Finnish researchers found that of more than 1,000 older men they followed, those with relatively high blood levels of the antioxidant lycopene were less likely to have a stroke over a dozen years.
But the study, published in the journal Neurology, does not prove that tomatoes and ketchup can cut anyone's stroke risk.
"Studies like this are interesting, but they have significant limitations," said Dr. Larry B. Goldstein, director of the Duke Stroke Center and a professor at Duke University Medical Center in Durham, North Carolina.
There may be other things about men with high lycopene levels, unmeasured in this study, that could explain the lower stroke risk, according to Goldstein, who was not involved in the work.
The study included 1,031 men ages 46 to 65 who had their blood levels of lycopene, alpha- and beta-carotene, and vitamins E and A measured.
Over the next 12 years, there were 11 strokes among the one-quarter of men with the highest lycopene levels; that compared with 25 among the one-quarter with the lowest levels.
The researchers then accounted for some major factors that affect stroke risk, like smoking, high blood pressure and diabetes. And the high-lycopene group still had a 55 percent lower risk of suffering a stroke.
The other nutrients were not linked to men's stroke risk.
It's plausible that lycopene could have a direct effect on stroke risk, according to Jouni Karppi, a researcher at the University of Eastern Finland, in Kuopio, who led the Lapland Central Hospital-funded
Lycopene is a "potent antioxidant," Karppi said in an email. That means it helps protect body cells from damage that can ultimately lead to disease. Lab research also suggests that lycopene helps fight inflammation and blood clots - and may be better at it than certain other antioxidants.
But that's lab research. And the current study lacked some critical information - like the men's overall diet habits - that might help explain why lycopene was linked to a lower stroke risk.
But Karppi said the findings support the current advice to get plenty of fruits and vegetables in your life.
'GET A WELL-BALANCED DIET'
Generally healthy eating is key, Goldstein said. He noted that we already have examples where researchers, and the public, may have put too much stock in a single nutrient.
Researchers once thought vitamin E and beta-carotene supplements might prevent heart disease, based on studies showing lower rates among people who got more of those nutrients.
But clinical trials - where people were randomly assigned to take supplements or a placebo - showed that vitamin E had no such benefit. Beta-carotene was even linked to increased heart risks in some people.
"These findings do reinforce the current recommendations for people to get a well-balanced diet, with fruits and vegetables," Goldstein said.
He said the "best example" of a diet that might curb your stroke risk is the "DASH" diet that experts generally recommend for lowering blood pressure and protecting your heart.
Clinical trials have shown that the DASH diet cuts blood pressure and cholesterol levels. The plan advocates cutting salt and getting more fiber-rich grains, nuts and legumes, and low-fat dairy.
The diet also calls for plenty of fruits and vegetables: four to five servings of each per day.
"If you want to eat tomatoes as part of that, that's fine," Goldstein said.
SOURCE: http://bit.ly/lUcacJ Neurology, online October 8, 2012.