Table 2.
Study characteristics and quality assessment.
| Study | Country | Type of Study | Population | Years of Enrollment | Age (y) | Follow-Up (y) | Exposure | Exposure Assessment | Exposure Follow-Up | Outcomes |
|---|---|---|---|---|---|---|---|---|---|---|
| Chan et al., 2019 [49] | China | Prospective cohort | 2262 men and women | 2001–2003 | 65 and over | 13.8 | Quantity and source of protein intake | 280-item FFQ | Every 1 year | Death from all causes, cancer, and CVD |
| Chen et al., 2019 [23] | Netherlands | Prospective cohort | 7786 men and women | 1989–2008 | 63.7 ± 8.7 | 13 (8.3–19.1) | Quantity and source of protein intake | 170-item FFQ, 389-item FFQ | Every 3–5 years | All-cause and cause-specific mortality |
| Dehghan et al., 2017 [50] | International | Prospective cohort | 135,335 men and women | 2003–2013 | 50.3 ± 10 | 7.4 (5.3–9.3) | Dietary intake of fats and carbohydrates | FFQ | Every 3 years | Total mortality and major cardiovascular events (fatal CVD, non-fatal MI, stroke, and heart failure), MI, stroke, CVD mortality, and non-CVD mortality. |
| Haring et al., 2015 [51] | US | Prospective cohort | 11,601 men and women | 1987–1989 | 45–64 | 22.7 | Dietary protein intake | 66-item FFQ | 6 years from baseline | Non-fatal stroke |
| Hernández-Alonso et al., 2015 [25] | Spain | Prospective cohort | 7216 men and women | 2003–2009 | men 55–80 women 60–80 | 4.8 | Quantity and source of protein intake | 137-item FFQ | Cardiovascular events (i.e., MI, stroke, or death from cardiovascular causes), and death by cardiovascular, cancer, and all-cause | |
| Liu et al., 2000 [52] | US | Prospective cohort | 75,521 women | 1984 | 38–63 | 10 | dietary glycemic load, carbohydrate content, and frequency of intake of individual foods | 126-item FFQ | every 2 years | Fatal CHD and nonfatal MI |
| Larsson et al., 2012 [15] | Sweeden | Prospective cohort | 34,670 women | 1997 | 61.4 (49–83) | 10.4 | Quantity and source of protein intake | 96-item FFQ | Non-fatal stroke | |
| Kelemen et al., 2004 [53] | US | Prospective cohort | 29,017 women | 1986 | 75.8 | 15 | Quantity and source of protein intake | FFQ | At 2, 5, and 7 years | Mortality from all causes, cancer, and CVD |
| Hu et al., 1999 [13] | US | Prospective cohort | 80,082 women | 1976 | 45.8 (34–59) | 14 | Quantity and source of protein intake | 61-item FFQ, 116-item FFQ | Every 2 years | Fatal CHD and nonfatal MI |
| Hu et al., 2000 [54] | US | Prospective cohort | 44,875 men | 1986 | 53.8 (40–75) | 8 | Prudent and Western dietary pattern score | 131-FFQ | Every 2 years | Fatal CHD and nonfatal MI |
| Preis et al., 2010 (2 studies) [55,56] | US | Prospective cohort | 43,960 men | 1986 | 40–75 | 18 | Quantity and source of protein intake | 131-FFQ | Every 4 years | Fatal CHD and nonfatal MI, non-fatal stroke |
| Guallar-Castillon et al., 2010 [57] | Spain | Prospective cohort | 40,757 men and women | 1992–1996 | 29–69 | 11 | Westernized and Evolved Mediterranean dietary pattern score | computerized dietary history | CHD events (fatal and non-fatal acute MI or angina requiring revascularization). | |
| Song 2016 [58] | US | Prospective cohort | 131,342 men and women | 1976–1986 | 30–75 | 32 | Animal versus plant protein | FFQ | Every 4 years | All-cause and cause-specific mortality |
FFQ: food frequency questionnaire; CVD: cardiovascular disease; MI: myocardial infarction; CHD: coronary heart disease. All studies were assessed as high quality.