Jean H. Hankin

Singapore Chinese Health Study: development, validation, and calibration of the quantitative food frequency questionnaire.

This report describes the development and validation/calibration of a structured food frequency questionnaire for use in a large-scale cohort study of diet and health in Chinese men and women aged 45-74 years in Singapore, the development of a food composition database for analysis of the dietary data, and the results of the dietary validation/calibration study. The present calibration study comparing estimated intakes from 24-hour recalls with those from the food frequency questionnaires revealed correlations of 0.24-0.79 for energy and nutrients among the Singapore Chinese, which are comparable to the correlation coefficients reported in calibration studies of other populations. We also report on the nutritional profiles of Singapore Chinese on the basis of results of 1,880 24-hour dietary recalls conducted on 1,022 (425 men and 597 women) cohort subjects. Comparisons with age-adjusted corresponding values for US whites and blacks show distinct differences in dietary intakes between the Singapore and US populations. The Singapore cohort will be followed prospectively to identify dietary associations with cancer risk and other health outcomes.

An epidemiologic study of thyroid cancer in Hawaii

A population-based case-control interview study was designed to test the hypothesis that dietary iodine or the consumption of goitrogenic vegetables increases the risk of thyroid cancer. A total of 191 histologically confirmed cases (64 percent female) and 441 matched controls from five ethnic groups in Hawaii were available for analysis. Among women, intake of seafood (especially shellfish), harm ha (a fermented fish sauce), and dietary iodine were associated with an increased risk of cancer, whereas consumption of goitrogenic (primarily cruciferous) vegetables was associated with a decreased risk. Non-dietary risk factors included miscarriage (especially at first pregnancy), use of fertility drugs, family history of thyroid disease, obesity, and work as a farm laborer. The odds ratio for the combined effect of a high iodine intake and a first-pregnancy miscarriage was 4.8 (95 percent confidence interval [CI]=1.2 – 19.2); and for high iodine intake and use of fertility drugs 7.3 (95 percent CI=1.5 – 34.5). Among men, positive associations were found for obesity, work as a farm laborer, and a past history of benign thyroid disease. Although this study identified several dietary and non-dietary risk factors for thyroid cancer, it could not fully explain the exceptionally high incidence rates among Filipino women in Hawaii.

Association of Dietary Vitamin A, Carotenoids, and Other Antioxidants with the Risk of Ovarian Cancer

Antioxidants may protect the ovaries from oxidative damage and reduce the risk of ovarian cancer. Although a few studies have examined the relation of antioxidant intake to the risk of ovarian cancer, the results have been inconclusive. Questions still remain regarding the effects of confounding factors, such as menopause, tobacco smoking, and alcohol drinking, on the association between antioxidants and ovarian cancer development. Objective: To examine the association of the consumption of micronutrients from foods and supplements with the risk of ovarian cancer. Methods: A structured questionnaire was administered to 558 histologically confirmed epithelial ovarian cancer cases and 607 population controls from a multiethnic, population-based case-control study conducted between 1993 and 1999 in Hawaii and Los Angeles. Results: Overall, vitamin A and carotene intakes were modestly associated with a reduced risk of ovarian cancer. Inverse gradients in ovarian cancer risk with increasing dietary intake of vitamin A and β-carotene were somewhat stronger among women with mucinous histologic types, smokers, and nondrinkers. A significant positive trend in risk associated with increasing β-cryptoxanthin intake was observed among postmenopausal women, among women with nonmucinous tumors, and among nonsmokers. The intake of other carotenoids and antioxidants, either from foods or supplements, was unrelated to ovarian cancer risk. Conclusion: Our findings suggest that dietary vitamin A and β-carotene are modestly protective against ovarian cancer, particularly among smokers. Our data suggest a role for retinoic acid signaling pathways in ovarian carcinogenesis.

Adherence to the Food Guide Pyramid recommendations among Japanese Americans, Native Hawaiians, and whites: Results from the Multiethnic Cohort Study

The Food Guide Pyramid is designed to help Americans make healthful food choices. Whereas national data have been collected to examine adherence to the pyramid recommendations in whites, African-Americans, and Latinos, there are virtually no data available for Japanese Americans or Native Hawaiians. Here we present data on intakes of the Food Guide Pyramid food groups (as servings per day) as well as of the components of the pyramid tip (discretionary fat, added sugar, and alcohol) in these ethnic groups and examine adherence to each of the food group recommendations. Degree of adherence to the fruit group recommendation was similar among the ethnic groups and energy-intake categories, but adherence to the other recommendations was greatest for those consuming more than 2,800 kilocalories per day. However, subjects in this energy-intake group also consumed more than three times as much discretionary fat, added sugar, and alcohol.

Atributable risk of breast, prostate, and lung cancer in Hawaii due to saturated fat

The dietary data from case-control studies of breast, prostate, and lung cancer in Hawaii revealed that saturated fat was a risk factor for these malignancies. The dietary intakes from the three studies were used to calculate the attributable risk (AR) due to saturated fat. For all ethnic groups combined, the ARs for the highest quartiles of intake were 14.9 percent for female breast cancer, 13.0 percent for prostate cancer, and 23.1 percent for male lung cancer. Our results suggested that a reduction of saturated fat to the lowest quartiles of intake could result in a 10 to 20 percent decrease in risk for these three cancers in Hawaii. We also examined the ethnic-specific risks associated with saturated fat consumption among the Japanese and the Caucasians in the three studies. The ARs for the highest quartiles of intake were notably higher among the Caucasians than the Japanese, primarily due to the difference in their dietary patterns. Although the calculated AR due to saturated fat was higher among the Caucasians than among the Japanese, all persons in the population would derive considerable benefit by reducing their intake of this nutrient.

Dietary and other correlates of melanoma in Hawaii: preliminary findings

The relationship of diet to malignant melanoma has remained rela tively unexplored. However, there is evidence, primarily from labora tory studies, that dietary factors may play a role in the etiology of melanoma [1]. Retinoids appear to inhibit the growth of murine and human melanoma cell lines [2,3], as well as that of transplanted melanocytic tumors in mice [4]. There has also been one report of successful treatment of melanoma with trans-retinoic acid [5].