Dietary fiber belongs to the polysaccharide category and is mainly found in vegetables, bran, and cereal grains. Pectin in fruits is also a substance similar to cellulose.
Epidemiological data indicates that the Western diet, which is low in dietary fiber, is a direct or indirect cause of many diseases, such as colon cancer, hypercholesterolemia, ischemic heart disease, diabetes, constipation, and hemorrhoids.
Cellulose is not easily digested and absorbed by the human body, so it is always excreted with feces.
In the process of forming feces, cellulose can increase its volume, decrease its density, and stimulate intestinal peristalsis to promote bowel movements. If the diet is too refined and fine, with excessive fat and meat, it can lead to a large proliferation of anaerobic bacteria in the intestine, causing the dissolution of neutral or acidic steroids, especially cholesterol, bile acids, and their metabolic products. The increased bile acid metabolites in the feces may be co-carcinogens. Dietary fiber can affect the activity of bacteria in the large intestine, reducing the amount of bile acid produced in the colon, diluting toxic substances in the intestine, softening the feces, and shortening the transit time through the intestine. This reduces the long-term contact of carcinogens with the susceptible intestinal mucosa, thereby preventing the occurrence of intestinal cancer. Due to a decline in gastrointestinal function, the elderly experience slower intestinal motility and a decrease in beneficial intestinal bacteria, such as lactic acid bacteria. Consuming an appropriate amount of dietary fiber can compensate for this deficiency and reduce the incidence of disease.
According to reports from relevant scholars, dietary fiber can affect blood sugar levels, reduce diabetics' dependence on insulin and medication, and has the effect of preventing excess calories and controlling obesity. Because high-fiber foods can delay gastric emptying time, increase satiety, reduce the amount and calories of food intake, which is beneficial for the elderly to lose weight and control obesity. It can also prevent gallstones and lower blood lipids.
It has been determined that for the elderly, consuming 6 to 10 grams of dietary fiber daily is very beneficial for preventing the aforementioned diseases. Foods rich in dietary fiber include wheat bran, rice bran, fresh bean pods, tender corn, strawberries, pineapples, peanuts, walnuts, spinach, garlic seedlings, potatoes, bamboo shoots, pumpkins, taro, carrots, sweet potatoes, mushrooms, kelp, and seaweed.
Dietary fiber has many benefits for the elderly, but excessive consumption can also be harmful. Experts have found that high-fiber foods can interfere with the absorption of elements such as calcium and zinc by the gastrointestinal tract. Excessive consumption of coarse fiber can also easily lead to stomach cancer and colon cancer. Therefore, the elderly should pay attention to a balanced diet of meat and vegetables, not be picky eaters, and on the basis of ensuring nutritional balance, they should appropriately eat more fiber-rich foods.