Total vegetables and all-cause mortality/survival.

25 articles, providing information about 16 different cohorts were found, including a total of 18,554 cases. Survival was the end point in one article (Nube M [2]), and mortality was the end point in all remaining articles.

Use of data from The EPIC Study: 7 publications were found about The EPIC Study (21). Publications included data about the same population with different length of follow-up (Trichopoulou A. 2003 vs Trichopoulou A. 2009), or about a subgroup of- vs all diabetic subjects from the cohort (Trichopoulou A. 2006 vs Nöthlings U. 2008). Obviously, the publications about longer length of follow-up, and about larger parts of the cohort were included.
The EPIC-Elderly study provided data about 74,607 elderly (aged ≥ 60) subjects - with or whithout diabetes - from 9 countries (including Greece & Spain), and including 4,047 deaths (Trichopoulou A. 2005b). But 3 other publications provided information about subgroups of this cohort from which the data partly overlapped with data from The EPIC-Elderly Study:

  • Agudo A (2007) 41.358 subjects aged 30-69 from EPIC-Spain, including 562 deaths.
  • Nöthlings U (2008) 10.449 subjects aged 35-70 with diabetes from 10 countries, and including 1,346 deaths.
  • Trichopoulou A (2009) 23,349 subjects aged 20-86 from EPIC-Greece, including 1,075 deaths.

The latter 3 publications were included in the systematic review, excluding data from The EPIC-Elderly Study. These 3 subcohorts included less deaths than the former subcohort (2,983 vs 4,047). But they all provided RR's as a categorized variable, allowing for analysis about effects at different levels of consumption, and for more precise analysis of the effect size. Whereas The EPIC-Elderly Study provided RR's as a continuous variable.
Also, a 4th publication about this cohort was included: Trichopoulou A (2005a) provided data about subjects from EPIC-Greece with CHD only, whereas he provided data about subjects from EPIC-Greece without CHD only in a later publication (Trichopoulou A. 2009).

Results: Significant protective effects were found in 3 cohorts (Sahyoun NR [7], Nöthlings U [21], and Seccareccia F [24]), and among men in a 4th cohort (Nube M [2]). These 4 cohorts included 3,383 cases (18 % of all cases). No other associations were found of high vs low consumption.
The average RR = 0.96 for all cohorts (excluding Knekt P [9], because no amount of cases was specified, stratified by sex. And excluding Strandhagen E [16], and Chang-Claude J [31] because of incomplete data).
Conclusion: Protective effects were found in 4 cohorts, including 18% of all cases. Inconclusive evidence was found for an association between vegetable consumption and all-cause mortality.

Prospective studies of total vegetables and all-cause mortality:
AuthorCohort nameCasesRelative Risk (RR)
33) González S (2008)No cohort name defined83RR = 1.20 (0.92-1.57; P = 0.18)
32) Nagura J (2009)The JACC Study7,606HR = 1.03 (0.96-1.10; P = 0.188).
31) Chang-Claude J (2005)The German Vegetarian Study456No association.
29) Tucker KL (2005)The Baltimore Longitudinal Study of Aging306RR = 0.94 (0.85-1.04)
27) Darmadi-Blackberry I (2004)The Food Habits In Later Life Study169RR = 1.00 (0.98-1.02; P = 0.70)
24) Seccareccia F (2003)The Seven Countries Study1,096HR = 0.82 (0.69-0.96)
22) Ness AR (2005)The Boyd Orr Cohort1,010RR = 0.95 (0.75-1.19; P = 0.4)
21) Trichopoulou A (2009)The EPIC-Greece Study (non-CHD cases)1,075MR = 0.90 (0.78-1.05; P = 0.18).
21) Nöthlings U (2008)The EPIC Study (diabetic subjects)1,346RR = 0.78 (0.63-0.98; P = 0.03).
21) Agudo A (2007)The EPIC-Spain Study562HR = 0.84 (0.66-1.06).
21) Trichopoulou A (2005a)The EPIC-Greece Study (CHD cases)131MR = 0.80 (0.62-1.02).
16) Strandhagen E (2000)The Study Of Men Born In 1913390No significant association.
15) Lasheras C (2000)No cohort name definedAge < 80: 38.

Age ≥ 80: 58.
Age < 80: RR = 1.44 (0.53-3.80; P = 0.46)

Age ≥ 80: RR = 1.03 (0.96-1.11; p = 0.37)
14) Kouris-Blazos A (1999)No cohort name defined38RR = 1.02 (0.99-1.07)
10) Knoops KT (2006)The HALE1,384HR = 0.99 (0.90-1.09)
9) Knekt P (1996)The Finnish Mobile Clinic Health EXamination Cohort1364Men: RR = 0.88 (0.73-1.06)

Women: RR = 0.97 (0.76-1.24)
7) Sahyoun NR (1996)No cohort name defined199RR = 0.49 (0.31-0.77; P = 0.01)
6) Trichopoulou A (1995)No cohort name defined53RR = 0.97 (0.93-1.02; P = 0.20)
2) Nube M (1987)No cohort name defined742 men.

448 women.
Men: A protective effect.

Women: No association.
Total number of cases: 18,554Average RR = 0.96