Walnut Consumption Is Associated with Lower Risk of Type 2 Diabetes in Women

Abstract

Walnuts are rich in polyunsaturated fatty acids and have been shown to improve various cardiometabolic risk factors. We aimed to investigate the association between walnut intake and incident type 2 diabetes in 2 large cohort studies: the Nurses’ Health Study (NHS) and NHS II. We prospectively followed 58,063 women aged 52–77 y in NHS (1998–2008) and 79,893 women aged 35–52 y in NHS II (1999–2009) without diabetes, cardiovascular disease, or cancer at baseline. Consumption of walnuts and other nuts was assessed every 4 y using validated food frequency questionnaires. Self-reported type 2 diabetes was confirmed by a validated supplemental questionnaire. We documented a total of 5930 incident type 2 diabetes cases during 10 y of follow-up. In the multivariable-adjusted Cox proportional hazards model without body mass index (BMI), walnut consumption was associated with a lower risk of type 2 diabetes, and the HRs (95% CIs) for participants consuming 1–3 servings/mo (1 serving = 28 g), 1 serving/wk, and ≥2 servings/wk of walnuts were 0.93 (0.88–0.99), 0.81 (0.70–0.94), and 0.67 (0.54–0.82) compared with women who never/rarely consumed walnuts (P-trend < 0.001). Further adjustment for updated BMI slightly attenuated the association and the HRs (95% CIs) were 0.96 (0.90–1.02), 0.87 (0.75–1.01), and 0.76 (0.62–0.94), respectively (P-trend = 0.002). The consumption of total nuts (P-trend < 0.001) and other tree nuts (P-trend = 0.03) was also inversely associated with risk of type 2 diabetes, and the associations were largely explained by BMI. Our results suggest that higher walnut consumption is associated with a significantly lower risk of type 2 diabetes in women.

Nut consumption for vascular health and cognitive function

“…Nut consumption has also been associated with a reduced risk of type 2 diabetes; evidence to support this comes from large epidemiological studies (51 -54) . The Nurses' Health Study demonstrated that consumption of nuts ($ 5 times per week), peanut butter ($ 5 times per week) or walnuts ($ twice per week) was associated with a 24, 21 and 15 % lower risk, respectively, of developing type 2 diabetes (51,54) compared with those who never or rarely ate nuts; the effect was greatest in those of healthy body weight (51) . In addition, the Shanghai Women's Health Study demonstrated that groundnut consumption was associated with a 22 % decreased risk of type 2 diabetes (55) .…”

The role of nuts consumption in the primary and secondary prevention of type 2 diabetes

“…A more frequent consumption of nuts was associated with a clearly lower risk of the development of noninsulin dependent diabetes mellitus [24]. The likelihood of the occurrence of this disease in people declaring the consumption of at least 2 portions/week (portion -28 g) vs. 1 portion/week and 1-3 portions per month was much lower.…”

“…It was shown that walnuts are particularly important in the primary prevention of type 2 diabetes due to the fact that they contain alpha-linolenic acid (9.08 g/100 g), which increases insulin sensitivity [6,24]. A more frequent consumption of nuts was associated with a clearly lower risk of the development of noninsulin dependent diabetes mellitus [24].…”

Diabetes Reversal by Plant-Based Diet

“…Also, three cohort studies could establish a reduced risk of type 2 diabetes by 27%, 20% and 33% respectively by nut intake in regular diet in women in the Nurses' Health Study (NHS, in the NHS and NHS II cohorts) [23,24] and women in the Shanghai Women's Health Study [25]. A significant research published in the Current Atherosclerosis Reports-2010 demonstrated that, the time of cooking is directly proportional to the increase in glycemic index (GI), resulting in lot of burden on the blood sugar making a person more prone to diabetes [26].…”