en Nutrition Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> Diet can play a significant role in sleep regulation, particularly in older adults. This study aimed to investigate the association between the Dietary Phytochemical Index (DPI) and sleep quality among the elderly in Amirkola City.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> This case-control study was part of the second phase of the Amirkola Cohort Study on aging. A total of 800 elderly individuals aged &ge;60 years (400 with good sleep quality and 400 with poor sleep quality, matched for age and sex) were randomly selected. Inclusion criteria comprised having complete demographic data in the cohort profile, no known history of malignancy (including gastric and intestinal cancers), absence of psychiatric or cognitive disorders (such as psychiatric hospitalization), and no drug addiction. Data were collected using the Pittsburgh Sleep Quality Index (PSQI) and a semi-quantitative food frequency questionnaire (SQ-FFQ), which were then analyzed statistically.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b> Total energy intake and the number of chronic diseases significantly impacted sleep quality (OR=1.002, 95% CI: 1.001-1.003, P = 0.004<b> </b>and OR=1.257, 95% CI:1.170-1.352, p < 0.001, respectively). Furthermore, Poorer sleep quality was significantly associated with a higher number of chronic diseases in both gender, male and female (OR=1.244, 95% CI: 1.097-1.411, P = 0.001 and OR=1.225, 95% CI: 1.106-1.357, P < 0.001).&nbsp;However, Dietary Phytochemical Index (DPI) and Energy intake from plant sources did not show a significant effect on sleep quality.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> Dietary modifications and management of chronic diseases could be effective in improving sleep quality among the elderly. However, further research is recommended.</span></span></span><br> &nbsp; Sleep Quality, Phytochemicals, Aged, Elderly. 181 190 http://caspjim.com/browse.php?a_code=A-10-810-1&slc_lang=en&sid=1 Masoomeh Rabipour masoomehrabipour@gmail.com 100319475328460055846 0009-0000-4990-9379 No Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran Angela Hamidia angela_7633@yahoo.com 100319475328460055847 100319475328460055847 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Reza Ghadimi rezaghadimi@yahoo.com 100319475328460055848 100319475328460055848 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Seyed Reza Hosseini hosseinirezaseyed@gmail.com 100319475328460055849 100319475328460055849 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Ali Bijani alibijani@yahoo.com 100319475328460055850 100319475328460055850 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Parvin Sajadi Kaboudi psajadi@yahoo.com 100319475328460055851 100319475328460055851 Yes Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran