the-shelf supplement containing seven mg of lycopene – or a placebo. As part of the double-blind trial, neither the participants nor the researchers were aware of which treatment was being provided.
All patients who had CVD were already on cholesterol-lowering drugs known as statins. However, all patients still had a relatively impaired function of the endothelium (inner lining of blood vessels) compared to the healthy participants. This function is determined by the response of blood vessels in the forearm to a naturally occurring molecule called acetylcholine. Since endothelial function predicts future events, a healthy endothelium is key to preventing future heart disease.
The research team found that seven mg of oral lycopene supplementation improved and normalized endothelial function in the CVD patients, but not in the healthy volunteers. Lycopene improved the responses of the blood vessels to acetylcholine by more than half (53 percent) compared to baseline in those taking the pill after correction for placebo effects. The team determine, however, that the supplement had no effect on blood pressure, arterial stiffness or lipid levels.
“We’ve shown quite clearly that lycopene improves the function of blood vessels in cardiovascular disease patients,” added Dr Cheriyan. “It reinforces the need for a healthy diet in people at risk from heart disease and stroke. A daily ‘tomato pill’ is not a substitute for other treatments, but may provide added benefits when taken alongside other medication. However, we cannot answer if this may reduce heart disease – this would need much larger trials to investigate outcomes more carefully.”
Despite the outcome of this trial, Dr Cheriyan cautions reliance on the use of lycopene solely as a way to fight the risk of CVD.
"A daily 'tomato pill' is not a substitute for other treatments, but may provide added benefits when taken alongside other medication. However, we cannot answer if this may reduce heart disease - this would need much larger trials to investigate outcomes more carefully,” noted Dr Cheriyan.
“Impaired endothelial function is a known predictor of increased risk of future heart disease. Further work is needed to understand whether the beneficial effects seen in this small study translate into clinical benefit for at-risk patients,” added Prof Jeremy Pearson, Associate Medical Director at the British Heart Foundation.
The “tomato pill” used for the study comes from CamNutra, a Cambridge University-based company that developed Ateronon as a way to help protect people from CVD. The study was funded and sponsored by Cambridge University Hospitals NHS Foundation Trust, and included further support from Wellcome Trust, the British Heart Foundation and the National Institute of Health Research Cambridge Comprehensive Biomedical Research Centre.