Drinking unsalted tomato juice can reduce the risk of heart disease, new research claims.
Scientists found drinking one 200ml bottle every day lowered blood pressure and cholesterol in people at risk of the condition.
But critics today urged caution over the study, warning it didn’t take into account other food and lifestyle choices.
Tokyo Medical and Dental University researchers studied 481 people over the course of a year, providing them with as much of the drink as they wanted.
Participants kept diaries in which they recorded exactly how much tomato juice they consumed each day, in addition to any health changes they noticed.
Most of the study participants consumed about one bottle (200 ml) of unsalted tomato juice every day, researchers said.
Blood pressure dropped by three per cent in 94 volunteers with untreated pre-hypertension or hypertension (high blood pressure), on average.
The beneficial effects were similar among men, women and different age groups, according to the findings published in the journal Food Science and Nutrition.
Researchers say lycopene – a chemical that gives tomatoes their famous red colour – prevented plaque from building up in participant’s arteries, causing a drop in blood pressure.
They claim lycopene works by inhibiting LDL – a harmful type of cholesterol that leads to hardening of the arteries.
The study also claims compounds found in tomatoes decrease the absorption of dietary cholesterol in the small intestine and cholesterol synthesis in the liver.
When there is too much cholesterol in blood, it builds up in the walls of arteries, causing a process called atherosclerosis, a form of heart disease.
But experts issued caution over the findings. Victoria Taylor, senior dietitian at the British Heart Foundation (BHF), said more research is needed to accurately represent the health benefits of tomato juice.
She said: ‘The Japanese population is likely to be different to that of the UK, so we shouldn’t generalise.
‘The study also fails to look at what else participants were eating or whether they had consumed tomatoes in other forms and it does not take lifestyle factors into account which could have affected their blood pressure and cholesterol levels.’
Ms Taylor said increasing your daily intake of fruit and vegetables, including tomatoes, helps maintain a healthy heart and circulatory system.
But she warned against drinking more than one 150ml portion of fruit or vegetable juice per day due to the high sugar content.
Chris P Gale, professor of cardiovascular medicine and honorary consultant cardiologist at the University of Leeds, was sceptical of the study but reiterated that a healthy diet does reduce the risk of heart disease.
He added: ‘This small study suggests that unsalted tomato juice was associated with lower blood pressure and an improved lipid profile.
‘However, it was not conducted with the rigor necessary to provide high quality evidence, such as that in randomised controlled trials.’