By Jimmy Downs

Saturday May 11, 2013 (foodconsumer.org) -- Stroke risk in men may be reduced by eating fiber-rich foods, according to a review authored by Diane Threapleton, MSc from University of Leeds in Leeds,  UK and colleagues.   It is a possibility only because prospective studies reviewed are not trials and a causal relationship between dietary fiber intake and lower risk of stroke has yet to be established.

For the review, authors searched multiple electronic databases for studies on the association between fiber intake and incidence of first hemorrhagic or ischemic stroke, published between Jan 1990 and May 2012.

A meta-analysis of data from eight cohort studies from the U.S., Northern Europe, Australia and Japan shows total dietary fiber intake was inversely correlated with the risk of hemorrhagic and ischemic stroke.

Specifically, intake of seven grams of dietary fiber per day was associated with 7% reduced risk for stroke whereas intake of four grams of soluble fiber intake per day was not significantly associated with stroke risk.

The study published in the journal Stroke concluded "Greater dietary fiber intake is significantly associated with lower risk of first stroke. Overall, findings support dietary recommendations to increase intake of total dietary fiber."

The researchers pointed out that more research is needed to establish an association between a specific type of fiber (soluble and insoluble) and the risk for a specific type of stroke (ischemic or hemorrhagic stroke).

Dietary fiber is high in cereal, vegetables and fruits.  High intake of plant-based foods or diet means low intake of meat and dairy products.   Thus, the studies could also imply that high intake of meat and dairy products may increase the risk of stroke.

Another study also published in the same journal suggests that high intake of red meat may increase the risk for stroke in men. The study found a positive association between intake of heme iron, which is found in red meat, and the risk of stroke.

Joanna Kaluza, PhD from Warsaw University of Life Sciences in Warsaw, Poland and colleagues found the associaiton after analysing data from 38,859 Swedish men aged 45 to 79 years who had no history of stroke, coronary heart disease or cancer at the start of the study 

Heme iron is high in red meat, which can be lamb, sheep meat, beef and pork.

Specifically, men in the highest quintile of heme iron intake were found 16 and 15% more likely to experience total stroke and cerebral infarction, respectively, compared with those in the lowest quintile.

The risk from high intake of heme iron was particularly high in men with a normal body mass index (< 25 kg/m2) of whom men with the highest intake were 40 and 38 percent more likely to suffer total stroke and cerebral infarction, respectively, than those with the lowest intake.

Intake of heme iron does not seem to affect the risk of stroke in overweight and obese men for whom other risk factors may be more detrimental than heme iron.

Iron can be released after oxidative scission of heme, leading to iron-driven plaque lipid oxidation, which could increase the risk for stroke and other cardiovascular events.

These two studies suggest that high intake of plant-based foods and low intake of animal based foods may help prevent stroke.   A total of 30 to 40 grams of dietary fiber per day is recommended for an adult and most Americans do not ingest this recommended amount of fiber and a supplemental dietary fiber, which can be purchased over the Internet, may be used.