31/01/2011 Watch out! Excess fibre intake can have ill effects A health enthusiast consuming fibre-laden oat bran muffins had recently landed up for an emergency surgery for a blocked intestine! He had eaten so much fibre that his digestive system could not handle it. Clearly too much of a good thing can be bad.
Fibre is considered important to maintain a healthy digestive tract. It has been shown to be beneficial in bowel regulation, constipation, irritable bowel syndrome, diverticulosis, haemorrhoids, diabetes, high cholesterol, cancer and weight management and also prevent bacterial infection of appendix. Fibre helps curb appetite because the stomach feels full. Fibre-rich foods require longer chewing, which stimulates digestive juices and helps digestion. Fibre displaces fat calories and slows fat digestion and absorption and therefore, it may help control obesity and reduce cholesterol. But how much is good, and how to supplement with extra fibre, needs to be addressed. A diet rich in whole grains, pulses, vegetables, fruits, nuts and seeds is likely to provide adequate fibre -- 25-35 gms a day. The optimum requirement of fibre varies and you should find out how much you are getting and what your body needs are. Fibre intake of 30-40 gms should be targeted for normal bowel function. Consuming 6-11 servings of grain-based foods, 2-4 servings of fruits and 3-5 servings of vegetables daily, will satisfy the recommended fibre intake. Fibre intake must be increased gradually in order to minimise gastro-intestinal discomfort. Fibre carries water out of the body and can cause dehydration. So increased fibre intake must be supplemented with an extra glass or two of water beyond the normal recommendation of 2-2.5 litres a day. Initially, a high fibre diet may produce some unpleasant effects, such as increased flatulence, diarrhoea, constipation or borborygmus also known as stomach growling, or rumbling. These symptoms are likely to resolve as one gets accustomed to the diet. Better tolerance can be expected if the total fibre intake is distributed throughout the day. A month may be required to adapt. Commercially available high fibre supplements like bran, bran tablets, guar gum, pectin or psyllium, cellulose powders may also cause nausea, flatulence, fullness, and abdominal discomfort. So initial steps can be eating fruits instead of juices, whole wheat instead of white bread. If intolerance occurs, one should try various sources of fibre to identify foods that are best tolerated. Excessive intake of fibre can be dangerous as it can lead to blocking of the gut. Consumption of over 50 gms has no extra benefits and may cause intolerance and/or problems with absorption of trace elements like iron, calcium, zinc, copper and other minerals and cause calcium losses. Iron absorption occurs mostly in the beginning of the intestinal tract and excess insoluble fibre as in wheat bran may limit absorption by speeding foods through the upper part of the digestive tract. Too much fibre can also limit the food consumed thereby the amount of nutrients and calories. This is especially bad for children, the elderly and malnourished. It is advisable to consult a physician when planning to take fibre supplements if you have a serious digestive problem such as divericulitis, ulcerative collitis, or Crohn's disease or if you plan a daily consumption of over 35 gms of fiber. Also, avoid fibre supplements that contain appetite suppressants as they can cause side effects. Good sources of fibre include whole grains like oats, barley, millets, ragi, amaranth, whole wheat flour (atta), brown rice, pulses, legumes, fruits and vegetables including green leafy vegetables, fruits like amla, apricots or prunes, citrus fruits, kiwi, strawberries, bael (woodapple) and pomegranate, low fat dairy, nuts and seeds like flaxseeds, sunflower seeds, water melon seeds. Take 5 - Increase fibre gradually, especially if using supplements. - Extra fibre is best tolerated in divided doses. - Excessive fibre can be harsh and harmful. - Additional fibre must be accompanied with additional water. - In case you have a medical condition, inform your physician before you start fibre supplements. Source: Ishi Khosla/Indian Express
