There’s no proven diet to treat ankylosing spondylitis (AS), a painful, inflammatory condition that causes arthritis in your spine and joints. Still, some foods may help support bone health and reduce inflammation. Eating healthy also helps you maintain a healthy weight to minimize pressure on your bones.

Osteoporosis is a condition that leads to thinning bones and bones that fracture easily. As many as half of all people with AS have osteoporosis, putting them at risk of spinal fracture.

Around 99 percent of the calcium you eat is stored in your bones and teeth. Eating more foods that contain calcium, the main mineral that makes bones strong, may help limit your osteoporosis risk.

Some foods high in calcium are:

  • low-fat dairy products such as milk, yogurt, and cheese
  • sardines
  • canned salmon
  • calcium-fortified cereals and pasta
  • calcium-fortified orange juice
  • calcium-fortified tofu
  • leafy green vegetables such as kale, turnip greens, and broccoli

For healthy bones, eating foods high in calcium isn’t enough. You also need vitamin D to help your body absorb calcium. Sunlight is a good source. It’s tricky though to get enough vitamin D through diet alone. Some foods with vitamin D are egg yolks, oily fish, and vitamin D-fortified cereals or milk.

Magnesium is an often-overlooked mineral for bone strength. According to research, magnesium deficiency may lead to thin or brittle bones and osteoporosis. Even so, it’s important to keep magnesium levels steady, as too much has been shown to weaken bones.

To get enough magnesium in your diet, eat:

  • shredded wheat
  • black beans
  • avocado
  • whole wheat bread
  • raisins
  • bananas
  • oatmeal
  • brown rice

Some foods may stop your body from absorbing calcium or cause you to excrete more calcium through your kidneys. Foods that contain oxalates aren’t the best choice if you’re worried about osteoporosis. Oxalates bind to calcium so your body can’t absorb it. For example, spinach is high in calcium, but it’s also high in oxalates.

Other foods and beverages that may interfere with calcium absorption or lead to bone loss are:

  • caffeinated coffee or tea
  • soda
  • chocolate
  • alcohol
  • wheat bran
  • rhubarb
  • beets
  • almonds
  • peanuts

AS causes inflammation in your spine, but other areas of your body may also be affected. More research is needed, but eating foods that fight inflammation may, in theory, help reduce the severity of AS flares.

Research shows omega-3 fatty acids (omega-3s) are as effective as ibuprofen at reducing pain and inflammation in people with arthritis. The form of omega-3s found in oily fish such as salmon, mackerel, and albacore tuna is thought to be superior to the type found in plant sources and some grass-fed animals.

Some herbs and spices contain calcium and other compounds that may support strong bones and help reduce inflammation. Even so, be cautious and talk to your doctor before using fresh herbs and spices or herbal supplements as medicine. They’re unregulated and may cause side effects or interact with prescription medications.

Consider these options:

  • Red clover is a good source of isoflavones, chemicals that act like estrogen in your body, as well as calcium. Some research has shown the isoflavones in red clover may boost bone density and prevent bone loss in menopausal women.
  • Alfalfa sprouts are a good source of vitamin K. According to a 2008 study, vitamin K deficiency is associated with low bone density and bone fractures.
  • Stinging nettle is high in calcium and magnesium, both of which are good for bone health. It’s also known as one of nature’s natural painkillers due to its anti-inflammatory effects.

It’s important to add foods that support bone health to your diet. Eating a wholesome diet is good for your health overall, especially if you have a chronic condition. Keep in mind that some foods that are high in calcium such as high-fat dairy products may also cause inflammation in some people. If you need help creating a healthy eating plan, consult your doctor or a registered nutritionist.