A meta-analysis of diet, physical activity and bc risk: An evolutionary perspective

[Hopeful]

http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=f95d8b1f-cabc-4994-b4d0-5fa3d527fed4&cKey=0c96be4d-6ce7-45a9-8921-f09b59fc9bb1&mKey=%7b507D311A-B6EC-436A-BD67-6D14ED39622C%7d

Hopeful

[sdstarfish]

Hi, Hopeful:
I can see you've been doing your homework by reading scientific abstracts. I commend you for empowering yourself with knowledge :)

My only word of caution to you would be this: sometimes it's hard to get the whole picture without reading the whole study. For instance, in this article, the abstract does not mention which types of fats were used. Certain fats are actually necessary and good for the body, while others are detrimental to health.

Another point is that the full article would contain a discussion, in which the researcher(s) assessed the shortcomings of their experiment - for example, maybe their group was too small, had too much in common, or maybe the experiment just wasn't conducted as well as it could have been for other reasons. This is valuable info that is rarely, if ever, in the abstract.

University libraries have scientific journals, and you can access them for free so that you can see the full articles. Also, you can sometimes access full articles for free via Google Scholar.

All the best,

Lisa
http://www.pinkkitchen.info (http://www.pinkkitchen.info/)

[Jackie07]

While attemping to (and 'failed' :) find the full-text article of the abstract posted by Hopeful, I found this 2005 article and thought the information is interesting:

http://www.ajcn.org/content/81/2/341.full

[sdstarfish]

Jackie, This is a great article. Thanks!
Lisa
http://www.pinkkitchen.info (http://www.pinkkitchen.info/)

[Jackie07]

Found a 'comment' on the same subject [No wonder my oncologist acted very concerned a year ago when he learned about my 'inactivity']:

Physical Activity, Weight, Diet, and Breast Cancer Risk Reduction
Comment on "Physical Activity and Risk of Breast Cancer Among Postmenopausal Women"
Anne McTiernan, MD, PhD
Arch Intern Med. 2010;170(20):1792-1793. doi:10.1001/archinternmed.2010.416


Since this article does not have an abstract, we have provided the first 150 words of the full text (http://archinte.ama-assn.org/cgi/content/full/170/20/1792) and any section headings.



Since a seminal prospective cohort study showing reduced breast cancer risk in physically active women1 13 years ago and my commentary2 calling for a broader research agenda in this area, more than 5 dozen studies have reported on the association of physical activity with breast cancer risk. The prospective cohort studies in postmenopausal women have shown a modest (approximately 10%-20%) but statistically significant association of reduced risk of breast cancer in women who engage in the equivalent of 3 h/wk of moderate-level physical activity or greater, ie, who meet or exceed the current recommendations for US adults.3 The associations have been confirmed consistently enough that the US Department of Health and Human Services Physical Activity Guidelines Advisory Committee concluded in 2008 that strong evidence demonstrates that, compared with less active persons, more active women have lower rates of breast cancer.3

[Hopeful]

Lisa,

The abstract was of a "meta analysis," which is not a single study, but a comprehensive review of many studies, wherein the results are reviewed together in order to arrive at a result. The authors stated:

"Published literature evaluating relationships between breast cancer risk and dietary fat, and exercise was systematically reviewed up to May of 2010. Descriptive data, estimates of relative risk and 95% confidence interval (CI) were extracted from relative studies, sorted according to inclusion criteria and analyzed using the random effects model of DerSimonian and Laird."

I will confess that I am not a statistics expert, and not at all familiar with the random effects model of DerSimonian and Laird, referenced in the abstract. My point being that this is not the same as a single study, so there will not be a single method or a single experiment, as your post posits. This is a distillation of many papers written on many different studies and experiments, all very different from each other. As such, the methodology has its own inherent shortcomings.

In general, I enjoy reading through the abstracts and posters that are presented at medical conferences, and posting those that I think may have interest or relevance to the audience that reads this message board. I don't necessarily agree with everything that is contained in the abstracts and articles I post, but I try to make sure that we all get the same information that our medical professionals are getting, to be able to ask them questions about our health and the care that we get, and to be our own advocates. I very much appreciate the fact that you took the time to read what I posted and comment on it.

Jackie, thank you for adding your research to the thread. Not all of the abstracts that are presented at these conferences turn into research papers, which is why you were not able to locate one. I do appreciate that you took the time to look for one.

Regards,

Hopeful

[Jackie07]

Thanks for the clarification, I think both Lisa and I were just very interested in the subject that you had presented and wanted to have more information.

Incidentally, I re-read the full-text article I posted and found there were more recent studies (those which had cited the 2005 article) listed at the end of the link. And some of them are full-text!

The summary of the 2005 article http://www.ajcn.org/content/81/2/341.full states:

"a. Higher levels of exercise could decrease breast cancer risk
b. Higher consumption of dietary fat may increase breast cancer risk
c. Reproductive status may influence breast cancer risk in women

These results have important implications for future breast cancer research. Interactions between modern cultural factors and ancestral biology may be expressed as higher rates of breast cancers in modern, industrialized nations. Clinical studies do not cumulatively examine population variations in socio-economic, cultural and biological risk factors and breast cancer occurrence. Applying an anthropological and biocultural perspective to future research could identify evolutionary roots to causes and risk factors of female reproductive diseases."

There were also articles about the Omega 3 and Omega 6 ratio (R.B. has been educating us on the subject) and the PH value that Elaine and others have been discussing.

I do want to point out a quick observation: The life expectancy has been steadily improving since the turn of the (20th) Century. People like me used not to live very long after a premature birth, would probably die young of childhood diseases, would definitely die from a huge brain tumor by 35 or 40 (after long torturing of the explosive headaches... :) The 'female reproductive diseases' would not have had a chance to appear... (one less breast cancer case.)

Really ought to bake another spice (fruit) cake for my oncologist who's been bugging me about getting in more exercise... :)