Rye came into cultivation later than wheat, barley and oats and was not known to the ancient Egyptians and Greeks. It was the main grain used for bread-making in Northern Europe and Russia for many centuries. This is partly because it grows well in colder, harsher climates and partly because it was preferred by some people. Scandinavian countries such as Denmark, Norway and Sweden eat a variety of bread and crispbreads made from rye flour, although wheat products are becoming more popular. Rye contains less gluten than wheat flour, and this makes rye bread significantly denser. Traditional rye breads are made with a sourdough method so have a slightly sour taste when compared to wheat bread. Dark rye flour bread is all whole grain flour. Light rye grain bread is a mixture of whole grain rye flour and refined rye flour. Bread made wholly from rye flour is made in Germany and called pumpernickel. Rye is unique among grains for having a high level of fibre in its endosperm not just in its bran. As such, the glycemic index (GI) of rye products is generally lower than products made from wheat and most other grains. Nutrition credentials of whole grain rye: High in carbohydrate (mainly starch), with a lower GI than most other grains. Relatively high protein content (around 15%), with a higher lysine content than most other cereals. Contains a protein complex which forms gluten. Low in fat (most of which is unsaturated). High in potassium and low in sodium. Excellent source of dietary fibre. Rye has more soluble fibre than wheat, however, less is known about the effect of dietary fibre found in rye. Contains B-group vitamins such as thiamin, riboflavin, niacin, vitamin B6 (pyridoxine), folate and pantothenic acid. Contains vitamin E. Contains iron, zinc, magnesium, phosphorus and selenium (depending on the soil content of selenium). Contains small amounts of copper, manganese and calcium. Contains phytochemicals including lignans, phenolic acids, phytic acid, plant sterols and saponins.