Fibre, or roughage, is the part of plants that our bodies can't digest. Fibre is either soluble or insoluble. Insoluble fibre doesn't dissolve in water. It encourages the movement of stool through the digestive system, making it useful for constipation. Whole wheat, grains and nuts are good sources of insoluble fibre. Soluble fibre can be dissolved in water and is beneficial for lowering cholesterol levels and maintaining steady blood sugar levels. Several foods contain high levels of soluble fibre.
Psyllium husk is also known as ispaghula and contains some of the highest levels of soluble fibre in any food at 7 grams of soluble fibre per 100 grams of psyllium husk. Psyllium husk is harvested from the seed of a plant native to India and Iran called the Plantago ovata. The FDA endorses 3 to 12 grams of psyllium husk as beneficial for lowering cholesterol. It is also beneficial for constipation and irritable bowel syndrome.
There are 5 grams of soluble fibre in 100mgs of oat bran. Oat bran lowers LDL, the "bad" cholesterol, while raising HDL, the "good" cholesterol. Oat bran also contains a compound called beta-glucan that can strengthen the immune system.
Brown rice is a good source of soluble fibre. Brown rice also has several health benefits. Unpolished, whole brown rice contains manganese, selenium and magnesium while retaining the aleurone layer, which is loaded with healthy fats that can reduce cholesterol. White rice has none of the health benefits of brown rice and has virtually no fibre content.
Apples contain a surprising amount of soluble fibre--2.3 grams in one small apple. Apples also contain antioxidants that protect the heart from damage and ageing. Another key component to apples is flavonoids. Flavonoids can reduce inflammation and prevent blood platelets from clumping together to form clots, along with regulating blood pressure and helping clear fat from the liver.
There are about 2 grams of fibre in 1/2 cup of peas. Peas are beneficial for bone health and repair because they contain vitamin K, folic acid and vitamin B6. Iron is another essential element found in peas. Iron can prevent or counter anaemia. Peas are also good for increasing energy because of the high levels of thiamine, niacin and vitamin C. The vitamins and minerals in peas are beneficial for ovarian and prostate health, reducing DNA damage and inhibiting nitrosamines, a compound found in meat that is carcinogenic.