Green and/or leafy vegetables and lung cancer.

Lung cancer risk: Data about the relation with green leafy vegetables was provided by a pooled analysis of 8 cohorts, and 1 additional cohort, including 4.332 cases. A nonsignificant protective effect was found for consumption of ≥ 1 vs < 1 servings/wk of green leafy vegetables in the pooled analysis (24) including 3,206 cases, but no association was found in the remaining cohort (19). The average RR = 0.90.
Data about the relation with total green vegetables was provided by 2 cohorts (4, 8). No associations were found.

**Prospective studies of (green) leafy vegetables and lung cancer risk:**
Author	Cohort name	Cases	Relative Risk (RR)
24) Smith-Warner SA (2003)	Pooled analysis of 8 cohorts	3,206	RR = 0.93 (0.81-1.07; P = 0.07)
19) Linseisen J (2007)	The EPIC Study	1,126	HR = 0.83 (0.60-1.15).
		Total number of cases: 4,332	Average RR = 0.90

Lung cancer mortality: Data about lung cancer mortality was provided by 2 cohorts. Food intake was measured prior to cancer diagnosis in one cohort (17), but following cancer diagnosis in the other one (19).
A significant protective effect of spinach/garland chrysanthemums among men - but not women - was found in one cohort (17), and a nonsignificant protective effect of leafy vegetables was found in the other one combining data from men & women (19).

Conclusion: A nonsignificant protective effect was found in a pooled analysis of 8 cohorts including 69% of all cases. No (non)significantly increased risks were found in the remaining cohorts. Suggestive evidence was found for a protective effect at consumption of ≥ 0.5 serving/day green leafy vegetables against lung cancer risk (- 10%). Inconsistent findings were done for lung cancer mortality.

Stratified by smoking status:

Current smokers

Former smokers

Never smokers

HR = 0.80 (0.52-1.24) for the highest vs lowest quintile of consumption.

Amount specific data (g/day):
0-1.5: HR = 1.
1.5-8.6: HR = 0.86 (0.69-1.07).
8.6-21.1: HR = 0.94 (0.70-1.26).
21.1-50.0: HR = 1.05 (0.75-1.46).
50.0-1074.3: HR = 0.80 (0.52-1.24).

HR = 0.68 (0.35-1.30) for the highest vs lowest quintile of consumption.

Amount specific data (g/day):
0-1.5: HR = 1.
1.5-8.6: HR = 0.86 (0.61-1.23).
8.6-21.1: HR = 0.99 (0.65-1.52).
21.1-50.0: HR = 0.98 (0.60-1.60).
50.0-1074.3: HR = 0.68 (0.36-1.30).

HR = 1.05 (0.38-2.93) for the highest vs lowest quintile of consumption.

Amount specific data (g/day):
0-1.5: HR = 1.
1.5-8.6: HR = 1.25 (0.58-2.71).
8.6-21.1: HR = 1.11 (0.45-2.76).
21.1-50.0: HR = 0.99 (0.38-2.57).
50.0-1074.3: HR = 1.05 (0.38-2.93).

South Europe:

North Europe:

RR = 1.85 (0.72-4.77; P = 0.4822) for the highest vs the lowest quintile of consumption.

Amount specific data (Quintiles not defined):
Q1: RR = 1.
Q2: RR = 2.01 (0.69-5.86).
Q3: RR = 1.74 (0.64-4.76).
Q4: RR = 1.90 (0.72-5.00).
Q5: RR = 1.85 (0.72-4.77).

RR = 0.77 (0.49-1.22; P = 0.0531) for the highest vs the lowest quintile of consumption.

Amount specific data (Quintiles not defined):
Q1: RR = 1.
Q2: RR = 0.89 (0.72-1.10).
Q3: RR = 0.87 (0.69-1.10).
Q4: RR = 0.89 (0.68-1.17).
Q5: RR = 0.77 (0.49-1.22).

Women:

Men:

RR = 0.90 (0.68-1.20) for the highest vs lowest quintile of consumption.

Amount specific data (servings/wk):
< 0.5: RR = 1.
0.5-1.0: RR = 0.88 (0.66-1.18).
1.1-1.6: RR = 1.12 (0.86-1.46).
1.7-3.5: RR = 1.11 (0.85-1.47).
> 3.5: RR = 0.90 (0.68-1.20).

RR = 0.99 (0.65-1.49) for the highest vs lowest quintile of consumption.

Amount specific data (servings/wk):
< 0.5: RR = 1.
0.5-1.0: RR = 1.15 (0.77-1.72).
1.1-1.9: RR = 1.09 (0.74-1.59).
2.0-3.5: RR = 1.19 (0.80-1.79).
> 3.5: RR = 0.99 (0.65-1.49).

Cooked leafy vegetables:

In g/day

In frequency

RR = 0.8 (0.6-1.1; P = 0.54) for the highest vs lowest quintile of consumption.

Amount specific data:
4: RR = 1.
12: RR = 0.8 (0.6-1.1).
19: RR = 0.8 (0.6-1.1).
26: RR = 1.0 (0.8-1.4).
41: RR = 0.8 (0.6-1.1).

RR = 0.9 (0.6-1.3; P = 0.68) for the highest vs lowest quintile of consumption.

Amount specific data:
< 1 x/month: RR = 1.
1 x/month: RR = 1.1 (0.7-1.7).
2-3 x/month: RR = 0.8 (0.6-1.1).
1 x/wk: RR = 0.9 (0.6-1.3).
: RR = 0.9 (0.6-1.3).

Raw leafy vegetables:

In g/day

In frequency

RR = 0.9 (0.8-1.1; P = 0.37) for the highest vs lowest tertile of consumption.

Amount specific data:
3: RR = 1.
8: RR = 1.0 (0.8-1.1).
18: RR = 0.9 (0.8-1.1).

RR = 0.9 (0.6-1.2; P = 0.19) for the highest vs lowest quintile of consumption.

Amount specific data:
< 1 x/month: RR = 1.
1 x/month: RR = 1.0 (0.6-1.5).
2-3 x/month: RR = 1.0 (0.7-1.3).
1 x/wk: RR = 0.8 (0.6-1.1).
: RR = 0.9 (0.6-1.2).

Stratified by histological type:

Adenocarcinoma
(45 cases)

Small cell carcinoma
(37 cases)

Squamous cell carcinoma
(25 cases)

Large cell carcinoma
(12 cases)

OR = 0.69 (0.30-1.57; P = 0.12) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 0.81 (0.38-1.74).
4-5: OR = 0.37 (0.14-0.99).
≥ 6: OR = 0.69 (0.30-1.57).

OR = 0.26 (0.08-0.87; P = 0.003) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 1.31 (0.59-2.93).
4-5: OR = 0.39 (0.14-1.10).
≥ 6: OR = 0.26 (0.08-0.87).

OR = 0.43 (0.14-1.39; P = 0.06) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 0.72 (0.24-2.11).
4-5: OR = 0.29 (0.08-1.00).
≥ 6: OR = 0.43 (0.14-1.39).

OR = 0.08 (0.01-0.73; P = 0.08) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 0.11 (0.01-0.91).
4-5: OR = 0.18 (0.04-0.87).
≥ 6: OR = 0.08 (0.01-0.73).

Stratified by smoking status:

Current smokers
(81 cases)

Exsmokers
(38 cases)

Never smokers
(19 cases)

OR = 0.54 (0.27-1.10; P = 0.01) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 1.10 (0.54-1.88).
4-5: OR = 0.44 (0.21-0.90).
≥ 6: OR = 0.54 (0.27-1.10).

OR = 0.25 (0.08-0.78; P = 0.007) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 0.86 (0.34-2.16).
4-5: OR = 0.44 (0.15-1.25).
≥ 6: OR = 0.25 (0.08-0.78).

OR = 0.84 (0.25-2.76; P = 0.44) for the highest vs lowest quartile of consumption.

Amount specific data (servings/wk):
≤ 1: OR = 1.
2-3: OR = 0.73 (0.23-2.33).
4-5: OR = 0.33 (0.07-1.63).
≥ 6: OR = 0.84 (0.25-2.76).

Men

Women

RR = 1.16 (0.71-1.91; No P-value) for the highest vs lowest tertile of consumption.

Amount specific data (servings/day):
< 0.11: RR = 1.
0.11-< 0.30: RR = 1.11 (0.67-1.84).
≥ 0.30: RR = 1.16 (0.71-1.91).

RR = 0.64 (0.35-1.18; No P-value) for the highest vs lowest tertile of consumption.

Amount specific data (servings/day):
< 0.13: RR = 1.
0.13-< 0.53: RR = 0.95 (0.55-1.63).
≥ 0.53: RR = 0.64 (0.35-1.18).

Men:

Women

HR = 0.95 (0.78-1.16) for the highest vs lowest tertile of consumption.

Amount specific data:
< 3/w: HR = 1.
3-4/w: HR = 1.01 (0.84-1.20).
≥ 5/w: HR = 0.95 (0.78-1.16).

HR = 1.19 (0.85-1.69) for the highest vs lowest tertile of consumption.

Amount specific data:
< 3/w: HR = 1.
3-4/w: HR = 1.14 (0.81-1.62).
≥ 5/w: HR = 1.19 (0.85-1.69).

Men:

Women

HR = 0.78 (0.66-0.93; P = < 0.01) for the highest vs lowest tertile of consumption.

Amount specific data:
< 3/w: HR = 1.
3-4/w: HR = 0.91 (0.76-1.08).
≥ 5/w: HR = 0.78 (0.66-0.93).

HR = 0.93 (0.66-1.31) for the highest vs lowest tertile of consumption.

Amount specific data:
< 3/w: HR = 1.
3-4/w: HR = 1.16 (0.82-1.63).
≥ 5/w: HR = 0.93 (0.66-1.31).

Stratified by sex:

Men

Women

HR = 0.76 (0.59-0.98; P = 0.035) for the highest vs lowest tertile of consumption.

Amount specific data (times):
≤ 2/we: HR = 1.
3-4/we: HR = 0.90 (0.71-1.14).
Almost every day: HR = 0.76 (0.59-0.98).

Male current smokers: RR = 0.80 (0.59-1.09; P = 0.18). RRs for increasing tertiles (1, 0.98, 0.80).
Male ex-smokers: RR = 0.65 (0.39-1.07; P = 0.096).

HR = 1.19 (0.75-1.90; P = 0.45) for the highest vs lowest tertile of consumption.

Amount specific data (times):
≤ 2/we: HR = 1.
3-4/we: HR = 1.18 (0.73-1.91).
Almost every day: HR = 1.19 (0.75-1.90).

Female nonsmokers: RR = 1.35 (0.79-2.30; P = 0.26).

Cancer & Diet. A systematic review.

Literature review.

Relating various aspects of our diet
to lung cancer risk & mortality.

Green and/or leafy vegetables and lung cancer.

Cancer & Diet. A systematic review.

Literature review.

Relating various aspects of our dietto lung cancer risk & mortality.

Green and/or leafy vegetables and lung cancer.

Relating various aspects of our diet
to lung cancer risk & mortality.