Hiroyuki Takeuchi

Preventing lifestyle-related diseases requires understanding and managing the intake of total fats and specific types of fatty acids, especially trans fatty acids. There are several methods for measuring fat intake, each with its own strengths and limitations. Guidelines for nutritional epidemiology studies recommend employing objective biomarkers. This study aimed to estimate fatty acid intake based on serum fatty acid levels using multiple regression analysis and a machine learning technique, and to compare their accuracy. The subjects were healthy women aged 18 to 64 living in Toyama, Japan. A dietary survey to determine fatty acid intake was conducted using a 3-day dietary record completed by the participant. Blood samples were collected after an overnight fast, and serum was obtained through centrifugation. A total of 300 women participated in the study. The fatty acid levels in serum were determined using gas chromatography with a capillary column. Using multiple regression analysis and neural networks, the intakes of saturated, monounsaturated, n-6 polyunsaturated, n-3 polyunsaturated, and trans fatty acids from serum fatty acid levels were predicted. Significant correlations were observed between the intakes of the five classified fatty acids and the predicted intakes obtained from the multiple regression analysis (r = 0.39 - 0.49, p < 0.01). Significant correlations were also observed between the five classified fatty acid intakes and the intakes predicted by the neural network (r = 0.52 - 0.79, p < 0.01), and the correlation coefficient showed a significantly higher value than that predicted by the multiple regression analysis. These results suggest that serum fatty acid levels may be used as biomarkers to estimate the intake of fatty acids, including that of trans fatty acids, and that machine learning may be able to predict fatty acid intake with higher accuracy than multiple regression analysis.

Hypertension is one of the most prevalent diseases and a risk factor for stroke and cardiovascular disease. Our previous study indicated a negative correlation between fat intake and blood pressure in subjects with a fat mass and obesity-associated gene variant. We investigated the effects of four fatty acid groups on blood pressure in healthy Japanese women with the gene variants, including the involvement of body mass index. A total of 227 Japanese women aged 18–64 years completed a 3-day nutritional intake diary and their blood pressure was measured. The single nucleotide polymorphism rs9939609 of the gene was genotyped, and the participants were divided into two genetic groups (those with or without at least one minor allele). Spearman’s rank correlation coefficient was applied to investigate the relationships between the fatty acids and blood pressure. A path analysis was performed to determine the effect of fatty acids on blood pressure including the involvement of body mass index. In the group with the gene variant, a significant negative correlation was detected between saturated fatty acid intake and systolic and diastolic blood pressures, and between monounsaturated fatty acid intake and only diastolic blood pressure. In a path analysis of both systolic and diastolic blood pressures, the path from only saturated fatty acid intake to blood pressure was significant, but the path from saturated fatty acids to body mass index was not significant. These results suggest that saturated fatty acid intake, without the involvement of body mass index, may be associated with the lower systolic and diastolic blood pressures in healthy Japanese women with a fat mass and obesity-associated gene variant.

Background and Objectives: The excessive intake of trans fatty acids increases serum low-density lipoproteincholesterol and reduces high-density lipoprotein-cholesterol. We studied the effects of 1% energy trans fatty acid supplementation on serum lipid concentrations in healthy adult Japanese with different obesity-related gene polymorphisms. Methods and Study Design: A randomized, double-blind, parallel trial was conducted in 53 healthy adults. The volunteers consumed one cookie containing either 1% energy or <0.01% energy (control) of trans fatty acids every day for 4 weeks, and a blood sample was then obtained after overnight fasting. The single nucleotide polymorphisms of the fat mass- and obesity-associated gene rs9939609 and beta-3 adrenergic receptor rs4994 were genotyped. Results: The mean trans fatty acid intake of the control and trans fatty acid groups corresponded to 0.28% and 1.31 % energy, respectively. There were no significant differences in serum cholesterol (total, low-density lipoprotein and high-density lipoprotein) or triacylglycerol between the control and trans fatty acid groups. The responses of serum cholesterol, triacylglycerol, glucose, insulin and hemoglobinAlc were also independent of the fat mass- and obesity-associated gene and beta-3 adrenergic receptor gene variants. Conclusions: Our findings indicate that supplementation with 1% energy trans fatty acids has little effect on serum cholesterol in healthy adult Japanese, regardless of genotype of fat mass- and obesity-associated gene or beta-3 adrenergic receptor. More systematic studies, with respect to dietary trans fatty acid intakes above those used here, may be warranted to determine the tolerable upper level of dietary trans fatty acid.

Transfatty acid (TFA) from partially hydrogenated oil is regarded as the worst dietary fatty acid per gram due to its role in coronary heart disease. TFA consumption is decreasing worldwide, but some but not all observational studies indicate that TFA intake has little relevance to serum cholesterol levels in populations with low TFA intake (E[percentage of total energy intake], E); no definite evidence is available on the tolerable upper level of the intake. A series of our intervention studies in Japanese suggested that an industrial TFA intake at Edoes not influence the serum cholesterol level. To establish allowable level, we must consider not only the dietary level of TFAs, but also the composition of dietary fats simultaneously consumed, that is, saturated and unsaturated fatty acids. These fatty acids strengthen or counteract the adverse effect of TFAs on serum cholesterol levels. In this review we describe the complex situation of the cardiovascular effects of industrial TFAs. The relationship between dietary industrial TFAs and concentration of plasma cholesterol should be evaluated from the viewpoint of dietary patterns rather than TFAs alone.　

The excessive intake of trans fatty acids (TFAs) increases serum LDL-cholesterol and reduces HDL-cholesterol. Limited data exist regarding the low-level intake of TFAs, and the tolerable upper-limit level remains to be fully elucidated. A randomized, double-blind, parallel trial was conducted to assess the effects of a low level of TFA supplementation on serum cholesterol levels in healthy adult Japanese women. The volunteers who participated in this examination took in approximately 0.4% of energy (%E) TFAs from daily meals. Fifty-one volunteers consumed one cookie containing 0.6%E (TFA) or 0.04%E (control) of TFAs every day for 4 wk, and blood was harvested after overnight fasting. The mean TFA intakes of the control and TFA groups during the experimental period were 0.4%E and 1.1%E, respectively. There were no significant differences in serum total, LDL- or HDL-cholesterol levels between the control and TFA groups. The serum glucose and insulin levels were not influenced by TFA supplementation. These results confirm that dietary supplementation with 0.6%E TFAs (a total TFA intake of approximately 1%E) would have little effect on serum cholesterol levels in healthy adult Japanese women.

【目的】トランス脂肪酸（トランス酸）の摂取は，血清LDL-コレステロール濃度を増加させ，動脈硬化性疾患のリスクを高める。日本人を対象にしたトランス酸の摂取量調査および目標量（上限）に関する研究は，限られている。本研究では日本人成人女性におけるトランス酸摂取量の調査を行い，血清コレステロール濃度との関連について検討した。 【方法】30～60歳代の日本人女性54名を対象に，3日間の食事調査を実施した。空腹時に採血を行い，血清脂質濃度を測定した。 【結果】対象者のトランス酸摂取量の中央値は0.36％エネルギー（％E）であり，平均値は 0.40％Eであった。トランス酸摂取量の最大値は1.47％Eであり，1％Eを超えた被験者は1名だけであった。脂質摂取量とトランス酸摂取量との間に，有意な正の相関が認められた。血清LDL-およびHDL-コレステロール濃度とトランス酸摂取量との間には，有意な相関はなかった。 【結論】本研究では，本研究対象者の日本人成人女性が摂取しているトランス酸量は1％E以下であり，この低レベル（％E）のトランス酸摂取では，健常人において血清コレステロール濃度に対して大きな影響を及ぼさない可能性のあることが示唆された。

The World Health Organization (WHO) has recommended that trans fatty acid (TFA) intake should be less than 1% of total energy intake, but few data are available as to the influence of energy TFA intake of as low as 1% on blood cholesterol levels. A randomized, double-blind, parallel trial was conducted to assess the effects of 1% TFA dietary supplementation on serum cholesterol levels in healthy young women. Sixty-five volunteers consumed cookies containing 1% (TFA) or 0.04% (control) energy of TFA for 4 weeks and blood was harvested after overnight fasting. There were no significant differences in serum LDL- or HDL-cholesterol levels between the two groups. The hemoglobin A1c level was not influenced by dietary TFA. These results suggest that energy of TFAs at less than 1% has little effect on serum cholesterol or hemoglobin A1c levels in healthy young women. This confirms the correctness of the WHO recommendation.

There are very limited data concerning the influence of low-level trans fatty acid (TFA) intake on blood lipid levels. In this study, correlation of total and diene TFA intake with serum cholesterol levels was studied in young Japanese women. The mean intakes of total and diene TFAs were 0.36% and 0.05% of energy, respectively. There was a significant correlation between total fat intake and TFA intake. TFA intake was significantly correlated with erythrocyte TFA content. Total TFA intake was not correlated with total, LDL- or HDL-cholesterol levels. No correlatuon was found between diene TFA intake and cholesterol level. Total and diene TFA intake were not correlated with hemoglobin A1c or C-reactive protein levels. These results suggest that the average TFA intake of young Japanese women does not adversely affect serum cholesterol levels.

A randomized crossover study in healthy young Japanese showed no significant effects of a 0.6% energy trans fatty acid (TFA) intake on the serum cholesterol concentrations and parameters of glucose metabolism. The results indicate that TFAs at this dietary level may have no adverse metabolic effects on healthy young Japanese.