Vegetables and type 2 diabetes mellitus.

Data was provided by 9 cohorts, including a total of 12,106 cases.
Protective effects were found in 2 cohorts (11, 14), including 2,340 cases (19% of all cases). No other (non)significant associations were found in any cohort.

Inclusion of intermediate levels of consumption:
Significant protective effects at any level of consumption were confined to results from 2 cohorts, including 1,988 cases (Montonen J, at 42-78 g/day; and Villegas R, at ≥ 182 g/day). No other (non)significant effects were found at any level of consumption.

RRs for the association between total vegetables and diabetes risk (g/day):

Conclusion: Protective effects were found in 2 out of 9 cohorts, including 19% of all cases. No evidence was found for an association between total vegetables and risk of diabetes type 2.

Prospective studies of vegetables and risk of type 2 diabetes mellitus:

Author

Cohort name

Subjects

Years of follow-up

Cases

End point

Consumption of

Relative Risk (RR)

Adjustments

14) Harding AH (2008)

The EPIC-Norfolk Study

21,831 individuals (9,815 men and 12,016 women) aged 40-75 from Norfolk.
(England)

12
(1993-97 to 2005)

735?

Type 2 diabetes incidence (self-reportend and confirmed by another data source)

Total vegetables (not defined)

OR = 0.94 (0.89-1.00) for the highest vs lowest quintile of consumption (not defined).

Age, sex, family history of diabetes, alcohol consumption, physical activity, smoking, educational level, occupational class, vitamin supplements, BMI, and waist circumference.

12) Nettleton JA (2008)

The Multi-Ethnic Study of Atheroslerosis (MESA)

5,011 white, black, Hispanic, and Chinese adults aged 45-84.
(USA)

413?

Type 2 diabetes incidence (defined as self-reported type 2 diabetes, fasting glucose ≥ 126 mg/dl at any exam, or use of antidiabetes medication)

Vegetables (not defined)

No significant association (HR = < 1.00; no data shown).

Energy, study center, age, sex, race/ethnicity, education, leisure time physical activity, current smoking status, smoking pack-years, current weekly supplement use, and waist circumference.

11) Villegas R (2008)

The Shanghai Women's Health Study

64,191 women aged 40-70.
(China)

4.6

See variables

Type 2 diabetes incidence (reported having been diagnosed with T2D and met at least one of the following criteria: fasting glucose level ≥ 7 mmol/l on at least two separate occasions, or an oral glucose tolerance test (OGTT) with a value ≥ 11.1 mmol/L, and/or use of hypoglycaemic medication (i.e., insulin or oral hypoglycaemic drugs).)

All vegetables (Green cabbage, Chinese cabbage, cauliflower, white turnip, greens, Chinese greens, spinach, sweet potatoes, carrots, Garlic, garlic shoots, heads of garlic, onions, green onions, Chinese chives, tomatoes, Soy bean sprouts, mug bean sprouts, black and white tree fungi, dried xiangu mushrooms, celery, eggplant, wild rice stems, asparagus lettuce, wax gourd, cucumbers, lufa, fresh mushrooms, peppers, bamboo shoots, lotus root.
Soy beans, dried beans, and other legumes were not included)


Self-reported cases: (1,605 cases)	Confirmed cases: (896? cases)
HR = 0.72 (0.61-0.85; P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.74 (0.64-0.87). 236.0: HR = 0.68 (0.58-0.80). 302.6: HR = 0.72 (0.61-0.84). 428.0: HR = 0.72 (0.61-0.85).	HR = 0.65 (0.52-0.81; P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.71 (0.58-0.87). 236.0: HR = 0.66 (0.54-0.81). 302.6: HR = 0.69 (0.56-0.85). 428.0: HR = 0.65 (0.52-0.81).

Very high vs very low consumption:
RRs for increasing deciles of vegetable intake: 1.00, 0.87, 0.68, 0.72, 0.61, 0.66, 0.67, 0.68, 0.64, 0.71 (P = < 0.001).

**Stratified by BMI:**
< 25	≥ 25
HR = 0.68 (0.51-0.90; P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.59 (0.45-0.76). 236.0: HR = 0.64 (0.49-0.83). 302.6: HR = 0.69 (0.53-0.90). 428.0: HR = 0.68 (0.51-0.90).	HR = 0.79 (0.64-0.96; P = 0.01) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.85 (0.71-1.02). 236.0: HR = 0.71 (0.59-0.87). 302.6: HR = 0.77 (0.63-0.94). 428.0: HR = 0.79 (0.64-0.96).

**Stratified by waist-to-hip ratio:**
< 0.85	≥ 0.85
HR = 0.69 (0.56-0.87; P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.77 (0.62-0.94). 236.0: HR = 0.62 (0.50-0.77). 302.6: HR = 0.69 (0.56-0.85). 428.0: HR = 0.69 (0.56-0.87).	HR = 0.72 (0.57-0.92; P = < 0.01) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.70 (0.56-0.88). 236.0: HR = 0.74 (0.58-0.93). 302.6: HR = 0.74 (0.58-0.93). 428.0: HR = 0.72 (0.57-0.92).

**Stratified by physical activity:**
Low	Medium/high
HR = 0.60 (0.43-0.84; P = < 0.01) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.74 (0.56-0.99). 236.0: HR = 0.56 (0.40-0.76). 302.6: HR = 0.75 (0.56-1.00). 428.0: HR = 0.60 (0.43-0.84).	HR = 0.75 (0.62-0.91; P = < 0.01) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.75 (0.62-0.89). 236.0: HR = 0.72 (0.60-0.86). 302.6: HR = 0.70 (0.58-0.84). 428.0: HR = 0.75 (0.62-0.91).

**Stratified by hyptertension status**
(No 95% CI available):
Hyptertension	No hypertension
HR = 0.75 (P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.81. 236.0: HR = 0.65. 302.6: HR = 0.72. 428.0: HR = 0.75.	HR = 0.70 (P = < 0.001) for the highest vs lowest quintile of consumption. Amount specific data (g/day): 121.5: HR = 1. 181.6: HR = 0.70. 236.0: HR = 0.71. 302.6: HR = 0.72. 428.0: HR = 0.70.

Age, daily energy intake, meat intake, BMI, WHR, smoking, alcohol consumption, physical activity, income level, education level, occupational status, and hypertension.

9) Hodge AM (2007)

The Melbourne Collaborative Cohort Study

31,641 men and women aged 27-75.

4
(1990-1994)

365?

Type 2 diabetes incidence (confirmed by a physician)

Vegetables (not defined)

OR = 0.93 (0.67-1.28; P = 0.55) for the highest vs lowest quartile of consumption (not defined).

Adjusted for age, sex, energy intake, family history of diabetes, and country of birth.

9) Hodge AM (2004)

The Melbourne Collaborative Cohort Study

31,641 men and women aged 40-69.

365?

Type 2 diabetes incidence (confirmed by doctor)

Vegetables (not defined)


Multivariate adjusted:	Additionally adjusted for BMI and WHR:
OR = 0.86 (0.59-1.24; P = 0.3) for the highest vs lowest quartile of consumption. Amount specific data (times/day): < 3.0: OR = 1. 3.0-4.9: OR = 1.00 (0.71-1.40). 5.0-6.9: OR = 0.92 (0.65-1.31). ≥ 7.0: OR = 0.86 (0.59-1.24).	OR = 0.88 (0.60-1.28; P = 0.3) for the highest vs lowest quartile of consumption. Amount specific data (times/day): < 3.0: OR = 1. 3.0-4.9: OR = 1.09 (0.78-1.54). 5.0-6.9: OR = 0.97 (0.68-1.39). ≥ 7.0: OR = 0.88 (0.60-1.28).

Age, sex, country of birth, physical activity, family history of diabetes, alcohol intake, education level, weight change in the last 5 years, and energy intake.

8) Liu S (2004)

The Women's Health Study

38,018 female health professionals aged ≥ 45.

8.8
(1993-2003)

1,614

Type 2 diabetes incidence (self-reported)

All vegetables (broccoli, cabbage, cauliflower, Brussels sprouts, carrots, yellow squash, yams, sweet potatoes, spinach, kale, lettuce, corn, mixed vegetables, celery, eggplant, mushrooms, and beets)


All women:	Overweight women (BMI ≥ 25) (1,361 cases):
RR = 1.03 (0.86-1.23; P = 0.83) for the highest vs lowest quintile of consumption. Amount specific data (Servings per day): 1.47: RR = 1. 2.49: RR = 1.01 (0.86-1.19). 3.40: RR = 0.98 (0.83-1.16). 4.58: RR = 0.99 (0.84-1.18). 6.84: RR = 1.03 (0.86-1.23).	RR = 1.00 (0.82-1.21; P = 0.83) for the highest vs lowest quintile of consumption. Amount specific data (Servings per day): 1.47: RR = 1. 2.49: RR = 1.00 (0.84-1.18). 3.40: RR = 0.87 (0.73-1.05). 4.58: RR = 0.96 (0.80-1.15). 6.84: RR = 1.00 (0.82-1.21).

No significant findings were observed in the lower BMI group (BMI < 25; ~ 15% of all case subjects. Data not shown).

Age, smoking, total calories, alcohol use, BMI, exercise, history of hypertension, history of high cholesterol, and family history of diabetes.

6) Montonen J (2005)

The Finnish Mobile Clinic Health Examination Survey

4,304 men and women aged 40-69.

23
(1967-72 to 1995)

383?

Type 2 diabetes incidence (users of drugs for diabetes)

Total vegetables (not defined)

RR = 0.77 (0.57-1.03; P = 0.22) for the highest vs lowest quartile of consumption.

Amount specific data (g/day):
< 42: RR = 1.
42-78: RR = 0.75 (0.56-1.00).
79-130: RR = 0.93 (0.70-1.22).
> 130: RR = 0.77 (0.57-1.03).

Effect modification: No significant interaction between food intake and age, sex, body mass index, or smoking was found (data not shown).

Age, sex, BMI, energy intake, smoking, family history of diabetes, and geographic area.

4) Meyer KA (2000)

The Iowa Women's Health Study

35,988 women aged 55-69.

6
(1986-1992)

1,141

Type 2 diabetes incidence (self-reported)

Total vegetables (not defined)

RR = 1.07 (0.86-1.32; P = 0.45) for the highest vs lowest quintile of consumption.

Amount specific data (servings/wk):
< 14: RR = 1.
14-19.4: RR = 1.03 (0.85-1.24).
19.5-25: RR = 0.99 (0.82-1.21).
25.1-33.5: RR = 1.09 (0.90-1.34).
> 33.5: RR = 1.07 (0.86-1.32).

Age, total energy intake, BMI, waist-to-hip ratio, education, pack-years of smoking, alcohol intake, and physical activity.

3) van Dam RM (2002)

The Health Professionals Follow-up Study

42,504 men aged 40-75.
(USA)

12
(1986-1998)

1,321?

Type 2 diabetes incidence (required at least one of the following: 1) an elevated plasma glucose level (fasting plasma glucose level ≥ 7.8 mmol/L [≥ 140 mg/dL]; random plasma glucose level ≥ 11.1 mmol/L [≥ 200 mg/dL]; or plasma glucose level after 2 hours or more during an oral glucose tolerance test ≥ 11.1 mmol/L [≥ 200 mg/dL]) plus at least one classic symptom (excessive thirst, polyuria, weight loss, or hunger); 2) at least two elevated plasma glucose levels measured on different occasions; or 3) treatment with insulin or oral hypoglycemic medication.)

Vegetables (not defined)

Not appreciably associated with risk (no data shown).

Age, BMI, total energy intake, time period, physical activity, cigarette smoking, alcohol consumption, ancestry, hypercholesterolemia, hypertension, and family history of type 2 diabetes mellitus.

3) Bazzano LA (2008)

The Nurses Health Study

71,346 women aged 38-63.
(USA)

18
(1984-2002)

4,529

Type 2 diabetes risk (any one of the following criteria was met: 1) one or more classic symptoms of diabetes and reported elevated plasma glucose levels (fasting plasma glucose ≥ 7.8 mmol/l [140 mg/dl] or randomly measured plasma glucose ≥ 11.1 mmol/l [200 mg/dl]), 2) reported elevated plasma glucose on at least two occasions in the absence of symptoms, or 3) treatment with oral hypoglycemic medication or insulin)

Vegetables (excluding potatoes)

HR = 1.05 (0.94-1.16; P = 0.22) for the highest vs lowest quintile of consumption.

Amount specific data (servings/day):
1.5: HR = 1.
2.3: HR = 1.00 (0.91-1.10).
3.0: HR = 1.02 (0.93-1.12).
3.7: HR = 1.08 (0.98-1.19).
5.2: HR = 1.05 (0.94-1.16).

Age, BMI, physical activity, family history of diabetes, postmenopausal hormone use, alcohol use, smoking, total energy intake, whole grains, nuts, processed meats, coffee, potatoes, and sugar-sweetened soft drinks.

3) Colditz GA (1992)

The Nurses' Health Study

84,360 women aged 34-59.
(USA)

6
(1980-86)

702?

NIDDM incidence (report of one of the following: 1) at least one classical symptom (weight loss, hunger, thirst, polyuria, or pruritis) plus a plasma fasting glucose concentration ≥ 7.77 mmol/L or a random plasma glucose ≥ 11.10 mmol/L, or 2) at least two elevated plasma glucose concentrations ≥ 11.10 mmol/L in the absence of symptoms.)

Vegetables (not defined)

Among women with a BMI < 29 [n = 252? cases]:
RR = 0.76 (0.50-1.16; P = 0.21) for consumption ≥ 2.9 vs < 1.2 servings/d.

BMI, alcohol intake, energy intake, and prior weight change.

Diabetes & Diet.

A systematic review.

Literature review

Relating various aspects of our
diet to diabetes type 2.

Vegetables and type 2 diabetes mellitus.

Diabetes & Diet.

A systematic review.

Literature review

Relating various aspects of ourdiet to diabetes type 2.

Vegetables and type 2 diabetes mellitus.

Relating various aspects of our
diet to diabetes type 2.