The purpose of this study was to investigate whether long-term television viewing patterns, a common sedentary behavior, in early to mid-adulthood is associated with gray matter brain volume in midlife and if this is independent of physical activity. We evaluated 599 participants (51% female, 44% black, mean age 30.3 ± 3.5 at baseline and 50.2 ± 3.5 years at follow-up and MRI) from the prospective Coronary Artery Risk Development in Young Adults (CARDIA) study. We assessed television patterns with repeated interviewer-administered questionnaire spanning 20 years. Structural MRI (3T) measures of frontal cortex, entorhinal cortex, hippocampal, and total gray matter volumes were assessed at midlife. Over the 20 years, participants reported viewing an average of 2.5 ± 1.7 h of television per day (range: 0–10 h). After multivariable adjustment, greater television viewing was negatively associated with gray matter volume in the frontal (β = − 0.77; p = 0.01) and entorhinal cortex (β = − 23.83; p = 0.05) as well as total gray matter (β = − 2.09; p = 0.003) but not hippocampus. These results remained unchanged after additional adjustment for physical activity. For each one standard deviation increase in television viewing, the difference in gray matter volume z-score was approximately 0.06 less for each of the three regions (p < 0.05). Among middle-aged adults, greater television viewing in early to mid-adulthood was associated with lower gray matter volume. Sedentariness or other facets of television viewing may be important for brain aging even in middle age.

本研究的目的是调查成年早期到中期的长期看电视模式（一种常见的久坐行为）是否与中年的灰质脑容量相关，以及这是否与身体活动无关。我们评估了前瞻性年轻人冠状动脉风险发展 (CARDIA) 研究中的 599 名参与者（51% 女性，44% 黑人，基线时平均年龄 30.3 ± 3.5 岁，随访和 MRI 时平均年龄 50.2 ± 3.5 岁）。我们使用跨越 20 年的采访者重复问卷评估电视模式。在中年时评估了额叶皮层、内嗅皮层、海马和总灰质体积的结构 MRI (3T) 测量值。在过去的 20 年中，参与者报告平均每天看电视 2.5 ± 1.7 小时（范围：0-10 小时）。多变量调整后，p  = 0.01) 和内嗅皮质 (β = − 23.83; p  = 0.05) 以及总灰质 (β = − 2.09; p  = 0.003) 但不是海马体。在对体力活动进行额外调整后，这些结果保持不变。对于电视观看中每增加一个标准差，三个区域中每个区域的灰质体积 z 分数的差异大约减少 0.06 ( p  < 0.05)。在中年人中，成年早期到中期看电视次数增多与灰质体积减少有关。即使在中年，久坐不动或看电视的其他方面也可能对大脑老化很重要。