Proteins are the building blocks of life, allowing the body to repair damaged cells and produce new ones. These macromolecules are composed of small molecules bound together (forming a string) called amino-acids. There are a total of 20 amino-acids; some are synthesized in the body (considered as non-essential) while others are not (essential). The latter group are found in the diet, making it necessary to regularly consume protein-rich foods. The proteins with more essential amino-acids or of great biological value are those originating from animals: cow milk, egg white, fish, beef, and chicken, among others. Gelatins, on the other hand, are the exception. Despite originating from animals (they derive from cartilage) their biological quality is low, in other words, they do not provide essential amino-acids.
Another important source of proteins are those found in vegetables, such as legumes (lentil beans, chickpeas and beans, among others) and cereals (wheat, corn and rice). However, the proteins that these foods provide are of lower quality, as they lack several of the essential amino-acids. Exceptionally, soy bean contains a similar amount of protein as meat. However, the best option to obtain high quality proteins is to combine legumes and cereals, as the amino-acids that are missing in former are found in the latter, and vice-versa. This is known as protein complementation. Many traditional gastronomic dishes follow this simple principle, such as couscous of the Maghreb region or the popular lentil beans with rice of the Iberian Peninsula.
Unfortunately, sarcopenia, or involuntary loss of muscle mass, is very frequent in the elderly. This can be due to an inadequate intake of proteins, as well as a decrease in exercise and/or the presence of a disease that causes loss of muscle protein. This affection is correlated with a loss of functional capabilities and causes the affected person to be less autonomous.
The World Health Organization and the RDA (Recommended Dietary Allowances) published in the US by the National Academy of Sciences recommends a daily consumption of 0.8 g of protein/kg of weight. Other publications suggest a higher amount, reaching 1-1.25 g/kg of weight per day. These recommendations seem to be the ideal amounts to cope with the “protein exchange” (balance between protein gain and loss). Protein gain in the body is obtained by the diet, in order to replace those proteins that are used or degraded throughout the day. To this end, the proteins ingested in the diet must be mainly of high biological value, in other words, they must provide the majority of the essential amino-acids in order to maintain the physiological structures and functions and consumed in the adequate amounts.
Carbohydrates are the primary energy nutrient and the main fuel for body movement. They are generally found in plant-based foods, and should comprise approximately 55-60% of our total daily energy requirements. It is recommendable to take them in the form of complex carbohydrates (cereals, bread, potatoes, legumes, rice), with a minimum of 4 rations/day. Whole grain should be always chosen whenever possible, as they contain higher amounts of dietary fiber. As for the simple carbohydrates, these are generally found in sweets, candies and pastries, are usually accompanied by fats, and should be consumed sporadically.
Fruits and vegetables, together with legumes, which has been mentioned above, are the major source of fiber, vitamins and minerals. It is recommended to consume 5 rations/day, preferably half of them as raw fruits and/or vegetables. For the elderly, in order to facilitate chewing and digestion, it is helpful to dice the fruit or make juice before consumption. As for legumes and vegetables, these can be prepared as a cream or paste.
Fiber also forms part of the carbohydrate group, however, unlike the others, it does not provide calories. There are two types of fibers: insoluble and soluble. Insoluble fiber (those found in whole grain cereals) help to increase the volume of the feces and speed its passage through the digestive system, favoring bowel movements and avoiding constipation. On the other hand, soluble fiber (found in fruits, vegetables, and legumes) are used by the intestinal flora for different processes, such as the cholesterol metabolization or decreasing the probabilities of intestinal pathologies, among other functions.
A very important effect of fiber (both soluble and insoluble) is its beneficial effect on constipation. Considering that this is a problem affecting the majority of the elderly, it is highly recommendable to include in their diet foods rich in both types of fibers.
Together with carbohydrates, fats are the major source of energy for the body, making them essential in the diet. Fats can be divided into two groups: essential and non-essential. The non-essential fats comprise the saturated fatty acids found mainly in animal-based foods, including dairy products. Included in this category are also the mono-unsaturated fats, which are abundant in vegetable oils, such as olive oil. These fats are considered nonessential as they are produced by the body. It is recommended to consume them moderately through functional foods such as skimmed dairy products and those with low fat. It is also important to choose lean meats (rabbit, beef), removing the visible fat and skin in the case of poultry (chicken, turkey). As for the mono-unsaturated fats, olive oil should be present in the diet and be the main source of fat. Approximately 2 spoonfuls (20 mL) of oil per day should be consumed, in toasts and salads, avoiding fried foods as much as possible.
Essential fats are also known as poly-unsaturated fats. They are considered essential because they cannot be produced in the body and must be consumed. These fats are present in vegetables (olive oil, dried fruits and nuts, etc) and fish (especially blue fish: red mullet, mackerel, anchovy, etc). They are also known as omega-3 and omega-6, and play an important role in preventing thrombosis.
Fats should not surpass more than 25-35% of the total amount of energy in the diet, with the saturated ones limited to only ¼ of the total fats. Therefore, processed baked goods should be very limited, and when taken, should be those with little fat such as cookies, home-baked pastries or toasted bread, more so than pastries filled with cream.
This type of fat is widely used in processed baked goods. It is the result of industrial processing where its molecular structure is modified. Since it is not a natural fat, they are very harmful for the organism, causing various pathologies in the circulatory system. Thus, these products should not be consumed, or do so sporadically.
The correct election of fat type and its quantity will help prevent obesity and cardiovascular disease, among other pathologies. Furthermore, fats in adequate amounts strengthen the flavor of foods, making them more appealing for the elderly.
In terms of fats, olive oil is unique in that it is the base of the Mediterranean diet and various studies have proven its benefits. According to the Spanish code of food (CAE), olive oil is defined as an oily liquid extracted from the olive´s mature fruit, and has not been submitted to unauthorized manipulation or treatments (extra virgin olive oil). Olive oils are classified according to the Ruling (CE) no1989/2003 considering its characteristics (purity, manipulations and/or treatments that the olive has been submitted to).
Extra virgin olive oil is considered the most beneficial. This is the oil obtained from the first pressing of the olive, with free acidity equal to or less than 0.8º, with no organoleptic defects and maintaining the fruity attribute of the olive. Its nutritional and gastronomic values are optimal.
Extra virgin olive oil is a base product of the Mediterranean diet. It is rich in oleic acid (a mono-unsaturated fatty acid), as well as in phenolic compounds and vitamin E (a very strong antioxidant), both very beneficial for the body. Epidemiologic studies of the Mediterranean population have noted the correlation with consumption of extra virgin olive oil and reduced risk of cardiovascular disease. Hyperlipemias and dislipemias are alterations of the amount of lipids that circulate in the blood, which is generally associated with increased risk for cardiovascular disease. The lipids in the diet and those processed by the liver circulate in the blood as triglycerides (which contain fatty acids) and cholesterol, but bound to lipoproteins that are necessary for their transportation. Several of these lipoproteins can be measured in routine blood analysis, giving information regarding cardiovascular risk. The HDL (also known as the “good” cholesterol) are those in charge of eliminating the cholesterol used by the body through the bile. These lipoproteins increase with regular consumption of extra virgin olive oil. The LDL (considered as the “bad” cholesterol) transport the cholesterol to different tissues, and if they surpass certain levels in the blood analysis can increase the risk of cardiovascular disease. The levels of these lipoproteins decrease with regular consumption of extra virgin olive oil. Furthermore, current data seem to indicate a positive correlation with the consumption of this oil and a decrease in the risk of developing certain tumors, possibly due to the large amounts of antioxidants that are present.
It is important to emphasize that the antioxidant content in regular olive oil is lower than extra virgin olive oil, due to the degradation of these compounds that takes place during the process of refining the oil. In a similar fashion, the cooking processes where high temperatures are used (such as frying) or an inadequate storage can cause loss or reduction of the antioxidants in the oil. Therefore it is recommended to always purchase extra virgin olive oil, to use it in salads and soft cooking and, and its storage should be in a cool, dark place.
Benefits of olive oil in the elderly:
Energy consumption decreases throughout life, reaching up to 300-600 kcal/day in the elderly. Knowing this, a daily consumption of 40-50mL of extra virgin olive oil (approximately 4-5 spoonfuls) both raw or as cooking oil, allows to maintain the necessary energy levels in a healthy, balanced and varied diet. In this manner, quality should be more important than quantity, making extra virgin olive oil the main source of fat in the diet.