The study – published in Neurology – examined whether serum concentrations of carotenoids from food intake had any relation to the incidence of stroke and ischemic stroke in men.
Led by Dr Jouni Karppi from the University of Eastern Finland, the research team studied data from more than 1,000 men – finding that that those with highest levels of lycopene in their blood were 55% less likely to have a stroke than those with the lowest amounts.
"This study adds to the evidence that a diet high in fruits and vegetables is associated with a lower risk of stroke," said Karppi.
"The results support the recommendation that people get more than five servings of fruits and vegetables a day, which would likely lead to a major reduction in the number of strokes worldwide, according to previous research."
Karppi noted that the study also looked at blood levels of other antioxidants, including alpha-carotene, beta-carotene, alpha-tocopherol and retinol, but found no association between the blood levels and risk of stroke.
Dr Clare Walton, of the UK-based Stroke Association said more research is now needed “to help us understand why the particular antioxidant found in vegetables such as tomatoes could help keep our stroke risk down.”
The Finnish study followed 1,031 men between the ages of 46 and 65 for an average of 12 years.
During that time, 67 men had a stroke, they reported.
Of those with the lowest levels of serum lycopene, 25 of 258 men had a stroke, whilst only 11 out of 259 men with the highest levels of lycopene suffered from a stroke.
Karppi explained that when his team then looked at just strokes due to blood clots, the results were even stronger – with high the highest levels of lycopene responsible for a 59% reduction in risk compared to the lowest levels.
“This prospective study shows that high serum concentrations of lycopene, as a marker of intake of tomatoes and tomato-based products, decrease the risk of any stroke and ischemic stroke in men,” confirmed the research team.
Volume 79, Number 15, Pages 1540-1547, doi: 10.1212/WNL.0b013e31826e26a6
“Serum lycopene decreases the risk of stroke in men. A population-based follow-up study”
Authors: Jouni Karppi, Jari A. Laukkanen, Juhani Sivenius, Kimmo Ronkainen, Sudhir Kurl