Background There is mixed evidence on the association between living arrangements and mid-late life cognition, which may be due to distinct familial arrangements and preferences between populations. To address such heterogeneity, we assessed these associations in China and England.

Methods Four-year trajectories of episodic memory scores (0–20, word recall test) by living arrangements (living with partner only, living with partner and children/grandchildren, living with no partner but with children/grandchildren, and living alone) were estimated using latent growth curve modelling for men and women aged 50+ from China (n=12 801) and England (n=10 964).

Results After adjusting for baseline socioeconomic, health behaviours and health covariates, worse baseline memory was found in Chinese adults living with no partner but with children/grandchildren and in Chinese women living with partner and children/grandchildren, compared with those living with partner only. Better baseline memory was associated with living alone in English women. A faster memory decline was found in Chinese men living with no partner but with children/grandchildren (−0.122 word/year, 95% CI −0.213 to –0.031), as well as in English women living with children/grandchildren with (−0.114, 95% CI −0.180 to –0.049) or without (−0.118, 95% CI −0.209 to –0.026) a partner, and those living alone (−0.075, 95% CI −0.127 to –0.024). No differences at baseline nor over follow-up were found between English men in different living arrangements.

Conclusion Overall, our findings did not confirm the protective effects of co-residence with children/grandchildren, nor the detrimental effects of living alone on mid-late life cognition in China and England.