Rheumatoid Arthritis: Include these four foods in your diet to relieve joint pain.

Rheumatoid arthritis is one of the most common types of arthritis. It causes pain, swelling and stiffness of the joints.

It usually affects the hands, feet and wrists and can worsen during periods of flare-ups.

According to the Arthritis Foundation, a Mediterranean diet is a proper diet for people suffering from arthritis because it is rich in omega-3 fatty acids and antioxidants.

"Although there are no specific nutritional guidelines for people with rheumatoid arthritis, the researchers found that a diet rich in omega-3 fatty acids, antioxidants, and phytochemicals provides the body with powerful anti-inflammatory nutrients, "said the Arthritis Foundation.

The following four foods are part of the Mediterranean diet.

Fish

Some types of fish are rich in anti-inflammatory omega-3 fatty acids, which reduce the C-reactive protein and interleukin-6 – two inflammatory proteins of the body.

The best sources come from salmon, tuna, sardines, anchovies and other cold water fish. Eat at least three to four ounces, twice a week.

Olive oil

Olive oil contains healthy mono-unsaturated fats for the heart, antioxidants and oleocanthal, a compound capable of reducing inflammation and pain.

The best sources come from extra virgin olive oil, less refined and less processed, which retains more nutrients than standard varieties.

Consume two to three tablespoons a day in the kitchen or in salad dressings or other dishes.

Fruits and vegetables

Fruits and vegetables are bursting with antioxidants, which support the immune system and can help fight off inflammation.

The best sources come from "colorful foods" such as blueberries, blackberries, cherries, strawberries, spinach, kale and broccoli.

Eat at least 1.5 to two cups of fruit and two to three cups of vegetables per meal.

Onions, rich in antioxidants, can also reduce inflammation.

Nuts and seeds

Nuts are loaded with protein, fiber and monounsaturated anti-inflammatory fats.

The best sources come from nuts, pine nuts, pistachios and almonds. Eat 1.5 ounces of nuts a day, which is about a handful.

"This diet has been analyzed in small studies for its impact on the symptoms of rheumatoid arthritis. The results showed improvement in pain, morning stiffness, disease activity and physical function, "said the Arthritis Foundation.