Psychophysiology Laboratory, Department of Social and Behavioural Sciences, City University of Hong Kong, Hong Kong.
Psychophysiology Laboratory, Department of Social and Behavioural Sciences, City University of Hong Kong, Hong Kong.
Med Hypotheses. 2019 Jan;122:1-4. doi: 10.1016/j.mehy.2018.09.041. Epub 2018 Sep 28.
A stronger motivation to cultivate social ties in older adults (ages range from 62 to 86 years) has been associated with a cortisol profile similar to that observed in undergraduate students, who are decades younger. We have shown the cultivation of social networks buffers against increases in diurnal cortisol common in old age. Cortisol is crucial for the response to stress and the process of ageing, and a recent study has demonstrated that a lower cortisol level is associated with longevity. We link the findings of social network cultivation and cortisol profile to the processes of biological ageing through DNA telomere length. Telomeres are repeated DNA sequences that cap and protect the ends of chromosomes, and telomere length is considered a potential biomarker for biological age because it is closely related to the cellular process of ageing and chronic stress and is inversely related to chronological age. Studies examining biological ageing have shown an association between an altered cortisol profile and telomere length dynamics. Together, these findings on social networks, cortisol profiles and telomere length suggest that seniors who are motivated to maintain social ties are biologically younger. We therefore propose the 'rejuvenation hypothesis', which posits that seniors with a stronger motivation for social network cultivation are biologically younger, as measured by cortisol levels and telomere length, than their peers who are less motivated to pursue social relationships. This idea suggests a new perspective and potentially fruitful direction for geriatric research. The focus on social network cultivation adds an important psychosocial dimension to rejuvenation therapies that so far have been dominated by biomedical approaches. The rejuvenation hypothesis also has important implications for social policy by supporting the viability of promoting network cultivation among the elderly to facilitate healthy ageing.
老年人（年龄在 62 至 86 岁之间）培养社会关系的强烈动机与大学生的皮质醇特征相似，而大学生比老年人年轻几十岁。我们已经表明，培养社交网络可以防止老年人常见的日间皮质醇升高。皮质醇对压力反应和衰老过程至关重要，最近的一项研究表明，较低的皮质醇水平与长寿有关。我们将社交网络培养和皮质醇特征的发现与通过 DNA 端粒长度来研究生物衰老过程联系起来。端粒是染色体末端的重复 DNA 序列，保护着染色体的末端，端粒长度被认为是生物年龄的潜在生物标志物，因为它与细胞衰老过程和慢性压力密切相关，与实际年龄呈反比。研究生物衰老的研究表明，皮质醇特征改变与端粒长度动态之间存在关联。综上所述，这些关于社交网络、皮质醇特征和端粒长度的研究结果表明，那些有动力维持社交关系的老年人在生物学上更年轻。因此，我们提出了“返老还童假说”，该假说认为，与那些不太热衷于建立社交关系的同龄人相比，有更强社交网络培养动机的老年人在生物学上更年轻，这可以通过皮质醇水平和端粒长度来衡量。这一观点为老年医学研究提供了一个新的视角和潜在的富有成效的方向。关注社交网络的培养为目前以生物医学方法为主导的返老还童疗法增添了一个重要的心理社会维度。返老还童假说也对社会政策具有重要意义，因为它支持在老年人中促进网络培养的可行性，以促进健康衰老。
