Coffee and Tea Aid Livers and Prostate
Caffeine may help prevent fatty liver; Coffee confirmed as a curb on prostate cancer
9/16/2013By Craig Weatherby
Health pundits have long denigrated coffee as devilish and acclaimed tea as angelic.
But – like other beliefs based on a faddish affinity for East Asian traditions – that divide has dissolved into an evidence-free distraction.
We reported some of the growing good news about coffee and caffeine previously … see the Cocoa, Tea & Coffee section of our news archive.
Two new studies add to growing evidence that the caffeine and polyphenol-type antioxidants in coffee and tea provide separate and overlapping health benefits.
Prior signs that coffee may deter prostate cancer
Two years ago, Harvard researchers reported their discovery of a link between higher coffee intake and lower risk of prostate cancer (Wilson KM et al. 2011).
Men who drank six or more cups per day were 18 percent less likely to develop prostate cancer compared with non-drinkers, and were 60 percent less likely to develop metastatic/lethal prostate cancer.
(High coffee consumption was not linked to a lower risk of early or low-grade cancers and was only weakly associated with a lower risk for uncommon, aggressive, “high-grade” cancer.)
The risk reductions were similar for drinkers of regular or decaf coffee, so, as the authors concluded, “The association appears to be related to non-caffeine components of coffee.” (Wilson KM et al. 2011)
By “non-caffeine components of coffee”, the authors meant polyphenol compounds, which are commonly called antioxidants.
However, the proven antioxidant and anti-inflammatory effects of polyphenols in the human body are indirect, and stem from their beneficial “nutrigenomic” influence on people’s genes.
Now, the results of a U.S.-Dutch study in men diagnosed with prostate cancer suggest that men who drink more than four cups of coffee a day are 59 percent less likely see their cancer recur and/or progress, compared with those who drink only one or fewer cups per week.
New U.S.-Dutch study sees coffee deterring prostate cancer
Researchers from the U.S. and the Netherlands report encouraging news for coffee lovers.
A team led by Dr. Janet Stanford from Seattle’s Fred Hutchinson Cancer Research Center and Milan Geybels of Holland's Maastricht University led the study.
Their team recruited 1,001 prostate cancer survivors who were aged 35-74 years when they were diagnosed (Geybels MS et al. 2013).
Participating men were asked to recount their diet and beverage habits during the two years before their diagnosis, as well as their demographic (age, education, etc.) and lifestyle information, family history of cancer, use of medications, and more.
The researchers contacted the prostate cancer patients more than five years after diagnosis to see whether their cancer had recurred and/or progressed.
All told, 630 men answered questions regarding coffee intake, fit the follow-up criteria, and were included in the final analysis.
Of those, 61 percent consumed at least one cup of coffee per day and 12 percent consumed four or more cups per day.
The U.S.-Dutch analysis showed that men who drank four or more cups of coffee per day experienced a 59 percent drop in the risk of prostate cancer recurrence and/or progression, compared with patients who drank one cup or less per week.
The study included too few men who died of prostate cancer to allow a meaningful conclusion about coffee’s ability to reduce the risk of dying from prostate cancer.
This international study had advantages over previous ones – such as the 2011 Harvard study described above – because the authors gathered detailed data on prostate-specific antigen (PSA) levels, secondary treatment for prostate cancer, and the results of scans and biopsies.
Access to such unusually detailed data allowed the authors to determine whether a patient showed evidence of prostate cancer recurrence or progression.
The U.S.-Dutch team proposed that coffee’s anti-inflammatory and antioxidant effects – produced by polyphenols – reduce the risk of recurrence or progression of prostate cancer.
They cautioned that men with hypertension should probably not drink four or more cups of regular coffee daily – due the blood-pressure-raising effects of caffeine – while other components in regular and decaf coffee (e.g., organic acids) may raise blood cholesterol levels in some men.
Caffeine deters fatty liver disease
An international team led by Duke University scientists linked higher intakes of caffeine with reduced risk of fatty liver in people with non-alcoholic fatty liver disease (NAFLD).
Worldwide, 70 percent of people diagnosed with diabetes and obesity have NAFLD, which is the major cause of fatty liver not caused by excessive alcohol consumption.
Excessive consumption of fructose, which – unlike glucose – is processed in the liver and is linked to increased risk for NAFLD.
(Both cane sugar and high-fructose corn syrup consist of one molecule each of glucose and fructose.)
Almost one in three American adults have NAFLD, for which diet and exercise remain the only effective treatments.
The study authors report that caffeine stimulated the metabolization (burning or excretion) of lipids (fats) stored in human liver cells, and lowered fat levels in mice fed a high-fat diet (Sinha RA et al. 2013).
Their findings suggest that consuming the amount of caffeine in of four cups of coffee or tea daily may help prevent NAFLD and/or protect against its progression.
The team said this research could serve as a starting point for studies on the full benefits of caffeine.
The study was supported by funding from Singapore’s Agency for Science, Technology, and Research.
Sources
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Duke University (DU). Coffee and Tea May Contribute to a Healthy Liver. August 16, 2013 Accessed at http://www.dukehealth.org/health_library/news/
Geybels MS, Neuhouser ML, Wright JL, Stott-Miller M, Stanford JL. Coffee and tea consumption in relation to prostate cancer prognosis. Cancer Causes Control. 2013 Aug 2. [Epub ahead of print]
Jang HH, Park MY, Kim HW, Lee YM, Hwang KA, Park JH, Park DS, Kwon O. Black rice (Oryza sativa L.) extract attenuates hepatic steatosis in C57BL/6 J mice fed a high-fat diet via fatty acid oxidation. Nutr Metab (Lond). 2012 Mar 30;9(1):27. doi: 10.1186/1743-7075-9-27.
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Sinha RA, Farah BL, Singh BK, Siddique MM, Li Y, Wu Y, Ilkayeva OR, Gooding J, Ching J, Zhou J, Martinez L, Xie S, Bay BH, Summers SA, Newgard CB, Yen PM. Caffeine stimulates hepatic lipid metabolism via autophagy-lysosomal pathway. Hepatology. 2013 Aug 8. doi: 10.1002/hep.26667. [Epub ahead of print]
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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. doi: 10.1093/jnci/djr151. Epub 2011 May 17.