Intake of whole grain foods and risk of type 2 diabetes: results from three prospective cohort studies

Yang Hu¹, Ming Ding¹, Laura Sampson¹, Walter C Willett^1 2 3, JoAnn E Manson^2 3 4, Molin Wang^2 5, Bernard Rosner^3 5, Frank B Hu^1 2 3, Qi Sun^6 3

全粒穀物および全粒食品(全粒シリアル・オートミール・ライ麦パン・玄米・ふすま入り・小麦胚芽など)の摂取量と2型糖尿病の関係について調査。

全体として全粒穀物は2型糖尿病のリスクを下げることは報告されているが、個々の関連については調査されていなかった。

女性158259名と男性36525名を対象とした前向き研究

追跡期間中に18629名が2型糖尿病を発症

全粒穀物の摂取量で5分位のグループ分けし、

最小摂取グループと最大摂取グループでは、2型糖尿病リスクが29(26-33)％低い(ハザード比0.71(0.67-0.74))。

表2の一番最後が全体の調整後のプールされた結果；

Table 2

Adjusted hazard ratios of type 2 diabetes for total whole grain consumption in the Nurses’ Health Study (1984-2014), Nurses’ Health Study II (1991-2017), and Health Professionals Follow-up Study (1986-2016). Model data are hazard ratio (95% confidence interval)

	Total whole grain consumption (divided into five equal groups)					P for trend§	Per serving daily
	Group 1	Group 2	Group 3	Group 4	Group 5	P for trend§	Per serving daily
Nurses’ Health Study
No of patients with diabetes/person years	2229/343 880	1855/344 836	1624/344 983	1342/344 421	1120/345 412	—	—
Age adjusted model	1.00	0.83 (0.78 to 0.88)	0.73 (0.68 to 0.77)	0.60 (0.56 to 0.64)	0.49 (0.46 to 0.53)	<0.001	0.71 (0.68 to 0.73)
Multivariable adjusted model*	1.00	0.85 (0.80 to 0.90)	0.76 (0.72 to 0.82)	0.65 (0.60 to 0.69)	0.55 (0.51 to 0.59)	<0.001	0.75 (0.73 to 0.78)
Additionally adjusting for body mass index†	1.00	0.86 (0.81 to 0.91)	0.80 (0.75 to 0.85)	0.71 (0.66 to 0.77)	0.68 (0.63 to 0.73)	<0.001	0.84 (0.81 to 0.87)
Nurses’ Health Study II
No of patients with diabetes/person years	2156/414 862	1609/415 300	1324/416 443	1079/416 435	904/416 499	—	—
Age adjusted model	1.00	0.77 (0.72 to 0.82)	0.64 (0.59 to 0.68)	0.52 (0.48 to 0.56)	0.42 (0.39 to 0.45)	<0.001	0.69 (0.67 to 0.71)
Multivariable adjusted model*	1.00	0.87 (0.81 to 0.93)	0.77 (0.72 to 0.82)	0.66 (0.61 to 0.71)	0.57 (0.53 to 0.62)	<0.001	0.79 (0.77 to 0.82)
Additionally adjusting for body mass index†	1.00	0.90 (0.84 to 0.96)	0.84 (0.78 to 0.90)	0.76 (0.70 to 0.82)	0.73 (0.68 to 0.80)	<0.001	0.88 (0.85 to 0.91)
Health Professionals Follow-up Study
No of patients with diabetes/person years	934/162 664	755/163 344	660/162 969	552/163 363	486/163 385	—	—
Age adjusted model	1.00	0.81 (0.74 to 0.90)	0.71 (0.64 to 0.79)	0.59 (0.53 to 0.66)	0.51 (0.46 to 0.57)	<0.001	0.81 (0.78 to 0.84)
Multivariable adjusted model*	1.00	0.85 (0.77 to 0.93)	0.76 (0.69 to 0.84)	0.65 (0.58 to 0.73)	0.59 (0.53 to 0.66)	<0.001	0.85 (0.82 to 0.88)
Additionally adjusting for body mass index†	1.00	0.84 (0.76 to 0.92)	0.81 (0.73 to 0.89)	0.72 (0.65 to 0.80)	0.72 (0.64 to 0.81)	<0.001	0.91 (0.88 to 0.95)
Pooled results‡
No of patients with diabetes/person years	5319/921 406	4219/923 480	3608/924 395	2973/924 219	2510/925 296	—	—
Age adjusted model	1.00	0.80 (0.77 to 0.84)	0.69 (0.66 to 0.72)	0.56 (0.54 to 0.59)	0.47 (0.45 to 0.49)	<0.001	0.73 (0.72 to 0.74)
Multivariable adjusted model*	1.00	0.86 (0.82 to 0.89)	0.76 (0.73 to 0.80)	0.65 (0.62 to 0.68)	0.57 (0.54 to 0.60)	<0.001	0.80 (0.78 to 0.81)
Additionally adjusting for body mass index†	1.00	0.87 (0.84 to 0.91)	0.82 (0.78 to 0.85)	0.73 (0.70 to 0.77)	0.71 (0.67 to 0.74)	<0.001	0.88 (0.86 to 0.89)

^*Adjusted for age (years), ethnicity (white, African American, Asian, others), smoking status (never smoked, past smoker, currently smoke 1-14 cigarettes/day, 15-24 cigarettes/day, or ≥25 cigarettes/day), alcohol intake (0, 0.1-4.9, 5.0-9.9, 10.0-14.9, 15.0-29.9, and ≥30.0 g/day), multivitamin use (yes, no), physical activity (divided into five equal groups), modified alternative healthy eating index (divided into five equal groups), and family history of diabetes. For women, postmenopausal hormone use (never, former, or current hormone use, or missing), and oral contraceptive use were further adjusted.

^†Additionally adjusted for time varying body mass index (<21.0, 21.0-22.9, 23.0-24.9, 25.0-26.9, 27.0-29.9, 30.0-32.9, 33.0-34.9, or ≥35.0).

^‡Study estimates from three cohorts were pooled with a fixed effects model.

^§Calculated with continuous exposure variables.

種類別では、

ポップコーン以外は、1ヶ月1サービングに比べ、1日1サービングの方がリスクが下がる。

ポップコーンは、1ヶ月1サービングと1週間1サービングではリスクが下がるが、1日1サービングでは1.08となった。

Table 3

Adjusted hazard ratios of type 2 diabetes for individual whole grain food consumption in the Nurses’ Health Study (1984-2014), Nurses’ Health Study II (1991-2017), and Health Professionals Follow-up Study (1986-2016). Model data are hazard ratio (95% confidence interval)

	Consumption level				P for trend‡	Per serving daily
	Never or <1 serving/month	1 serving/month to 1 serving/week	1 serving/week to 4-6 servings/week	≥1 serving/day	P for trend‡	Per serving daily
Whole grain cold breakfast cereal
No of patients with diabetes/person time	6948/1 385 562	4113/919 380	5571/1 664 324	1997/649 531	—	—
Multivariable adjusted model*	1.00	0.92 (0.89 to 0.96)	0.67 (0.65 to 0.70)	0.66 (0.63 to 0.70)	<0.001	0.62 (0.59 to 0.65)
Additionally adjusting for body mass index†	1.00	0.93 (0.89 to 0.97)	0.75 (0.73 to 0.78)	0.81 (0.77 to 0.86)	<0.001	0.78 (0.74 to 0.82)
Dark bread
No of patients with diabetes/person time	2559/490 667	4117/916 951	6376/1 728 628	5577/1 482 551	—	—
Multivariable adjusted model*	1.00	0.94 (0.90 to 0.99)	0.77 (0.73 to 0.80)	0.78 (0.74 to 0.82)	<0.001	0.91 (0.89 to 0.93)
Additionally adjusting for body mass index†	1.00	0.91 (0.87 to 0.96)	0.78 (0.75 to 0.82)	0.79 (0.75 to 0.83)	<0.001	0.93 (0.91 to 0.95)
Popcorn
No of patients with diabetes/person time	4487/1 093 043	8979/2 323 828	4221/1 025 642	942/176 283	—	—
Multivariable adjusted model*	1.00	1.06 (1.03 to 1.11)	1.09 (1.04 to 1.14)	1.46 (1.35 to 1.57)	<0.001	1.25 (1.20 to 1.30)
Additionally adjusting for body mass index†	1.00	0.96 (0.92 to 1.00)	0.92 (0.87 to 0.96)	1.08 (1.00 to 1.17)	0.002	1.07 (1.03 to 1.12)
Oatmeal
No of patients with diabetes/person time	9723/2 248 899	6821/1 685 499	2085/684 398	—	—	—
Multivariable adjusted model*	1.00	0.94 (0.91 to 0.97)	0.69 (0.66 to 0.72)	—	<0.001	0.56 (0.49 to 0.63)
Additionally adjusting for body mass index†	1.00	0.95 (0.92 to 0.98)	0.79 (0.75 to 0.83)	—	<0.001	0.75 (0.66 to 0.84)
Brown rice
No of patients with diabetes/person time	11 861/2 610 337	5855/1 684 788	913/323 671	—	—	—
Multivariable adjusted model*	1.00	0.93 (0.90 to 0.96)	0.79 (0.74 to 0.85)	—	<0.001	0.72 (0.61 to 0.86)
Additionally adjusting for body mass index†	1.00	0.96 (0.93 to 0.99)	0.88 (0.82 to 0.94)	—	0.11	0.87 (0.74 to 1.03)
Added bran
No of patients with diabetes/person time	15 419/3 634 960	1989/566 549	1221/417 288	—	—	—
Multivariable adjusted model*	1.00	0.88 (0.84 to 0.92)	0.72 (0.68 to 0.77)	—	<0.001	0.78 (0.72 to 0.84)
Additionally adjusting for body mass index†	1.00	0.93 (0.89 to 0.98)	0.85 (0.80 to 0.90)	—	0.002	0.90 (0.84 to 0.96)
Wheat germ
No of patients with diabetes/person time	17 399/4 189 252	914/303 909	316/125 634	—	—	—
Multivariable adjusted model*	1.00	0.83 (0.77 to 0.88)	0.68 (0.61 to 0.76)	—	<0.001	0.61 (0.50 to 0.73)
Additionally adjusting for body mass index†	1.00	0.92 (0.86 to 0.99)	0.88 (0.78 to 0.98)	—	0.14	0.88 (0.74 to 1.04)