This article presents baseline characteristics and relative risks (RRs) of type 2 diabetes
according to frequency of nut and peanut butter consumption. Data are derived from
prospective cohort analyses, with adjustments for age, BMI, lifestyle, and dietary factors.
Frequent nut consumption has been associated with reduced risk of coronary heart disease in epidemiologic studies, but its relation with diabetes risk has not been evaluated.
To investigate the relationship between frequency of nut consumption and risk of type 2 diabetes.
In 1995 to 1996, a total of 83,818 women in the Nurses’ Health Study with no previous history of diabetes, cardiovascular disease, or cancer completed a validated food frequency questionnaire regarding their diet, including consumption of peanuts, peanut butter, and other nuts. These women were followed up until 2001 for incident diabetes.
During 6 years of follow-up, 3206 new cases of type 2 diabetes were documented. After adjusting for age, body mass index (BMI), family history of diabetes, physical activity, smoking, alcohol use, and total energy intake, the relative risks (RRs) of type 2 diabetes across categories of nut consumption (never/almost never, <once per week, 1–4 times per week, and ≥5 times per week) were 1.00, 0.92, 0.84, and 0.73 (95% confidence interval [CI], 0.60–0.89; P for trend <.001), respectively. Further adjustment for dietary factors, including cereal fiber, glycemic load, magnesium, and polyunsaturated fat, yielded similar results (multivariate RR, 0.71; 95% CI, 0.57–0.87; P for trend <.001). Peanut butter consumption showed a similar inverse association.
Our findings suggest that frequent nut and peanut butter consumption is associated with a reduced risk of type 2 diabetes in women.
| Variable | Never/Almost Never (n = 28,989) |
<Once/wk (n = 30,411) |
1–4 Times/wk (n = 20,104) |
≥5 Times/wk (n = 4314) |
|---|---|---|---|---|
| Age, mean (SD), y | 46.4 (7.15) | 46.1 (7.12) | 46.7 (7.13) | 47.9 (7.02) |
| Body mass index, mean (SD) | 24.7 (4.59) | 24.3 (4.29) | 24.0 (4.05) | 23.4 (3.74) |
| Family history of diabetes, % | 18.6 | 19.0 | 18.3 | 17.6 |
| Moderate/vigorous exercise, h/wk | 3.6 (2.81) | 3.9 (2.88) | 4.2 (2.92) | 4.4 (2.96) |
| Current smoker, % | 31.7 | 27.7 | 25.5 | 25.1 |
| Alcohol consumption, g/d | 5.8 | 6.3 | 7.2 | 7.8 |
| Multivitamin use, % | 30.3 | 32.9 | 38.0 | 45.6 |
| Polyunsaturated fat, % energy | 4.9 (1.58) | 5.2 (1.48) | 5.5 (1.42) | 6.8 (1.81) |
| Saturated fat, % energy | 15.6 (3.75) | 15.7 (3.49) | 15.6 (3.41) | 15.1 (3.63) |
| Trans-fat, % energy | 2.3 (0.77) | 2.3 (0.72) | 2.2 (0.69) | 2.0 (0.64) |
Values are means (SD) or percentages and have been standardized to the age distribution of the study population.
| Never/Almost Never | <Once/wk | 1–4 Times/wk | ≥5 Times/wk | P for Trend | |
|---|---|---|---|---|---|
| Cases, No. | 1314 | 1133 | 644 | 115 | — |
| Person-years | 441,007 | 466,464 | 309,608 | 66,468 | — |
| Age-adjusted RR (95% CI) | 1.00 | 0.82 (0.76–0.89) | 0.69 (0.63–0.76) | 0.55 (0.45–0.66) | <0.001 |
| Age- and BMI-adjusted RR (95% CI) | 1.00 | 0.91 (0.84–0.99) | 0.83 (0.75–0.91) | 0.74 (0.61–0.89) | <0.001 |
| Multivariate RR (95% CI) | 1.00 | 0.92 (0.85–1.00) | 0.84 (0.76–0.93) | 0.73 (0.60–0.89) | <0.001 |
| Diet-adjusted RR (95% CI)† | 1.00 | 0.91 (0.84–0.99) | 0.81 (0.74–0.90) | 0.71 (0.57–0.87) | <0.001 |
† Additionally adjusted for dietary variables as described in study footnote.
| Variable | <Once/wk | 1–4 Times/wk | ≥5 Times/wk | P for Trend |
|---|---|---|---|---|
| Body mass index | ||||
| <25 | 0.95 | 0.71 | 0.55 (0.32–0.94) | .003 |
| 25–29 | 0.83 | 0.77 | 0.75 (0.54–1.05) | .01 |
| ≥30 | 0.96 | 0.91 | 0.75 (0.56–0.98) | .02 |
| Family history of diabetes | ||||
| Yes | 1.00 | 0.82 | 0.75 (0.55–1.04) | .004 |
| No | 0.89 | 0.85 | 0.69 (0.54–0.87) | <.001 |
| Never/Almost Never | <Once/wk | 1–4 Times/wk | ≥5 Times/wk | P for Trend | |
|---|---|---|---|---|---|
| Cases, No. | 1392 | 747 | 836 | 231 | — |
| Person-years | 510,775 | 294,723 | 364,960 | 113,089 | — |
| Age-adjusted RR (95% CI) | 1.00 | 0.96 (0.88–1.05) | 0.88 (0.81–0.96) | 0.78 (0.68–0.90) | <.001 |
| Age- and BMI-adjusted RR (95% CI) | 1.00 | 1.00 (0.91–1.09) | 0.90 (0.83–0.98) | 0.86 (0.75–0.99) | .01 |
| Multivariate RR (95% CI)† | 1.00 | 0.98 (0.90–1.08) | 0.91 (0.83–0.99) | 0.79 (0.68–0.91) | <.001 |
| Diet-adjusted RR (95% CI)‡ | 1.00 | 0.98 (0.90–1.07) | 0.91 (0.84–1.00) | 0.81 (0.69–0.94) | .002 |
*Servings of peanut butter were equivalent to 15 mL or 28 g of peanuts.
†Multivariate model adjusted for age, BMI, lifestyle factors, and total energy intake.
‡Additionally adjusted for dietary variables including glycemic load, multivitamin use, polyunsaturated fat, saturated fat, trans fat, cereal fiber, magnesium, vegetables, fruits, whole grains, and fish intake.