Antioxidant Capacities of Plant-Derived Foods Commonly Consumed in Japan

Antioxidant potential of the diet in Italian children with food allergies

A reduced fruit and vegetable consumption, which implies a decreased intake of antioxidant compounds, seems to play a role in allergic diseases onset. Data on the antioxidant capacity of diet in children with food allergies, who are on an avoidance diet, are still lacking. This pilot study aims to assess the antioxidant potential of diet in Italian children with food allergies, compared to healthy children, using the oxygen radical absorbance capacity (ORAC) method. 95 children (54 with confirmed food allergies and 41 controls), with a median age of 7.8 years, were enrolled and underwent a nutritional assessment. Mean nutrient intakes were compared using the Mann–Whitney test. ORAC resulted significantly lower in allergic children (median 2,908, IQR: 1450;4,716) compared to control children (median 4,392, IQR: 2523;5,836; p = 0.049). Among micronutrients with antioxidant properties, vitamin A intakes were significantly higher in controls than in allergic children. Using Spearman’s correlation, a moderate-to-strong correlation between ORAC and vitamin C, potassium and magnesium was observed (ρ = 0.648, p < 0.001; ρ = 0.645, p < 0.001; ρ = 0.500, p < 0.001, respectively). Iron, phosphorus, vitamin E and vitamin A intakes were also moderately-to-low correlated with ORAC values (ρ = 0.351, p < 0.001; ρ = 0.367, p < 0.001; ρ = 0.346, p < 0.001; and ρ = 0.295, p = 0.004, respectively). We hypothesize that the reduced antioxidant potential of the diet might be related to a reduced variety of the diet in children with food allergies. Our study suggests that the diet of children with food allergies has a lower antioxidant potential (expressed as ORAC value) compared to the diet of healthy children, regardless of the allergenic food excluded from the diet. This issue should be further investigated in prospective, powered studies.

Garland chrysanthemum consumption ameliorates age-related hearing loss in C57BL/6 mouse; model system to explore hearing loss prevention foods in a short period

Garland chrysanthemum (Glebionis coronaria L.) is an antioxidant-rich leafy vegetable. We found that garland chrysanthemum consumption ameliorated age-related hearing loss (AHL) in C57BL/6J mice, an early onset model. We also found that AHL progression was significantly ameliorated by three of ten products. Metabolome analysis of the 10 products using nuclear magnetic resonance (NMR) spectroscopy indicated that phytosterols may be involved in the amelioration of AHL. However, the direct inhibitory effect of phytosterol mixture on mouse AHL progression was not identified. These results suggest that garland chrysanthemum consumption delays AHL development in mice and its efficiency varies depending on the source of product. Our findings also suggest that phytosterol content in garland chrysanthemum function as an evaluation marker for the efficiency. Furthermore, to accelerate the search for foods that prevent AHL, we have used these data to develop an automatic threshold determination method for auditory brainstem response using machine learning.

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.