Tomato extract could stop platelet build-up, boost heart health

Extracts from tomatoes offer heart health benefits by reducing the accumulation of platelets that lead eventually to blood clots, heart attacks and strokes, say two complimentary studies from the UK.

Aggregation of platelets is one of the three major components of heart disease, but is an area that has largely been ignored by products makers looking to tap into the growing heart health market.

"As a functional food or dietary supplement, tomato extract may have a role in primary prevention of cardiovascular disease by reducing platelet activation, which could contribute to a reduction in thrombotic events," wrote the researchers in the current issue of the American Journal of Clinical Nutrition (Vol. 84, pp. 561-569)CVD causes almost 50 per cent of deaths in Europe, and is reported to cost the EU economy an estimated €169bn ($202bn) per year. According to the American Heart Association, 34.2 per cent of Americans (70.1m people) suffered from some form of cardiovascular disease (CVD) in 2002.

The first of the studies, both led by Niamh O'Kennedy from Provexis, was a randomised, double-blinded, placebo-controlled crossover study using 90 healthy human subjects with normal platelet function. The volunteers were given either an extract-enriched or control supplement and measurements were made three hours after consumption.

It is well known that the bioactive compounds of tomatoes, notably the carotenoid lycopene, are more bioavailable when the tomatoes are processed and/or cooked.

The researchers found that significant reductions in the build-up of platelets (stimulated by administration of ADP and collagen) were observed three hours after supplementation with tomato extract equivalent to two and six tomatoes (by 21.3 per cent for six tomato equivalents, and 12.7 per cent for the two tomato equivalents for the ADP administered groups, and by 17.5 per cent for six tomato equivalents, and 7.8 per cent for the two tomato equivalents for the collagen administered groups), while no significant effects were measured for control group.

O'Kennedy and her co-workers, including researchers from Rowett Research Services, the Robert Gordon University, University of Oslo, and Centre for Cardiovascular Science, Edinburgh, also found that the inhibition of platelet function was greatest in a participants with the highest blood levels of homocysteine and C-reactive protein (CRP).

An in vitro study was also undertaken by the same researchers, and published in the same journal (AJCN, Vol. 84, pp. 570-579), in order to study the mechanism behind the apparent benefits. The researchers report that the tomato extract appears to work by inhibiting the build-up of platelets by inhibiting the so-called glycoprotein IIb/IIIa and platelet secretory mechanisms.

Thus, by decreasing the accumulation of platelets, the risk of forming a blood clot that could lead to stroke or heart attack is reduced.

Provexis continues to be very active in building the science behind their extracts. Indeed, clinical trials are about to start on a medical food based on a patented extract from the plantain banana for the dietary management of Crohn's disease. The food is being developed in conjunction with the University of Liverpool, and Provexis is also collaborating with a global clinical nutrition company.

Northwest Development Agency recently granted the company a £180,000 research grant for Crohn's disease technology.

Work is also continuing on the development of a broccoli-derived bioactive ingredient associated with reducing the risk of certain types of cancer. Provexis is working closely with The Institute for Food Research on this project.