Oleuropein, rutin and curcumin versus osteoarthritis
Olives, turmeric and buckwheat contain substances that protect joints against osteoarthritis. At high doses they reduce the speed at which osteoarthritis damages joints in laboratory animals at least. Nutritionists from the Nestle Research Center have written about this in Osteoarthritis & Cartilage.
Osteoarthritis is a disease in which cartilage gradually wears away in the joints, making movement more and more difficult and painful. The exact cause is not known. Genetic makeup plays an important role, but lifestyle factors such as obesity are also significant.
Some studies have shown that obese people are 5-6 times more likely to develop osteoarthritis than people whose weight is healthy. This is probably because the excess fat reserves exacerbate inflammation in joints affected by osteoarthritis.
In 2011 Italian pharmacologists published the results of an animal study in which they inhibited the development of osteoarthritis by giving the animals oleuropein, a phenol found in olives and olive oil. [J Pharmacol Exp Ther. 2011 Dec;339(3):859-69.]
Scientists at the Nestle Research Center in Lausanne, Switzerland, wondered whether other plant-based substances might have the same effect. So they tested three candidates - oleuropein, rutin [found in buckwheat, apples and onions] and curcumin [found in turmeric] - on Dunkin-Hartley guinea pigs. These are a type of guinea pig that spontaneously develop osteoarthritis.
The researchers gave the guinea pigs either standard food [Control], food consisting of 0.025 percent oleuropein, food consisting of 0.5 percent rutin or food that consisted of 0.5 percent curcumin and 0.25 percent rutin, for 31 weeks. The human equivalent of these doses would be 275 mg oleuropein, 5.2 g rutin and 5.2 g curcumin plus 2.6 g rutin daily.
The last two doses mentioned are high, possibly poisonous. The oleuropein dose is more reasonable. Oleuropein is found in Olive Leaf Extract, which you can buy almost any supplements store. You would need about 1100-1200 mg daily of a good-quality extract.
Oleuropein in particular inhibited osteoarthritis the researchers discovered when they studied the animals' joints at the end of 31 weeks [OA histological score Global]. The cartilage was in a better state in all three experimental groups than in the control groups [OA histological score Cartilage structure].
The substances that were tested didn't all work in the same way. Oleuropein, for example, reduced the synthesis of inflammatory factor PGE2, whereas rutin and curcumin did not. Rutin and curcumin inhibited the enzyme Coll2-1, a marker for osteoarthritis, whereas oleuropein did not.
"While the mixture of curcumin and rutin did not provide additive or synergistic effects compared to rutin alone on histological score, the combination of rutin and oleuropein might be worth investigating further due to their complementary mechanisms of action, protecting against proinflammatory and catabolic processes involved in development of osteoarthritis", the researchers write.
Osteoarthritis Cartilage. 2015 Jan;23(1):94-102.
Olive Leaf Extract helps damaged cartilage to heal more quickly 09.08.2012