ω-3 polyunsaturated fatty acids PUFAs are essential structural and functional nutrients in humans with numerous studies demonstrating their lipid - lowering anti - inflammatory cardiovascular protective and tumor microenvironment - improving effects. However the inconsistent results from ω-3 PUFAs intervention trials hinder their widespread application in medical guidelines and limit their clinical use in disease management. As another class of polyunsaturated fatty acids ω-6 PUFAs are commonly found in excess in global diets leading to an imbalance in the ω- 6 / ω- 3 ratio and potentially impeding the health effects of ω- 3 PUFAs. Research has shown that high ω-6 / ω-3 ratios may hinder the beneficial effects of ω-3 PUFAs and are closely associated with the development of numerous chronic diseases due to cellular membrane structure competition and metabolic interference between ω-6 and ω-3 PUFAs. This review analyzes the interaction between ω-3 and ω-6 PUFAs in the body and highlights the importance of the ω-6 / ω-3 ratio in modulating the effects of ω-3 PUFAs. Furthermore it emphasizes that the oversight of the ω-6 / ω-3 ratio in previous ω-3 PUFAs studies may be a key reason for inconsistent results suggesting the need to standardize research protocols and include the ω-6 / ω-3 ratio as a quality control parameter to objectively elucidate the health effects of ω-3 PUFAs and promote their standardized application in disease management.