Manual of Nutrition and Bone Health. Coordinated by: Prof. Dr. Manuel Díaz Curiel, Head of the Internal Medicine-Metabolic Diseases Department of the Jiménez Díaz Foundation and Associate Professor of Medicine at the Autonomous University of Madrid; Prof. Dr. Ángel Gil Hernández, Professor of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Granada; Prof. Dr. José Mataix Verdú, Director of the Institute of Nutrition and Food Technology, Professor of Physiology at the University of Granada.
A balanced diet and outdoor physical exercise are two of the main allies to keep bones healthy and strong throughout life. Experts recommend following a healthy and balanced diet by boosting the consumption of calcium-rich foods.
To strengthen bones, the key is to follow a varied diet. Usually, the hardness of bones is related to a mineral: calcium; But it is important to remember that the bone is formed by a network of minerals and proteins that changes every day, and that adapts to the physiological conditions of each moment.
A bone is not just calcium, is a living tissue that acts as a support and mineral reserves, so it is constantly renewed, and needs to be fed with vitamins and minerals. A bone is composed of a framework of calcium phosphate (65%) responsible for the resistance and 35% of collagen, more flexible and damping to avoid fractures. To maintain strong bones, they are important calcium and minerals such as phosphorus and magnesium.
Other minerals are found to a lesser extent, these trace elements give bone stiffness such as boron, silicon, manganese, nickel, and molybdenum. To ensure the quality of the bone, you have to feed the collagen matrix, which needs amino acids, sulfur, and copper. Vitamin D is essential for calcium absorption, along with vitamins K and C.
What foods do bones like?
Milk. Three glasses of whole milk contain about 900 mg of calcium, which is the amount an average adult needs each day. These amounts vary by age, increasing in older people, pregnant women, and nursing mothers. The calcium that is best absorbed is that of milk and other dairy products.
The importance of milk consumption during childhood and adolescence is known to later reduce the risk of fractures. While some studies there was a significant relationship between milk consumption during childhood and adolescence with BMD (Bone Mineral Density) in adults and after menopause can be seen, others do not find this association. On the other hand, it has been observed that the increase in the consumption of milk or dairy products in populations with low habitual intakes, in general, improves markers of bone formation, decreases losses and increases bone mineral density. In addition, it has been reported that the increase in daily calcium intake through the use of foods rich in this action, such as milk, is more consistently associated with bone measurements than when the increase in intake comes from supplements.
Cheese. Most cheeses are obtained by curdling the milk until it loses water and acquires a more solid consistency so that they are authentic concentrates of the minerals and vitamins of the milk. They are a source of calcium, protein and vitamin B2 and B12. The most calcium-rich cheeses are parmesan (1,183 mg / 100g) and cured manchego (1,200 mg / 100g).
Yogurt. The best choice among dairy. Not only does it provide calcium to the bones, it also brings beneficial bacteria to the intestinal flora and has the advantage that lactose is partially digested by microorganisms.
Vegetables. Vegetables are foods that contribute to our diet high amounts of magnesium, potassium, vitamin C and other constituents which may counteract the acid load generated by the high protein intakes. Studies have linked fruit and vegetable intakes with increased bone mineral density: each serving of fruit or vegetables consumed per day was associated with a 1% increase in BMD.
Algae. Sea vegetables like hijiki, wakame or wire contain up to 1,400 mg (100 g) of vegetable calcium, which although absorbed worse, is very interesting for vegetarians, and a lot of potassium.
Sesame. This seed can be taken the toast, in bread, biscuits, sticks or in the traditional oriental tahini. It is very nutritious because of its richness in calcium and unsaturated fatty acids.
Nuts. Almonds, walnuts, and hazelnuts are the richest nuts in calcium, they also provide magnesium and zinc for the bones.
Bluefish with spinach (sardines, whitebait, anchovies, etc.). The combination of vitamin D and calcium (in the spines) is essential for absorption of the mineral during digestion.
Soja. At the moment there is a great interest in the protective effects of soy on the bone, but there is no agreement on who or what are the soy constituents responsible for the improvement in the health of the bone that causes this food. Although a large number of authors have associated the beneficial effect (increased BMD and decreased bone resorption) to the isoflavones present in soybeans, the existing results only mark a trend, requiring further studies to confirm this. However, other authors find that beneficial effects on the skeleton appear to be due to soy protein.Likewise, there was no association between phytoestrogen intake and BMD in premenopausal women.
Mineral water. Different studies in populations consuming mineral water high in calcium show that in these populations mineral water intake is associated with increased BMD. It has been estimated that for every 100 mg / day of calcium from water, femoral BMD increased by 0.5%.
Tea. Although it contains caffeine, tea contributes to increased levels of bone density, especially in the lower back and hip, as shown by a work done at the Cambridge School of Medicine.
Lemon. Dressing salads with lemon favors the absorption of calcium. A naturist cure consists of taking a glass of warm water in the morning with freshly squeezed lemon juice in the morning.
Foods to Restrict
Alcohol. Although if you have to drink a drink, beer is recommended, because it contains polyphenols that prevent loss of bone density. In addition, beer has substances similar to estrogens that delay the onset of menopause and increase the level of female estrogens.
The effect of alcohol consumption on bone appears to be related to the amount of alcohol ingested. Misuse increases the risk of fractures by increasing the risk of falls or being associated with malnutrition and tobacco use. Studies in these patients show a reduction of BMD and histological evidence of osteoporosis. However, studies in populations that consume moderate amounts (11-30 g / day or 1-2 units / day) show that it increases BMD and protects against bone loss. It has been suggested that this beneficial effect could be related to its effect on androgen or estrogen levels. It has also been indicated that silicon present in alcoholic beverages, particularly beer, could contribute to the aforementioned positive effect of alcohol on the bone.
Sugar. Foods rich in refined sugars such as pastries, sweet drinks, ready meals, etc. Favor the demineralization of the bone by acidifying the medium.
Salty foods. Each gram of sodium taken (2 g of cooking salt) causes the loss of 26 mg of calcium. It is advisable to avoid adding salt to food and using herbs in the kitchen.
Carbonated drinks. In recent decades there has been a sharp increase in the consumption of carbonated beverages. These beverages have displaced milk and have introduced phosphoric acid without calcium and when the diet is high in phosphorus and low in calcium, bone resorption increases to recover the serum levels of this mineral. There are epidemiological studies in which the consumption of carbonated beverages is associated with an increased risk of fracture in children, young and postmenopausal women and women with high physical activity. However, in others, it has not been possible to relate the consumption of carbonated beverages to BMD in postmenopausal women. Recent works have shown that only those containing caffeine, besides phosphoric acid, are those that increased urinary calcium and those containing only phosphoric did not produce calciuria. These authors conclude that the greatest effect of carbonated beverages is mainly due to the displacement of milk in the diet.
Caffeine. Caffeine high dose increases urinary losses of calcium and magnesium. Studies examining the effect of caffeine intake on bone conclude that moderate intake has no negative effects on young and adult women because urinary losses are offset by increased absorption. However, older women are not able to compensate for these losses. For these reasons, the effects of high caffeine intakes appear to be restricted primarily to postmenopausal women with a low calcium intake. Thus, 2 or more cups / day of coffee has been associated with a decrease in BMD among people with low milk consumption, but not among women who drink one or more glasses of milk a day.
Diets rich in proteins, especially those who avoid carbohydrates to lose weight. Proteins acidify the medium, hinder the absorption of calcium from food and cause a rebound effect of calcium out of the bones to alkalize the medium.
Diets high in fat. The fat acts as a coat that wraps food and hinders the absorption of minerals. In addition, fat increases the absorption of phosphorus that causes calcium to escape from the bones.
Whole grains. The healthiest vegetable foods such as whole wheat bread have a hidden side that must be taken into account because they contain phytic acid, a substance that sequesters calcium and prevents its absorption. To avoid this, whole yeast bread must be chosen, because the fermentation process reduces the proportion of this acid, facilitating the intake of calcium.
Spinach and oxalic acid. Some fruits and vegetables and cocoa powder contain oxalic acid (AO) which in contact with calcium forms an insoluble salt (calcium oxalate) that can not be absorbed. That’s why it’s important not to mix vegetables like spinach (571 mg of AO / 100g) or rhubarb (537 mg) with foods rich in calcium.
Three glasses of whole milk contain about 900 mg of calcium, the average amount needed each day.