Ligaments are tough bands of fibrous connective tissue (mainly collagen) that link two bones together at a joint. Injuries to ligaments are notoriously slow to heal. Researchers at Purdue University now report the results of an intriguing experiment which shows that eicosapentaenoic acid (EPA - the main component of fish tissue oils) materially speeds up the healing of "wounded" ligament cells in vitro. The experiment was carried out on three cultures of animal medial collateral ligament cells. The first culture was treated with arachidonic acid (an n-6 polyunsaturated fatty acid), the second with eicosapentaenoic acid (an n-3 polyunsaturated fatty acid), and the third served as a control.
After four days the cells were analyzed to determine their fatty acid profile. The AA (arachidonic acid) treated cells were found to have an n-6 to n-3 ratio of 24.3 while the EPA (eicosapentaenoic acid) treated cells had a ratio of 1.1. This indicates that the two fatty acids were well-absorbed and incorporated into the cells. Next a "wound" was introduced into the surface layers of the cell cultures by streaking a sterile pipette across them. The rate at which ligament cells grew back into the "wound" was measured over a 72-hour period and taken as an indication of wound healing speed. Both the AA and EPA treated cultures showed a higher degree of regrowth in the wound area than did the control. However, while AA decreased the synthesis of collagen by the ligament cells, EPA markedly increased it.
The researchers conclude that dietary supplementation with fish oils (n-3 polyunsaturated fatty acids) could be used to improve the healing of ligament injuries by enhancing the entry of new cells into the wound area and by speeding up collagen synthesis.
Hankenson, Kurt D., et al. Omega-3 fatty acids enhance ligament fibroblast collagen formation in association with changes in interleukin-6 production. Proceedings of the Society for Experimental Biology and Medicine, Vol. 223, January 2000, pp. 88-95.