As healthcare professionals have long known, the Mediterranean diet has consistently been shown to have beneficial effects on musculoskeletal, cardiovascular, metabolic, and cognitive diseases, but can it also be associated with a lower prevalence of osteoarthritis of the knee?
Osteoarthritis (OA) is the most prevalent joint disease and a leading source of chronic pain and disability in the United States and other developed nations. Knee OA accounts for more than 80% of cases of OA and affects at least 19% of American adults over the age of 45. (1)
In a recent study, researchers have concluded that the Mediterranean diet does indeed impact the prevalence of knee OA–study participants who followed the Mediterranean diet had a 17% lower prevalence of knee OA than those who did not follow that diet.
An Abundance of Plant Foods, Fresh Fruit and Olive Oil
The Mediterranean diet is based on the traditional dietary habits of people from countries that surround the Mediterranean Sea, including Greece, Italy, France and Spain. It is not a single prescribed diet but encourages the consumption of fresh, seasonal, and local foods.
Usually depicted as a food pyramid (2), the Mediterranean diet is characterized by abundant plant foods (fruit, vegetables, breads, other forms of cereals, potatoes, beans, nuts, and seeds), fresh fruit as the typical daily dessert, and olive oil as the principal source of fat.
In the Mediterranean diet, dairy products (principally cheese and yogurt), fish, and poultry are consumed in low-to-moderate amounts. No more than four eggs are consumed weekly, red meat is consumed in low amounts, and wine is consumed in low-to-moderate amounts (normally with meals).
Because it focuses on plant foods and natural sources, the Mediterranean diet contains valuable nutrients such as healthy fats and fiber; it is also low in sugar and has a high vitamin and mineral content. Moderation in the amount of food consumed is advised, as the diet does have a high-fat content.
How A Mediterranean Diet Helps Osteoarthritis and Pain
While a direct cause and effect between following a Mediterranean diet and lower incidence of knee OA have not been determined, there are a number of factors that help explain the link:
- A higher adherence to a Mediterranean diet is linked to a decrease in inflammation (3) and inflammation is acknowledged as an important pathway in the development of knee OA. (4) (There is a lot of evidence on the overall benefits of an anti-inflammatory diet.)
- A Mediterranean diet may influence a reduction in oxidative stress markers (5) which may delay the onset of OA.
- The extracellular matrix (ECM) is frequently defective in those who have or will develop OA. (6) A Mediterranean diet could play a role in the remodeling of ECM, promoting effective repair.
There is an added health bonus for people following a Mediterranean diet: Doing so can significantly lower their BMI and they tend to experience fewer medical morbidities and chronic diseases (particularly diabetes).
A Combination of Ingredients is Key
Past studies have suggested that that the supplementation of olive oil (an essential component of the Mediterranean diet) may preserve the articular cartilage, reducing the risk of knee OA. (7) Additionally, eating cereals has been linked to a lower prevalence of knee OA, but this could be because cereals are a good source of vitamins and minerals (such as magnesium) in addition to their anti-inflammatory and anti-oxidative stress properties.
It appears that the combination of the different ingredients of the Mediterranean diet — rather than any one single element — is responsible for the reduction in the prevalence of knee OA in people who adhere to this dietary lifestyle.
Dr. Tatta’s simple and effective pain assessment tools. Quickly and easily assess pain so you can develop actionable solutions in less time.
The Mediterranean Diet as a Lifestyle
For people who want to follow a Mediterranean diet for health or enjoyment reasons, there are more choices than the food pyramid might suggest:
- Vegetables: tomatoes, kale, broccoli, spinach, carrots, cucumbers, and onions
- Fruits: apples, bananas, figs, dates, grapes, avocados and melons
- Nuts and seeds: almonds, walnuts, sunflower seeds, and cashews
- Whole grains: whole wheat, oats, barley, buckwheat, corn, and brown rice
- Fish and poultry (in moderation): chicken, duck, turkey, salmon, sardines, and oysters
- Cheese and yogurt (in moderation), including Greek yogurt
- Eggs (in moderation) including chicken, quail, and duck eggs
Water is specified as the main beverage of the Mediterranean diet, but it does include one glass of wine per day. Red wine is more closely associated with the Mediterranean diet than white wine, as red wine is made with the skins and seeds of the grape, which contain most of the healthy compounds.
By all accounts, the Mediterranean diet should be paired with an active lifestyle for the best results.
Have you used a Mediterranean style diet as an intervention with your patients? Did it help with weight loss, pain, or inflammation?
(1) Wallace IJ, Worthington S, Felson DT, Jurmain RD, Wren KT, Maijanen M, Woods RJ, Lieberman DE. Knee osteoarthritis has doubled in prevalence since the mid-20th century. PNAS August 29, 2017. 114 (35) 9332-9336.
(2) Willett WC, Sacks F, Trichopoulou A, Drescher G, Ferro-Luzzi A, Helsing E, et al. Mediterranean diet pyramid: a cultural model for healthy eating. Am J Clin Nutr 1995;61.
(3) Chrysohoou C, Panagiotakos DB, Pitsavos C, Das UN, Stefanadis C. Adherence to the Mediterranean diet attenuates inflammation and coagulation process in healthy adults: the ATTICA study. J Am Coll Cardiol 2004;44:152e8.
(4) Sokolove J, Lepus CM. Role of inflammation in the pathogenesis of osteoarthritis: latest findings and interpretations. Ther Adv Musculoskelet Dis 2013;5:77e94.
(5) Chatzianagnostou K, Del Turco S, Pingitore A, Sabatino L, Vassalle C. The Mediterranean lifestyle as a non-pharmacological and natural antioxidant for healthy aging. Antioxidants 2015;4:719e36.
(6) Scoditti E, Calabriso N, Massaro M, Pellegrino M, Storelli C, Martines G, et al. Mediterranean diet polyphenols reduce inflammatory angiogenesis through MMP-9 and COX-2 inhibition in human vascular endothelial cells: a potentially protective mechanism in atherosclerotic vascular disease and cancer. Arch Biochem Biophys 2012;527:81e9.
(7) Musumeci G, Trovato FM, Pichler K, Weinberg AM, Loreto C, Castrogiovanni P. Extra-virgin olive oil diet and mild physical activity prevent cartilage degeneration in an osteoarthritis model: an in vivo and in vitro study on lubricin expression. J Nutr Biochem 2013;24:2064e75.