Options for basing Dietary Reference Intakes (DRIs) on chronic disease endpoints: report from a joint US-/Canadian-sponsored working group.
Am J Clin Nutr. 2016 Dec 07;:
Authors: Yetley EA, MacFarlane AJ, Greene-Finestone LS, Garza C, Ard JD, Atkinson SA, Bier DM, Carriquiry AL, Harlan WR, Hattis D, King JC, Krewski D, O'Connor DL, Prentice RL, Rodricks JV, Wells GA
Dietary Reference Intakes (DRIs) are used in Canada and the United States in planning and assessing diets of apparently healthy individuals and population groups. The approaches used to establish DRIs on the basis of classical nutrient deficiencies and/or toxicities have worked well. However, it has proved to be more challenging to base DRI values on chronic disease endpoints; deviations from the traditional framework were often required, and in some cases, DRI values were not established for intakes that affected chronic disease outcomes despite evidence that supported a relation. The increasing proportions of elderly citizens, the growing prevalence of chronic diseases, and the persistently high prevalence of overweight and obesity, which predispose to chronic disease, highlight the importance of understanding the impact of nutrition on chronic disease prevention and control. A multidisciplinary working group sponsored by the Canadian and US government DRI steering committees met from November 2014 to April 2016 to identify options for addressing key scientific challenges encountered in the use of chronic disease endpoints to establish reference values. The working group focused on 3 key questions: 1) What are the important evidentiary challenges for selecting and using chronic disease endpoints in future DRI reviews, 2) what intake-response models can future DRI committees consider when using chronic disease endpoints, and 3) what are the arguments for and against continuing to include chronic disease endpoints in future DRI reviews? This report outlines the range of options identified by the working group for answering these key questions, as well as the strengths and weaknesses of each option.
PMID: 27927637 [PubMed - as supplied by publisher]
Dietary soy and natto intake and cardiovascular disease mortality in Japanese adults: the Takayama study.
Am J Clin Nutr. 2016 Dec 07;:
Authors: Nagata C, Wada K, Tamura T, Konishi K, Goto Y, Koda S, Kawachi T, Tsuji M, Nakamura K
BACKGROUND: Whether soy intake is associated with a decreased risk of cardiovascular disease (CVD) remains unclear. A traditional Japanese soy food, natto, contains a potent fibrinolytic enzyme. However, its relation to CVD has not been studied.
OBJECTIVE: We aimed to examine the association of CVD mortality with the intake of natto, soy protein, and soy isoflavones in a population-based cohort study in Japan.
DESIGN: The study included 13,355 male and 15,724 female Takayama Study participants aged ≥35 y. At recruitment in 1992, each subject was administered a validated semiquantitative food-frequency questionnaire. Deaths from CVD were ascertained over 16 y.
RESULTS: A total of 1678 deaths from CVD including 677 stroke and 308 ischemic heart disease occurred during follow-up. The highest quartile of natto intake compared with the lowest intake was significantly associated with a decreased risk of mortality from total CVD after control for covariates: the HR was 0.75 (95% CI: 0.64, 0.88, P-trend = 0.0004). There were no significant associations between the risk of mortality from total CVD and intakes of total soy protein, total soy isoflavone, and soy protein or soy isoflavone from soy foods other than natto. The highest quartiles of total soy protein and natto intakes were significantly associated with a decreased risk of mortality from total stroke (HR = 0.75, 95% CI: 0.57, 0.99, P-trend = 0.03 and HR = 0.68, 95% CI: 0.52, 0.88, P-trend = 0.0004, respectively). The highest quartile of natto intake was also significantly associated with a decreased risk of mortality from ischemic stroke (HR = 0.67, 95% CI:0.47, 0.95, P-trend = 0.03).
CONCLUSION: Data suggest that natto intake may contribute to the reduction of CVD mortality.
PMID: 27927636 [PubMed - as supplied by publisher]
Associations between iodine intake, thyroid volume, and goiter rate in school-aged Chinese children from areas with high iodine drinking water concentrations.
Am J Clin Nutr. 2016 Dec 07;:
Authors: Chen W, Li X, Wu Y, Bian J, Shen J, Jiang W, Tan L, Wang X, Wang W, Pearce EN, Zimmermann MB, Carriquiry AL, Zhang W
BACKGROUND: Excessive iodine intake may have adverse effects on the thyroid, particularly in children, but the safe upper iodine intake concentration in children is unclear.
OBJECTIVE: We assessed the adverse effects of high iodine intake from iodine-rich drinking water on thyroid size in children by examining associations between thyroid volume (Tvol), total goiter rate (TGR), and iodine intake.
DESIGN: In a multistage cross-sectional survey, we collected two 24-h urine samples on 2 nonconsecutive days and determined 24-h urinary iodine excretion, then calculated habitual daily iodine intake. Ultrasonographic Tvol was measured, and TGR was calculated based on international and Chinese reference ranges for Tvol in children.
RESULTS: This study included 2089 children from Shandong province, where the median (IQR) drinking water iodine concentration was 183 μg/L (69-406 μg/L). The median (IQR) 24-h urinary iodine concentrations for the 2 collections were 381 μg/L (203-649 μg/L) and 398 μg/L (202-687 μg/L), respectively. The median (IQR) habitual daily iodine intake of children was 298 μg/d (186-437 μg/d). Tvols were slightly higher in boys than in girls (P = 0.035). The overall TGR was 9.7% and did not differ by sex. The TGR was ∼5% for children aged 7-10 and 11-14 y at iodine intakes of 200-249 and 250-299 μg/d, respectively. With the use of logistic regression and 2-step linear regression, a nonlinear association was observed between Tvol, TGR, and iodine intake, with a threshold intake of 150 μg/d.
CONCLUSIONS: Tvol begins to increase in children when iodine intake is ≥150 μg/d, and the TGR exceeds 5% when daily iodine intake is ≥250 μg/d for children aged 7-10 y and ≥300 μg/d for children aged 11-14 y. Our findings suggest that 150-249 and 150-299 μg/d seem to be safe upper iodine intake ranges for children aged 7-10 and 11-14 y, respectively. This trial was registered at clinicaltrials.gov as NCT02915536.
PMID: 27927635 [PubMed - as supplied by publisher]
Prenatal exposure to famine and the development of hyperglycemia and type 2 diabetes in adulthood across consecutive generations: a population-based cohort study of families in Suihua, China.
Am J Clin Nutr. 2016 Dec 07;:
Authors: Li J, Liu S, Li S, Feng R, Na L, Chu X, Wu X, Niu Y, Sun Z, Han T, Deng H, Meng X, Xu H, Zhang Z, Qu Q, Zhang Q, Li Y, Sun C
BACKGROUND: There has been increased recognition that prenatal or perinatal nutrition has an effect on the development of type 2 diabetes (T2D) in adulthood, although studies that have directly examined whether the effect could be transmitted to the next generation remain sparse.
OBJECTIVE: We investigated the role of prenatal exposure to the Chinese famine in affecting future T2D risk in adulthood in 2 consecutive generations.
DESIGN: A total of 1034 families, including 2068 parents [parental generation (F1)] and 1183 offspring [offspring generation (F2)], were recruited from the Suihua rural area that was affected by the Chinese Famine of 1959-1961. Participants born between 1 October 1959 and 30 September 1961 were defined as famine exposed, and those born between 1 October 1962 and 30 September 1964 were defined as nonexposed. The F2 were classified as having 1) no parent exposed to famine, 2) only a mother exposed to famine, 3) only a father exposed to famine, or 4) both parents exposed to famine. Classical risk factors for T2D as well as fasting-glucose- and oral-glucose-tolerance tests were measured in both the F1 and F2.
RESULTS: Prenatal exposure to famine was associated with elevated risks of hyperglycemia (multivariable-adjusted OR: 1.93; 95% CI: 1.51, 2.48) and T2D (OR: 1.75; 95% CI: 1.20, 2.54) in adulthood in F1. Furthermore, compared with the offspring of nonexposed parents, the F2 with exposed parents- especially both exposed parents-had increased hyperglycemia risk (OR: 2.02; 95% CI: 1.12, 3.66) in adulthood.
CONCLUSION: Prenatal exposure to famine remarkably increases hyperglycemia risk in 2 consecutive generations of Chinese adults independent of known T2D risk factors, which supports the notion that prenatal nutrition plays an important role in the development of T2D across consecutive generations of Chinese adults. This trial was registered at www.chictr.org.cn as ChiCTR-ECH-13003644.
PMID: 27927634 [PubMed - as supplied by publisher]