Periconceptional maternal diet quality influences blood heavy metal concentrations and their effect on low birth weight: the Japan Environment and Children's Study

BACKGROUND

Both poor maternal nutrition and toxic heavy metal exposure influence foetal growth and development. However, whether consumption of a variety of healthy foods modifies the association between prenatal heavy metal exposure and foetal growth is unknown.

OBJECTIVE

We examined whether long-term maternal diet quality in periconception modifies the associations between maternal circulating concentrations of heavy metals and foetal growth.

DESIGN

Data of 72,317 Japanese women who delivered singleton infants was extracted from the Japan Environment and Children's Study. Maternal diet over a 1-year before the first trimester of pregnancy was assessed using a validated food frequency questionnaire, and overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Maternal whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were measured during the second/third trimester of pregnancy. Bayesian inference of multiple linear regression analysis was performed to evaluate the relationships between maternal diet quality and the blood concentrations of heavy metals; Bayesian logistic regression was used to analyse the risk of low birth weight (LBW; <2,500 g).

RESULTS

After controlling for confounders, a high maternal balanced diet score was associated with low concentrations of blood Pb and Cd and high Hg. While all heavy metals assessed were positively associated with LBW risk, a higher maternal balanced diet score was negatively associated with LBW risk. A high-quality maternal diet attenuated the effect of Pb on LBW, an effect that was more marked at high blood Pb concentrations.

CONCLUSION

A high-quality, 'well-balanced' diet prior to conception may reduce exposure to some heavy metals and mitigate the elevated risk of LBW associated with prenatal Pb exposure in Japanese mother-child pairs.

Dose-Response Relationships between Diet Quality and Mortality among Frail and Non-Frail Older Adults: A Population-Based Kyoto-Kameoka Prospective Cohort Study

OBJECTIVES

Although better diet quality is inversely associated with mortality risk, the association between diet quality and mortality remains unclear in frail and non-frail older adults. Thus, we aimed to examine this association in older Japanese adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We used the data of 8,051 Japanese older adults aged ≥65 years in the Kyoto-Kameoka study.

MESUREMENTS

Dietary intake was estimated using a validated food frequency questionnaire. Diet quality was evaluated by calculating the adherence scores to the Japanese Food Guide Spinning Top (range, 0 [worst] to 80 [best]), which were stratified into quartiles. Frailty status was assessed using the validated self-administered Kihon Checklist (KCL) and the Fried phenotype (FP) model. Survival data were collected between February 15, 2012 and November 30, 2016. Statistical analysis was performed using the multivariate Cox proportional hazard analysis and the spline model.

RESULTS

During the median 4.75-year follow-up (36,552 person-years), we recorded 661 deaths. After adjusting for confounders, compared with the bottom adherence score quartile, the top quartile was associated with lower hazard ratio (HR) of mortality in frailty (HR, 0.73; 95% confidence interval [CI], 0.54-1.00) and non-frailty, as defined by the KCL (HR, 0.72; 95% CI, 0.52-1.01). In the spline model, regardless of frailty status defined by the KCL and FP model, adherence score showed a strongly dose-dependent inverse association with mortality up to approximately 55 points; however, no significant differences were observed thereafter. This association was similar to the results obtained in individuals with physical, cognitive, and depression as domains of KCL in the spline model.

CONCLUSIONS

Our findings demonstrate an L-shaped association between diet quality and mortality in both frail and non-frail individuals. This study may provide important knowledge for improving poor diet quality in older individuals with frailty or domains of frailty.

Adherence to the food-based Japanese dietary guidelines and prevalence of poor oral health-related quality of life among older Japanese adults in the Kyoto-Kameoka study

Although better diet quality is inversely related to the risk of geriatric disorders, the association of adherence to dietary guidelines with oral health-related quality of life (OHRQoL) is unclear. We aimed to investigate this association in older Japanese adults. This cross-sectional study included 7984 Japanese participants aged ≥ 65 years from the population-based Kyoto-Kameoka study. Dietary intake was estimated using a validated self-administered FFQ. The scores for adherence to the Japanese Food Guide Spinning Top (range: 0 (worst) to 80 (best)) were calculated. These scores were stratified into quartiles (Qs). Poor OHRQoL was defined as a score ≤ 50 using a 12-item Geriatric Oral Health Assessment Index. The OR and 95 % CI were calculated using multivariable logistic regression and the spline model. Higher adherence score was associated with a lower prevalence of poor OHRQoL (Q1-Q4:36·0 %, 32·1 %, 27·9 % and 25·1 %, respectively). An inverse association was found between the score for adherence to the food-based Japanese dietary guidelines and the OR of poor OHRQoL among all the participants (Q1: reference; Q2: OR, 0·87 (95 % CI: 0·75, 1·00); Q3: OR, 0·77 (95 % CI: 0·66, 0·90); Q4: OR, 0·72 (95 % CI: 0·62, 0·85); P_{for trend} < 0·001). These relationships were similar to the results in the spline model. Higher adherence to the food-based Japanese dietary guidelines is inversely associated with the prevalence of poor OHRQoL in older adults. Our results may provide useful insights to improve and maintain oral health.

Dietary Patterns and Muscle Mass, Muscle Strength, and Physical Performance in the Elderly: A 3-Year Cohort Study

OBJECTIVES

Nutritional support effectively prevents and treats sarcopenia; however, the influence of overall dietary patterns on sarcopenia parameters is less investigated. This study aimed to determine the association between adherence to Mediterranean-style diet (MD), Dietary Approaches to Stop Hypertension (DASH), Japanese Food Guide Spinning Top (JFG-ST), and modified JFG-ST (mJFG-ST) and muscle mass, muscle strength, and physical performance in community-dwelling Japanese elderly.

DESIGN AND SETTINGS

This prospective cohort study recruited individuals aged over 60 years from a community college in Nagoya, Japan.

PARTICIPANTS AND MEASUREMENTS

A total of 666 participants were followed up annually from 2014 to 2017. Demographic data, anthropometric measurements, and sarcopenia parameters including walking speed (WS), hand grip strength in the dominant hand (HGS), and skeletal mass index (SMI) were recorded. Self-recall dietary intake was assessed using a validated food frequency questionnaire comprising 29 food groups. Adherence to MD, DASH, JFG-ST, and mJFG-ST was determined by tertiles.

RESULTS

At baseline, the mean age of all participants (56.5% women) was 69.4±4.4 years. WS, HGS, and SMI were 1.4±0.2 (m/s), 28.9±8.1 (kg), and 6.7±1.0 (kg/m2), respectively. In longitudinal analysis, participants with higher JFG-ST adherence scores were more likely to have higher SMI (Q3 vs. Q1: mean difference, 0.048; p=0.04) after adjustment, and its benefits were more evident in men (Q2 vs. Q1: mean difference, 0.098; p=0.047; Q3 vs. Q1: mean difference, 0.091; p=0.017) than in women. WS and HGS were not associated with any type of dietary pattern.

CONCLUSIONS

Adherence to JFG-ST was positively associated with SMI in Japanese community-dwelling elderly adults aged over 60 years, specifically in men. The country-specific dietary recommendations are required to be developed for sarcopenia prevention.

Diet Quality Affects the Association between Census-Based Neighborhood Deprivation and All-Cause Mortality in Japanese Men and Women: The Japan Public Health Center-Based Prospective Study

Background: Individuals residing in more deprived areas with a lower diet quality might have a higher mortality risk. We aimed to examine the association between deprivation within an area and all-cause mortality risk according to diet quality. Methods: We conducted a population-based prospective study on 27,994 men and 33,273 women aged 45–75 years. Neighborhood deprivation was assessed using the Japanese areal deprivation index (ADI). Dietary intakes were assessed using a validated 147-item food frequency questionnaire. Results: Individuals residing in the most deprived area had the lowest dietary scores. During the 16.7-year follow-up, compared to individuals with a high quality diet residing in the least deprived area, individuals with a low quality diet had a higher risk of mortality according to increment of ADI (p trend = 0.03); the multivariate-adjusted hazard ratio (95% confidence interval) was 1.09 (0.999–1.19), 1.17 (1.08–1.27), and 1.19 (1.08–1.32) in those residing in the lowest through the highest third of ADI, respectively. However, individuals with a high quality diet had no significant association between ADI and mortality. Conclusion: A well-balanced diet may prevent early death associated with neighborhood socioeconomic status among those residing in highly deprived areas.

Dietary Guidelines for Chinese Residents (2016): comments and comparisons

A high quality diet is believed to play a functional role in promoting the healthy growth of mankind and preventing many kinds of chronic degenerative diseases, including cancer, cardiovascular disease, diabetes, and obesity. Adherence to a high quality diet has been strongly associated with a lower risk of mortality. To help promote healthy lifestyles and physical strength, the Chinese government has produced a new revised version of the Dietary Guidelines for Chinese Residents (2016) and the Chinese Food Pagoda, as guidance for dietary intake among its population. Similarly, the Japanese government has produced the Japanese Food Guide Spinning Top Model, and the US government has recently published revised dietary recommendations in its 2015-2020 eighth edition of Dietary Guidelines for Americans. The evidence from all respective cohort studies involved in producing these guidelines shows a reduced risk of many chronic diseases and mortality if the guidelines are followed. All scientific findings support encouraging the general population to consume a broad variety of food on the basis of nutrient and food intakes in order to prevent deficiency diseases and a surplus of energy and nutrients, and recommend daily physical activity for health promotion.

Adherence to the food-based Japanese dietary guidelines in relation to metabolic risk factors in young Japanese women

While Japanese diets have attracted considerable attention because of, for example, the long-life expectancy in Japan, their health benefits have not been examined. In the present study, we cross-sectionally examined whether adherence to the food-based Japanese dietary guidelines is associated with metabolic risk factors in 1083 Japanese women aged 18-22 years. Based on the Japanese Food Guide Spinning Top, adherence to the food-based Japanese dietary guidelines was assessed using dietary information on consumed servings of grain dishes, vegetable dishes, fish and meat dishes, milk and fruits and energy from snacks and alcoholic beverages during the preceding month, which was derived from a comprehensive diet history questionnaire. Higher dietary adherence was associated with higher intakes of protein, carbohydrate, dietary fibre, Na, K and vitamin C, and lower intakes of total and saturated fat. There was also an inverse association between dietary adherence and dietary energy density. After adjustment for potential confounding factors, dietary adherence was inversely associated with waist circumference (P for trend = 0·002). It also showed an inverse association with LDL-cholesterol concentrations (P for trend = 0·04). There was no association with the other metabolic risk factors examined, including BMI, systolic and diastolic blood pressure, total and HDL-cholesterol, TAG, glucose, glycated Hb and insulin concentrations. In conclusion, higher adherence to the food-based Japanese dietary guidelines, which was characterised by favourable dietary intakes of foods and nutrients as well as lower energy density, was associated with lower waist circumference and LDL-cholesterol concentrations in this group of young Japanese women.