Dietary concepts are on everyone’s lips today, but they are not always used well. Making sound nutrition decisions requires knowledge of the meaning of certain terms.
In this article we will try to explain some basics of modern nutrition.
The increasingly widespread concern to follow a healthier diet means that many terms are colloquially used that, in reality, are sometimes not understood very well.
For reasons of space, it is not possible to present a “complete dictionary” because the nutrients are dozens and the concepts too, but we hope that the reading is enjoyable and serves to expand knowledge.
Fatty acids are components of lipids (oils and fats). Consumed alone they are toxic, while together with glycerin they form one of the immediate principle’s indispensables in the diet.
Depending on the number of double bonds present in the carbon chain that compose them, they can be saturated (without double bonds), monounsaturated (a double bond) and polyunsaturated (more than one double bond).
In dietetics, balance is a fundamental concept, as can be seen in the recommended intake of unsaturated fatty acids, which should be distributed among the omega-3, omega-6 and omega-9 families.
OMEGA-3 FATTY ACIDS
These are essential polyunsaturated fatty acids, as they cannot be synthesized by the body and must be provided by the diet.
They are found especially in oily fish, although vegetables such as flax oil, walnuts or hemp oil contain significant amounts.
Foods that originate from animals that have consumed a lot of omega-3s, such as certain eggs and cheeses, also contain this essential fatty acid.
The most important are linolenic acid, Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The effect of the set is greater than that of each isolated one.
OMEGA-6 FATTY ACIDS
Present mainly in vegetable oils, margarines, wheat germ and nuts.
Linoleic and arachidonic acids are the most important.
They are also found in large quantities in the seeds of evening primrose and borage, rich in dihomogamalinolenic acid (DHGLA).
Its consumption must be moderate and must keep a proportion with omega-3.
OMEGA-9 FATTY ACIDS
Although the best known are omega-3 and omega-6, omega-9 without being essential are gaining in importance because they explain some of the benefits of olive oil (oleic acid is one of them).
They are often used to improve taste, preservation or appearance and are identified on labels with an E-, which indicates that it has been approved in Europe, followed by three or four digits, although now the name is sometimes put to avoid consumer rejection of “the Es”.
Some foods such as vinegar, salt or sugar can be considered ancestral additives, but the vast majority are of modern creation.
There are currently more than one thousand five hundred additives cataloged and approved for human use. Some are of natural origin; others are copies of natural products made in the laboratory and others are artificial creations.
They are classified by their functions, including acidifiers, anti-caking agents, defoamers, antioxidants, thickeners, colorants, color preservatives, emulsifiers, aromas, flavor enhancers, humectants, preservatives, propellants, stabilizers, sweeteners …
The additives most questioned for their possible negative effects – especially in children – are preservatives and dyes.
These are non-genetically modified foods, produced without resorting to antibiotics, medicines, additives, pesticides or artificial fertilizers, and following the methods of organic farming, which are therefore more respectful of the environment than conventional ones.
Only products that show an officially recognized endorsement can be considered as biological, ecological or organic, which guarantees that they have passed the controls specified by the law that regulate organic production. In Spain, guarantees are granted by regional regulatory committees.
These are foods to which some substance has been added (vitamins, phytosterols, isoflavones, fiber, omega-3 fatty acids, minerals …) that can improve their effect on health.
Although reference is made to scientific studies that demonstrate its effectiveness, a functional food is not necessarily healthier, but a product that sells better.
These are substances naturally present in food that interfere with the assimilation of some nutrients.
Examples are fiber or oxalic acid from pistachios and spinach, which can interfere with the absorption of iron and other minerals. Other antinutrients are caloric oils such as olestra, which reduce the absorption of fat-soluble vitamins.
But some antinutrients have been shown to have remarkable antioxidant capacity and therefore may produce more benefits than disadvantages, such as tannins or lignans, which seem to prevent cancer.
Antioxidants are substances that reduce oxidation, especially of organic fats.
Fresh plant foods provide the vast majority of antioxidants in the diet and their consumption is vitally important.
They help reduce free radicals, which are produced in the body during the metabolic process or arrive from outside, through exposure to toxic agents such as tobacco smoke, and can cause degenerative diseases, cancer and premature aging.
Among the antioxidants there are various substances, such as vitamins A, C and E, flavonoids (which are abundant in berries and fruits such as pomegranate, blackberries or grapes), anthocyanidins (which protect from ultraviolet radiation and are found in plums or bilberries), isoflavones (such as those present in soybeans), organic acids …
Antioxidants are often abundant in plants with bold colors.
A sugar is any simple carbohydrate with a sweet taste.
However, popularly sugar is sucrose, a disaccharide formed by a molecule of glucose and another of fructose.
White sugar is extracted from sugar beet, from which a white, crystalline powder is obtained through refining and bleaching processes.
The whole grain is extracted from sugar cane, and as it is refined less it contains some vitamin more than white sugar.
Sugar provides immediate energy, but also favors overweight with its “empty” calories, as well as bone decalcification, so its consumption should always be moderate, or null if you have diabetes, a disease that does not allow you to metabolize glucose.
Calcium is an essential mineral for the proper development of teeth and bones and for the contractibility of muscles. Too much can lead to kidney stones.
Although dairy products seem to be the best source of calcium, other foods such as legumes, seaweed, nuts, or vegetables such as broccoli can provide as much or more calcium than dairy products.
Dairy products, in excess, especially if they are whole, can interfere with the absorption of calcium itself, so it is convenient to diversify the sources that provide this mineral.
A calorie is the energy needed to raise the temperature of one gram of water one degree. In dietetics, this unit is used to measure the energy provided by food and although we usually talk about calories (lime) it is actually kilocalories (Kcal).
Knowing them is useful for designing diets, especially weight loss. Every food has calories, some many (oils, chocolate) and others few (vegetables in general).
The term “empty calories” refers to foods high in calories and poor in other nutrients, usually because they have undergone intense refining processes. Sugar is one of them.
They are orange or red pigments present in many plant-based foods. More than five hundred are known and are divided into xanthophiles and carotenes.
Lutein, zeaxanthin, lycopene or beta-carotene are some of the most important for health due to their antioxidant and anticancer action. The body converts them into vitamin A.
Fiber is the part of plant foods that is not absorbed but passes through the digestive system and is eliminated, taking with it substances that are not beneficial to health, such as excess cholesterol.
A distinction is made between soluble and insoluble fiber according to its behavior with water. The soluble, like apple pectin, gels and is useful in cholesterol control; the insoluble, such as wheat bran, accelerates intestinal transit, so it is used against constipation.
A diet rich in fiber – more than 35 grams a day – positively influences diabetes, cholesterol, constipation, vascular problems, heart disease, intestinal diverticulitis and colon cancer, among other alterations. Fruits, vegetables, whole grains and legumes are foods rich in fiber.
The term flavonoid or bioflavonoid refers to phenolic compounds discovered in 1930 by Nobel laureate Albert Szent-Gyorgyi, who had found vitamin C two years earlier.
Flavonoids were originally called vitamin P (because they regulate the permeability of blood capillaries) and also vitamin C2, for their properties similar to vitamin C. However, they were not confirmed to be vitamins and both denominations were abandoned around 1950.
Since then, more than five thousand different flavonoids have been identified. They stand out for their antioxidant effect, although they also intervene in the regulation of cell growth, the transport of hormones, the assimilation of nutrients and in the processes of self-detoxification.
Most natural fatty acids have bonds in cis arrangement (turned to the left), while those of trans arrangement (to the right) are very rare (less than 0.05%).
However, the latter predominate in the hydrogenated fats that the food industry uses so much, disguised under the term vegetable oil.
The processes of hydrogenation and refining of oils, for example to make margarines, are the great producers of trans bonds in fatty acids.
Many experts recommend zero consumption of trans fats, as they have been associated with immune deficiencies, cancer, cholesterol Mia, atherosclerosis, coronary heart disease and degenerative diseases.
Industrial chips have up to 35% trans-fat, while if they are made at home with olive oil their content is zero. Pastries, margarines, snacks, refined oils and ready meals provide most trans fats and should be avoided.
Iron is one of the minerals necessary for the maintenance of health. Its deficiency causes many problems.
The most common is anemia, since iron is part of the hemoglobin of red blood cells. In fact, it is the substance that gives it its characteristic red color. Women with heavy periods may have anemia, and therefore need iron supplements.
This mineral is present in meats, fish, poultry, legumes, green leafy vegetables and strawberries.
It is difficult to consume too much iron through food alone, but it often occurs if dietary or drug supplements are taken. The body regulates the level of iron through modifications of its absorption, since eliminating it is very difficult. The excess is toxic and can even induce cancer by increasing free radicals.
It is a carbohydrate evaluation system, developed by Dr. Jenkins in 1981. It indicates the effect of ingesting a carbohydrate-rich food on blood glucose levels.
The simplest carbohydrates (in sugars, flours …) that are absorbed quickly have a high glycemic index, while those of slower absorption (legumes, whole grains …) have a low index.
The higher the glycemic index, the greater the demand for insulin and the greater the risk of developing obesity, diabetes or cholesterol. People suffering from these problems should monitor the glycemic index of the carbohydrate-rich foods they consume.
White bread, desserts with white flour, cornflakes or baked potatoes have a high index, so their consumption should be moderated and mixed with foods of lower index in the same meal. It is advisable that the main ingredient, the one that provides more energy, has a low index.
They are flavonoids that exert an action similar to that of hormones.
They are present in some legumes and especially in soy (tofu, whole soy and soy milk are the main sources), although they also contain them in significant quantities beans, peanuts, chickpeas and germinated alfalfa.
They have become popular because they reduce the symptoms of menopause (hot flashes) and diseases derived from it (osteopenia and osteoporosis). They also relieve painful periods and lower the cholesterol level and the incidence of hormone-dependent cancers, such as breast and prostate.
PREBIOTICS AND PROBIOTICS
Prebiotics are indigestible components that are added to food to improve its digestibility as they stimulate the growth of intestinal flora.
They are usually carbohydrates and fibers that favor the multiplication of lactobacilli and bifidobacterial in the intestine.
Inulin, common in artichokes or oats, is an excellent prebiotic, although there are many others of artificial addition, such fructooligosaccharides.
Probiotics, on the other hand, are beneficial microorganisms that are added to foods and cause their fermentation.
The best-known probiotics are yogurt microbes (lactobacilli and bifidobacterial, especially) that cause milk fermentation, but microorganisms present in soy sauce, fermented choucroute (Leuconostoc sp), kefir, miso (soy paste) or brewer’s yeast (Saccharomyces sp) are also probiotics.
It is considered that they stimulate immunity and serve to improve diseases such as Candida albicans infection, which causes, among others, vaginal candidiasis, very common in women.
Proteins are essential for the body, but cases of excess consumption are much more frequent than deficiencies.
The term protein derives from the Greek protos, meaning “of utmost importance.” They are formed by the succession of numerous amino acids, of which 8 are essential, that is, they cannot be synthesized by our body and must be obtained from food. Proteins are macromolecules that sometimes exceed 10,000 amino acids.
They play a major role in the formation of cell structure, immunity and enzymatic processes.
A diet too rich in protein causes excess function of the liver, immune system or bone fragility and osteoporosis. The deficit is usually very rare.
SOME ESPECIALLY PROTEIN FOODS (PROTEIN CONTENT PER 100 G OF FOOD)
- Soybeans: 36 g
- Manchego cheese: 29 g
- Sunflower (pipe): 27 g
- Peanut: 26 g
- Mungo: 25 g
- Lentil: 24 g
- Chicken: 22 g
- Pork: 21 g
- Beef: 20 g
- Chickpeas: 20 g
- Sardine: 19.5 g
- Almond: 19 g
- Cod: 17.5 g
- Shrimp 17 g
- Walnut: 15 g
- Wholemeal pasta: 15 g
- Quinoa: 14 g
- Egg: 12.9 g
- Soft cheese: 12 g
- Whole wheat bread: 8 g
- Brown rice: 8 g
- White rice: 7g
- Tender pea: 6 g
- Goat’s milk: 3.7 g
- Skimmed yogurt 3,5 g
- Broccoli: 3.5 g
- Cow’s milk 3,3 g
- Mushroom: 2.7 g
- Potato: 2 g
- Chard: 2 g
Resveratrol is a substance identified in the skin of grapes with preventive effects against cardiovascular disorders and some types of cancer.
It is a substance that in the physiology of the vine has an antifungal action and prevents grape rot.
The fermentation process of the must improves the solubility and use of resveratrol, which is found in significant proportion in red wine.
It is the most consumed legume in the world, although in Spain it is not so well known. It is the richest in protein and also helps reduce cholesterol.
However, its current popularity is mainly due to its enormous content of isoflavones such as genistein and daidzein, which exert an action on hormonal balance and are useful in the treatment of menopause. These isoflavones are concentrated in tofu and soy milk or smoothie. Instead, they are not in the oil.
GMO foods (Genetically Modified Organisms) are the product of altering the genome in the laboratory, usually through the introduction of genetic information from other species. The foods that may most often be GMOs are soybeans, corn, and tomatoes.
There is no clear and definitive information on the potentially harmful effects of GMOs, partly because there does not seem to be much interest in investigating them, but these have been regulated by the European Union to limit their presence on the market and in human consumption.