Food Cures (38 page)
Authors: Carol Svec
As we physically develop, our bones get denser and denser if we supply them by eating calcium-rich foods. After about age 30, our bones are as dense as they will ever be. That’s why it is so important for children and young adults to get enough calcium in their diets; if they later need to “borrow” calcium from their bones, strong dense bones are the equivalent of a high spending limit on a credit card. 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 1,500 milligrams of calcium daily. But some folks can’t help but go overboard when they finally see the light about 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 milligrams 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), enriched/fortified soy milk, calcium-fortified fruit juice, cheese (fat-free, reduced-fat), tofu with calcium, sardines (with bones), wild salmon (with bones), soybeans, frozen yogurt (fat-free, low-fat), low-fat ice cream, calcium-fortified whole grain waffles, bok choy, white beans, kale, broccoli, almonds
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 10 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 from food sources and supplements.
BEST FOODS FOR VITAMIN D
:
Wild salmon (with bones), mackerel (not king), sardines (with bones), herring, fortified milk (fat-free, 1% reduced-fat), enriched/fortified soy milk, egg yolks, mushrooms (especially shiitake), vitamin-D-fortified margarine (soft tub, trans fat-free), fortified whole grain cereals
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.
FAQS
I’ve heard that calcium can be leeched from bones by the phosphorus in soft drinks. Is that true?
No, it’s a fallacy. In reality, there is much more phosphorus naturally found in meat than there is in soda. The main problem with soft drinks is that they replace calcium and vitamin D-rich milk in the diet. Back in the “good old days,” kids drank milk with lunch and dinner, and they often started the day with a bowl of cereal and milk. More recently, milk has fallen out of favor, and soda has become the drink of choice. Studies have shown that kids who drink soft drinks instead of milk often have less bone density than kids who get plenty of calcium in their diets. The same is true for adults. So while soft drinks are partly to blame for low bone density, it’s not because of the phosphorus.
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.
In scientific research, dietary magnesium gets mixed reviews—some studies show little or no effect, while others show significant increases in bone density or decreases in fractures. Despite these conflicting findings, magnesium is necessary for health, and I believe it is impossible to properly treat osteoporosis without including magnesium.
BEST FOODS FOR MAGNESIUM
:
Pumpkin seeds, spinach, Swiss chard, amaranth, sunflower seeds, cashews, almonds, quinoa, tempeh, sweet potatoes, white potatoes, soybeans, millet, beans (black, white, navy, lima, pinto, kidney), artichoke hearts, peanuts, peanut butter, chickpeas (garbanzo beans), brown rice, whole grain bread, sesame seeds, wheat germ, flaxseed
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 pre- 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. A few studies have shown that supplements of potassium salts can reduce the amount of calcium lost in urine, but no one has yet determined whether that translates into healthier bones. The important thing to take away from all this is that potassium-rich
foods
will help keep your bones as healthy and strong as possible.
BEST FOODS FOR POTASSIUM
:
White potatoes, yams, yogurt, soybeans, Swiss chard, snapper, sweet potatoes, avocado, cantaloupe, artichokes, bananas, spinach, lettuce (especially romaine), radicchio, arugula, endive, black cod (sablefish), honeydew melon, pumpkin, milk (fat-free, 1% reduced-fat), carrots, beans (white, black, navy, kidney, pinto), lentils, lima beans, apricots, papaya, split peas, pistachio nuts, winter squash (acorn, butternut), enriched/fortified soy milk, watermelon, beets, tomatoes (including sauce, juice), kale, mushrooms, raisins, peanuts, plums, almonds, sunflower seeds, prunes (and juice), chickpeas (garbanzo beans), oranges (and juice), broccoli
FAQS
My kids won’t drink milk, and I can’t stand drinking it myself—should I worry about the amount of calcium we’re getting?
Milk is an easy way to get calcium, but it is certainly not the only way. All dairy foods contain calcium, and many kids enjoy eating yogurt and string cheese. Whenever possible, substitute foods your kids already eat with calcium-fortified versions. For example, there are calcium-fortified waffles and orange juice. If they still don’t get enough calcium, you can always try one of the candy-flavored chewable calcium supplements, such as Viactiv or Nature’s Made brands. My experience has shown that most kids don’t like the chocolate flavors that adults are drawn to—they may eat them for a couple days, but then the appeal wears off. Instead, choose one of the other flavors, such as orange, strawberry, or caramel. (Always be careful to store the supplements where your children can’t get them—if they think of them as candy, you can bet they’ll be looking for opportunities to sneak extras. Too much calcium can be dangerous.) Another sneaky—but effective!—way to ensure your children get the calcium and vitamin D they need, is to buy a pill crusher at your local pharmacy, and mix one crushed calcium pill with a few tablespoons of yogurt or low-fat pudding.
Vitamin K
is important for the formation of osteocalcin, a type of protein found only in bone. People who suffer from fractures tend to have low vitamin K levels…and those who have high blood levels of vitamin K also tend to have high bone density. In studies of people with vitamin K deficiencies, those who took vitamin K supplements had less bone loss and fewer fractures. Therefore I highly recommend loading up on foods rich in vitamin K. One caveat: vitamin K is a natural blood thinner, 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, Brussels sprouts, watercress, asparagus, okra
Folate:
Homocysteine is an amino acid that is usually a marker for atherosclerosis and heart disease. But scientific research now suggests that homocysteine may also be a marker for osteoporosis. In a 2006 Norwegian study, women with high levels of homocysteine also had low bone mineral density. In addition, women with low bone density also had low levels of the B vitamin called folate, which is known to lower homocysteine levels. Although more research needs to be done to clarify the role of folate, the hope is that women can reduce their risk of osteoporosis by eating more folate-rich foods.
BEST FOODS FOR FOLATE
:
Fortified whole grain cereals, lentils, black-eyed peas, soybeans, oatmeal, turnip greens, spinach, mustard greens, green peas, artichokes, okra, beets, parsnips, broccoli, broccoli raab, sunflower seeds, wheat germ, oranges (and juice), Brussels sprouts, papaya, seaweed, berries (boysenberries, blackberries, strawberries), beans (black,
pinto, kidney, garbanzo, navy), cauliflower, Chinese cabbage, corn, whole grain bread, pasta (preferably whole wheat)
Vitamin C
is essential for the health of collagen and other connective tissue, including the connective tissue in bones. Without enough vitamin C, bone density loss accelerate. Some studies have shown that eating lots of foods high in vitamin C increases bone mineral density and results in fewer fractures.
BEST FOODS FOR VITAMIN C
:
Guava, bell peppers (yellow, red, green), orange juice, hot chile pepper, oranges, grapefruit juice, strawberries, pineapple, kohlrabi, papaya, lemons, broccoli, kale, Brussels sprouts, kidney beans, kiwi, cantaloupe, cauliflower, red cabbage, mangos, grapefruit (pink, red), white potatoes (with skin), mustard greens, cherry tomatoes, sugar snap peas, snow peas, clementines, rutabagas, turnip greens, tomatoes, raspberries, Chinese cabbage, blackberries, green tomatoes, cabbage, watermelon, tangerines, lemon juice, 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 only help women 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. But 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 soy foods into your diet a few times each week.
Important caveat:
although the topic of soy intake and breast cancer remains controversial because of the estrogen-like activity, I do NOT recommend soy foods for women who have had breast cancer. Furthermore, I would never recommend isoflavone
supplements
for anybody (breast cancer or not) because they have not yet been proven safe at high doses.