Eating too much will reduce immunity. Because coarse grains contain more cellulose and phytic acid, the daily intake of cellulose exceeds 50g. Long-term consumption will hinder people's protein supplement, reduce the utilization rate of fat, damage the functions of bones, heart, blood and other organs, reduce human immunity and even affect fertility. In addition, the phytic acid content in buckwheat, oats and corn is high, which will hinder the absorption of calcium, iron, zinc and phosphorus and affect the metabolic balance of minerals in the intestine. Therefore, it is necessary to increase the intake of these minerals when eating coarse grains.
The high cellulose content in coarse grains is harmful to adolescent girls, because the cholesterol in food will be excreted in the intestine with the fiber in coarse grains. The decrease of cholesterol absorption will lead to the decrease of female hormone synthesis and affect the development of reproductive organs such as uterus.