Here's some information regarding the primary source provided by the National Institutes of Health (NIH) -- U.S. Department of Health and Human Services:
The Journal of the National Cancer Institute:
Mission
The National Cancer Institute is the world’s largest organization solely dedicated to cancer research.
NCI supports researchers at universities and hospitals across the United States and at NCI-Designated Cancer Centers, a network of facilities that not only study cancer in laboratories, but conduct research on the best ways to rapidly bring the fruits of scientific discovery to cancer patients.
In NCI’s own laboratories, almost 5,000 principal investigators, from basic scientists to clinical researchers, conduct earliest phase cancer clinical investigations of new agents and drugs. Recent advances in bioinformatics and the related explosion of technology for genomics and proteomics research are dramatically accelerating the rate for processing large amounts of information for cancer screening and diagnosis. The largest collaborative research activity is the Clinical Trials Program for testing interventions for preventing cancer, diagnostic tools, and cancer treatments, allowing access as early as possible to all who can benefit. NCI supports over 1,300 clinical trials a year, assisting more than 200,000 patients.
NCI’s scientists also work collaboratively with extramural researchers in order to accelerate the development of state-of-the-art techniques and technologies. In addition to direct research funding, NCI offers the Nation's cancer scientists a variety of useful research tools and services, including tissue samples, statistics on cancer incidence and mortality, bioinformatic tools for analyzing data, databases of genetic information, and resources through NCI-supported Cancer Centers, Centers of Research Excellence, and the Mouse Models of Human Cancer Consortium. NCI researchers are also seeking the causes of disparities among underserved groups and gaps in quality cancer care, helping to translate research results into better health for groups at high risk for cancer, including cancer survivors and the aging population.
As the leader of the National Cancer Program, NCI provides vision and leadership to the global cancer community, conducting and supporting international research, training, health information dissemination, and other programs. Timely communication of NCI scientific findings help people make better health choices and advise physicians about treatment options that are more targeted and less toxic.
Information about the National Cancer Institute's research and activities is available through its Web site, http://cancer.gov.
Here's the study abstract:
Journal of the National Cancer Institute Advance Access published online on August 8, 2007
JNCI Journal of the National Cancer Institute, doi:10.1093/jnci/djm082
© The Author 2007. Published by Oxford University Press.
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ARTICLES
Dietary Choline and Betaine and the Risk of Distal Colorectal Adenoma in Women
Eunyoung Cho, Walter C. Willett, Graham A. Colditz, Charles S. Fuchs, Kana Wu, Andrew T. Chan, Steven H. Zeisel, Edward L. Giovannucci
Affiliations of authors: Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA (EC, WCW, CSF, ATC, ELG); Departments of Nutrition (WCW, KW, ELG) and Epidemiology (WCW, ELG), Harvard School of Public Health, Boston, MA; Department of Surgery and Alvin J. Siteman Cancer Center, Washington University School of Medicine, St Louis, MO (GAC); Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA (CSF); Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA (ATC); Department of Nutrition, University of North Carolina, Chapel Hill, NC (SHZ)
Correspondence to: Eunyoung Cho, ScD, Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Ave, Boston, MA 02115 (e-mail: eunyoung.cho@channing.harvard.edu).
Background: Choline and betaine are involved in methyl-group metabolism as methyl-group donors; thus, like folate, another methyl-group donor, they may be associated with a reduced risk of colorectal adenomas. No epidemiologic study has examined the association of intake of these nutrients and colorectal adenoma risk.
Methods: We investigated the relationship between intakes of choline and betaine and risk of colorectal adenoma in US women enrolled in the Nurses’ Health Study. Dietary intake was measured by food-frequency questionnaires, and individual intakes of choline and betaine were calculated by multiplying the frequency of consumption of each food item by its choline and betaine content and summing the nutrient contributions of all foods. Logistic regression models were used to calculate adjusted odds ratios (as approximations for relative risks) and 95% confidence intervals (CIs) of colorectal adenoma. All statistical tests were two-sided.
Results: Among 39246 women who were initially free of cancer or polyps and who had at least one endoscopy from 1984 through 2002, 2408 adenoma cases were documented. Increasing choline intake was associated with an elevated risk of colorectal adenoma; the multivariable relative risks (95% CIs) for increasing quintiles of intake, relative to the lowest quintile, were 1.03 (0.90 to 1.18), 1.01 (0.88 to 1.16), 1.23 (1.07 to 1.41), and 1.45 (1.27 to 1.67; Ptrend<.001). Betaine intake had a nonlinear inverse association with colorectal adenoma; the multivariable relative risks (95% CIs) for increasing quintiles of intake were 0.94 (0.83 to 1.07), 0.85 (0.75 to 0.97), 0.86 (0.75 to 0.98), and 0.90 (95% CI = 0.78 to 1.04; Ptrend = .09). Among individual sources of choline, choline from phosphatidylcholine and from sphingomyelin were each positively related to adenoma risk.
Conclusions: Our findings do not support an inverse association between choline intake and risk of colorectal adenoma. The positive association between choline intake and colorectal adenoma that we observed could represent effects of other components in the foods from which choline was derived and should be investigated further.
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CONTEXT AND CAVEATS
Prior knowledge
Epidemiologic studies have suggested that lower dietary intake of folate and methionine and higher intake of alcohol are associated with an increased risk of colorectal adenoma (polyps in the colon or rectum that may develop into colorectal cancer). All of these dietary factors are involved in a biochemical pathway(s) referred to as one-carbon metabolism. Choline and betaine in the diet also affect one-carbon metabolism, but their association with the risk of colorectal cancer was not known.
Study design
Dietary intake of choline and betaine and incidence of colorectal adenoma were assessed by a questionnaire that was sent to a large group of female nurses every 2 years, and statistical methods were used to assess the association between choline intake and the risk of colorectal adenoma.
Contribution
Increased dietary intake of choline was associated with an elevated risk of colorectal adenoma. The association with betaine intake was not clear.
Implications
Additional work will be needed to clarify the relationship between choline and risk of colorectal adenoma.
Limitations
Other components of the diet, the intakes of which are highly correlated with choline consumption, may be the source of the increased risk of colorectal adenoma that was observed.
Manuscript received December 6, 2006; revised June 5, 2007; accepted June 26, 2007.
HealthDay News Issued a mainstream news report on these findings, and it's called:
Red Meat, Dairy Nutrient May Raise Colon Cancer Risk
In this case, I am not sure if it's necessarily the choline involved that seems to be causing increased colorectal adenoma; and neither do the researchers. Do you think that consumption of red meat could be the cause?
However, considering the possible association, and how many folks take choline supplements in Alpha GPC form, CDP choline form, etc. I guess further investigation is definitely warranted...but geez, with all of this evidence suggesting no benefit from vitamins, minerals...now it's choline...maybe I should throw away all of my supplements. (just kidding!)
Also, this study was just in women. And I don't like the questionnaire methodology. In sum, I am not convinced it's choline causing increased colorectal adenoma.
Does anyone else have any thoughts or comments?
Take care.