Disruptions in the circadian rhythm and a high fat diet could worsen symptoms of osteoarthritis, according to a new study.
Rotational night shift work, frequent travel to places in different time zones, and increased artificial light exposure at night affect the body’s circadian rhythm. Night shift workers particularly have a higher risk of becoming obese due to changes in their eating habits. A recent study published in Scientific Reports has found that changes in the circadian rhythm combined with a high fat diet aggravated symptoms of osteoarthritis in animal experiments. Osteoarthritis develops when the cartilage between the joints wears away, leading to joint pain and swelling.
The group of researchers previously discovered that mice exposed to prolonged disruption of light and dark cycles developed symptoms of osteoarthritis in the knee joint. To find out whether diet and changes in the circadian rhythm influence the progression of osteoarthritis, the circadian rhythm in a group of mice was shifted by reversing the light and dark cycle at the end of each week for 22 weeks. The mice were fed with either a regular diet or a high fat diet to simulate a Western type of diet. The high fat diet caused weight increase in mice with normal and shifted circadian rhythms but only mice with shifted circadian rhythms developed osteoarthritis. The study found that symptoms of osteoarthritis were more severe and present in other joints in mice fed with a high fat diet and exposed to changing light and dark cycles compared to shifted mice on a normal diet.
The study provided evidence that disrupting the circadian rhythm coupled with a high fat diet exacerbate symptoms of osteoarthritis. The results also have implications in reducing the risk of osteoarthritis and improving the health of night shift workers.
Kc R, Li X, Forsyth CB, Voigt RM, Summa KC, Vitaterna MH, Tryniszewska B, Keshavarzian A, Turek FW, Meng QJ, Im HJ. Osteoarthritis-like pathologic changes in the knee joint induced by environmental disruption of circadian rhythms is potentiated by a high-fat diet. Scientific Reports. Published online on 20 November 2015; 5: 16896. DOI: 10.1038/srep16896
Written by Ana Victoria Pilar, PhD