Here we examine the evidence of coffee drinking and its effect on causing or preventing cancer, likewise its effect upon cancer deaths as well as cardiovascular disease deaths (which includes heart disease, strokes etc) and deaths form all-causes. Further we will look at the few studies that deal with coffee enemas and its effects compared to coffee drinking. Finally we will look at treatments that include coffee enemas for cancer treatment and compare them to conventional mainstream treatment.
Coffee enemas have been used for some time particularly before the age of evidence-based medicine and has been based mainly upon the concept of purging excesses from the body in order to achieve ‘humoral’ balance. It is currently advocated in many illnesses particularly by naturopaths to treat cognitive problems, colonic infections & parasites, anxiety, depression and even insomnia (despite the caffeine effect which is still absorbed rectally). However are these claims substantiated by evidence?
Observational studies, Evidence and Terminology
Studies involving diet and life style are difficult to interpret due to confounding factors. Patterns of diet are interrelated with other habitual behaviour that may affect the risk of cancer, such as smoking, obesity or physical activity; people who habitually consume any type of diet for the sake of their health or for reasons of belief, may also modify other aspects of their way of life. This is likely to confound results that appear to show associations with the risk of cancer. An array of prospective cohort studies have reported for both men and women that heavy coffee drinkers were likely to smoke more cigarettes, consume more alcoholic beverages and do less physical exercise which are all independent risk factors (called confounding factors) for illness such as cancer. One needs to keep these confounding factors in mind and see how any investigators have adjusted for them. Observational studies are of varying quality and levels of strength.
- If several robust studies point to the same significant effect then we would regard that as a convincing evidence in the prevention of that illness.
- If the studies are slightly weaker or a robust isolated study (particularly if industry funded) then it maybe said it is a possible or plausible effect.
- If there are several weaknesses with preliminary study or studies pointing in a general trend they would be regarded as being limited evidence.
- If similar quality studies are conflicting it would be regarded as inconclusive or inconsistent evidence.
- If the evidence is all glamour and no real case study or trial then it is said there is no evidence.
It is upon the promoter of any treatment to prove effectiveness with evidence of any benefits out-weighing any harms. All treatments are false until proven otherwise by way of evidence. If the situation was reversed, anyone could sell anything as a claimed treatment or illness prevention. Theoretical arguments are a means to undertake a study thereby testing a hypothesis, they are not the means to claim cure merely because the explanation appears plausible. Unfortunately in the age of social media, YouTube and movie documentaries, fraudsters have turned to public relation advertisements to promote their quackery. However the origin is that clinical evidence is required to prove a beneficial effect; either an increase in survival, relief or an absolute cure. As for experimentation than that is left for the realm of clinical trials and not advocated as treatment except where there is no other known cure or partial treatment for longevity. Unfortunately these plausible theoretical concepts are promoted and accepted as realities and cures. This is clear fraudulent behaviour that is in need of being reprimanded. These reprimands become more severe when the specialists in the fields of those illnesses inform of the lack of evidence of such promoted treatments.
Do the claims of coffee enemas compared to coffee drinking stand up to the required evidence? Is it a cancer cure or is it quackery?
Does Drinking Coffee cause Cancer?
There were some earlier concerns as investigated by International Agency for Research on Cancer (IARC), a group of international cancer experts convened by the World Health Organisation, that the studies prior to 1991 possibly suggested that drinking coffee may have been a cause for increasing the risk of developing cancer; namely oesophageal and bladder cancer. Since then, larger and more robust trials have failed to show that drinking coffee increases the risk of bladder cancer. In the light of such studies, IARC have recently re-evaluated the research thereby concluding that hot beverages, above 65 degrees Celsius, are linked to oesophageal cancer, however drinking coffee itself has no strong evidence to support the notion that coffee increases the risk of developing cancer. Incidently, they have also recently discussed ‘processed red meat’ as a carcinogen which received a great amount of publicity.
There are some concerns of lung cancer being more prevalent in coffee drinkers (particularly caffeinated coffee) however as confounding of smoking has not been accounted for, as it is highly likely that those that smoke drink more coffee (as stated earlier); hence more research is required before plausibility can be stated. Studies that have accounted for smoking suggested the increased risk among high intake (> 4 cups/day) coffee drinkers was in smokers and not found in non-smokers. This increased association was seen in men and not women. This association has likewise been seen in another more robust meta-analysis as we will go onto discuss later.
Does Drinking Coffee Reduce Cancer from Developing?
There are some studies to suggest drinking coffee may reduce the risk of developing liver cancer (hepatocellular carcinoma) as assessed by a meta-analysis of 6 cohort studies in 2015 by World Cancer Research Fund (which is charity/community funded). Although they concluded there was a strong risk reduction however the studies did not account for all the risk factors such as underlying liver disease and thus further studies are required before being conclusive; hence they are regarded as plausible only. Incidentally green tea drinking did not have any significant effect on risk reduction. Likewise they have also looked at endometrial (womb) cancer in 2013 which suggested a probable reduced risk in women who drank coffee daily (with the effect seen both in caffeinated and decaffeinated coffee). This meta-analysis of cohort studies was only pushed in to the positive effect by less robust studies, and again further studies are required for a conclusive convincing effect.
A more updated meta-analysis, that we mentioned earlier, looked at prospective cohorts and demonstrated that drinking coffee can reduce the risk of oral cancer, pharyngeal (throat) cancer, colon cancer, liver cancer, prostate cancer, endometrial cancer and melanoma (skin). While no significant association were found with esophageal (food-pipe) cancer, stomach cancer, rectal cancer, pancreatic cancer, renal (kidney) cancer, bladder cancer, prostate cancer, breast cancer, ovarian cancer and lymphoma. Despite this, coffee intake appeared to increase the risk of lung cancer. However not all confounders were accounted for making the results plausible but not convincingly conclusive. There are individual studies that point to a similar pattern with this increase in smokers only.
Does Drinking Coffee reduce Deaths from Cancer, Heart disease & All-causes?
One must also keep in mind, our experience where treatments and preventative measures that can help with one illness but then cause harm with other illnesses; at times this can lead to overall more harm and early death. This has been the case with multivitamins & antioxidant supplements which had no benefit in cancer prevention rather increased the risk of bladder cancer. Furthermore, Vitamin A, Vitamin E and beta-carotene increased all-cause mortality (deaths). This effect is with supplements alone and not food that contains those elements. This is despite evidence that clearly shows benefits with similar supplements in some illnesses such as eye-diseases like age-related macular degeneration. There are many other examples of this such as medication that reduced muscle inflammation but increased cardiovascular deaths. Thus this topic of looking at hard-endpoints of death or morbidity is always our main focus rather than looking at surrogate soft-endpoint markers such as the of effect on blood pressure, cholesterol, oxidative stress or inflammation etc. These latter soft-end points are often the theoretical explanations used to try to convince the everyday person of an effect of cure.
A meta-analysis of 31 prospective cohort studies of the general population from US, Europe and Far East populations comparing coffee drinkers to non drinkers and assessing if the amount of coffee per day (dose-dependence) made a difference. The endpoints were deaths (mortality) caused by cancers, cardiovascular disease (CVD) and deaths from all causes (all-cause mortality).
Compared with no coffee consumption, all-cause mortality for 4 cups/day of coffee was reduced by 16% and for cardiovascular disease (CVD) mortality was reduced by 17%, while increased intake of coffee showed no further lowering of risk. Risk of stroke was lowered by 28%. No statistical significant association was found between coffee consumption and cancer mortality risk.
Adjustment for smoking status did not change findings other than resulting in a stronger association between coffee and CVD mortality. When considering non-smokers alone, there was a significant decreased risk with a linear dose-response such that the risk reduced by 6 % for each additional cup of coffee per day consumed for all-cause and CVD mortality and borderline significant decreased risk of 2 % for cancer mortality (RR 0.98, 95 % CI = 0.96, 1.00).
Interestingly, older studies (publication year prior 2010) and consumption of caffeinated, rather than decaffeinated coffee were mostly trending towards an increased risk of cancer mortality associated with increased intake of coffee, although not reaching statistical significance except at 6 or more cups per day.
In summary a relatively robust meta-analysis gives convincing evidence to support that coffee drinking gives a reduction in all cause mortality of about 16% (for 3-4 cups daily). It appears that the effect is more by way of cardiovascular deaths than cancer deaths.
Is the evidence at the level where this can be advocated to the general public? We are not quite there yet and several other questions remain unanswered as to which type of coffee is best, such as boiled, filtered, instant, roasted, etc. Also caffeinated verses decaffeinated needs a further investigation to reduce the confidence intervals thereby giving greater element of certainty. But if one is already drinking coffee then it isn’t a bad thing. Personally I don’t drink coffee as I have never liked it, the main effect is thought (will discuss in detail later) to be the result in polyphenols which are found in many fruits, nuts and olive oil with the latter two giving more impressive results (almost double at 30% reduction of all cause mortality) as we have discussed elsewhere.
Can Coffee Drinking Cure Established Cancer?
All the aforementioned studies looked at associations of reducing the risk of developing cancer and then dying from it or dying from other causes. The fact that people were still dying from cancer (although at a reduced rate) even though they drank coffee many years prior to developing cancer shows it is unlikely to be a major cure. There are no studies of suitable standard that use coffee drinking as a means to shrink or cure cancer or even increase in patient longevity/survival.
The means of preventing illness are not necessarily the same as the means to curing that same illness. For example drinking water is needed to prevent dehydration and in turn renal impairment, however chronic dehydration can lead to chronic renal impairment and once this been fully established over a prolonged period than drinking water even at an increased rate will not cure the chronic renal impairment. Hence the means of prevention are not the means to a cure. Rather coffee drinking as a means to cure an established cancer requires verification by way of acceptable evidence independent of prevention.
There are no such studies. We do have some preliminary studies as discussed in a review article that shows glutathione may help to reduce some of the neurological side-effects of some chemotherapy agents in cancer patients and also to help make the chemotherapy more sensitive in resistant cancers. However the glutathione was not given in the form of coffee (as coffee has more than glutathione effect) and secondly the glutathione was not treating the cancer it was helping to reduce side-effects and also helping chemotherapy-resistant tumours to become more sensitive to the original chemotherapy. If glutathione had some great cancer treating property than those studies would have identified that. Hence the notion of glutathione as a convincingly established adjuvant treatment is underpinned with a poor scientific basis.
Coffee enema is inserting the coffee, usually after brewing and then cooling, into the back passage (rectum) and holding it for at least 15 minutes before defecation. Some have hypothesized that this may give a faster or greater effect as it avoids the digestive process. There is no problem postulating this however before it can be advocated as a reality, or even as a treatment, there needs to be evidence to confirm that the hypothesis is true. Historically, scientific and medical studies have shown in the majority of cases hypotheses are not proven to be true.
Suggested Mechanism of action
The protective mechanism of possible reduction in developing cancer and heart disease is unknown but several have been hypothesized that it maybe an antioxidant effect in particular the chlorgenic acids and other polyphenols which improve insulin sensitivity and inhibit key enzymes involved in tumour genesis and metastasis. Among other components, kaweol and cafestol have been proposed as possible antitumour agents due to their capacity of regulating angiogenesis, apoptosis, inflammation process partially by promoting glutathione S-transferase (GST) enzyme.
Aflaxatoxins are fungi that can grow on certain foods and there is convincing evidence that they are a cause liver cancer and likewise there is convincing evidence that glutathione S-transferase (GST) is an enzyme involved in the metabolic pathway that protects against aflatoxins and several other carcinogens. This protective effect only occurs at the time those carcinogens are exposed to the body. There is no evidence of coffee, kaweol and cafestol, glutathione (GSH) or glutathione S-transferase (GST) enzyme promotion cure once liver cancer has been established, by way of aflaxatoxins or any other carcinogen.
As mentioned before, protection against an illness is not the same as its cure once the illness has established itself. We have already discussed glutathione been used as adjuvant in the last heading without any major break through in cancer cure. The ‘coffee enema proponents’ promoted their treatment well before glutathione and GST protection against aflatoxins was recognised. But once GST was recognised they jump on these studies and try to use them to push an agenda that they had already pre-conceived without any plausible evidence.
Coffee Drinking compared to Coffee Enemas: Are the Anti-oxidant effects different?
‘Coffee enema proponents’ claim kaweol and cafestol from coffee enemas has a greater effect on glutathione and glutathione-S transferase enzyme and becomes more available to the liver more so than when taken orally, yet again without any plausible evidence to support such notions rather what little evidence that does exist opposes such a concept, as we will go onto discuss.
Coffee enemas became popular in modern times following Max Gerson’s Protocol which we have discussed in detail elsewhere. In particular we discussed Gerson not having any expertise in oncology (cancer care) and neither nutritional medicine. As a result the evidence he presented, so-called fifty cases, composed predominately (but not exclusively) of misdiagnoses of cancers; thereby falling into error regarding their cures. Likewise we discussed the inability of the two centers, in Hungary & Mexico, advocated by the Gerson Institute, with the former two charging large sums of money, in the tens of thousands for 2 weeks, yet being unable to produce any evidence of cure or even longevity til this day. Furthermore the Gerson Institute claims:
Doctors at the University of Minnesota showed that coffee administered rectally also stimulates an enzyme system in the liver called glutathione S-transferase by 600%-700% above normal activity levels References: ... Liver Detoxification with Coffee Enemas by Morton Walker, DPM excerpted from July 2001 edition of Townsend Newsletter.
However if one follows up the Gerson Institutes reference citation we find the details that led to the above quoted statement of “600-700%” is based upon studies in rodents like mice where the coffee was added to their diets (i.e. taken by mouth). There is no mention of the rodents being given enemas so the very evidence they are claiming does not substantiate their claim. Further they are making the assumption that the effect in the rodent diet will translate into an enema effect in humans, again without providing any plausible evidence; on the contrary, such a claim is very dubious indeed. Furthermore there was no comparison between the effects of coffee in the diet compared to that taken as an enema. Rather they use anything they can find to try to deceive everyday people into thinking they pre-conceived theory is plausible and backed with evidence, which is a complete contradiction to the reality. Their statements are in the caption below.
In contrast if we explore the only limited human study that compared the effects of coffee orally against that of cofffee enema. In healthy individuals (a randomized two-phase crossover) study investigated the antioxidant effects after single and multiple doses of a coffee enema compared against drinking coffee orally. The researchers used three different measurements of antioxidant activity from blood samples: levels of glutathione hormone (GSH), malondialdehyde (MDA) and trolox equivalent antioxidant capacity (TEAC). For all three measurements, there was no major difference between drinking a cup of coffee versus administration via enema, even when repeated over many days. This study like several others is not without limitations in their size, duration and not measuring tissue concentrations of glutathione hormone (GSH). However, there is limited evidence to support that the concentration of blood GSH reflects the liver cell concentration.
This study gives support to the refutation of the false claims of many ‘coffee enema proponents’ who frequently state coffee enemas have a greater effect than drinking coffee in humans.
Coffee Drinking compared to Coffee Enemas : Is there a greater Caffeine effect?
Some ‘coffee enema proponents’ also claim that caffeine has a greater effect on biliary duct dilation when given as enemas as compared to drinking, again doing so without any substantiated evidence. What limited evidence that does exist demonstrated caffeine from oral coffee consumption (CC) was greater than that from a coffee enema (CE) in humans. Furthermore, human studies demonstrate coffee enemas do not increase bile salt secretion in to the bowels as compared to no coffee usage; refuting the very concept of ‘bad bile detoxification’.
But Coffee Enemas are harmless !? …Aren’t they?
Furthermore, there are case studies showing potential harm from coffee enemas including several cases of rectal burns induced by hot enema fluid and even rectal perforation, however one could argue that was the effect of heat. However, even in the absence of heat, there have been several case reports of proctocolitis, polymicrobial enteric septicemia, electrolyte imbalance and even deaths. With the presence of considerable life threatening side effects then again studies are needed to determine their frequency which is a duty upon those that advocate such treatment; their inability to fulfill such basic professional duties is a demonstration of their serious of their ‘duty to care’ or the lack there of.
So clearly coffee enemas are not a harmless procedure but one that comes with many serious risks to health, risks that are not seen with ordinary moderate coffee drinking with the latter reducing all-cause mortality in the general population and even cancer mortality in non-smokers (although only marginally statistically significant) as already discussed.
Likewise if a person leaves a proven treatment for an unproven treatment their cancer will progress and possibly spread (metastasize). This makes the later return to efficacy proven conventional treatments more riskier with a more poor outcome (prognosis).
Do Coffee Enemas treat Cancer or improve survival?
So far we have discussed the effects of coffee enema treatment in the general population or in healthy individuals. It could be argued the case is different in cancer treatment, just as if you gave immunotherapy or cancer hormonal treatments to healthy individuals you would expect to see some harmful side effects. In reply to this notion, firstly, it would not be advocated by medical experts to healthy individuals (except in preliminary studies), secondly, the side effects would not be as serious as the harms of septicaemia and death as reported with coffee enemas, and thirdly, coffee enemas as a treatment of cancer has been investigated as we will go onto discuss.
Gonzalez regimen is a derivative of the Gerson Protocol. The Gonzalez regimen includes use of pancreatic enzymes, along with nutritional supplements, coffee enemas, and prescriptive diets based on a theory of autonomic dominance. The exact diet is different from patient to patient. An example of the Gonzalez regimen for a patient with pancreatic cancer (adenocarcinoma) would be the following:
- A diet that emphasizes fresh raw fruits, raw and lightly steamed vegetables, and freshly made vegetable juice daily. The diet protocol relies on plant-based sources such as cereals, nuts, and seeds and whole-grain products such as whole-grain bread and brown rice. The patient may eat one or two eggs daily, whole-milk yogurt daily, and fish two or three times a week, but no red meat or poultry.
- Nutritional supplements that include vitamins, minerals, and trace elements. Also prescribed are certain freeze-dried organ concentrates such as thymus and liver, derived from beef or lamb. (similarly, Gerson advocated daily injectable calf or veal raw liver extract with vitamin B12).
- Ingestion of 25 g to 40 g of porcine lyophilized pancreas product daily, in capsule form, taken away from meals and spread evenly throughout the day. The total number of capsules taken per day by each cancer patient on the Gonzalez regimen typically ranges from 130 to 160, taken with and away from meals. (similarly, Gerson advocated prancreatin, pancreatic enzymes).
- Coffee enemas are also included as part of the “detoxification” process. The enemas were administered twice daily.
An initial very limited pilot study on 11 patients performed by Gonzalez himself showed some encouraging results of slightly increased longevity although no full cure at 5 years. Gonzalez reported a median survival time of 17 months and a mean survival time of 25.2 months for these patients. There were problems with the study, firstly there was no control group, secondly, up to 25 patients who were already taking Gonzalez regimen were excluded from the study some on the grounds of poor compliance others on the grounds of other co-morbidities (other unlinked illnesses). These encouraging finding were not were not reproducible in a more robust trial as we will go onto discuss where a median survival of 4.3 months was demonstrated.
The larger more robust study, a prospective case-control observational study, sponsored by the National Center for Complementary and Integrative Health and the National Cancer Institute was undertaken. Here Gonzalez regimen (32 patients) was compared to (23 patients on) standard mainstream therapy of mainly chemotherapy like gemcitabine. The results demonstrated median survival and quality of life were found to be better in patients treated with chemotherapy than for patients treated with the Gonzalez regimen. The two groups had similar clinical characteristics. The median survival for the patients in the chemotherapy arm was 14 months, while on the enzyme arm was 4.3 months. The quality of life as measured by the FACT-PA was also better in the chemotherapy arm.
This is the only real trial that we have that involved nutrition and coffee enema’s compared to standard chemotherapy with the latter having triple the median survival.
Chemotherapy does not cure all cancers, that is well recognised among oncologists and the general public, however what is not recognised is that it does help to cure some cancers and in others types of cancers it helps to prolong survival and quality of life.
Cancer survival has doubled in the last 40 years for overall-cancer with evidence to back this up. Further, there are more promising treatments as time progresses like newer hormonal therapy, immunotherapy and germline antigen vaccines. This has always been the case throughout history that illness that were once regarded as possibly terminal are no longer classed as such with the advancement of modern medicine; illnesses like tuberculosis, certain malaria’s, etc.
The bottom line is that there is convincing evidence that drinking coffee helps to reduces several cancers. There is inconclusive evidence that it may increase lung cancer development particularly in cigarette smokers.
That coffee drinking reduces all-cause mortality (16% reduction for 4 cups/day), with a similar reduction in cardiovascular disease mortality and only a marginal statistical significant reduction in cancer mortality (2% reduction for 4 cups daily in non-smokers).
In contrast, there is no evidence to directly suggest coffee enemas help to prevent cancer, cancer deaths, cardiovascular deaths or all-cause deaths.
There is limited evidence that in humans drinking coffee has a similar effects to coffee enemas on glutathione hormone and a few other antioxidant biochemical markers. However whether this translates in to coffee enemas reducing all-cause death, cardiovascular death or even cancer deaths is not yet been established by way of any direct evidence.
Coffee enemas can present with serious side effects including septicaemia and deaths; which is not see with drinking coffee.
There is no evidence that drinking coffee cures cancer and likewise no evidence for coffee enemas. On the contrary, there is plausible evidence that Gonzalez regimen that includes coffee enemas gives a three times worse survival outcome compared to conventional treatment that includes chemotherapy in pancreatic cancer patients.
This discussion of coffee enemas is not an issue of conflicting evidence, or differing views among oncologists,nutritional physicians or dietitians, rather experts point out the weakness of evidence of coffee enema treatment in cancer. Given the serious potential harms of coffee enemas, then advocating such treatments needs to be reprimanded. So when oncologist, nutritional physicians and dietitians state that there is no evidence for such blatant quackery then the reprimand is far worse from an Islamic perspective.