Institute for Nutrition Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.
Medical School, Royal Perth Hospital Unit, The University Western Australia, Perth, Western Australia, Australia.
J Nutr. 2021 May 11;151(5):1222-1230. doi: 10.1093/jn/nxaa415.
Nitrate supplements can improve vascular and muscle function. Whether higher habitual dietary nitrate is associated with better muscle function remains underexplored.
The aim was to examine whether habitual dietary nitrate intake is associated with better muscle function in a prospective cohort of men and women, and whether the relation was dependent on levels of physical activity.
The sample (n = 3759) was drawn from the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab) (56% female; mean ± SD baseline age: 48.6 ± 11.1 y). Habitual dietary intake was assessed over 12 y by obtaining an average [of at least 2 time points, e.g., baseline (2000/2001) and 2004/2005 and/or 2011/2012] from a food-frequency questionnaire. Nitrate intake was calculated from a validated nitrate database and other published literature. Muscle function was quantified by knee extension strength (KES) and the 8-ft-timed-up-and-go (8ft-TUG) test performed in 2011/2012. Physical activity was assessed by questionnaire. Generalized linear models and logistic regression were used to analyze the data.
Median (IQR) total nitrate intake was 65 (52-83) mg/d, with ∼81% derived from vegetables. Individuals in the highest tertile of nitrate intake (median intake: 91 mg/d) had 2.6 kg stronger KES (11%) and 0.24 s faster 8ft-TUG (4%) compared with individuals in the lowest tertile of nitrate intake (median intake: 47 mg/d; both P < 0.05). Similarly, individuals in the highest tertile of nitrate intake had lower odds for weak KES (adjusted OR: 0.69; 95% CI: 0.47, 0.73) and slow 8ft-TUG (adjusted OR: 0.63; 95% CI: 0.50, 0.78) compared with those in the lowest tertile. Physical activity did not influence the relationship between nitrate intake and muscle function (KES; P-interaction = 0.86; 8ft-TUG; P-interaction = 0.99).
Higher habitual dietary nitrate intake, predominantly from vegetables, could be an effective way to promote lower-limb muscle strength and physical function in men and women.
硝酸盐补充剂可以改善血管和肌肉功能。较高的习惯性饮食硝酸盐是否与更好的肌肉功能相关仍未得到充分探索。
本研究旨在检查习惯性饮食硝酸盐摄入与男性和女性肌肉功能之间的关系，并探讨这种关系是否依赖于身体活动水平。
该样本（n=3759）来自澳大利亚糖尿病、肥胖和生活方式研究（AusDiab）（56%为女性；平均±标准差基线年龄：48.6±11.1 岁）。通过获得食物频率问卷中至少 2 个时间点的平均值[例如基线（2000/2001 年）和 2004/2005 年和/或 2011/2012 年]，在 12 年内评估习惯性饮食摄入情况。硝酸盐摄入量是从经过验证的硝酸盐数据库和其他已发表文献中计算得出的。肌肉功能通过膝关节伸展力量（KES）和 8 英尺计时起身行走测试（8ft-TUG）进行量化，这些测试在 2011/2012 年进行。身体活动通过问卷进行评估。使用广义线性模型和逻辑回归分析数据。
中位数（IQR）总硝酸盐摄入量为 65（52-83）mg/d，其中约 81%来自蔬菜。硝酸盐摄入量最高三分位组（中位数摄入量：91mg/d）的 KES 强 2.6kg（11%），8ft-TUG 快 0.24s（4%），与硝酸盐摄入量最低三分位组（中位数摄入量：47mg/d；均 P<0.05）相比。同样，硝酸盐摄入量最高三分位组发生弱 KES 的可能性较低（校正比值比：0.69；95%CI：0.47，0.73），发生 8ft-TUG 慢的可能性也较低（校正比值比：0.63；95%CI：0.50，0.78），与最低三分位组相比。身体活动水平不会影响硝酸盐摄入与肌肉功能之间的关系（KES；P 交互作用=0.86；8ft-TUG；P 交互作用=0.99）。
较高的习惯性饮食硝酸盐摄入，主要来自蔬菜，可能是促进男性和女性下肢肌肉力量和身体功能的有效方法。
