References to Recent Studies on Diet and Cancer

BrooklynDodger received the blogs first posting. No longer a virgin. The post complained about omiting references to recent studies on diet and cancer. The Dodger apologizes, but blames it on editing clumsiness of Blogspot, since the Dodger never makes a mistake. This post conveys the references in JAMA.

Unfortunately, the more interesting reference is the editorial cited below, which has no abstract and is available only in full text. That contains the history of Doll and Peto's canonical assertion that 35% of cancer is due to diet.

The Dodger has chopped the abstracts to the breast and colon cancer studies, which are fully available on medline. The breast cancer and fruit study was very large and very null. The red meat and colon study was null for current consumption, and found an association for high to low long term consumption of red meat.

Although large and powerful, the Dodger suggests these studies must be viewed in context because some unknown artifact in collection of diet data, or unaccounted for social variable in the population [the canonical "uncontrolled confounding"] may account for the results. People who claim the healthy diet may enjoy other aspects of clean living. Therefore, the Dodger gives greater weight to the null study for breast cancer than the association found in the study for nasty red meat.

[For the record, the Dodger pretty much eschews chewing beef at home, although a brat and a beer at the game is a treasured guilty pleasure.]

Thus, this salvo of studies would appear to put "lifestyle" on a diet when weighting causes of variation of rates of cancer in the population.

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JAMA. 2005 Jan 12;293(2):233-4.

Diet and cancer: an evolving picture.Willett WC.Publication Types:
· Comment
· Editorial

JAMA. 2005 Jan 12;293(2):183-93.

Consumption of vegetables and fruits and risk of breast cancer.

van Gils CH, Peeters PH, Bueno-de-Mesquita HB, Boshuizen HC, Lahmann PH, Clavel-Chapelon F, Thiebaut A, Kesse E, Sieri S, Palli D, Tumino R, Panico S, Vineis P, Gonzalez CA, Ardanaz E, Sanchez MJ, Amiano P, Navarro C, Quiros JR, Key TJ, Allen N, Khaw KT, Bingham SA, Psaltopoulou T, Koliva M, Trichopoulou A, Nagel G, Linseisen J, Boeing H, Berglund G, Wirfalt E, Hallmans G, Lenner P, Overvad K, Tjonneland A, Olsen A, Lund E, Engeset D, Alsaker E, Norat T, Kaaks R, Slimani N, Riboli E.Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.…

Prospective study of 285,526 women between the ages of 25 and 70 years, … No significant associations between vegetable or fruit intake and breast cancer risk were observed. Relative risks for the highest vs the lowest quintile were 0.98 (95% confidence interval [CI], 0.84-1.14) for total vegetables, 1.09 (95% CI , 0.94-1.25) for total fruit, and 1.05 (95% CI , 0.92-1.20) for fruit and vegetable juices. For 6 specific vegetable subgroups no associations with breast cancer risk were observed either. CONCLUSION: Although the period of follow-up is limited for now, the results suggest that total or specific vegetable and fruit intake is not associated with risk for breast cancer.

JAMA. 2005 Jan 12;293(2):172-82.

Meat consumption and risk of colorectal cancer.

Chao A, Thun MJ, Connell CJ, McCullough ML, Jacobs EJ, Flanders WD, Rodriguez C, Sinha R, Calle EE.Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Ga 30329-4251, USA.…

A cohort of 148 610 adults aged 50 to 74 years (median, 63 years), residing in 21 states with population-based cancer registries…High intake of red and processed meat …was associated with higher risk of colon cancer after adjusting for age and energy intake but not after further adjustment for body mass index, cigarette smoking, and other covariates. When long-term consumption was considered, persons in the highest tertile of consumption … had higher risk of distal colon cancer associated with processed meat (RR, 1.50; 95% confidence interval [CI], 1.04-2.17), and ratio of red meat to poultry and fish (RR, 1.53; 95% CI, 1.08-2.18) relative to those persons in the lowest tertile at both time points. Long-term consumption of poultry and fish was inversely associated with risk of both proximal and distal colon cancer. … long-term meat consumption in assessing cancer risk and strengthen the evidence that prolonged high consumption of red and processed meat may increase the risk of cancer in the distal portion of the large intestine