CONSUMPTION OF RED MEATS AND RISK OF CANCER COLORECTAL

During the first half of this year different films and documentaries have appeared trying to instruct general society about unhealthy eating habits and the risks of certain diseases. I remember one in which the director which is the same presenter, spent all movie length fighting with the American health societies. I think the evidence is clear, here I put it , with some technical evidence of epidemiology.

CURRENT STATUS OF THE PROBLEM

• Colorectal cancer is the third most diagnosed cancer in men and the second most diagnosed in women.
• 694,000 deaths during 2012.
• The highest incidences (new cases) occur in Australia, New Zealand, Europe and the USA. The lowest incidences occur in South Asia and Africa.
• Age is one of the strongest factors; the cases presented before the 40 years are few common, however after the 50 years the incidence of presentation increases.
• It is important to note that; is a preventable disease with early screening strategies.

RISK FACTORS - RED MEAT CONSUMPTION.

In addition to the consumption of red meats we have; Genetic factors (Lynch syndrome), Obesity, diabetes mellitus, insulin resistance syndrome, smoking and alcohol consumption.

We will focus on the consumption of red meats, because as other risk factors is totally modifiable.

• The consumption of processed red meat seems to be related to the appearance of cancerous lesions predominantly in the left colon.
• High cooking temperatures (Barbecue, or frying in frying pan) is directly related to the risk of cancer arising from the production of polyaromatic hydrocarbons. These products are waste from the carbonization process.

http://chemistry.tutorvista.com/inorganic-chemistry/aromatic-hydrocarbons.html

In 2015 the WHO makes the evidence to date to evaluate the association between the consumption of red meat and red meat processed with colorectal cancer. It was found that there are multiple follow-up studies of cohorts, cases and controls that find a positive association. A meta-analysis of follow-up studies of 10 cohort studies found that; there is a positive dose-response relationship between meat consumption and the occurrence of colorectal cancer (17% increased risk per 100g / day of red meat consumed, and 18% increased risk per 50g / day of meat red processed consumed). The evidence was strong enough to classify "sausages, bacon, ham, dried meat, canned meat "as carcinogens type 1, assimilated with tobacco and alcohol among other compounds.

The following is the epidemiological and statistical evidence supporting the above mentioned;

JAMA, January 12, 2005-Vol 293, No. 2

• This is a cohort study involving 148610 patients between 50 and 74 years of age (mean age 63 years) who provided information about their consumption of red meat in different surveys (one conducted in 1982 and another in 1992/1993) , the follow-up of the patients arrived until 2001. We identified 1667 cases. The measure of association used was RR (Annex 1).
• Results: In general men reported a higher consumption of red meat and processed red meat, the average consumption was 427 gr / week for men and 274 gr / week for women.
• Statistical evidence is not strong in showing correlation between consumption of red meat and onset of cancer the right colon, however; a high intake of red meat and processed red meat were associated with an increase in RECTAL cancer (RR, 1.71, 95% CI, 1.15-2.52, P = .007).
• Problems of the current study: a subgroup and population analysis was not performed to discriminate the associated consumption of tobacco, which could generate a bias associated to the result.

Chan DSM, Lau R, Aune D, Vieira R, Greenwood DC, et al. (2011) Red and Processed Meat and Colorectal Cancer Incidence: Meta-Analysis of Prospective Studies. PLoS ONE 6 (6): e20456. doi: 10.1371 / journal.pone.0020456

• This is a meta-analysis (what more statistical evidence can generate in the epidemiological area) that brings together the statistical evidence of 10 prospective studies.
• From the combined RRs it is established that consumption of red meat and processed red meat was associated with an increase in colorectal cancer. The RRs combined for the highest consumption possible Versus the lowest possible consumption generated an RR of 1.22 (95% CI = 1.11 - 1.34).
• The RR (relative risk) per 100 grams / day of red meat consumed was 1.14 (95% CI = 1.04 - 1.24)
• However the risk did not follow a linear dose - response association, since after 140 gr / day consumed, the risk did not vary, reaching its plateau.

For those most experienced in epidemiology, the statistical weight diagram;

CONCLUSIONS

• The evidence is very clear, if you are eating meat, stop doing it, or at least reevaluate your cooking methods
• With the above articles it is not intended to discourage the consumption of red meat, it is only intended to expose a risk associated with this activity.

BIBLIOGRAPHY

https: // www-uptodate-com / contents / colorectal-cancer-epidemiology-risk-factors-and-protectivefactors? source = machineLearning & search = network% 20meat% 20consumption & selectedTitle = 1 ~ 150 & sectionRank = 1 & anchor = H93030307 # H2

http://chemistry.tutorvista.com/inorganic-chemistry/aromatic-hydrocarbons.html

Chao A, Thun MJ, Connell CJ, McCullough ML, Jacobs EJ, Flanders WD, Rodriguez C, Sinha R, Calle EE. Meat consumption and risk of colorectal cancer. JAMA. 2005 Jan 12; 293 (2): 172-82.

Chan DS, Lau R, Aune D, Vieira R, Greenwood DC, Kampman E, Norat T. Red meat and colorectal cancer incidence: meta-analysis of prospective studies. PLoS One. 2011; 6 (6): e20456. doi: 10.1371 / journal.pone.0020456. Epub 2011 Jun 6.

https://es.wikipedia.org/wiki/Riesgo_relativo

Appendix 1
RR: In statistics and epidemiology, the relative risk is the quotient between the risk in the group with the exposure factor or risk factor and the risk in the reference group (which does not have the exposure factor) as the association index.