Citations: 1-4
<1>
Authors
Le Marchand L. Hankin JH. Wilkens LR. Kolonel LN. Englyst HN. Lyu LC.
Institution
Etiology Program, University of Hawaii Cancer Research
Center, Honolulu, USA.
Title
Dietary fiber and colorectal cancer risk.
Source
Epidemiology. 8(6):658-65, 1997 Nov.
Abstract
We conducted a population-based case-control study among different ethnic
groups in Hawaii to evaluate the role of various types and components of
fiber, as well as micronutrients and foods of plant origin, on the risk of
colorectal cancer. We administered personal interviews to
698 male and 494 female Japanese, Caucasian, Filipino, Hawaiian, and Chinese
cases diagnosed during 1987-1991 with adenocarcinoma of the colon or rectum
and to 1,192 population controls matched to cases by age, sex, and ethnicity.
We used conditional logistic regression to estimate odds ratios, adjusted for
caloric intake and other covariates. We found a strong, dose-dependent,
inverse association in both sexes with fiber intake measured as crude fiber,
dietary fiber, or nonstarch polysaccharides. We found inverse associations of
similar magnitude for the soluble and insoluble fiber fractions and for
cellulose and noncellulosic polysaccharides. This protective effect of fiber
was limited to fiber from vegetable sources, with an odds ratio of 0.6 (95%
confidence interval = 0.4-0.9) and 0.5 (95% confidence interval = 0.3-0.7)
for the highest compared with the lowest quartile of intake for men and
women, respectively. We found associations of the same magnitude for soluble
and insoluble vegetable fiber, but no clear association with fiber from
fruits or cereals. This pattern was consistent between sexes, across segments
of the large bowel (right colon, left colon, and rectum), and among most
ethnic groups. The effect of vegetable fiber may be independent of the
effects of other phytochemicals, since the effect estimates remained
unchanged after further adjustment for other nutrients. Intakes of
carotenoids, light green vegetables, yellow-orange vegetables, broccoli,
corn, carrots, bananas, garlic, and legumes (including soy
products) were inversely associated with risk, even after adjustment for
vegetable fiber. The data support a protective role of fiber from vegetables
against colorectal cancer, which appears independent of its
water solubility property and of the effects of other phytochemicals. The
data also indicate that certain vegetables and fruits may be protective
against this disease through mechanisms other than their fiber content.
<2>
Authors
Sankaranarayanan R. Varghese C. Duffy SW. Padmakumary G. Day NE. Nair
MK.
Institution
Regional Cancer Centre, Trivandrum, Kerala, S. India.
Title
A case-control study of diet and lung cancer in Kerala,
south India.
Source
International Journal of Cancer. 58(5):644-9, 1994 Sep 1.
Abstract
A total of 281 male lung-cancer patients were identified
from the hospital cancer registry in the Regional
Cancer Centre in Trivandrum. The controls were selected from
the visitors and patients' bystanders in the hospital. The recruitment of
cases and controls started in 1990, and the present study used the cases
registered in the first year. The questionnaire administered to cases and
controls collected information on tobacco smoking and alcohol habits. Dietary
data were collected using a food frequency questionnaire and were analyzed by
multiple logistic regression producing odds ratio estimates of the relative
risk and deviance chi-squared tests of significance. Analysis was done on the
computer package, EGRET. All models included age, education, religion and
smoking to adjust for the effect of confounding. Green vegetables and
bananas were found to have a protective association with
lung cancer. The odds ratio associated with the highest
quartile of vegetable consumption compared with the lowest was 0.32 (95%
confidence interval 0.13, 0.78). Forward stepwise regression analysis
indicated pumpkins and onions as the most consistently significant protective
factors. Animal protein foods and dairy products were found to have a
predisposing effect on lung cancer in this study. The
expected influence of smoking on lung cancer (a considerable
increase in risk among smokers) provided evidence of the reliability of the
data. In conclusion the results from this study show that diet has a role in
lung cancer aetiology, although the association is weak
compared to the effects of smoking.
<3>
Authors
Zheng T. Boyle P. Willett WC. Hu H. Dan J. Evstifeeva TV. Niu S.
MacMahon B.
Institution
Division of Epidemiology and Biostatistics, European Institute of Oncology,
Milan, Italy.
Title
A case-control study of oral cancer in Beijing, People's
Republic of China. Associations with nutrient intakes, foods and food groups.
Source
European Journal of Cancer. Part B, Oral Oncology.
29B(1):45-55, 1993 Jan.
Abstract
A case-control study of oral cancer was conducted in
Beijing, People's Republic of China to examine the association between
dietary nutrient intake and risk of oral cancer, both in
terms of estimated intake of nutrients and micro-nutrients, and in terms of
specific foods and food groups. The study was hospital-based and controls
were hospital in-patients matched for age and sex with the cases. The
response rate for cases and controls was 100% and 404 case/control pairs were
interviewed. The results suggest that increased protein and fat intake are
related to a decreased risk of oral cancer. Carbohydrate
intake, however, showed a moderate increased risk for oral
cancer. Total carotene intake and carotene intake from
fruits and vegetables are inversely associated with risk of oral
cancer. A similar pattern was observed for dietary vitamin C
intake. Dietary fibre derived from fruits and vegetables showed a strong
negative association with oral cancer risk, but fibre
derived from other sources did not exhibit any protective effect. At the
level of foods and food groups, increased consumption of fresh meat, chicken
and liver was significantly associated with a reduction in oral
cancer risk: the tests for trend were all statistically
significant at the P < 0.01 level. Consumption of common carp, hairtail,
shrimp and lobster were also associated with decreased risk. Risk was found
to increase with increasing consumption of millet and corn bread (P < 0.01)
but to decrease with increasing consumption of rice (P < 0.01). Increased
consumption of grapes, bananas, oranges, tangerines, peaches
and pears were associated with reduced risk.(ABSTRACT TRUNCATED AT 250 WORDS)
<4>
Authors
Jansson B.
Institution
Department of Biomathematics, University of Texas M.D. Anderson
Cancer Center, Houston 77030.
Title
Dietary, total body, and intracellular potassium-to-sodium ratios and their
influence on cancer. [Review] [9 refs]
Source
Cancer Detection & Prevention. 14(5):563-5, 1990.
Abstract
One of the greatest changes in the human diet, a change that has occurred
only within the past few thousand years, is the immense increase in the
intake of sodium (Na) caused by use of table salt in the preparation and
preservation of food. At the same time, man's intake of potassium (K) has
decreased. The result is that from Paleolithic times to modern times the
dietary K/Na ratio has been reduced by a factor of about 20. Based on a
comparison of modern people in civilized areas with the primitive Yanomamo
Indians in South America (who do not eat salt but who do grow and eat
potassium-rich cooking bananas), this factor may even be on
the order of 100 to 200. Humans, who initially had to adapt to retain sodium
from a sodium-poor diet and to excrete potassium from a potassium-rich diet,
have not yet evolutionarily adapted to today's high-sodium, low-potassium
diet. This failure has caused increased rates of a number of diseases in
civilized man, among them cancer. The influence of the K/Na
ratio on cancer development--first discovered by
epidemiologic studies--has been confirmed by various means, such as dietary
studies, gerontological studies, studies of relationships between hyper- and
hypokalemic diseases and cancer, and review of the cellular
changes of this ratio induced by carcinogenic and anticarcinogenic agents.
Recently, animal experiments have also confirmed the results. The recommended
dietary K/Na ratio should be well above 1, preferably 5 or higher, and the
cellular K/Na ratio should be above 10. [References: 9]