A recent article (1) considered multiple nutritional factors associated with a reduction in strokes. It reviewed much of the medical literature concerning diet and stroke reduction. The authors found an association of stroke reduction with antioxidants, fiber, the DASH and Mediterranean diets, whole-grain foods, fruits and vegetables, and increased potassium and decreased sodium in the diet. It did not find an association with saturated fat, polyunsaturated fat, monounsaturated fat, but did find an association with DHA and EPA.
Nutritional Factors Associated With Stroke Reduction
There is a great deal of overlap in these factors. The DASH and Mediterranean diets include more fruits and vegetables than the typical Western diet. Increased fiber is found in fruits, vegetables and intact grains. Antioxidants are also found in these foods. As found in fruits, vegetables and grains, antioxidants are associated with stroke reduction. But as found in supplements, most studies have not shown any consistent association with health benefits.
Main Nutritional Factor For Stroke Reduction
While these factors most likely provide some benefits, the main beneficial factor in fruits, vegetables and grains is their potassium sodium ratio. Previous posts discussed how fruits and vegetables are not associated with improved cardiovascular mortality if salt is added to them.
In India, Iran, and Korea people eat more fruits and vegetables than found in a Western diet. But they have an increased sodium intake because they salt their vegetables. As a result, they have the same stroke incidence as Western countries. So the fruits and vegetables are only associated with an improved cardiovascular and stroke mortality if they retain their high potassium sodium ratio.
Even without an increase in fruit and vegetable consumption, reducing the sodium and increasing the potassium in the salt added to food can reduce stroke and cardiovascular mortality. The post about stroke rates falling in Finland discussed how Finland did this.
This means that there really is only one conclusion about what the most important factor is. It is not something magical about fruits and vegetables, or something magical about the DASH or Mediterranean diet that results in improved cardiovascular health. It is the improved potassium to sodium ratio found in these foods and diets. Of course, the fiber, antioxidants, types of fats, and phytochemicals found in fruits and vegetables provide healthful benefits. But to get improved cardiovascular and stroke mortality, food must retain its high potassium sodium ratio.
This is backed by a great deal of basic science research. There are multiple posts on this blog about basic science research on the potassium sodium ratio. These studies confirm the potassium sodium ratio's importance.
Tables Of High Potassium Foods
To find links to tables of the sodium and potassium content of food, click on the tab at the top of the table entitled Links to Potassium Food Tables.
1. Stroke and nutrition: a review of studies. Foroughi M, Akhavanzanjani M, Maghsoudi Z, Ghiasvand R, Khorvash F, Askari G. Int J Prev Med. 2013 May;4(Suppl 2):S165-79.