Positive Health Online

Abstract

HIGUCHI and COLLEAGUES, 1. Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Toon, Japan; Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan; 2. Department of Basic Nursing and Health Science, Ehime University Graduate School of Medicine, Toon, Japan. Electronic address: saitoi@m.ehime-u.ac.jp ; 3. Department of Basic Medical Research and Education, Ehime University Graduate School of Medicine, Toon, Japan; 4. Department of Public Health, Ehime University Graduate School of Medicine, Toon, Japan; Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; 5. Department of Public Health, Ehime University Graduate School of Medicine, Toon, Japan; 6. Center for Sleep Medicine, Ehime University Hospital, Toon, Japan; 7. Department of Clinical Laboratory Science, Faculty of Health Care, Tenri Health Care University, Tenri, Japan; 8. Faculty of Agriculture, Ehime University, Matsuyama, Japan; 9. Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan; Nishida Wataru Diabetes Clinic, Matsuyama, Japan; 10. Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan; 11. Department of Public Health, Juntendo University Graduate School of Medicine, Bunkyo, Japan studied the associations of serum β-carotene and retinol concentrations with glucose and insulin concentrations.

Background

Although green and yellow vegetables have beneficial effects against type 2 diabetes, the relationship of their nutritive content with insulin resistance is poorly understood. The aim of this study was to examine the associations of serum β-carotene and retinol concentrations with glucose and insulin concentrations.

Methodology

We recruited 951 Japanese men and women ages 30 to 79 yr who were not undergoing treatment for diabetes and measured their serum β-carotene and retinol concentrations. A 75-g oral glucose tolerance test was performed and the homeostasis model assessment for insulin resistance (HOMA-IR) and the Matsuda Index were calculated as measures of insulin resistance. Several confounding factors were adjusted for with multivariable logistic models.

Results

Multivariable-adjusted odds ratios of the highest quartile of serum β-carotene compared with the lowest quartile for HOMA-IR >1.6 and Matsuda Index <4.9 were 0.56 (95% confidence interval, 0.34-0.94) and 0.62 (0.37-1.02), respectively. When stratified by sex and overweight status, these associations were observed for women and non-overweight individuals. Serum retinol concentration was not associated with either index. Furthermore, according to the nutritional survey, serum β-carotene concentration was associated with green and yellow vegetable intake (P = 0.01).

Conclusion

Our findings suggest that higher serum β-carotene levels, associated with higher intake of green and yellow vegetables, confer beneficial effects against insulin resistance.

References

Higuchi K1, Saito I2, Maruyama K3, Eguchi E4, Mori H5, Tanno S6, Sakurai S7, Kishida T8, Nishida W9, Osawa H10, Tanigawa T11. Associations of serum β-carotene and retinol concentrations with insulin resistance: the Toon Health Study. Nutrition. 31(7-8):975-80. Jul-Aug 2015. doi: 10.1016/j.nut.2015.02.015. Epub Mar 24 2015.

Comment

The above research suggest that higher serum β-carotene levels along with higher intake of green and yellow vegetables are beneficial against insulin resistance.