Continuing from part 1 of these same blog article of last week, today we are going to list a few more details for why cereals, legumes, vegetables and fruit are so important. If you haven’t read the first part we suggest you go ahead and read that first at this link here so that you will have a better understanding of this topic.
Because they supply fiber
Grains and derivatives, legumes, vegetables and fruit are also good sources of dietary fiber. Dietary fiber in itself has no nutritional or energy value (except for the small amount of energy from fatty acids formed by fermentation in the colon), but it is also very important for the regulation of different physiological functions in the body. It consists mostly of complex carbohydrates, not directly usable by the human body. Some of these compounds (cellulose, hemicellulose and lignin) are insoluble in water, and act mainly on the functioning of the gastrointestinal tract, delaying gastric emptying and facilitating the passage of the food bolus and the evacuation of feces in the intestine. Instead other compounds (pectins, gums and mucilages) are soluble in water – in which they form resistant gels – and regulate the absorption of some nutrients (for example sugars and fats) reducing and slowing it down, thus contributing to the control of the level of glucose and of cholesterol in the blood.
Insoluble fiber is contained above all in whole grains and vegetables, while soluble fiber is present above all in legumes and fruit, although some vegetable products contain both types of fiber. Dietary fiber facilitates the achievement of a sense of satiety, as it helps to increase the volume of ingested food and slow down the emptying of the stomach. It also appears to be able to reduce the risk of some bowel diseases (such as colon diverticulosis) and veins (such as varicose veins), as well as of important chronic-degenerative diseases, such as in particular colorectal tumors (probably due to the dilution of any carcinogenic substances, to the reduction of their contact time with the intestinal mucosa, and to other mechanisms yet to be clarified), diabetes and cardiovascular diseases (probably by regulating blood glucose and cholesterol levels). The recommended fiber intake is around 30 grams / day. To reach the recommended levels it is good to consume fiber-rich foods more often instead of using dietary fiber-based products.
Because they supply important vitamins and minerals
Fruit and vegetable products are an excellent source of some vitamins: for example orange, tomato and vitamin C and folate kiwi, carrot, apricot, green leafy vegetables of pro- vitamin A, legumes and thiamine, niacin and folate cereals. They are also an important source of minerals (green leaf calcium and iron vegetables, potassium and tomato potassium), although the absorption of the latter is generally lower than that of the same minerals contained in the foods of animal origin.
Because they contain substances with a protective action
The beneficial effects of the consumption of fruit, vegetables and legumes also depend on the fact that some of their components carry out a protective action, mainly of antioxidant type, which is expressed by contrasting the action of free radicals, which are able to alter the structure of cell membranes and genetic material (DNA), paving the way for premature aging processes and a whole series of reactions that are at the origin of different cancers. This protective action, in addition to the components already mentioned (vitamins and minerals), is also performed by other components, which, although present in relatively small quantities, are equally very active from a biological point of view through various mechanisms: the main one of these it is precisely the antioxidant one.
Among the different classes of antioxidants present in fresh fruit and vegetable products the most common are:
- ascorbic acid (vitamin C);
- carotenoids (yellow, orange and red pigments of which vegetables and yellow-orange fruits are rich – due to the presence of ß-carotene – and those red like tomatoes – due to the presence of lycopene);
- phenolic compounds (present in high concentration practically in all foods of vegetable origin and in grapes and, therefore, in wine);
- tocopherols (found in oilseeds and green leafy vegetables).
Dr. Clark Supplements
The consumption of fruit and vegetables can also ensure a significant supply of some minerals (such as selenium and zinc) which are part of the body’s antioxidant defense systems. Other substances present in them have been studied in relation to their potential preventive effects against cancer. For example, different classes of sulfur compounds facilitate the elimination of carcinogenic substances at the cellular level: the isothiocyanates and dithiolites of which the vegetables of the cruciferous family such as broccoli, cauliflower, cabbage and allilsulfides of which garlic is rich are rich. etc. The cruciferous women are also rich in indoles, which seem to have some efficacy in counteracting the development of tumors, while soy is one of the few food sources of isoflavones, phytoestrogens that seem to inhibit the growth of some cancer cells. Folate, vitamins of which leafy vegetables are rich, some citrus fruits and other vegetables, which together with other B vitamins, can help reduce the level of homocysteine, a known risk factor for cardiovascular diseases. Their adequate intake by women of childbearing age also protects against the appearance of neural tube defects (spina bifida) in the fetus. Finally, the intake of high potassium levels, which are rich in fruits and vegetables, has been associated with a reduced rate of mortality from heart attacks. It is very important to stress that so far no study has shown that the administration of individual components in the form of supplements can give the same beneficial effects that are associated with the ingestion of fruit and vegetables. Consequently, it is thought that these effects are due above all to the joint and synergistic action of multiple constituents, many of which probably still to be identified, present in the food. This action seems to cease when the beneficial compounds are ingested individually and in a relatively concentrated form (supplements, etc.).
In conclusion, how to behave:
- Consume more portions of vegetables and fresh fruit daily, and increase the consumption of both fresh and dried vegetables, always taking care to limit the additions of oils and fats, which may need to be replaced with aromas and spices.
- Consume bread, pasta, rice and other grains regularly (preferably whole grains), avoiding adding too much fatty toppings.
- When you can, choose products made from wholemeal flour and not with the simple addition of bran or other fibers (read the labels).
- To put these tips into practice, refer to the portions indicated in Guideline number 8 “Vary your choices at the table”.
Helen Charlotte is a health centre assistant three days per week and a Biologist Student who enjoys running listening to music and walking. She is brave and entertaining, and loves competitions.