[A Study on the Scientific Reliability of Notification Data in the Foods with Function Claims].

We conducted a comprehensive survey of Foods with Function Claims (FFC) submitted from April to August 2022 to examine the scientific reliability of the systematic review (SR), which is the basis for functional claims. The results of the review of 611 functional claims for 398 products showed that there were 121 functionally active substances and 87 health claims (Hc) that were labeled, with some functionally active substances having multiple functions. SRs, meta-analyses, and clinical studies were submitted as the basis of functionality for 87%, 10%, and 3% of the reports, respectively. Of these SRs, 39% of the SRs included a single paper. In 67% of the SRs with a single paper included, some of the authors of the included paper and the person who conducted the SR had the same affiliation, which raises concerns about conflicts of interest. The median of clinical trial participants in papers included for SR was relatively small, 38, and the smallest total number of SRs was 6. Thus, it was shown that there are many SRs for FFC that are based on only a single paper or a small-scale clinical trial and that lack reliability as scientific evidence.

The Major Source of Antioxidants Intake From Typical Diet Among Rural Farmers in North-eastern Japan in the 1990s.

BACKGROUND: Previous Japanese studies have led to the erroneous conclusion of antioxidant capacity (AOC) intakes of the overall Japanese diet due to limitations in the number and types of food measured, especially in rice and seafood intake. The aims of the study were to construct an AOC database of foods representative of the typical Japanese diet and to clarify the high contributors to AOC intake from the overall diet of the Japanese population. METHODS: Commonly consumed foods were estimated using 3-day dietary records (DRs) over the four seasons among 55 men and 58 women in Japan. To generate an AOC database suitable for the typical Japanese diet, hydrophilic (H-)/lipophilic (L-) oxygen radical absorbance capacity (ORAC) values of foods in each food group were measured via validated methods using the food intake rankings. Subsequently, we estimated the AOC intake and the AOC characteristics of a typical Japanese diet. RESULTS: Of 989 food items consumed by the participants, 189 food items were measured, which covered 78.8% of the total food intake. The most commonly consumed types of antioxidant-containing food were tea, soybean products, coffee, and rice according to H-ORAC, and soybean products, fish and shellfish, vegetables, and algae according to L-ORAC. CONCLUSIONS: The characteristics of high AOC intake in rice and seafood more appropriately reflected the Japanese-style diet. Further studies are expected to clarify the association between food-derived AOC and its role in preventing or ameliorating lifestyle-related diseases.

[Method Verification for Vitamin D Analysis in Processed Foods Based on the Analytical Manual for the Standard Tables of Food Composition in Japan 2015 (Seventh Revised Edition)].

Considerable amounts of processed foods contain vitamin D (ergocalciferol (D2) and cholecalciferol (D3)) as food additives. For field surveys on food additives, the analytical method for vitamin D should be well-validated. However, the current official method in Japan cannot separately determine the concentrations of D2 and D3, whereas the method for the Standard Tables of Food Composition in Japan 2015 (STFC method) can. Therefore, in this study, we verified the applicability of the STFC method to processed foods. During the course of this research, we added some improvements to the original method. Spike and recovery experiments using vegetable juice, soymilk, and corn flakes as food matrices showed that the recovery rates (relative standard deviation) of D2 and D3 were 103-112% (4.7-12.6%) and 102-109% (2.4-21.8%), respectively, at the estimated method limit of quantification (EMLOQ) level; and 100-110% (4.0-7.4%) and 102-105% (3.8-4.8%), respectively, at 10 times the EMLOQ level. These results indicated that accuracy and precision of the modified STFC method were enough to determine dietary D2 and D3 as endogenous nutrients and/or food additives, and suggested that this method is appropriate for analyzing vitamin D concentrations in processed foods.

[Proficiency Testing Schemes for Food Nutrition Analysis in Japan (2017-2018)].

This paper deals with proficiency testing schemes for food nutrition analysis in Japan. In schemes in 2017 and 2018, 65 and 73 organizations participated, respectively, and more than 70% of the participants were public organizations responsible for a nutrition-labeling compliance test. The food matrices were pork and chicken sausages, and analytes were protein, fat, ash, moisture, carbohydrate, energy, sodium, salt equivalent, calcium (2018 only), and iron (2018 only). The organizations reporting inadequate laboratory values in one or more nutrients for mandatory declaration (energy, protein, fat, carbohydrate, or salt equivalent) were 11 and 15% of all organizations and 9 and 13% of public organizations in the 2017 and 2018 schemes, respectively. The approximate relative standard deviations for proficiency assessment (RSDr) were as follows: protein, 2%; fat, 3%; ash, 2%; moisture, 0.5%; carbohydrate, 9%; energy, 1%; sodium (salt equivalent), 4%; calcium, 7%; and iron, 7%. Notably, the large RSDr value for carbohydrate may cause inconsistency among laboratories in compliance tests for foods containing several grams or less of carbohydrate per 100 grams.

Safety and Efficacy Assessment of Isoflavones from Pueraria (Kudzu) Flower Extract in Ovariectomised Mice: A Comparison with Soy Isoflavones.

Numerous Foods with Function Claims that contain the extract of Pueraria flower (kudzu) isoflavones (PFI) are available in the Japanese market. These are labelled with function claims of reducing visceral fat. However, these foods have not undergone proper safety assessment such as the evaluation of their oestrogenic activity and effects on drug-metabolising enzymes (cytochrome P-450: CYP) in the liver. This study evaluated the estrogenic effect and the hepatic CYP activity and mRNA expression in normal female mice as a safety assessment of PFI (Experiment 1). In addition, the bone mineral density and visceral fat weight in ovariectomised mice (OVX) compared to soy isoflavones (SI) was evaluated to assess the efficacy of PFI (Experiment 2). OVX control fed a control diet, OVX fed a PFI diet (the recommended human intake of PFI), OVX fed a PFI20 diet (20- times the recommended PFI), OVX fed an SI diet (the recommended human intake of SI), and OVX fed an SI20 diet (20 -times the recommended intake of SI) for 28 days in Experiment 2. Body, liver, and visceral fat weights were not affected by the PFI, PFI20, SI, or SI20 diets. The hepatic CYP1A and CYP3A activities were elevated by the SI20 treatment. Ovariectomy-induced bone loss was inhibited by the SI20 treatment, but not by the PFI20 treatment. These results suggest that (1) PFI intake in human doses had no oestrogenic properties and did not affect CYP activity in the liver; (2) there was no evidence that PFI affects the amount of visceral fat in OVX mice.

[Improved Reliability of Vitamin Analysis in Foodstuffs Using a Microbiological Assay Method: Construction of Calibration Curves Using Logistic Modeling].

Vitamins are essential nutrients for human beings. Therefore, accurate determination of vitamin levels in foodstuffs is vital to confirm the proper intake of vitamins. The microbiological assay (MBA), which is used worldwide for the determination of several vitamins in foodstuffs, is very sensitive and can determine ng/mL levels of vitamins. However, the correlation between vitamin concentrations in a sample solution and the plotted growth is usually shown as a sigmoid curve. Therefore, a calibration curve derived from a linear regression may lead to error. In this study, we evaluated the effects of various models (linear, quadratic, and cubic regression models and a four-parameter logistic model (4PLM)) for calibration curve construction on the determination of vitamin B6 in infant formula. Among the four models, the calibration curve constructed with 4PLM was the most reliable for vitamin B6 determination. Moreover, the calibration curve based on 4PLM showed robustness for extrapolation; even if the vitamin concentration in the sample solution deviated from the range of the standard solution, a reasonable result could be obtained. Similarly, the 4PLM calibration curve was the most reliable for niacin determination. We conclude that 4PLM should be used for calibration curve construction to improve the reliability of vitamin determination in foodstuffs using MBA.

Association between an Antioxidant-Rich Japanese Diet and Chronic Kidney Disease: The Ohasama Study.

AIMS: Although physiological effects of hydrophilic- (H-) and lipophilic- (L-) antioxidant capacities (AOCs) are suggested to differ, the association of an antioxidant-rich diet and chronic kidney disease (CKD) incidence has not been examined. We therefore explored the association between the H- or L-AOC of a whole Japanese diet and CKD risk in a general population. METHODS: A total of 922 individuals without CKD (69.2% women; mean age, 59.5 years old) from Ohasama Town, Japan, were examined. CKD incidence was defined as the presence of proteinuria and/or an estimated glomerular filtration rate (eGFR) of ＜60 ml/min/1.73 m2. Consumption of H-/L-AOC was determined based on the oxygen radical absorbance capacity in a specially developed Japanese food AOC database. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for new-onset CKD using a Cox proportional hazards model. RESULTS: During the median follow-up of 9.7 years, 137 CKD incidents were recorded. After adjusting for potential confounding variables, the highest quartile of L-AOC was significantly associated with a 51% reduced CKD risk among only women. An increased L-AOC intake was more effective in preventing eGFR reduction than in preventing proteinuria in women. These associations were not seen for H-AOC intake in both sexes and L-AOC intake in men. CONCLUSIONS: A high intake of lipophilic antioxidants may be associated with a reduced CKD risk. The balance between dietary antioxidant intake and pro-oxidants induced by unhealthy lifestyles may be crucial for preventing future kidney deterioration.

Improvement of the lipophilic-oxygen radical absorbance capacity (L-ORAC) method and single-laboratory validation.

We improved the procedure for lipophilic-oxygen radical absorbance capacity (L-ORAC) measurement for better repeatability and intermediate precision. A sealing film was placed on the assay plate, and glass vials and microdispensers equipped with glass capillaries were used. The antioxidant capacities of food extracts can be evaluated by this method with nearly the same precision as antioxidant solutions.

Evaluation of cyanocobalamin in multivitamin tablets and their Standard Reference Material 3280 by HPLC with visible detection.

As a part of the development of an alternative to microbiological assay for vitamin B12, we performed a quantitative analysis of cyanocobalamin (CN-cbl) in a National Institute of Standards and Technology Standard Reference Material (SRM 3280) by HPLC. Using this method, the observed value (4.64 microg/g) of CN-cbl in SRM 3280 was found to be in good agreement with the certified value (4.80 microg/g). The accuracy was over 95%, with a corresponding measurement precision value of 5%. To evaluate the applicability of the method on commercial multivitamin tablets, the method was applied to a variety of these samples. The present method has a good accuracy and precision to evaluate CN-cbl with respect to all of the examined tablets.

Reliability in viscosity measurement of thickening agents for dysphagia management: Are results obtained by cone-and-plate rheometers reproducible between laboratories?

Viscosity measurement using a cone-and-plate rheometer is considered to provide an objective and reliable evaluation of thickening agents for dysphagia management. Here, we showed its measurement uncertainty in the context of an inter-laboratory study. Eight test samples (i.e., four viscosity standard liquids, one xanthan gum reagent powder, and three commercial thickening agent powders) were distributed to 10 laboratories in a blinded manner. According to the same standard operating procedure, each laboratory dissolved the xanthan gum or thickening agents at four concentrations (0.5-4.0 g/100 g) and then measured their viscosity (35-803 mPa∙s). As for the viscosity of the standard liquids, the grand means were 98-100% of the certified values, and the relative standard deviations for repeatability (RSDr ) and reproducibility (RSDR ) were ca. 1% and ca. 5%, respectively, suggesting good accuracy in the measurement process. On the other hand, as for the viscosity of the thickening agents, RSDr and RSDR were ca. 2-6% and ca. 5-8%, respectively; however, heterogeneity in the preparation process comprising a manual dissolving step may increase these to near 60%. Furthermore, RSDr and RSDR of estimated additive concentrations to achieve targeted viscosities (50-500 mPa∙s) based on concentration-viscosity curves were ca. 1-3% and ca. 3-5%, respectively, with a few exceptions. These findings suggest that a strictly standardized procedure provides reliable data on the viscosity measurements for thickening agents.

Nutrient Profiles of Dishes Consumed by the Adequate and High-Salt Groups in the 2014-2018 National Health and Nutrition Survey, Japan.

Dish-based nutrient profile analyses are essential for setting goals to achieve a balanced diet. In 2014, the Japanese government proposed the "Healthy Meal" criteria, which requires a salt content of 3 g/650 kcal per meal. To examine the current intake status of a nationally representative sample, we conducted a series of secondary analyses of the 2014-2018 National Health and Nutrition Survey data. Participants (aged 18-74 years) were grouped as "high-salt" consumers if their salt intake was 3 g/650 kcal or higher and "adequate" consumers if they consumed less than 3 g/650 kcal. A total of 13,615 participants were identified as "adequate" consumers and 22,300 as "high-salt" consumers. The median salt intake in the "high-salt" group was 11.3 g/day, while that in the "adequate" group was 7.5 g/day. Almost all dishes consumed by the "adequate" group had significantly high energy and fat content but low salt content, compared with those consumed by the "high-salt" group. For example, the median energy, fat, and salt contents in the main dishes consumed by the "adequate" group were 173 kcal, 10.4 g, and 0.9 g/dish, respectively, while those in the main dishes consumed by the "high-salt" group were 159 kcal, 8.9 g, and 1.1 g/dish, respectively. Examples of balanced dishes that are low in both salt and fat content can be proposed to help improve the Japanese consumers' dietary behavior.

Estimated average daily intake of antioxidants from typical vegetables consumed in Japan: a preliminary study.

The hydrophilic antioxidant content of 23 vegetables commonly consumed in Japan was assessed by the hydrophilic oxygen radical absorbance capacity (H-ORAC) method to estimate the dietary intake of total antioxidants in Japan. The estimated average H-ORAC value for "typical vegetables" consumed in Japan was 594.3 µmol Trolox equivalent (TE)/100 g. Hence, 2080 µmol TE/d of hydrophilic antioxidants would be ingested when 350 g of vegetables a day are consumed.

Assessment of safety and efficacy of pine bark extract in normal and ovariectomized mice.

We evaluated the influence of pine bark extract (PBE) on organs, the cytochrome-P450 (CYP) activities in liver and estrogenic effects in normal and ovariectomized (OVX) female mice. The PBE did not affect organ weights and liver-function indexes (activities of alkaline phosphatase, aspartate amino transferase, and alanine amino transferase) at doses; 0.04%, 0.4%, and 2.0% PBE in the diet, in normal and OVX female mice. In the OVX mice, CYP1A1 activity was significantly higher in the 0.4% and 2.0% PBE groups than in the OVX control group, and in the 0.4% and 2.0% PBE groups were significantly higher than in the 0.04% PBE group. CYP1A2 and 3A4 activities were significantly higher in the 2.0% PBE group than in all other groups. The PBE did not affect uterine weight and femoral bone mineral density at all PBE doses. These results showed that the dose of PBE at the recommended human intake, had no toxic and estrogenic effects in normal female and OVX mice, however, it may need attention to use the excess intake of PBE with some drugs in postmenopausal women.

Antioxidant Capacities of Plant-Derived Foods Commonly Consumed in Japan.

To provide reliable data for high quality epidemiological studies examining the relationship between health and antioxidant intake from daily foods, 107 plant-derived food items (12 rice, bread and noodles, 5 potatoes and starches, 9 pulses, 6 nuts/seeds, 29 vegetables, 22 fruits, 5 mushrooms, 7 algae, and 12 beverages) were selected as commonly consumed foods in Japan based on dietary records, and their antioxidant capacities were evaluated by validated hydrophilic- and lipophilic-oxygen radical absorbance capacity (H-ORAC and L-ORAC) methods. The food items covered more than 60% of total food intake for each category on a weight basis. The H-ORAC and L-ORAC values were widely distributed at 0-210 and 0-30 µmol-Trolox equivalent/g, respectively. The foods possessing potent antioxidant capacities were found in vegetables and fruits as well as other plant-derived foods. In most foods measured, the H-ORAC values were much larger than the L-ORAC values, except for certain kinds of pulses, nuts/seeds, mushrooms, and algae. The ORAC data shown here is sufficient to accurately estimate the antioxidant intake from plant-derived foods in Japan, and should be useful in future epidemiological studies aiming to clarify the biological significance of ORAC values.

Tandem Cation/Anion Exchange SPE Cartridge Method for Sample Desalting for HPLC Analysis of Soluble Dietary Fiber: Development and Inter-laboratory Validation.

In HPLC analyses of soluble dietary fiber, desalting processes using open, mixed-bed ion-exchange columns are time-consuming and labor-intensive. We developed and validated a simple desalting method using tandem cation/anion exchange SPE cartridges. We found that combining Bond Elut Jr SCX (upstream) and Bond Elut PSA (downstream) cartridges provided adequate desalting of test solutions. The developed method was then validated in an inter-laboratory study. Five test samples were prepared by mixing food matrixes with purified soluble dietary fiber and treated to generate solutions to test the desalting process. These solutions were then analyzed by eight different laboratories. The results demonstrated that the developed method is simple and reliable for desalting samples containing 140 to 945 mg/100 mL of soluble dietary fiber in preparation for HPLC analysis of soluble dietary fiber.

A redox-silent analogue of tocotrienol inhibits hypoxic adaptation of lung cancer cells.

We have previously reported that a redox-silent analogue of alpha-tocotrienol (T3), 6-O-carboxypropyl-alpha-tocotrienol (T3E) shows more potential anti-carcinogenic property than T3 in a lung cancer cell (A549 cell). However, the mechanisms by which T3E exerts its potential anti-carcinogenic effect is still unclear. As tumor malignancy is associated with hypoxia adaptation, in this study, we examined whether T3E could suppress survival and invasion in A549 cells under hypoxia. Hypoxia treatment drastically-induced activation of the protein tyrosine kinase, Src, and its regulated signaling required for hypoxia adaptation of A549 tumor cells. The survival and invasion capacity of the tumor cells under hypoxia was suppressed by T3E via the inactivation of Src. More specifically, T3E-dependent inhibition of Src-induced Akt activation contributed to suppression of cell survival under hypoxia, and the reduction of fibrinolytic factors such as plasminogen activator-1(PAI-1) via the decrease of hypoxia-inducible factor-2alpha by T3E led to inhibition of hypoxic invasion. Overall these results suggest that T3E suppresses hypoxia adaptation of A549 cells by the inhibition in hypoxia-induced activation of Src signaling.

Antioxidant properties of 2-O-beta-D-glucopyranosyl-L-ascorbic acid.

The antioxidant activity of a provitamin C agent, 2-O-beta-D-glucopyranosyl-L-ascorbic acid (AA-2betaG), was compared to that of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and ascorbic acid (AA) using four in vitro methods, 1,1-diphenyl-picrylhydrazyl (DPPH) radical-scavenging assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*+))-scavenging assay, oxygen radical absorbance capacity (ORAC) assay, and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis inhibition assay. AA-2betaG slowly and continuously scavenged DPPH radicals and ABTS(*+) in roughly the same reaction profiles as AA-2G, whereas AA quenched these radicals immediately. In the ORAC assay and the hemolysis inhibition assay, AA-2betaG showed similar overall activities to AA-2G and to AA, although the reactivity of AA-2betaG against the peroxyl radical generated in both assays was lower than that of AA-2G and AA. These data indicate that AA-2betaG had roughly the same radical-scavenging properties as AA-2G, and a comprehensive in vitro antioxidant activity of AA-2betaG appeared to be comparable not only to that of AA-2G but also to that of AA.

Inhibition of free radical-induced erythrocyte hemolysis by 2-O-substituted ascorbic acid derivatives.

Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was AA-2S> or =Trolox=uric acid> or =AA-2P> or =AA-2G=AA>glutathione. Although the reactivity of the AA derivatives against AAPH-derived peroxyl radical (ROO(*)) was much lower than that of AA, the derivatives exerted equal or more potent protective effects on AAPH-induced hemolysis and membrane protein oxidation. In addition, the AA derivatives were found to react per se with ROO(*), not via AA as an intermediate. These findings suggest that secondary reactions between the AA derivative radical and ROO(*) play a part in hemolysis inhibition. Delayed addition of the AA derivatives after AAPH-induced oxidation of erythrocytes had already proceeded showed weaker inhibition of hemolysis compared to that of AA. These results suggest that the AA derivatives per se act as biologically effective antioxidants under moderate oxidative stress and that AA-2G and AA-2P may be able to act under severe oxidative stress after enzymatic conversion to AA in vivo.

Effect of docosahexaenoic acid intake on lipid peroxidation in diabetic rat retina under oxidative stress.

Docosahexaenoic acid (DHA) plays an important role in visual function but has a highly oxidation-prone chemical structure. Therefore, we investigated how dietary DHA affects the generation of lipid peroxides in rat retina under oxidative stress in diabetes with/without vitamin E (VE) deficiency. Streptozotocin-induced (50 mg i.p./kg B.W.) diabetic Sprague-Dawley (SD) rats were assigned to four groups: (i) control/VE(+), (ii) DHA/VE(+), (iii) control/VE( - ) and (iv) DHA/VE( - ), and raised for 28 days. We then measured lipid peroxide levels in the retina, serum and liver. With a normal intake of VE, dietary DHA increased only the retinal level of thiobarbituric acid-reactive substances (TBARS) slightly. In contrast, in rats with VE deficiency, dietary DHA increased serum and liver lipid peroxide levels but not in the retina. These results suggest that dietary DHA does not necessarily promote lipid peroxidation in the retina even under high oxidative stress.

An isocratic HPLC method for the simultaneous determination of novel stable lipophilic ascorbic acid derivatives and their metabolites.

2-O-alpha-D-glucopyranosyl-6-O-hexadecanoyl-L-ascorbic acid (6-sPalm-AA-2G), a novel stable lipophilic ascorbic acid derivative, was hydrolyzed to 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G), ascorbyl 6-palmitate (6-sPalm-AA) and ascorbic acid (AA) with alpha-glucosidase and lipase. An HPLC method for the simultaneous determination of AA, AA-2G, 6-sPalm-AA and 6-sPalm-AA-2G was developed using a cyanopropyl column with an isocratic solution of methanol-phosphate buffer (pH 2.1) (65:35, v/v) containing 20mg/l of dithiothreitol at a detection wavelength of 240 nm. The calibration curves were found to be linear in the range of 10-200 microM. Linear regression analysis of the data demonstrated the efficacy of the method in terms of precision and accuracy. This method was satisfactorily applied to the determination of 6-sPalm-AA-2G and its three metabolites in a 6-sPalm-AA-2G solution treated with purified enzymes or a small intestine post-mitochondrial supernatant and to the separation of novel stable lipophilic AA derivatives other than 6-sPalm-AA-2G and their metabolites. AA, AA-2G and other well-known stable AA derivatives, ascorbic acid 2-phosphate and ascorbic acid 2-sulfate, were also separated under the same conditions. The results show that the procedure is rapid and simple and that it can be employed for in vitro metabolic analysis of various AA derivatives.