Glycaemic responses to glucose and rice in people of Chinese and European ethnicity

Authors

  • M. Kataoka,

    1. Department of Human Nutrition, University of Otago, Dunedin, New Zealand
    2. Edgar National Centre for Diabetes and Obesity Research, Dunedin, New Zealand
    3. Riddet Institute, Massey University, Palmerston North, New Zealand
    Search for more papers by this author
  • B. J. Venn,

    1. Department of Human Nutrition, University of Otago, Dunedin, New Zealand
    Search for more papers by this author
  • S. M. Williams,

    1. Edgar National Centre for Diabetes and Obesity Research, Dunedin, New Zealand
    2. Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
    Search for more papers by this author
  • L. A. Te Morenga,

    1. Department of Human Nutrition, University of Otago, Dunedin, New Zealand
    2. Riddet Institute, Massey University, Palmerston North, New Zealand
    Search for more papers by this author
  • I. M. Heemels,

    1. Department of Human Nutrition, University of Otago, Dunedin, New Zealand
    Search for more papers by this author
  • J. I. Mann

    Corresponding author
    1. Edgar National Centre for Diabetes and Obesity Research, Dunedin, New Zealand
    2. Riddet Institute, Massey University, Palmerston North, New Zealand
    • Department of Human Nutrition, University of Otago, Dunedin, New Zealand
    Search for more papers by this author

Correspondence to: Jim I. Mann. E-mail: jim.mann@otago.ac.nz

Abstract

Aims

Diabetes rates are especially high in China. Risk of Type 2 diabetes increases with high intakes of white rice, a staple food of Chinese people. Ethnic differences in postprandial glycaemia have been reported. We compared glycaemic responses to glucose and five rice varieties in people of European and Chinese ethnicity and examined possible determinants of ethnic differences in postprandial glycaemia.

Methods

Self-identified Chinese (n = 32) and European (n = 31) healthy volunteers attended on eight occasions for studies following ingestion of glucose and jasmine, basmati, brown, Doongara® and parboiled rice. In addition to measuring glycaemic response, we investigated physical activity levels, extent of chewing of rice and salivary α-amylase activity to determine whether these measures explained any differences in postprandial glycaemia.

Results

Glycaemic response, measured by incremental area under the glucose curve, was over 60% greater for the five rice varieties (P < 0.001) and 39% greater for glucose (P < 0.004) amongst Chinese compared with Europeans. The calculated glycaemic index was approximately 20% greater for rice varieties other than basmati (P = 0.01 to 0.05). Ethnicity [adjusted risk ratio 1.4 (1.2–1.8) P < 0.001] and rice variety were the only important determinants of incremental area under the glucose curve.

Conclusions

Glycaemic responses following ingestion of glucose and several rice varieties are appreciably greater in Chinese compared with Europeans, suggesting the need to review recommendations regarding dietary carbohydrate amongst rice-eating populations at high risk of diabetes.

Ancillary