White Fruit for Stroke Prevention: Docs Sound off on New Study
Posted Sep 20 2011 12:00am
Maintaining a diet high in fruits and vegetables with “white” flesh, such as apples and pears, can significantly reduce an individual’s stroke risk, says a new study. However, some doctors are cautioning that there is much more to preventing stroke through diet than color alone.
The study, which came from a group of researchers in the Netherlands, examined the relationship between consumption of several different color groupings of fruits and vegetables and a 10-year stroke risk. The researchers divided the produce into three different color groups including green (spinach, broccoli, leafy greens), orange/yellow (carrots, citrus fruits, squash), red/purple (berries, beets, tomatoes) and white (apples, pears, cauliflower, cucumbers, bananas).
After evaluating over 20,000 adult men and women the researchers found that those who ate at least 171 grams (approximately the size of a large pear) of “white” produce – the most popular of which were apples and pears – had a 52% decrease in stroke incidences after 10 years compared to those who ate less than 78 grams. The other color groups did not show any impact on stroke risk.
“The results of the present study, suggest that high consumption of white fruit and vegetables, comprising of mainly apples and pears, may protect against stroke,” wrote the authors in the study published in the journal Stroke from the American Medical Association. “This is the first [study] to our knowledge that examined consumption of fruit and vegetable color groups in relation to stroke incidence.”
However, researchers are still a bit unclear as to why this affect may have taken place. Lead study author and postdoctor fellow at Wageningen University, Linda Oude Griep, suggested that perhaps dietary fiber, micronutriets, or phytochemicals may be responsible.
“It is difficult to say which nutrients are responsible in white fruits and vegetables. We know that apples and pears are high in dietary fibre, but there may be other explanation.”
However, some doctors have raised questions about exactly how much this study actually proves. Dr. Michael Stokes, cardiologist and specialist in specialist in carotid artery stenosis treatment cautions that there is much more that goes into the dietary prevention of strokes than just the color of the fruits and vegetables.
“The white fruit and vegetable eaters were compared to what group of people and what diet?,” questioned. Dr. Stokes. “The article makes no mention of meats, dairy products or eggs,” which have each been shown to have a significant impact on cardiovascular health. “One needs to look further into the nutrients of the vegetables and fruits which were considered white as apposed to those considered orange/yellow, red/purple and green”.
Dr. Stokes and his colleges, who were not involved in the study, say that the only real diet that has been scientifically proven to reduce the risk of heart disease and stroke are those high in fresh fruits, vegetables, nuts, olive oil, fish and poultry – with no relationship to color. “This combination has been shown to reduce an individual's LDL cholesterol levels which is known to reduce athersclerosis. Reduction in athersclerosis leads to reduction in strokes, heart attacks and peripheral vascular disease,” explained Stokes.
Admittedly, the authors of the study say that more studies on these findings need to be performed before any real recommendations can be made about increasing white fruit or vegetable consumption over other colors. In fact, most experts agree that an important part of a heart-healthy diet is getting a wide variety of vegetables and fruits. “All fruit and vegetables have health benefits and remain an important part of a stable diet,” said Dr. Sharlin Ahmed from The Stroke Association.
Griep, Linda M. Oude, W.M , et al. (2011) Colors of Fruit and Vegetables and 10-year Incidence of Stroke. Stroke, published online September 15, 2011.