In the first study of its kind, a link is found between the consumption of animal fats and an increased risk of osteoarthritis. The findings are published this week in the journal Scientific Reports.
The condition is characterized by the slow breakdown of cartilage, which acts as a buffer between joints. As the cartilage degenerates, joints can become swollen, stiff, and painful, and the condition tends to worsen with time.
Osteoarthritis can affect any joint in the body but is most often found in the knees, hips, hands, and spine.
Traditionally, osteoarthritis is referred to as a condition of wear and tear - in other words, joints that are used most often or most heavily are more likely to experience a steady breakdown of cartilage, eventually leading to osteoarthritis.
There are some known risk factors for osteoarthritis - for instance, it more commonly affects older adults, and women are more likely to develop it than men. Similarly, previous joint injuries and bone deformities also increase the chances of developing the condition.
High-fat diet linked to osteoarthritis onset
Another known risk factor for osteoarthritis is obesity. This is partly because of the excess stress put on joints when carrying around more weight, but the connection between excess weight and osteoarthritis may run a little deeper than that.
A team of researchers from the Queensland University of Technology and the University of Southern Queensland, both in Australia, recently investigated a connection between dietary fat and the onset of osteoarthritis. The group was led by professors Yin Xiao and Lindsay Brown.
This recently published study follows on from Prof. Xiao's earlier work, which found that antioxidants and anti-cholesterol drugs may slow the progression of the joint damage attributed to the fatty acids found in foods such as palm oil and butter.
In this research project, Prof. Xiao looked specifically at the effects of a diet rich in saturated fatty acids and simple carbohydrates on osteoarthritis. These dietary components mirror the nutritional elements commonly found in junk food - high fats and high carbohydrates.
The study demonstrates that osteoarthritis may be less to do with the general usage of our joints and more to do with what we eat on a regular basis. As Prof. Xiao says: "Our findings suggest that it's not wear and tear but diet that has a lot to do with the onset of osteoarthritis."
According to their results, a diet containing 20 percent saturated fats and simple carbohydrates "produced osteoarthritic-like changes in the knee."
"Saturated fatty acid deposits in the cartilage change its metabolism and weaken the cartilage, making it more prone to damage. This would, in turn, lead to osteoarthritic pain from the loss of the cushioning effect of cartilage. We also found changes in the bone under the cartilage on a diet rich in saturated fat."
Prof. Yin Xiao
Replacing animal fat with coconut oil
Long-term use of animal fat, butter, and palm oil all appeared to weaken cartilage. However, when they replaced meat fat with lauric acid - a saturated fat commonly found in coconut oil - the opposite effect was observed. Lauric acid seemed to be beneficial. According to Ph.D. student Sunder Sekar, who was also involved in the trial, "when [the researchers] replaced the meat fat in the diet with lauric acid, [they] found decreased signs of cartilage deterioration and metabolic syndrome, so it seems to have a protective effect."
The researchers conclude that: "Replacement of traditional diets containing coconut-derived lauric acid with palm oil-derived palmitic acid or animal fat-derived stearic acid has the potential to worsen the development of both metabolic syndrome and osteoarthritis."
Although the results will need to be replicated, this could be yet another reason to avoid a high-fat, high-carbohydrate diet.