Flavonol and Flavone Intakes in US Health Professionals

https://doi.org/10.1016/S0002-8223(02)90314-7Get rights and content

Abstract

Objective To determine flavonoid content of US foods, mean individual intakes, major food sources, and associations with other nutrients.

Subjects US men (n=37,886) and women (n=78,886) who completed a semiquantitative food frequency questionnaire in 1990.

Design Men and women completed a questionnaire that listed 132 items, including onions as a garnish and as a vegetable, rings, or soup. Foods known to be important sources of flavonols (quercetin, myricetin, and kaempferol) and flavones (luteolin and apigenin) were analyzed biochemically. The database contained values from the analyzed foods, previously published values from Dutch foods, and imputed values.

Statistics Means and standard deviations, contributions of foods to summed intake of each flavonoid, and Pearson correlation coefficients were calculated.

Results Of the flavonols and flavones studied, quercetin contributed 73% in women and 76% in men. The mean flavonol and flavone intake was approximately 20 to 22 mg per day. Onions, tea, and apples contained the highest amounts of flavonols and flavones. Correlations between the intakes of flavonols and flavones and intakes of beta carotene, vitamin E, vitamin C, folic acid, and dietary fiber did not exceed 0.35.

Conclusion Although flavonols and flavones are subgroups of flavonoids hypothesized to be associated with reduced risk of coronary heart disease, data on flavonoid intake has been limited due to the lack of food composition data. Nutrition professionals can use these and other published data to estimate intake of flavonoids in their populations. This work should facilitate the investigation of this class of dietary antioxidants as a contributor to disease prevention. J Am Diet Assoc. 2002; 102:1414-1420.

Section snippets

Food Collection and Analysis

We collected foods that are known to be important sources of flavonols and flavones (11), (12). Three samples of the following fresh product were purchased at local Boston area supermarkets: Macintosh, Granny Smith and Red Delicious apples; Spanish, white, and all-purpose yellow onions; avocado; cantaloupe; watermelon; alfalfa sprouts; and green pepper. Mixed fresh and frozen samples were used for blueberries and yellow squash. Corn and green beans consisted of a mix of fresh, frozen, and

Results

Flavonoid content of foods Values in US foods were similar to those previously reported by us in European foods (Table 1). By far the highest amounts of quercetin (when expressed on a weight basis) were in yellow and Spanish onions. Considering realistic serving sizes, however, the amounts in tea and apples were also high. Apple juice and wine contained modest amounts of quercetin. Few foods except tea contained appreciable amounts of kaempferol and myricetin; and no apigenin or luteolin was

Discussion

We found that the mean intake of quercetin plus related flavonols and flavones in two US adult populations was approximately 20 to 22 mg per day. These figures are based largely on new chemical analyses of US foods; these newly analyzed foods contributed approximately 74% of the men's and 69% of the women's summed flavonol and flavone intake. Spices and herbs in the amounts normally added to food probably only increase flavonoid intake marginally as only chili powder contains a high quantity of

Applications

Flavonoids can function as antioxidants and are hypothesized to be important determinants of diseases related to oxidative stress. Studies of flavonoid intake in relation to hypertension, plasma low-density lipoprotein cholesterol, coronary artery disease, stroke, gastric cancer, chronic obstructive pulmonary disease, and dementia have been published. Results have been inconsistent and are hampered by lack of comprehensive data on the flavonoid content of foods. We have therefore analyzed US

References (24)

  • C. Tabak et al.

    Chronic obstructive pulmonary disease and intake of catechins, flavonols, and flavonesthe MORGEN Study

    Am J Respir Crit Care Med.

    (2001)
  • D. Commenges et al.

    Intake of flavonoids and risk of dementia

    Eur J Epidemiol.

    (2000)
  • Cited by (0)

    View full text