Antioxidant flavonols and ischemic heart disease in a Welsh population of men: the Caerphilly Study

Am J Clin Nutr. 1997 May;65(5):1489-94. doi: 10.1093/ajcn/65.5.1489.

Abstract

Antioxidant flavonols and their major food source, black tea, have been associated with a lower risk of ischemic heart disease (IHD) and stroke in Dutch men. We investigated whether flavonol intake predicted a lower rate of IHD in 1900 Welsh men aged 45-59 y, who were followed up for 14 y. Flavonol intake, mainly from tea to which milk is customarily added, was not related to IHD incidence [relative risk (RR), highest compared with lowest quartile: 1.0; 95% CI: 0.6, 1.6; P for trend = 0.996; n = 186] but was weakly positively related to IHD mortality (RR: 1.6; 95% CI: 0.9, 2.9; P = 0.119; n = 131) and cancer mortality (RR: 1.3; 95% CI: 0.7, 2.3; P = 0.150; n = 104) and strongly related to total mortality (RR: 1.4; 95% CI: 1.0, 2.0; P = 0.014; n = 334). Men with the highest consumption of tea (> 1.2 L, or > 8 cups/d) had an RR of 2.4 (95% CI: 1.5, 3.9) of dying in the follow-up period compared with men consuming < 300 mL/d (< 2 cups/d). We conclude that intake of antioxidant flavonols is not inversely associated with IHD risk in the United Kingdom. Possibly, flavonols from tea to which milk is added are not absorbed; experimental evidence suggests that adding milk to tea abolishes the plasma antioxidant-raising capacity of tea. The apparent association between tea consumption and increased mortality in this population merits further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / administration & dosage*
  • Flavonoids / administration & dosage*
  • Flavonoids / adverse effects
  • Flavonols
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Milk
  • Myocardial Ischemia / epidemiology*
  • Myocardial Ischemia / mortality
  • Myocardial Ischemia / prevention & control
  • Neoplasms / mortality
  • Risk Factors
  • Tea
  • Wales

Substances

  • Antioxidants
  • Flavonoids
  • Flavonols
  • Tea