Strong bones are essential for healthy living, but there’s no guarantee that any of us will have them as we grow up and grow older. While we don’t think about it very much unless something goes wrong, we need to do our part to develop and protect our bones. Proper nutrition is part of that.

Your skeleton is a living organ that needs nutrients in order to rebuild bone in areas where it is continually being broken down. Osteoporosis, a condition in which bones lose mass and density and are at greater risk for fractures, occurs in 55% of Americans over 50. Millions of fractures occur every year as a result of poor bone health.

The most common osteoporosis-related bone fractures among the elderly affect the hips, vertebrae, wrists and ribs. Vertebral fractures are the most common, and occur most often in women. You may see an elderly woman with hunched shoulders, head propped forward and unable to stand straight, because a few of her vertebrae have essentially collapsed. This condition is sometimes called “dowager’s hump”.

How do we prevent this from happening to us? In addition to regular weight-bearing exercise, diet can make a big difference. Here are some bone-friendly foods you can add to your diet to help keep your bones strong:

Seeds—Though we usually think of bones as being made of calcium, they also consist of other elements. For instance, half of the body’s magnesium is found in the bones. A great source of magnesium is seeds, particularly pumpkin seeds. Brazil nuts are also rich in magnesium.

Nuts—Walnuts are rich in alpha linolenic acid, which helps to keep bones building up instead of breaking down.

Leafy greens—Leafy greens (particularly the dark green kind), provide a host of nutrients and vitamins, including magnesium, calcium and vitamin K. Vitamin K helps to cut calcium loss in urine and is essential in building new bone matter to replace old.

Beans—Pinto beans, kidney beans, black beans and white beans all contain magnesium and even a little calcium. Beans not only help your bones, they help prevent obesity, heart disease and cancer.

Sardines—Canned sardines contain a substantial amount of calcium. A 3 oz. can typically contains 320 mg of calcium.

Swiss cheese—One ounce usually contains 270 mg of calcium.

Dried plums (Prunes)—Dried plums are a reliable source of dietary fiber, phenols and vitamin K. They’ve been shown to suppress the rate of bone resorption, or the breakdown of bone.

Besides eating well, it’s very important to remember to exercise. In fact, one of the greatest health risks faced by astronauts when they go into orbit is bone loss. Bones deteriorate more quickly in zero gravity unless exercise is included in the daily routine. The same idea applies here on earth. Stressing bones with physical activity (particularly weight-bearing exercise and exercise that involve some type of impact, such as running) seems to trigger bone-building activity and prevents the body from using bone-building nutrients for other things.