Fibre forms an essential part of our daily diet. It is not only good for our digestive system, but also has several other health benefits. We have always heard nutritionists and health experts saying that that fibre is important in our diet as it keeps us full for longer time, promoting weight loss. A new research that analysed 25 different studies, as per an IANS report, has found that eating a diet, which is high in fibre, can be associated with a reduced risk of colorectal cancer. Analysis compared groups with the highest intake of fibre daily with groups with the lowest intake.
Colorectal cancer is the seventh most common cancer diagnosed in both men and women in India. The cause of colon cancer is multifactorial and complex. Risk factors include sedentary lifestyle, obesity, tobacco use, low fibre diet and alcohol consumption. People with high-risk for colon cancer include- aged above 60 years, a positive family history of colorectal cancer and having familial polyposis syndrome. For screening, colonoscopy is recommended starting at age 50 and then every 10 years after that, if the results be normal.
In this regard, Dr. Niranjan Naik, Director, Surgical Oncology, Fortis Memorial Research Institute, Gurugram sheds some light on the need for a high fibre diet to lower the risks. High dietary fibre is thought to reduce the risk of colon cancer is by decreasing gastrointestinal transit time, dilution of fecal carcinogens, increasing stool bulk and causing bacterial fermentation of fibre to short-chain fatty acids with anti-carcinogenic properties.
Colonic adenomas are formed initially, which may progress to become cancer in some individuals. Individuals consuming the highest intake of dietary fibre have reduced risks of developing colorectal adenoma and distal colon cancer and that this effect of dietary fibre, particularly from cereals and fruit, may begin early in colorectal carcinogenesis. Dietary fibre may act early in the adenoma- carcinoma sequence and reduce both the risk of adenoma and cancer.
As per the IANS report, The European Prospective Investigation of Cancer and Nutrition (EPIC) Study evaluated diet and colon cancer in 519,978 people living in 10 countries with a broad range of dietary habits. The volunteers, who ranged in age from 25 to 70, were tracked for six years. Compared with the people who ate the least fibre, those who ate the most enjoyed a 42 per cent reduction in the risk of colon cancer. No source of fibre was more protective than others; the study did not evaluate fibre supplements. Another study of 2,157 residents of Utah and California linked high consumption of fibre to a 46 percent reduction in the risk of rectal cancer.
Dietary fibre is a non-starch complex carbs which is found in plant foods. They are of 2 types: soluble and insoluble. There are no non-vegetarian (animal) sources for fibre.
Soluble fibre dissolves in water to form a gel, which promotes delayed emptying and early satiety. It is easily digested in the colon, which also can cause bloating and gas. Soluble fibre is often associated with cardiovascular and diabetes prevention and colon health, as it reduces blood cholesterol and glucose levels. It does this in 2 ways. Firstly, the soluble fibre is fermented to the short-chain fatty acids; these are absorbed and metabolized by the liver for bile synthesis. Second, fibre passes through the body undigested. Soluble-fibre sources include apples, barley, citrus fruits, peas, avocado, husks, legumes, oats, rye, and many vegetables, such as broccoli and carrots.
Insoluble fibre does not dissolve in water and is much less fermentable or gassy. It promotes bowel movements by adding bulk and water to stool, creating a stool softening action in the digestive system. Insoluble-fibre sources include brown rice, fruits like apples, legumes, seeds, whole grains, vegetables such as Brussels sprouts and cabbage, and wheat bran.
Fibre supplements available include gums, inulins, lignins, pectins, and psyllium or isabgol husk. Juice is not a good source of fibre. Even if juice is made from fresh fruits and vegetables, the fibre is often gets removed in the juicing process. Ideally, you should get fibre from whole food sources, not supplements or juices.
Researches showed that each 10-gram a day increase in total fibre and cereal fibre was linked with a 10 percent reduction in colorectal cancer risk. Aim for fibre intake amounts of 25 to 35 grams per day or a ratio of 14 grams of fibre/1000kCal consumed. In regard with fibre, more is not necessarily better, so do not overdo it. Too much of high fibre can be disruptive, in turn affecting mineral absorption and GI distress.
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Colon cancer does not happen overnight. Usually it can take many years to develop. So starting to eat whole grains at an early age is important.
Eat more whole grains. It not only reduces colorectal cancer risk, they and other sources of fibre have other health benefits like reduced cholesterol levels, better blood sugar levels and less constipation. Whole grains and total dietary fibre have already been identified as protective against cardiovascular disease. Fibre slows the absorption of carbohydrates, reducing insulin levels. It also binds bile acids, lowering blood levels of LDL cholesterol. When a high-fibre diet includes lots of fruit and vegetables, it helps to lower blood pressure.
Be sure to increase your fibre intake gradually. Adding large quantities of fibre into the diet too quickly can cause gas or discomfort. Instead, try to add a little more fibre to each of your meals by including a piece of fruit or by switching processed or refined grains with whole grains.
Fibre could reduce exposure of the colorectal passage to carcinogenic N-nitroso compounds produced on processed meat consumption. Drink plenty of water, staying hydrated will help ensure that the additional fibre doesn't cause stomach problems.
(This content including advice provides generic information only. It is in no way a substitute for qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.)