Milk Intake, Circulating Levels of Insulin-Like Growth Factor-I, and Risk of Colorectal Cancer in Men
* Received December 15, 2000.
* Revision received June 27, 2001.
* Accepted July 6, 2001.
Abstract
Background: Milk and dietary calcium may have antiproliferative effects against colorectal cancer, but milk intake also raises serum levels of insulin-like growth factor-I (IGF-I). A high ratio of IGF-I to IGF-binding protein-3 (IGFBP-3) has been linked to an increased risk of colorectal cancer. Methods: In a case–control study nested in the Physicians' Health Study, plasma samples were collected from the period 1982 through 1983 from 14 916 men, aged 40–84 years, who also answered dietary questionnaires. Circulating levels of IGF-I and IGFBP-3 were assayed among 193 men who developed colorectal cancer during 13 years of follow-up and 318 age- and smoking-matched cancer-free control men. Conditional logistic regression was used to assess relative risks (RRs) of colorectal cancer for tertiles of IGF-I/IGFBP-3 and dietary factors. Statistical tests were two-sided. Results: Overall, there was a moderate but statistically nonsignificant inverse association between intake of low-fat milk or calcium from dairy food and colorectal cancer risk. Intake of dairy food (especially low-fat milk) was also positively and moderately associated with plasma levels of IGF-I, IGFBP-3, and IGF-I/IGFBP-3 among control men. We observed a statistically significant interaction between low-fat milk intake and IGF-I/IGFBP-3 in association with risk of colorectal cancer (Pinteraction = .03). Nondrinkers with IGF-I/IGFBP-3 in the highest tertile had a threefold higher risk than nondrinkers with IGF-I/IGFBP-3 in the lowest tertile (RR = 3.05; 95% confidence interval [CI] = 1.29 to 7.24), but no such increase was seen among frequent low-fat milk drinkers (RR = 1.05; 95% CI = 0.41 to 2.69). Conversely, among men with high IGF-I/IGFBP-3, frequent low-fat milk drinkers had a 60% lower risk (95% CI = 0.17 to 0.87; Ptrend = .02) than nondrinkers.
Conclusion: Intake of dairy products was associated with a modest increase in circulating IGF-I levels, but intake of low-fat milk was associated with lower risk of colorectal cancer, particularly among individuals with high IGF-I/IGFBP-3. This subpopulation, which is at increased risk of colorectal cancer, might benefit the most from specific dietary intervention.Milk consumption and cancer incidence: a Norwegian prospective study.
Relationships between milk intake and cancer incidence were investigated after 11 1/2 years of follow-up of 15,914 individuals. A diagnosis of cancer was made in a total of 1,422 individuals. No association was established with total cancer incidence, in analyses adjusted for sex, age and residential characteristics. However, a strong positive association with milk consumption was observed for cancers of the lymphatic organs (odds ratio 3.4 for greater than or equal to 2 glasses per day vs less than 1; 95% confidence interval 1.4-8.2). An inverse association was found for cancer of the bladder. Kidney cancer and cancers of the female reproductive organs (except the uterine cervix) showed weak positive associations with milk intake.
Adolescent milk, dairy product and fruit consumption and testicular cancer.
There is an association between dairy product consumption and the incidence of testicular cancer in different countries. To test the hypothesis that milk and dairy products are risk factors, a case-control study was performed in East Anglia, UK. All the cases were men with testicular cancer and for each of the 200 cases there were four controls, two cancer controls and two population controls. The response rate of those eligible subjects who received a questionnaire was: cases 73%, cancer controls 65% and population controls 57%. All responding subjects completed a dietary questionnaire including questions on current and adolescent milk, dairy product and fruit and vegetable consumption. The answers were corroborated when possible by the subjects' mothers using a separate questionnaire. Cases consumed significantly more milk in adolescence than population controls, but this difference did not apply to other dairy products or fruit. The consumption of milk by cancer controls was intermediate between cases and population controls. Cancer controls with non-epithelial cancers had a milk consumption similar to cases, whereas subjects with epithelial cancers had a consumption similar to population controls. In a multivariate analysis the odds ratio between cases and population controls for the association of undescended testis and testicular cancer was 7.19 (95% CI 2.36-21.9) and for each extra quarter pint of milk consumed it was 1.39 (95% CI 1.19-1.63).
Titre du document / Document title
Prospective study on milk products, calcium and cancers of the colon and rectum
Auteur(s) / Author(s)
JÄRVINEN R. (1) ; KNEKT P. (2 3 4) ; HAKULINEN T. (5 6) ; AROMAA A. (2 3 4) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Department of Clinical Nutrition, University of Kuopio, Kuopio, FINLANDE
(2) National Public Health Institute, Helsinki, FINLANDE
(3) The Social Insurance Institution, Helsinki, FINLANDE
(4) The Social Insurance Institution, Turku, FINLANDE
(5) Finnish Cancer Registry, Helsinki, FINLANDE
(6) Unit of Cancer Epidemiology, Radiumhemmet, Karolinska Institute, Stockholm, SUEDE
Résumé / Abstract
Objective: To study the relationship between consumption of milk and milk products, calcium, lactose and vitamin D and occurrence of colorectal cancers. Design: Prospective cohort study. Subjects: A total of 9959 men and women aged 15 y or older without history of cancer at baseline. During a 24 y follow-up, 72 new cancers of the large bowel (38 in the colon and 34 in the rectum) were detected. Results: Consumption of milk and total milk products was suggested to be inversely related to colon cancer incidence, whereas no similar association was seen for rectal cancer. The relative risk between the highest and lowest quartiles of intake adjusted for potential confounding factors was 0.46 (95% confidence interval 0.14- 1.46, P for trend 0.09) for milk and 0.37 (95% Cl = 0.12- 1.39, P for trend 0.06) for total milk products. Lactose intake showed a similar inverse relationship with colon cancer: the relative risk was 0.31 (95% CI = 0.08-1.15, P for trend 0.03). Intake of vitamin D or total dietary calcium was not significantly related to colorectal cancer risk, whereas calcium provided by fermented milk products was associated with increased colorectal cancer incidence; in the highest quartile the multivariate adjusted relative risk for colorectal cancer was 2.07 (95% CI = 1.00-4.28).
Conclusions: Our results indicate that individuals showing high consumption of milk have a potentially reduced risk of colon cancer; however, the association does not appear to be due to intake of calcium, vitamin D, or to specific effects of fermented milk.A Role for Milk Proteins and their Peptides in Cancer Prevention
Author: Parodi, P. W.1
Source: Current Pharmaceutical Design, Volume 13, Number 8, March 2007 , pp. 813-828(16)
Abstract:
A role for the amount and type of dietary protein in the etiology of cancer has not been studied extensively. Nevertheless, there is no compelling evidence from epidemiological studies to indicate that protein, at levels usually consumed, is a risk factor for cancer. On the other hand, animal studies suggest that certain peptides and amino acids derived from dietary proteins may influence carcinogenesis. The predominant protein in milk, casein, its peptides, but not liberated amino acids, have antimutagenic properties. Animal models, usually for colon and mammary tumorigenesis, nearly always show that whey protein is superior to other dietary proteins for suppression of tumour development. This benefit is attributed to its high content of cystine/cysteine and γ-glutamylcyst(e)ine dipeptides, which are efficient substrates for the synthesis of glutathione. Glutathione is an ubiquitous cellular antioxidant that directly or through its associated enzymes destroys reactive oxygen species, detoxifies carcinogens, maintains proteins in a reduced state and ensures a competent immune system. Various experiments showed that tumour prevention by dietary whey protein was accompanied by increased glutathione levels in serum and tissues as well as enhanced splenic lymphocyte proliferation, phagocytosis and natural killer, T helper and cytotoxic T cell activity. Whey protein components, β-lactoglobulin, α-lactalbumin and serum albumin were studied infrequently, but results suggest they have anticancer potential. The minor component lactoferrin has received the most attention; it inhibits intestinal tumours and perhaps tumours at other sites. Lactoferrin acts by induction of apoptosis, inhibition of angiogenesis, modulation of carcinogen metabolising enzymes and perhaps acting as an iron scavenger. Supplementing cows with selenium increases the content of selenoproteins in milk, which on isolation inhibited colon tumorigenesis in rats. that study is interesting ^^^
anyway, if anyone has any more REAL studies, post em`..
peace
