How Food Affects Osteoporosis

Find out how to make healthy food choices that can help prevent or reduce dangerous bone loss that leads to osteoporosis.

Next to genetic predisposition, poor nutrition is the most common cause of osteoporosis. Making healthy food choices can help prevent dangerous bone loss, and food is one of the most important treatments recommended by physicians and nutritionists alike once osteoporosis is diagnosed.

Good Foods to Choose

Calcium and Vitamin D
When it comes to osteoporosis prevention or treatment, the two most important nutrients are calcium and vitamin D. Bone is made mostly of calcium. In addition, calcium fuels many other body functions, such as muscle movement, nerve operation, and immune activation. Typically, we get our daily dose of calcium from food. But if your diet isn’t the greatest, your body will use your bones as a bank, borrowing the calcium it needs today from the abundant supply in your bones. This creates a kind of calcium debt to your bones. If you eat enough high-calcium foods to keep functioning, any excess will be used to pay back the debt. But if you eat poorly, the debt never gets repaid. While you can skate by for a few years, eventually the debt will catch up with you in the form of weakened, thinning bones.

As we physically develop, our bones get denser and denser if we supply them by eating calcium-rich foods. By age 30, our bones are as dense as they will ever be. That’s why it is vital for children and young adults to get enough calcium in their diets, so that they start out with strong, dense bones. After menopause, all women lose bone density because of hormonal changes. A woman with dense bones will be able to lose some density without developing osteoporosis. After menopause, it is still important to get enough calcium so that you don’t run up a calcium debt any larger than necessary.

On the other hand, it is possible to get too much of good thing. Most people struggle to get the recommended 1,000 to 1,200 mg of calcium daily. But some folks can’t help but go overboard when they finally appreciate the connection between calcium and bone health — they change their diets and take supplements . . . lots of supplements. Unfortunately, you can’t make up for lost calcium overnight. The upper recommended limit for calcium consumption is 2,500 mg per day — taking more can reduce the body’s ability to absorb other minerals and may lead to kidney stones.

One interesting note: Some foods — most notably spinach and rhubarb — contain lots of calcium, but they also contain oxalates, substances that bind to the calcium, making it unavailable to your body. My list of calcium-rich foods includes only the absolute best sources, so every serving serves your bones.

BEST FOODS FOR CALCIUM: Yogurt (fat-free, low-fat), milk (fat-free, 1% reduced-fat), soy milk, tofu with calcium (check nutrition label), soybeans (edamame), frozen yogurt (fat-free, low-fat), low-fat ice cream, bok choy, white beans, kale, collard greens, broccoli, almonds and almond butter

Calcium is useless without vitamin D. Vitamin D allows calcium to move from the gastrointestinal tract to the parts of the body that need it — including the bones. Without enough vitamin D, a child’s bones can become so weak that they bow under the body’s own weight, a condition called rickets. In adults, lack of vitamin D means that the body borrows calcium from bones to feed the rest of the body’s needs. Eventually osteoporosis will set in.

Vitamin D can be made in the body through a reaction of the skin and sunlight. Just ten to 15 minutes of sun on the bare skin of the arms three or four times a week is enough to keep most of us healthy. Of course, too much sunlight causes skin damage and premature aging, and may lead to skin cancer. That’s why I recommend getting vitamin D primarily from food sources and supplements. Since few foods are rich in vitamin D, you may need to take a supplement (or multivitamin that contains vitamin D) in order to take in at least 800 International Units (IU) of vitamin D daily, my personal recommendation for healthy adults.

BEST FOODS FOR VITAMIN D:Wild salmon, mackerel (not king), sardines, herring, fortified milk (fat-free, 1% reduced-fat), soy milk, fortified non-fat or low-fat yogurt, egg yolks, UV-treated mushrooms,

Other Nutrients

Although calcium and vitamin D are the superstars of osteoporosis prevention and treatment, there are many other nutrients that play a supporting role, including:

Magnesium You don’t need a chemistry class to know that acids can be corrosive. The same is true for acids formed in your body during the process of metabolism. These metabolic acids need to be balanced and neutralized by alkaline compounds, otherwise they can cause bone loss. Magnesium can help neutralize these acids.

Furthermore, magnesium plays an integral role in bone crystal growth, thereby helping to strengthen bone structure. In addition, magnesium helps your body absorb calcium. For calcium to be absorbed in the body, it needs two things: vitamin D (as we already discussed) and parathyroid hormone (PTH). Because magnesium affects PTH, it indirectly — but very critically — affects how much calcium is available for building and maintaining bone.

While the scientific research is mixed, some studies show that a high magnesium intake can increase bone density or decrease the risk for fractures. Despite the conflicting findings, magnesium is necessary for health, and I believe it is impossible to properly treat osteoporosis without including magnesium. You don’t necessarily need to reach for a supplement though. Magnesium is found in a wide variety of healthful foods, so you can definitely reach your daily quota if you make an effort to load up on magnesium-rich ingredients.

Calcium supplements may cause constipation in some individuals. In such cases, taking a calcium/Vitamin D supplement that also contains magnesium (which acts as a gentle laxative) may help keep bowel habits regular.

BEST FOODS FOR MAGNESIUM: Pumpkin seeds, spinach, Swiss chard, amaranth, sunflower seeds, cashews, almonds, quinoa, tempeh, sweet potatoes, white potatoes, soybeans, millet, starchy beans (such as black, navy, pinto, garbanzo, kidney), artichoke hearts, peanuts and peanut butter, brown rice, whole grain bread, sesame seeds, wheat germ, flaxseed

Potassium Potassium helps to increase bone formation, improves calcium balance, increases bone mineral density, and reduces bone resorption by neutralizing metabolic acids.

Researchers from the United Kingdom looked at the effects of dietary potassium on bone mineral density of more than 3,000 premenopausal and postmenopausal women. For women who were still menstruating, eating lots of potassium-rich foods increased bone mineral density by 8 percent — a relatively modest gain, but one that the researchers estimated could translate into a 30 percent reduced risk of fracture in later years.

Of course, it is difficult to separate the effects of potassium specifically from the effects of fruits and vegetables in general. Fruits and veggies, many of which contain significant quantities of potassium, have a whole rainbow of nutrients that contribute to bone health. The most important takeaway from this encouraging research is that potassium-rich produce and other foods can help keep your bones healthy and strong.

BEST FOODS FOR POTASSIUM: White potatoes, yogurt (fat-free, low-fat), soybeans, Swiss chard, all fish, sweet potatoes, avocado, cantaloupe, artichokes, bananas, spinach, lettuce (especially romaine, radicchio, arugula, and endive), honeydew melon, pumpkin, milk (fat-free, 1% reduced-fat), carrots, starchy beans (such as  black, navy, kidney, pinto, garbanzo), lentils, lima beans, apricots, papaya, split peas, pistachio nuts, winter squash (acorn, butternut), soy milk, watermelon, beets, tomatoes (including sauce, juice), kale, mushrooms, raisins, peanuts,  plums, almonds, sunflower seeds, prunes (and juice), oranges (and juice), broccoli

Vitamin K Vitamin K is essential for the formation of osteocalcin, a type of protein found only in bone. High intake of vitamin K has been linked to lower risk of fractures in some populations. Therefore I highly recommend loading up on foods rich in vitamin K. One caveat: Vitamin K is a natural blood thickener that plays a role in the formation of blood clots, so people who are taking blood-thinning medication (such as warfarin) should talk with their doctors before eating vitamin K–rich foods.

BEST FOODS FOR VITAMIN K: Kale, spinach, collard greens, Swiss chard, turnip greens, endive, escarole, mustard greens, lettuce (all varieties), parsley, broccoli, broccoli raab, Brussels sprouts, watercress, asparagus, okra

Vitamin C Vitamin C is essential for the health of collagen, a key protein in bone tissue that contributes strength and resilience. Some studies have shown that eating lots of foods high in vitamin C increases bone mineral density and results in fewer fractures. A Tufts University study found that older men who consumed the most vitamin C experienced less bone loss over a 4-year period, but the same relationship was not seen in women. More research is needed to understand the relationship between vitamin C and bone health during aging, but regardless of future findings, it’s a good idea to consume plenty of vitamin C-rich produce like peppers, citrus fruits, and broccoli.

BEST FOODS FOR VITAMIN C: Guava, bell peppers (yellow, red, green), oranges and orange juice, grapefruit (and juice), strawberries, pineapple, kohlrabi, papaya, lemons and lemon juice, broccoli, kale, Brussels sprouts, kidney beans, kiwi, cantaloupe, cauliflower, cabbage (all varieties), mangoes, white potatoes (with skin), mustard greens, tomatoes, sugar snap peas, snow peas, clementines, rutabagas, turnip greens, raspberries, blackberries, watermelon, tangerines, okra, lychees, summer squash (all varieties), persimmons

Soy Protein Soy foods contain natural chemicals called isoflavones, which are phytoestrogens — plant substances that mimic estrogen. Knowing that women lose bone density after menopause because of the loss of estrogen, some scientists believe that the plant estrogens in soy foods could help increase bone density. It’s still not clear whether that’s true. In laboratory rats, isoflavones helped preserve bone, but in people, the effects are more complicated. Scientists theorize that soy may help women only before menopause (when they lose estrogen receptors as well as estrogen), or it could be that only certain forms of soy protein may be beneficial after menopause. For example, a Japanese study of postmenopausal women found that bone mineral density was higher in women who ate fermented soybeans (natto) but not in women who ate tofu or other soy products. Yet other studies have shown that long-term addition of soy protein in the diet seems to reduce bone turnover and may prevent bone loss after menopause. Although the optimal amounts of soy protein haven’t been determined, I recommend you try to incorporate high-quality, whole soy foods into your diet a few times each week.

Note: If you have a history of breast cancer, it’s always wise to speak with your physician about incorporating soy foods into your diet, although many health organizations and researchers have concluded that moderate amounts of whole soy foods like tofu, edamame, and tempeh are perfectly safe.

BEST FOODS FOR SOY PROTEIN:Tempeh, tofu, soybeans (edamame), natto (fermented soybeans), soy nuts, soy flour, soy milk, soy yogurt, soy cheese, soy crisps

Protein For many years, conventional wisdom was that protein increased the risk of osteoporosis because people who ate large amounts of protein had a large amount of calcium in their urine. Scientists thought that protein was somehow leeching calcium from the bones, which then found its way out of the body through urine. Excessive amounts of protein may indeed pose a problem. However, more recent research suggests that eating too little protein is just as harmful to bone health, if not more so, than overdoing it.

Protein is an important component of bone and absolutely necessary for bone strength. Studies show that people who don’t get adequate protein may have reduced calcium absorption, reduced bone density, and higher rates of bone loss. People who eat relatively large amounts of protein have a reduced risk of fractures and higher bone mineral density. Older women, the primary group affected by osteoporosis, are especially at risk for low protein intakes and need to take extra care to make sure they’re incorporating quality proteins into meals and snacks.

Although more research needs to be done to unravel the complicated relationship between protein intake and bone health, a few studies suggest that vegetarian proteins (like beans, lentils, and whole soy foods) may be more beneficial to bone health than animal proteins. But, as mentioned earlier, too much protein from any source may still be harmful, so don’t go protein crazy: no high-protein/no-carb diets or excessive amounts of protein bars or shakes.

The bottom line is that you need to ensure that you’re getting an appropriate amount of protein through lean meats, skinless poultry, fish, eggs, beans, lentils, dairy, soy foods, and nuts. What defines appropriate depends on your weight. Here’s a simple rule of thumb: Take your weight and divide it in half — that’s approximately how many grams of protein you need to eat every day for good bone health. For example, if you weigh 140 pounds, you need about 70 g of protein each day. And remember that lean animal proteins, such as skinless poultry, seafood, and lean steak, are incredibly rich sources of protein, meaning just a small 3-ounce cooked portion (about the size of your palm) can provide between 20 and 25 grams. Depending on your size, that can be a third of your daily protein needs.

Also keep in mind that fattier cuts of beef will provide less protein ounce per ounce when compared with leaner cuts. That’s because the fat content takes up space and displaces protein. Reduced-fat and fat-free milk, cheese, and yogurts can sometimes even provide more calcium ounce per ounce than their full-fat counterparts, for the same reason. When fat is removed, the lost volume is replaced with more calcium-rich, reduced-fat dairy. Double bonus — less saturated fat, more calcium!

BEST FOODS FOR PROTEIN:Skinless turkey, skinless chicken, seafood and fish, pork tenderloin, lean beef, egg whites, yogurt (fat-free, low-fat), milk (fat-free, 1% reduced-fat), soy milk, cheese (fat-free, reduced-fat), starchy beans (such as black, navy, pinto, garbanzo, kidney), lentils, split peas, tofu, tempeh, soybeans, all nuts and nut butters, seeds and seed butters
(Of course, many more foods than those listed above provide protein — even breads, cereals, and grain products contain small amounts of protein. I encourage you to read labels, and tally your protein grams for a day or two to make sure you’re on track.)

Foods to Limit

Vitamin A
Too much vitamin A can harm bones, increasing the risk of fractures. Although more research needs to be done, it looks as though too much vitamin A may stop vitamin D from doing its job of making calcium available to bones. In food, vitamin A comes from two sources: beta-carotene and retinol — and recent studies suggest that only retinol causes problems. To avoid overdosing on retinol, the troublesome form of vitamin A, do not regularly eat liver or foods that are fortified with vitamin A. Furthermore, don’t take any supplement that contains more than 2,000 IU retinol, including your multivitamin. Your multivitamin should provide no more than 100 percent DV for vitamin A (5,000 IU) and at least 50 percent should come from beta-carotene or mixed carotenoids. Look for this information on your bottle’s nutrient listing, right next to vitamin A.

Salt causes the body to lose a little bit of calcium through what scientists call renal excretion (and what everyone else calls peeing!). The actual amount is very small, but if you are already fighting a calcium deficiency, or if you have bone-density problems, every little bit counts. In addition, salt seems to increase bone resorption. Limit your salt intake, and on those days when salt can’t be avoided, just try to eat an extra serving of reduced-fat dairy to make up for it.


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