Depressive symptoms are significantly more prevalent among cancer patients representing one of the most common psychological disorders in this population. These symptoms often diminish patients' enthusiasm for treatment thereby weakening the effectiveness of their care and posing obstacles to their clinical recovery which adversely affects their prognosis. This article aims to analyze the current epidemiological characteristics of depression in cancer patients comprehensively and systematically identify the risk factors closely associated with it. This article examines how various dietary patterns and specific nutrients subtly influence depressive symptoms highlighting the critical role of nutritional intervention in the prevention and alleviation of depression. Through scientific demonstration we emphasize the considerable potential of optimizing dietary structures and rationally supplementing nutrients as non-pharmacological therapies to enhance patients' psychological well-being and improve their quality of life. Additionally this article proposes several prospective directions for future research aiming to bridge existing knowledge gaps foster the cross-integration of nutrition psychology oncology and other disciplines and explore more precise and effective strategies for clinical depression management. In summary this article serves not only as an in-depth review of depressive symptoms in cancer patients but also as a strong advocacy for the potential application of nutritional therapy within the realm of mental health. It is hoped that this work will contribute valuable insights and support to promote the overall health of cancer patients.