Diet quality and risk and severity of COVID-19: a prospective cohort study
Merino et al.
, Diet quality and risk and severity of COVID-19: a prospective cohort study
, Gut, doi:10.1136/gutjnl-2021-325353 (date from earlier preprint)
Retrospective 592,571 participants in the UK and USA with 31,815 COVID-19 cases, showing lower risk or COVID-19 cases and severity for higher healthful plant-based diet scores. Notably, the assocation was less evident with higher levels of physical activity.
risk of severe case, 41.0% lower, HR 0.59, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted per study, model 3, high vs. low hPDI, multivariable, Cox proportional hazards.
risk of case, 18.0% lower, HR 0.82, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted per study, model 3, high vs. low hPDI, PCR+, multivariable, Cox proportional hazards.
risk of case, 9.0% lower, HR 0.91, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted per study, model 3, high vs. low hPDI, multivariable, Cox proportional hazards.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Merino et al., 25 Jun 2021, retrospective, multiple countries, peer-reviewed, survey, 30 authors, study period 24 March, 2020 - 2 December, 2020.
Jordi Merino ,1,2,3 Amit D Joshi ,4,5 Long H Nguyen ,4,5,6
Emily R Leeming ,7 Mohsen Mazidi,7 David A Drew ,4,5 Rachel Gibson,8
Mark S Graham,9 Chun-Han Lo ,4,5 Joan Capdevila,10 Benjamin Murray,9
Christina Hu,10 Somesh Selvachandran,10 Alexander Hammers,9,11
Shilpa N Bhupathiraju,3,12 Shreela V Sharma,13 Carole Sudre,9 Christina M Astley,2,14
Jorge E Chavarro,12,15,16 Sohee Kwon,4,5 Wenjie Ma,4,5 Cristina Menni ,7
Walter C Willett,12,15,16 Sebastien Ourselin,9 Claire J Steves,7 Jonathan Wolf,10
Paul W Franks,12,17 Timothy D Spector,8 Sarah Berry,8 Andrew T Chan4,5,18
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10.1 136/gutjnl-2 021-325353).
For numbered affiliations see
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Dr Andrew T Chan, Harvard
Medical School, Boston, USA;
a firstname.lastname@example.org arvard.edu
JM, ADJ and LHN are joint first
TDS, SB and ATC are joint senior
Received 7 June 2021
Accepted 19 August 2021
Published Online First
6 September 2021
© Author(s) (or their
employer(s)) 2021. No
commercial re-use. See rights
and permissions. Published
To cite: Merino J, Joshi AD,
Nguyen LH, et al. Gut
Objective Poor metabolic health and unhealthy
lifestyle factors have been associated with risk and
severity of COVID-19, but data for diet are lacking. We
aimed to investigate the association of diet quality with
risk and severity of COVID-19 and its interaction with
Design We used data from 592 571 participants of
the smartphone-based COVID-19 Symptom Study. Diet
information was collected for the prepandemic period
using a short food frequency questionnaire, and diet
quality was assessed using a healthful Plant-Based
Diet Score, which emphasises healthy plant foods such
as fruits or vegetables. Multivariable Cox models were
fitted to calculate HRs and 95% CIs for COVID-19 risk
and severity defined using a validated symptom-based
algorithm or hospitalisation with oxygen support,
Results Over 3 886 274 person-months of follow-up,
31 815 COVID-19 cases were documented. Compared
with individuals in the lowest quartile of the diet score,
high diet quality was associated with lower risk of
COVID-19 (HR 0.91; 95% CI 0.88 to 0.94) and severe
COVID-19 (HR 0.59; 95% CI 0.47 to 0.74). The joint
association of low diet quality and increased deprivation
on COVID-19 risk was higher than the sum of the risk
associated with each factor alone (Pinteraction=0.005).
The corresponding absolute excess rate per 10 000
person/months for lowest vs highest quartile of diet
score was 22.5 (95% CI 18.8 to 26.3) among persons
living in areas with low deprivation and 40.8 (95% CI
31.7 to 49.8) among persons living in areas with high
Conclusions A diet characterised by healthy plant-
based foods was associated with lower risk and severity
of COVID-19. This association may be particularly
evident among individuals living in areas with higher
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