Sunday, February 10, 2013

Red Meat and Cancer? Not if You Protect Yourself With Coffee. A Cup of Coffee With / After Meals Will Do the Trick

Coffee-Chile-Cocoa Rubbed Sirloin, Creamed Kale (recipe) - The perfect way to eat your red meats?
I just realized that the last SuppvVersity article on coffee is about three months old. In view of the myriad of health benefits that have and (I guarantee) will still be associated with habitual coffee consumption (examples: heart disease - Lopez-Garcia. 2006; diabetes - van Dam. 2005; cancer - Wilson. 2011). This is obviously something that has to be changed. Luckily, there are scientists like Roman Sirota and his colleagues from the Hebrew University of Jerusalem who keep the interesting papers coming. For the Israeli scientists, the beneficial effects the consumption of coffee - roasted-ground coffee, to be precise - appears to have on the influx of maldonialdehyde (MDA) from the gut was at the center of their latest experiments.

Real coffee, real benefits - Filter coffee, but not instant will do the trick

While this is not directly related to the MDA issue, it is still intriguing that past studies on the role of coffee consumption in the etiology of gastric cancer are highly inconclusive. While studies conducted in the US and Europe have shown hardly relevant increases (US) and decreases (EU) in gastric cancer risk with high vs. low coffee intake, data from South America suggests that coffee consumption reduces the incidence of gastric cancer by 46% (Botelho. 2006). Without understanding the underlying effects the consumption of coffee has on both, the gastrointestinal tract and the stuff that comes into our system via that route, it is however difficult to come up with potential explanations for this discrepancy; and this is where the observations Sirota et al. made could actually come handy.
Figure 1: A coffee made from ground Turkish coffee or green coffee bean powder enriched (2%) ground coffee with (and most likely also after) a red meat meal reduces the AUC of the serum MDA levels (nmol/L*min) in the postprandial phase by ~30% (* indicates p < 0.05; data based on Sirota. 2013)
As you can see in figure 1, the co-ingestion of coffee with a standardized  red-meat cutlet meal significantly the absorption of MDA and subsequent changes in plasma MDA concentration in the ten volunteers who participated in this randomized cross-over trial (all volunteers participated in all conditions).

While green bean enriched coffee is slightly more potent, regular ground coffee does suffice

Green coffee beans suppements which contain up to 80% polyphenols of which∼50% are CGAs can be used as an alternative to coffee from ground roasted bean and may also help you burn body fat (read more)
With MDA being the most abundant active carbonyl generated in foods from lipid peroxidation in vitro, and a concentration of up to 300 mol/kg in red meat, food borne malondialdehyde appears to pla an important role not only locally, but also systemically. And this can have far reaching health effects, since the surge of plasma MDA levels following a red-meat meal has the potential to oxidize the low density lipoproteins (LDL; Kanner. 2012). With oxidize LD being one of the main initiators of atherogenesis and in view of the fact that the removal of circulating modified-LDL (=oxidized LDL) particles from the blood  has been shown to prevent the development of atherosclerosis without having to resort to statin therapy and irrespective of the total amount of LDL (Ishigaki. 2008), the importance Sirota et al.'s results can hardly be overestimated.

And while it is important to note that green coffee bean powders and extracts could be an alternative (see image on the right) for all of you who are not into drinking coffee, the instant and most probably even the standard "pad coffees" are no suitable alternative to the ground coffee beans used in this study, because their MDA inhibitory effect on muscle food lipid peroxidation is 2-5x lower than that of a cup of coffee from ground roasted beans.
Did you know that Coffee is also a testosterone booster? In this case it does yet appear as if the major player is caffeine, which probably does not play a role as far as the anti-MDA effects in the study at hand are concerned (learn more).
How does the protective effect work and is it red meat specific? The anti-oxidants blunt the pro-oxidative iron-redox cycle catalysis. Obviously this does happen in the gut first, but the beneficial effects don't stop at the wall of your intestines. The combination of lower MDA influx and increased circulating antioxidants will have systemic effects and could also help blunt the exercise induced increases in malondialdehyde (specifically in the presence of high amounts of highly oxidizable omega-3s, cf. "Increased Lipid Oxidation in Athletes With Omega-3 PUFAs"). What's more, the beneficial effects on lipid peroxidation appear for once to be independent of the caffeine content of coffee... the word "appear" does yet indicate that this hypothesis of mine and the efficacy of decaf. would still have to be experimental verified.
As Sirota et al. hypothesize, this is probably due to the extraction process that's used to produce instant, coffee. The latter extracts "only the hydrophilic, more soluble, and small polyphenols molecules" and leaves the more efficient hydrophobic polyphenols in the "waste" that's generated during this process. Similar but less pronounced differences will obviously be observed when you compare different brands of  roasted coffee or - as the producer of the enriched coffee brand used in the study did it - simply add a couple of mg of coffee bean extract.

So thumbs up for the post-meat-meal-coffee, right?

Table 1: Coffee doesn't only have the highest polyphenol content on a per serving base (compared to other "high potentials" as black tea, green tea, cacao and even berries and cherries), the polyphenols also make it into the lumen, where they work (among other things) their anti-MDA effects (Williamson. 2012).
As the researchers, whose study was supported by a grand from the Israeli National Science Foundation and who declare no conflict of interest point out, their
"[...] results seem to be of great importance for further investigations on the involvement of dietary polyphenols and other antioxidants in human health." (Sirota. 2013)
Moreover, their study appears to support their hypothesis that "coffee, the most popular beverage in the world, supplies the most significant portion of daily in-take of dietary antioxidants" (Sirota. 2013) - a contribution that's significant enough to "effectively control lipid peroxidation in the stomach medium and thus prevent post-prandial absorption and plasma MDA modification" (Sirota. 2013).

And the researchers even have a very concrete advice for you: Time your coffee intake so that you get it either the Italian way, right after, or as in their study right with a potential high MDA meal. Ok, I got to admit this is no exact quotation any longer, but basically it is what they wrote. Plus, this way it spares me to write an extra "bottom line" to which I just have to add that taking up drinking coffee (or tea) if you don't like it is not mandatory to survive meat consumption and that people who suffer from low iron levels should keep in mind that the coffee and tea (and other) phenols will inhibit the absorption of heme- and even more non-heme iron. 

References:
  • Botelho F, Lunet N, Barros H. Coffee and gastric cancer: systematic review and meta-analysis. Cad Saude Publica. 2006 May;22(5):889-900. Epub 2006 Apr 28. Review. 
  • Ishigaki Y, Katagiri H, Gao J, Yamada T, Imai J, Uno K, Hasegawa Y, Kaneko K, Ogihara T, Ishihara H, Sato Y, Takikawa K, Nishimichi N, Matsuda H, Sawamura T, Oka Y. Impact of plasma oxidized low-density lipoprotein removal on atherosclerosis. Circulation. 2008 Jul 1;118(1):75-83.
  • Kanner J, Gorelik S, Roman S, Kohen R. Protection by polyphenols of postprandial human plasma and low-density lipoprotein modification: the stomach as a bioreactor. J Agric Food Chem. 2012 Sep 12;60(36):8790-6.
  • Lopez-Garcia E, van Dam RM, Willett WC, Rimm EB, Manson JE, Stampfer MJ, Rexrode KM, Hu FB. Coffee consumption and coronary heart disease in men and women: a prospective cohort study. Circulation. 2006 May 2;113(17):2045-53. 
  • Sirota R, Gorelik S, Harris R, Kohen R, Kanner J. Coffee polyphenols protect human plasma from postprandial carbonyl modiļ¬cations.Mol. Nutr. Food Res. 2013; 00: 1–4.
  • van Dam RM, Hu FB. Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA. 2005 Jul 6;294(1):97-104. Review.
  • Williamson G. Possible effects of dietary polyphenols on sugar absorption and digestion. Mol Nutr Food Res. 2013 Jan;57(1):48-57. doi: 10.1002/mnfr.201200511. Epub 2012 Nov 26.
  • Wilson KM, Kasperzyk JL, Rider JR, Kenfield S, van Dam RM, Stampfer MJ, Giovannucci E, Mucci LA. Coffee consumption and prostate cancer risk and progression in the Health Professionals Follow-up Study. J Natl Cancer Inst. 2011 Jun 8;103(11):876-84.