Rye probably first grew wild in southwest Asia, but it was first cultivated in north and northwestern Europe, where it remains a staple food and the most common flour used for baking breads. To this day, nearly 95 percent of the world's rye is grown in the area between the Ural Mountains and the Nordic Sea. The top rye growers are Russia, Belarus, Poland and Germany. Rye was a food staple throughout all of Europe until the 19th century, when it was outpaced by wheat. Though rare now, epidemics of St. Anthony's Fireâ€”a condition caused by eating the ergot fungus that grows on ryeâ€”were common throughout the Middle Ages. Nutrition One slice (one serving) of whole grain rye bread has more than two and a half grams of protein, nearly two grams of dietary fiber, and only one gram of fat. Soluble fiber, which may help reduce the risk of heart disease by helping lower blood LDL cholesterol levels, makes up about 17 percent of the dietary fiber found in whole grain rye foods. The insoluble fiber found in whole grain rye has a high concentration of lignansâ€”more than any other cereal crop. Lignans not only make up part of the insoluble fiber content found in seeds and grains, they are also a phytonutrient (called phytoestrogens), similar to those in flaxseed and soy. Studies support the theory that lignans may help inhibit the development and growth of hormone-dependent cancers, such as prostate and breast cancer and reduce the risk of coronary disease. Whole grain rye also contains many important vitamins and minerals, such as B vitamins, vitamin E, calcium, magnesium, phosphorus, potassium, iron, zinc, and folate.