6 replies to this topic

[doug123]

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.

[kodi]

It would be interesting to know the biggest sources of choline for those women who consumed the most choline. Egg yolks and beef seem to be likely candidates; but the study also mentioned phosphatidylcholine (though it didn't say how much it separately increased the risk -- does anyone have the full text to find out?). Where does most phosphatidylcholine in typical diets come from? Perhaps from soy products and/or lecithin used as a food additive in processed foods.

Like you, I think it's more likely that the choline-rich foods being consumed also had other attributes that happened to be harmful.

In 1998, the National Academy of Sciences established Adequate Intake (AI) levels for choline as 550 milligrams for men and 425 milligrams for women. Is it just me, or is it virtually impossible to get that much from diet alone unless you regularly eat egg yolks and/or beef and/or liver? (Soy lecithin is of course a great source, though I think of it more as a supplement.)

[efosse]

I remember reading that some think vitamins are beneficial for their anti-inflammatory rather than antioxidants benefits. As far as choline, it could be anything of which choline has a content, imo.

[doug123]

Metabolic syndrome: click here for definition

A related story published in the media Aug 1 (related to Colorectal Adenoma at least):

Here is some information regarding the primary source, The Journal Cancer Epidemiology Biomarkers & Prevention, published by The American Association for Cancer Research, as found at Wikipedia:

The American Association for Cancer Research (AACR) is an organization based in Philadelphia, Pennsylvania, that focuses on all aspects of cancer research including basic, clinical and translational research into the etiology, prevention, diagnosis, and treatment of cancer. Founded in 1907 by eleven physicians and scientists, the organization now has over 24,000 members, approximately a third of which are outside the United States. Hence it is one of the largest scientific organization in the world, according to its web site.

The AACR publishes Cancer Research, one of the high rated peer-reviewed journals in the field, and also publishes four other well-respected scientific journals covering specific areas of cancer research: Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and, Cancer Epidemiology, Biomarkers & Prevention, as well as CR Magazine, a communication for cancer survivors, patient advocates, physicians and scientists.

The organization holds workshops and scientific conferences throughout the year involving various disciplines of cancer research, and its key event is the AACR Annual Meeting held in the Spring of each year in a major North American city. The Annual Meeting typically draws over 17,000 attendees.

The AACR also provides information for patients, families, survivors and advocates including organ site fact sheets and Cancer Concept fact sheetsexplaining treatments, new technologies and research areas.

Here is the study abstract as published in Cancer Epidemiology Biomarkers & Prevention:

Cancer Epidemiology Biomarkers & Prevention 16, 1543-1546, August 1, 2007. doi: 10.1158/1055-9965.EPI-07-0199
© 2007 American Association for Cancer Research

Is Metabolic Syndrome A Risk Factor for Colorectal Adenoma?

Jeong Hwan Kim1, Yun Jeong Lim4, Young-Ho Kim2, In-Kyung Sung1, Sang Goon Shim5, Sung-Ook Oh2, Sin-Sil Park2, Sun Yang2, Hee Jung Son2, Poong-Lyul Rhee2, Jae J. Kim2, Jong Chul Rhee2 and Yoon-Ho Choi3
1 Department of Internal Medicine, Konkuk University Hospital, Konkuk University School of Medicine; 2 Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine; 3 Center for Health Promotion, Samsung Medical Center, Seoul, Korea; 4 Department of Internal Medicine, Dongguk University International Hospital, Dongguk University College of Medicine, Goyang, Korea; and 5 Department of Internal Medicine, Masan Samsung Hospital, Masan, Korea

Requests for reprints: Young-Ho Kim, Division of Gastroenterology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Dong 50, Gangnam-gu, Seoul 135-710, Korea. Phone: 82-2-3410-3409; Fax: 82-2-3410-3849. E-mail: bowelkim@smc.samsung.co.kr

Background and Aims: Epidemiologic studies provide evidence for a link between obesity or diabetes and the risk for colorectal cancer. However, there is a lack of information about the relationship between metabolic syndrome and colorectal adenoma. Therefore, we investigated whether metabolic syndrome is a risk factor for colorectal adenoma.

Methods: We did a study for consecutive subjects who underwent colonoscopy as a screening exam at the Center for Health Promotion, Samsung Medical Center, from March 2004 to December 2005. According to the modified ATP III criteria, metabolic syndrome was diagnosed. We classified a total of 2,531 subjects into the adenoma group (n = 731) and the control group (n = 1,800), including normal colonoscopic finding, nonpolyp benign lesions, or histologically confirmed hyperplastic polyp.

Results: The prevalence for metabolic syndrome was 17% in the adenoma group and 11% in the control group. On the multiple logistic regression analyses, metabolic syndrome was found to be associated with an increased risk of colorectal adenoma (odds ratio, 1.51; 95% confidence interval, 1.18-1.93). Also, waist circumference among the individual components of metabolic syndrome was an independent risk factor for colorectal adenoma. An increased risk for metabolic syndrome was more evident for proximal than distal colon, for multiple (3), and for advanced adenoma in the adenoma group.

Conclusion: Metabolic syndrome was associated with colorectal adenoma. Abdominal obesity of the individual components of metabolic syndrome was an important risk factor for colorectal adenoma. (Cancer Epidemiol Biomarkers Prev 2007;16(8):1543–6)

Thoughts, comments?

Take care.

[kodi]

I don't have any comment on the above, but I did have a flash of insight. Here's a chain of logic that may explain the findings of the study in the topmost post:

Soy -> Hypothyroidism -> Reduced flow through colon -> Colorectal polyps and cancer!

FACTS:
1) Assuming that women eat more soy then men, it's likely that soy is a major source of choline for the women in the study.
2) Soy is known to cause or aggravate hypothyroidism.
3) Hypothyroidism often reduces flow rate through the colon, often leading to constipation.
4) Reduced flow rate implies increased chance of polyps and colorectal cancer.

MORE SUPPORT:
[*]Undiagnosed and subclinical hypothyroidsm might be extremely common (20-40% of women?) Get your TSH and free T3/T4 checked!
[*]Hypothyroidism is more common in women than men (7-to-1)
[*]Besides soy, the only common/major sources of choline seem to be egg yolks, liver, and meat/fish (though meat/fish have much less choline than the others). Thus, soy is likely to be a major hidden factor in the study.

OPEN QUESTION: Assuming soy tends to cause or aggravate hypothyroidism, does that also apply to soy extracts such as lecithin and phosphatidylcholine?

(I've sent a copy of this to one of the study's authors in case it's of use.)

Edited by kodi, 16 August 2007 - 12:38 PM.

[krillin]

OPEN QUESTION: Assuming soy tends to cause or aggravate hypothyroidism, does that also apply to soy extracts such as lecithin and phosphatidylcholine?

The isoflavones are to blame, and are not present in lecithin or PC.

[kodi]

That's good to know; thanks!