Osteoporosis and diet: what foods to favor and avoid?

Osteoporosis is a disorder characterized by progressive loss of bone mass. Bone renewal is no longer effective enough to fill it, the bones become fragile, increasing the risk of fractures, the main complication of osteoporosis.

There are many risk factors accelerating the onset of osteoporosis:

• Decrease in the production of sex hormones (estrogen, testosterone): particularly visible during menopause in women in particular, the reduction in estrogen production generates a drop in osteoblast activity.

• Slimming and dietary deficiency(ies): excessive thinness and dietary deficiencies, particularly in vitamin D and calcium, modify the normal role of proteins: they are used for energy purposes. This bifurcation decreases the availability of proteins to muscles and bones. The diet must then compensate for protein and mineral deficiencies so that the bones have all the elements necessary for their constitution.

• Lack of physical activity: regular physical activity allows, on the one hand, to increase muscle mass and strength, and on the other hand, to develop and preserve bone mass. The stress on bones and muscles during physical exercise generates mechanical stress which has positive effects on bone mineralization.

To prevent osteoporosis and slow its progression, it is essential to take care of your diet and to favor a diet rich in:

• Calcium : it is the most abundant mineral in the body, more than 99% stored in bones. Calcium is undeniably essential to the skeleton, it constitutes the solid mineralized part of bone tissue. How ? By forming the hydroxyapatite crystals: it is a salt whose hardness is high and which surrounds the collagen forming the bone tissue. In other words, calcium ensures bone strength and formation. Ideally, for good absorption of calcium, it is preferable to focus on foods with a good phosphorus ratio, around 1. This means that the phosphorus and calcium contents are balanced: they do not compete at the time of intestinal absorption.

• Vitamin D : it increases intestinal absorption and renal reabsorption of calcium, while boosting the activity of osteoblasts, the cells that build bone. Vitamin D has real remineralizing power, it stimulates ossification.

• Proteins: these macronutrients are essential for the body, they represent the building blocks of the bone matrix in particular. In addition, proteins increase muscle mass, which helps better protect bones and limit fractures. Namely that animal proteins are better absorbed and used by the body than plant proteins. However, they are also more acidifying. Metabolic acidosis is a phenomenon favoring the excretion of calcium through the urine and therefore bone decalcification.

• Alkalizing foods: among them fruits and vegetables in particular. They help counter acidosis. Since proteins are at the heart of nutritional care in cases of osteoporosis, reducing them would be counterproductive. This is why it is best to compensate for them with an alkalizing diet.

• Phytoestrogens : through their structure similar to estrogens, these plant compounds indirectly boost bone mineralization by attaching to the same receptors as estrogens. These sex hormones promote bone formation. However, the intake of phytoestrogens remains to be nuanced, not all the forms found in the diet being biologically active and the effects on bone remodeling not being fully demonstrated, studies are still necessary.

On the other hand, it will be important to limit salt. Salty products and salt (NaCl, sodium chloride) in excess (hypernatremia) increase the urinary elimination of certain minerals, such as calcium. This loss of calcium leads to bone demineralization.

Dairy products take first place on the podium since their nutritional composition is very rich in calcium and vitamin D; the two essential micronutrients in the prevention of osteoporosis. THE calcium dairy products is very well assimilated by the body since it is associated with phosphorus in an ideal phosphocalcic ratio, slightly greater than 1. In addition, dairy products are, with fatty fish, the products richest in vitamin D. The fattest dairy products will be the richest: butter, whole milk, cheese for example.

The benefits of dairy products do not stop at these two nutrients. THE caseins, major milk proteins, are involved in bone health although this is subject to debate. Dairy proteins have a real biochemical complexity explaining their “matrix effect”, that is to say the interaction between the different nutrients. The calcium-casein association, for example, is essential for bone health via the fixation and absorption of this mineral. Additionally, caseins appear to increase the production of IGF-1, a growth factor hormone involved in bone mineralization. Finally, caseins and other proteins in dairy products allow the inhibition of PTH, a parathyroid hormone which, in high concentrations, is involved in bone demineralization. Finally, the carbohydrates in dairy products, lactose and galactose, increase nitrogen savings. This means that carbohydrates save the use of proteins. The latter can therefore be used for their rightful role: construction and functioning of the body.

We recommend you :

• Two dairy products per day according to ANSES.

• Three dairy products per day for the elderly, needs increase with age.

• D’alternate dairy products during meals, whole and semi-skimmed milk, cheese and yogurt, the dairy products richest in vitamin D also being the most caloric.

• Of privilege milk and cheese yogurts. Although cheeses are richer in protein and calcium than other dairy products, they are also richer in salt. We then prefer low sodium cheeses : ricotta, Faisselle, Gouda, mozzarella, Emmental or even Saint-Nectaire.

• To bring alkalizing foods to your diet: fruits, vegetables in particular. Animal (and to a lesser extent plant) proteins in excess are acidifying, metabolic acidosis promotes the excretion of calcium through the urine. Alkalizing foods help counteract this acidity.

Where to find it?

• Fresh fruits and vegetables: spinach, carrot, kale, beans, fig, arugula, rhubarb, lemon are just a few examples of the fruits and vegetables richest in calcium according to Ciqual, the nutritional composition table of foods.  Calcium from fruits and vegetables is also well absorbed since the phosphocalcic ratio is greater than 1.

• Spices and aromatic herbs: There are several benefits to sprinkling your dishes with spices and aromatic herbs. They are certainly rich in calcium, but they also enhance the taste of the preparations, which helps you to have less of a heavy hand on the salt. Among the herbs richest in calcium, we find basil, savory, marjoram, thyme, sage, oregano, mint, rosemary and even cinnamon.

• Seeds and oilseeds: chia, sesame, almonds, flax, soy, lupine, Brazil nuts, alfalfa, hazelnuts are the seeds and oilseeds richest in calcium. To give an idea, a daily portion of chia seeds (15 g) provides the same amount of calcium as a serving of classic hard cheese.

We recommend you :

• Five fruits and vegetables a day (2 servings of fruit and 3 servings of vegetables).

• D’incorporate daily spices and aromatic herbs within your varied and balanced diet.

• A handful of seeds and nuts per day, or approximately 15 g.

Calcium of plant origin has the same benefits mentioned above for the bone system as calcium of animal origin. However, some foods of plant origin contain a considerable amount of inhibitors such as oxalates and phytates (depending on the food). By binding to calcium, these reduce its absorption and bioavailability. It is therefore important to vary the different sources of calcium to achieve your daily recommendations.

Mineral waters are also an interesting source of calcium to include in your diet. Some waters are richer in calcium than others : tap water has a variable calcium content depending on whether it is “hard” or “soft”. The calcium content varies from 1 mg per liter for very soft water, to 160 mg per liter for very mineralized water. In comparison, the scale of contents is even greater for mineral waters: from 10 to more than 500 mg of calcium per liter. The minerals in water are well absorbed, which makes mineral water a good source of calcium, certainly the most interesting after dairy products. Enough to meet your calcium needs through drinking. Let's not forget that water also helps fight hypernatremia: a factor in bone demineralization.

We recommend you :

• Courmayeur®, Tallians®, Hépar® and Contrex®, the mineral waters richest in calcium. Generally speaking, still waters have a better calcium content than sparkling waters.

• To drink small sips regularly, to optimize calcium absorption.

In addition to calcium, vitamin D is essential in the prevention and management of osteoporosis. Fatty fish are very rich in it and have a complete and very interesting nutritional profile in cases of osteoporosis. Vitamin D is better absorbed in the presence of lipids, an advantage of fatty fish which, as their name suggests, are lipid carriers. In fatty fish, we find cholesterol. It has a bad press, but it is nevertheless essential for the proper functioning of the body since it participates in the structure of cell membranes. Above all, cholesterol is none other than a precursor of vitamin D. In fact, in addition to food, our majority source of vitamin D is endogenous: our body knows how to synthesize it from cholesterol. There is no point in excluding it from the diet, only excess “bad” cholesterol (HDL) promotes hypercholesterolemia. Oily fish benefit from a balanced composition omega-6/omega-3. They help limit the unfavorable ratio between these two fatty acids which is associated with bone loss in addition to the well-known role on inflammation. Note that osteoporosis can also be the consequence of certain chronic inflammatory diseases such as rheumatoid arthritis. Finally, fatty fish provide proteins.

We recommend you :

• At minimum one fatty fish per week according to ANSES. Oily fish are anchovies, mackerel, salmon, eels, tuna, herring and even sardines.

• To encourage gentle cooking, at low temperatures such as steam, bain-marie, cooking in foil, to preserve the nutrients. Raw and marinated, these fish are also sublimated.

• Of limit salted fatty fish : breaded, smoked or dried these fish are richer in salt.

Fruits and vegetables are a category of foods necessary for everyone and for everything, osteoporosis is no exception, on the contrary. If they are particularly useful here, it is for their alkalizing power. They prevent acidosis, caused in particular by animal proteins, which, as a reminder, increases bone decalcification. In addition, fruits and vegetables are, after dairy products, the food category richest in calcium. Added to this is the interest of polyphenols, antioxidant and anti-inflammatory molecules, interesting for the prevention of osteoporosis. Finally, fruits and vegetables are rich in vitamin K, the latter stimulates bone mineralization.

We recommend you :

• Five fruits and vegetables a day (2 servings of fruit and 3 servings of vegetables).

• Opt for seasonal, local, fresh and raw fruits and vegetables to benefit from all their benefits and nutritional density. Also be sure to diversify them.

Phytoestrogens have the ability to cause estrogen-like effects by promoting bone mineralization.

Where to find phytoestrogens?

• Nuts and oilseeds: nuts in particular;

• Seeds: particularly flax, sesame, squash, chia;

• Legumes: notably soya, chickpeas, peas, beans, lentils;

• Cereals: rye, wheat, oats, barley;

• Certain plants: licorice, hops, red clover, rhubarb, fennel, alfalfa, etc.

The seeds are all the more interesting since they are rich in lipids, which improve the absorption of vitamin D. Seeds, nuts and soy are also good sources of vegetable proteins and of calcium for certain varieties (chia seeds, almonds, flax seeds and lupine are the richest).

Be careful, however, this intake of phytoestrogens remains to be qualified, as not all forms found in food are biologically active. In addition, when consumed in excess, they may present undesirable effects for certain populations at risk (infants, pregnant women, thyroid disorders or hormone-sensitive tumors).

We recommend you :

• A handful of seeds and nuts per day, or approximately 15 g.

• At least a legume twice a week. Consider incorporating soy products into your diet: soy milk, soy sprouts, soy oil, etc.

Salty products and salt (NaCl, sodium chloride) in excess increase the urinary elimination of certain minerals, such as calcium. This loss of calcium leads to bone demineralization.

We recommend you :

• Of ne do not exceed 5 g of salt per day.

• Of limitate foods high in salt : prepared meals, processed products, aperitif biscuits, vegetable and meat broths, bread, etc.

• From fpay attention to low-fat products in salt, in fat: they can encourage you to consume more, but “less” does not mean “not at all”. On the contrary, in this case we are often dealing with foods that are too rich in salt.

• From gouter your dishes before salting. You can add spices or aromatic herbs to enhance the taste of your dishes.

• Of varier cheeses.

• Decweconsume occasionally cold meats, once every two weeks for example.

• Enjoy the sun's rays: the sun's ultraviolet rays are essential for the endogenous synthesis of vitamin D, it is even our main contribution.

• Limit or even stop smoking: the High Authority of Health recommends starting smoking cessation to limit osteoporosis.

• Practice regular physical activity: sport stimulates ossification: during a sports session, impacts cause small lesions on the bones. The body compensates by increasing ossification to prevent bone loss from the next sports training.

• Favor soft raw butter: Butter is a food which provides a significant amount of vitamin D, well surrounded by lipids which facilitate the absorption of the latter. If not for vitamin D, butter is full of cholesterol, the precursor which allows us the endogenous synthesis of vitamin D. Butter consumption must still remain reasonable: 20 grams of butter maximum per day.