Some of more than 8,000lbs of locally grown broccoli from a partnership between Farm to School and Healthy School Meals is served in a salad to students at Marston Middle School in San Diego.
Broccolli and sweet potatoes are some good sources of potassium, important for bone health.Reuters/Mike Blake

Potassium salts (bicarbonate and citrate) abundant in fruits and vegetables improve bone health and reduce bone resorption to increase bone strength, says research from University of Surrey.

Bone resorption is a process involving the breakdown of bone by specialised cells known as osteoclasts. It results in a transfer of calcium from bone to the blood.

Broken down bone being replaced by new bone growth is a natural and continual process. However, as people age, resorption tends to exceed the rate of replacement, with more bone broken down than replaced. This results in osteoporosis and other problems.

The study, published in the journal Osteoporosis International, showed that high intake of potassium salts significantly reduces the excretion of calcium and acid in urine.

Lead author Dr Helen Lambert from the University of Surrey said, "Excess acid in the body, produced as a result of a typical Western diet high in animal and cereal protein, causes bones to weaken and fracture. Our study shows that these salts could prevent osteoporosis, as our results showed a decrease in bone resorption."

Sweet potato, yoghurt, banana, broccoli, spinach and kiwifruits are some good sources of potassium.