Budhathoki S, Sawada N, Iwasaki M, et al. - Through a cohort study involving Japanese adults followed up for a mean of 18 years, researchers assessed the relationships between animal and plant protein consumption and all-cause and cause-specific mortality. According to findings, higher plant protein consumption was correlated to lower total and cardiovascular disease (CVD)-related mortality. The replacement of red meat protein or processed meat protein with plant protein was correlated with lower total, cancer-related, and CVD-related mortality; however, animal protein consumption was not related to mortality outcomes.

Methods

• This prospective cohort study included 70,696 participants aged 45-74 years from the Japan Public Health Center–based Prospective Cohort; they had no history of cancer, cerebrovascular disease, or ischemic heart disease at study baseline.
• From January 1, 1995, through December 31, 1999—with follow-up completed December 31, 2016—data were collected, during which time 12,381 total deaths were recorded.
• Via a validated food frequency questionnaire, dietary consumption information was gathered and utilized to estimate protein consumption in all participants.
• Participants were classified into quintile categories on the basis of their protein consumption, expressed as a percentage of total energy.
• Data analysis was done from July 18, 2017, through April 10, 2019.

Results

• In all, 45.5% and 54.5% of participants were male and female, respectively.
• Consumption of animal protein exhibited no clear correlation with total or cause-specific mortality.
• On the contrary, consumption of plant protein was related to lower total mortality, with multivariable-adjusted HRs of 0.89 (95% CI, 0.83-0.95), 0.88 (95% CI, 0.82-0.95), 0.84 (95% CI, 0.77-0.92), and 0.87 (95% CI, 0.78-0.96) for quintile 2, quintile 3, quintile 4, and quintile 5, respectively—with quintile 1 as the reference category (P = 0.01 for trend).
• This correlation with plant protein consumption was evident for CVD–related mortality (HRs, 0.84 [95% CI, 0.73-0.96] to 0.70 [95% CI, 0.59-0.83]; P = 0.002 for trend), for cause-specific mortality.
• For red meat protein, isocaloric substitution of 3% energy from plant protein was related to lower total (HR, 0.66; 95% CI, 0.55-0.80), cancer-related (HR, 0.61; 95% CI, 0.45-0.82), and CVD-related (HR, 0.58; 95% CI, 0.39-0.86) mortality and substitution for processed meat protein was correlated with lower total (HR, 0.54; 95% CI, 0.38-0.75) and cancer-related (HR, 0.50; 95% CI, 0.30-0.85) mortality.