Hearty tomatoes

Tomatoes serve no end of purposes: they are essential for a bruschetta, add something wonderful to a gaspacho, bring a dash of colour to your kitchen decor, can be grown almost anywhere, and make for an entertaining evening discussing the difference between a fruit and a vegetable. On top of all this tomatoes are also healthy. They are an important part of the Mediterranean diet which we recently discussed in this column as being good for your blood pressure. Now a new study adds further to our knowledge as to why a Mediterranean style of diet is good for you by showing that tomatoes are good for your blood vessels too.

Every year more than 130 million tons of tomatoes are produced around the world and it is regarded as being grown “worldwide”. There are more than 7500 varieties of this fruit which originally was yellow in colour when it was grown first by the Aztecs of central America. Nutritionally tomatoes are very rich containing good amounts of vitamins C, A, and lycopene (a powerful anti-oxidant), and it is the lycopene that was focussed on in the new research.

The study involved 36 patients with cardiovascular disease (CVD) who were compared to 36 “healthy” people without CVD. The people in the study continued with their regular diets over the course of two months but half of each group were randomly assigned to take a pill containing 7mg of lycopene daily. That amount of lycopene is equivalent to 900 grams of fresh tomatoes or one tablespoon (15mls) of tomato paste.

At the beginning and end of the study the subject’s forearm blood flow, arterial stiffness, cholesterol, and blood fats levels were measured. Even though the subjects who had CVD were taking statin drugs at the beginning of the trial they still showed as having blood vessels that were not as healthy as the “healthy” participants. The endothelium is the lining of blood vessels and in narrowing the arteries the endothelium cells do not respond properly to acetylcholine.

The results of the study showed that after two months of taking lycopene people with CVD showed a 53 per cent improvement in the response of their endothelium to acetycholine, apparently because of an increase in nitric oxide production.

The researchers say that this shows that tomato consumption would improve the function of blood vessels. This would be especially true of tomato paste because it is a concentrated form of lycopene. In case you needed another reason to go “Mediterranean” with your diet, looks like you’ve found it.