%0 Journal Article
%T Relations of magnesium intake to cognitive impairment and dementia among participants in the Women¡¯s Health Initiative Memory Study: a prospective cohort study
%A Aladdin Shadyab
%A Jiu-Chiuan Chen
%A JoAnn Manson
%A Kenneth Lo
%A Lubna Pal
%A Marian Neuhouser
%A Qing Liu
%A Sally Shumaker
%A Simin Liu
%A Steve Rapp
%A Tracy Madsen
%A Xiaochen Lin
%A Ying-Qing Feng
%J -
%D 2019
%R 10.1136/bmjopen-2019-030052
%X Objective To examine the associations of dietary and supplemental magnesium (Mg) as assessed by a semi-quantitative food frequency questionnaire with cognitive outcomes among ageing women.

Design This work conducts a prospective cohort study of participants enrolled in the Women¡¯s Health Initiative Memory Study (WHIMS), which was subsequently extended and named WHIMS-Epidemiology of Cognitive Health.

Setting Forty clinical centres in the USA.

Participants Postmenopausal women aged 65¨C79 years without dementia on enrolment.

Main outcome measures Physician-adjudicated mild cognitive impairment (MCI) and/or probable dementia (PD).

Results Participants were excluded (n=1006) if they had extreme values of dietary energy intake, had missing or extreme body mass index values, with prevalent MCI/PD at baseline, received only one cognitive assessment or had been followed up for <1£¿year. During >20 years of follow-up, 765 (11.8%) out of 6473 participants developed MCI/PD. For MCI/PD and MCI, the risks tended to be lower among participants in quintiles Q2¨CQ5 of Mg consumption compared with those in the lowest quintile. Participants in Q3 had a significantly lower risk of MCI/PD (HR 0.69, 95% CI 0.53 to 0.91) and MCI (HR 0.63, 95% CI 0.45 to 0.87) after multivariate adjustments. No significant association was observed between total Mg intake and PD. The association between total Mg intake, MCI/PD and MCI was non-linear as suggested by the likelihood test.

Conclusions Total Mg intake between the estimated average requirement and the recommended dietary allowances may associate with a lower risk of MCI/PD and MCI.

Trial registration number [NCT00685009][1].

 [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00685009&atom=%2Fbmjopen%2F9%2F11%2Fe030052.ato
%U https://bmjopen.bmj.com/content/9/11/e030052