Every morning, many of us sip our coffee with no real thought given to the beans behind the brew. But coffee beans are extra-ordinarily complex fruits containing over 1,000 compounds – only a handful of which have ever been individually investigated by scientists. Not only is coffee packed with antioxidants, but it is the greatest source of antioxidants in the American diet.
The average American coffee drinker consumes about 3.1 cups of coffee a day,5 but extensive research has found that higher volumes – as much as 4 to 12 cups daily – can help prevent most major killers, including cardiovascular disease, cancer, diabetes, liver disease, and Alzheimer’s disease.
For instance, in case-controlled human studies, compared to coffee abstainers, those who drank the most coffee cut their risks of breast cancer by 57% and diabetes by 67%.
In this article, you will learn about recent research into the benefits of coffee consumption, what’s missing from most commercial coffee beans, and what people should do who are overly sensitive to coffee beverages.
Health authorities expressed alarm over the mushrooming epidemic status of diabetes after a July, 2011, study in Lancet shocked even experts with its estimate of 347 million diabetics worldwide. Then, the International Diabetes Federation presented evidence on September 13, 2011, that the real total is closer to 366 million.
Scientific studies have found that regular coffee consumption (with its chlorogenic acid content) lowers the risk of type 2 diabetes by up to 67%. This appears to result from reduced levels of blood glucose, increased insulin sensitivity, and decreased storage of both fat and carbohydrate.
In one of a number of studies, a 2009 meta-analysis in the Annals of Internal Medicine combined data on over 450,000 people and found that every additional cup per day of caffeinated or decaffeinated coffee lowered the risk of diabetes by 5 to 10%.
Many epidemiological studies show that the risk of diabetes drops directly according to the amount of coffee consumed. For instance, scientists found that overall risk is reduced by:
- 1. 13% with one cup a day,
- 2. 47% with 4 cups a day
- 3. 67% with 12 cups a day.
Scientists are beginning to learn how chlorogenic acid, a potent constituent of both raw and brewed coffee, can be directly tied to an anti-diabetic effect. Investigation has shown it substantially interferes with glucose synthesis and release in the body. It appears to accomplish this by inhibiting the pathway of glucose-6-phosphatase, a glucose-regulating enzyme, which in turn results in a reduction of sugar levels in the blood.
Chlorogenic acid also lessens the hyperglycemic peak associated with carbohydrate ingestion. This results in a downturn in insulin activity, and a reduced accumulation of adipose (fat-storing) tissue.
Unidentified compounds in coffee, as well as caffeine itself, may be boosting the preventive effect of chlorogenic acid against diabetes. Preliminary studies suggest that these chemicals may lower carbohydrate storage by 35% and improve insulin sensitivity.
Coffee was previously found to inhibit iron absorption.29 Later, in 2004, scientists found a direct link between reduced storage of iron in the body and a lower risk of diabetes type 2, independent of other risk factors.
Cancer Risk Reduction
Early studies are reporting an association between higher coffee consumption and a reduced risk of various cancers.
For instance, at a time when prostate cancer is the second leading cause of cancer death among American men (after lung cancer), a promising study appeared in the June 8, 2011, issue of the Journal of the National Cancer Institute. The research team reported that men who drank over 6 cups of coffee a day had an 18% lower risk of prostate cancer – and a 40% lower risk of aggressive or lethal prostate cancer. This effect was noted for decaffeinated as well as caffeinated coffee – indicating that compounds other than caffeine are responsible for this preventive effect. Constituents in coffee seem to improve insulin levels and sensitivity, hypothesized to play a role in prostate cancer progression.
With breast cancer ranked as the second leading cause of cancer death among American women (after lung cancer), potentially good news arrived recently in the form of a study finding that coffee consumption may help prevent a specific form of this disease. The May 14, 2011, issue of Breast Cancer Research reported that postmenopausal women who consumed cups of coffee daily exhibited a 57% decrease in their risk of developing ER-negative (non-hormone-responsive) breast cancer, a form of cancer that is especially difficult to treat. This builds on an earlier study in which 2 or more cups of coffee per day was shown to delay the onset of breast cancer in women with a certain genetic type. Chlorogenic acid, caffeic acid, phytoestrogens, and caffeine – all found in coffee – are suspected of playing a major role.
Colorectal cancer is the second most common cause of cancer-related deaths in the US overall (when the statistics for both sexes are combined). While colonoscopy screening is a useful tool for detecting cancers or pre-cancerous polyps, researchers have long hoped to find ways to prevent these cancers in the first place. The good news is that a large meta-analysis has reviewed the combined data from 24 previous studies and found an overall 30% lower incidence of colorectal cancer among those categorized as heavy coffee drinkers. This confirms the findings from several earlier studies.
There is a 15% chance that patients who are diagnosed with an oral or pharyngeal cancer will be found to have another cancer somewhere in the same area of the body such as the larynx (voice box), esophagus, or lung. But early research suggests the promise of preventing these types of cancers from occurring. A case control study found that individuals who consumed more than three cups of coffee daily had a 40% lower risk of oral, pharyngeal, and esophageal cancers, compared to those who drank one cup of coffee or less each day. A second study made the same strong connection.
For several decades, liver cancer has been on the rise among Americans. Liver cancer has become a leading cause of cancer deaths worldwide, due to higher rates in some other parts of the world. In recent years, however, studies have been accumulating that suggest a substantially reduced risk of this disease among coffee drinkers. In a 2005 study, for example, just one cup a day was associated with a 42% lower risk of liver cancer. A number of studies have reported similar conclusions.
As the leading cause of death, cardiovascular disease (CVD) kills over one third more Americans than cancer.
You may have heard the common misconception that coffee raises blood pressure and increases the risk of CVD. However, scientific studies show that coffee’s compounds lower blood pressure over the long term, decrease the risk of cardiovascular disease, and may reduce the risk of stroke.
Drinking coffee can raise blood pressure briefly, right after consumption. But its compounds have a longer-term benefit: daily coffee consumption decreases blood pressure readings after just 8 weeks, believed to be a result of the beneficial action of chlorogenic acids on the arteries.
Longer-term, drinking coffee cuts the risk of death from cardiovascular disease. A 15-year study of over 41,000 women found that the risk of death from cardiovascular disease was 24% lower among those consuming 1 to 3 cups of coffee daily, which was confirmed by other studies on men and women.
Preventing cardiovascular disease at the cellular level, just one cup of coffee inhibited platelet aggregation within one hour, regardless of its caffeine content.
More good news: studies found that regular coffee consumption improved inflammation and HDL (“good”) cholesterol, and decreased coronary calcification.
Chronic liver disease and cirrhosis cause 35,000 deaths per year in the United States. Cirrhosis is the ninth leading cause of death in America, responsible for 1.2% of all US deaths. However, scientists have found that the risk of liver cirrhosis, and of dying from this disease, can be greatly reduced by coffee consumption.
Those drinking 4 cups of coffee daily exhibited a full 84% lower risk of cirrhosis, according to a study in the Annals of Epidemiology. This is consistent with an earlier 8-year study of over 120,000 people that found that each cup of coffee daily lowered the risk of dying from cirrhosis by 23%.
Also, patients with hepatitis B or C have been shown to be less likely to develop nonalcoholic cirrhosis if they are also coffee drinkers.
Alzheimer’s disease becomes increasingly prevalent with aging, striking more than 40% of those over 84. Promising studies are finding that greater daily consumption of caffeinated coffee cuts the risk of both Alzheimer’s and dementia later in life.
Scientists have discovered that long-term coffee intake exhibits a dose-dependent association with improved cognitive function and memory, and it protects primary neuronal cells.
In fact, one mouse study has far-reaching implications for humans. Researchers found that moderate caffeine intake – equivalent to human consumption of 5 cups of coffee daily – began to reverse Alzheimer’s damage in just 5 weeks.
Although the mechanism by which coffee lowers the risk of cognitive decline is not known, a 2009 study on mice found that caffeine decreases levels, in both the blood and the brain, of amyloid-beta, a substance involved in the development of Alzheimer’s. Later, a 2010 review of previous mouse studies found that caffeine – the equivalent of 5 cups of coffee daily in humans – decreases levels of beta- and gamma- secretase, proteins used in amyloid-beta production in the first place.
Then, in 2011, scientists concluded that coffee may be the best source of the caffeine shown to protect against cognitive decline. The reason is that another unknown component in coffee appears to synergize with the caffeine to increase blood levels of a factor (granulocyte colony-stimulating factor, or GCSF) associated with improved cognitive function in Alzheimer’s.
Caffeinated coffee has also been associated with protection against Parkinson’s disease, the second most common neurodegenerative disorder after Alzheimer’s. A study of 29,000 individuals found that one to four cups daily decreased the risk of Parkinson’s by 47% and 5 or more cups decreased the risk by 60%. Increasing granulocyte colony-stimulating factor using drugs like Neupogen® is demonstrating efficacy in animal models of established Parkinson’s disease. Several other studies confirmed an inverse dose-dependent relationship – the greater the number of daily cups of caffeinated coffee, the lower the risk of Parkinson’s disease.
DNA damage is characterized as a physical abnormality within the genetic makeup of a cell, such as a break in a DNA strand. It usually occurs to greater extent within cells that frequently divide. DNA damage can lead to genetic mutations that cause cancer. And when DNA damage occurs within cells that divide less frequently, it can promote aging.
It’s difficult to avoid the many causes of DNA injury. Oxidizing agents produced by normal metabolic processes promote this type of damage. Also, DNA defects can be triggered by numerous external agents such as ultraviolet light, radiation, chemotherapy, industrial chemicals, and certain environmental chemicals such as polycyclic hydrocarbons, found in smoke.
Scientists have discovered a surprisingly simple way to help decrease DNA damage. Studies show that higher coffee consumption decreases levels of oxidative DNA damage, which in turn inhibits both cancer and aging.
A 2011 study confirmed coffee’s DNA-related effect on cancer risk. The researchers found that regular coffee drinkers enjoyed a 13% decreased risk of cancers generally, and those who consumed high levels of coffee enjoyed an 18% decreased risk. Additionally, they enjoyed specific protection against prostate, breast, colorectal, pharyngeal, esophageal, hepatocellular, pancreatic, bladder, and endometrial cancers.
How Do Coffee Compounds Work?
Despite coffee’s powerful antioxidant punch, the mechanism for coffee’s protection against a host of diseases may involve a lot more than a fierce battle between antioxidants and free radicals. Scientists are beginning to discover that coffee’s phytochemistry also exerts direct biological actions on the body, which may underpin a web of indirect, protective effects against diseases from diabetes to cancer.
Early studies suggest that the polyphenols in coffee (both caffeinated and decaffeinated) may modify key enzymes that improve intracellular signaling, the communication system that facilitates cellular actions such as tissue repair, immunity, and homeostasis. Poor cell signaling may be a factor in cancer, diabetes, and more. (A subsequent study suggested in 2008 that this cellular signaling effect could also explain coffee’s inhibition of blood platelet aggregation and cardiovascular risk.)
Then, in 2009, a study found that by modulating specific cell signaling pathways (known as ERK1/2 and JNK), the various polyphenols in coffee – especially chlorogenic acid – help prevent the degeneration of those human cells that are rich in lipids. Brain cells are lipid-rich and this may explain coffee’s neuroprotective effect against cognitive decline and diseases of the brain.
Similarly, one study suggested that polyphenols – for which coffee is the prime dietary source – may affect cellular response and sensitivity by interacting with nuclear receptors. Receptors are molecules that pick up intracellular signals, determining whether a cell gets the right instructions to divide, die, or release molecules – thus regulating body functions to fight disease.
A 2006 review of animal and human studies found that coffee compounds raise levels of detoxifying enzymes that protect against DNA damage and – likely as a direct result – reduce the susceptibility of lymphocytes (white blood cells involved in immune response) to damage from reactive oxygen species (ROS). This may partly explain how coffee lowers the incidence of DNA damage and related diseases such as cancer.
One 2009 study on humans found that 3 cups of coffee daily for 3 weeks increased the number and metabolic activity of beneficial bacteria called bifidobacteria. These intestinal bacteria may explain one mechanism for coffee’s benefits: bacteria can boost immunity, lower blood pressure, and increase mineral absorption.
In 2010, researchers discovered that the phenolics in 4-8 cups of coffee daily have the direct action of dampening inflammatory activity. Chronic low-level inflammation has been associated with diseases ranging from cancer to diabetes, as well as aging.
A 2011 randomized, controlled trial found that consumption of (caffeinated or decaffeinated) coffee produces specific improvements in the function of the liver and of adipocytes (fat-storing cells), both associated with a healthy metabolism. This provides further insight into the possible mechanisms behind coffee’s benefits, because disrupted metabolic activity is a biological risk factor for a number of chronic diseases (including type 2 diabetes).
In addition to the numerous other antioxidants in coffee, a 2011 study confirmed that caffeine itself is a potent scavenger of oxygenated free radicals. Caffeine was found in another 2011 study to work synergistically with other coffee antioxidants. However, caffeine may also work along direct cellular pathways unrelated to its antioxidant action.
Scientists determined in 2011 that caffeine protects the integrity of the blood-brain barrier – which suggests that caffeine may reduce the risk of some diseases by limiting the transport of blood-borne pathogens, drugs, cells, and other substances into the brain, where they might affect brain synapses. The team also found that caffeine defends against the specific blood-brain barrier dysfunction linked to Alzheimer’s and Parkinson’s disease.
Although many people assume they should limit their coffee intake, a wealth of scientific research suggests that its wide-ranging health benefits increase with the amount consumed.
Numerous studies show that higher daily coffee consumption results in a lower risk of diabetes, cardiovascular disease, cancer, Alzheimer’s, and a host of other chronic diseases, including obesity.
There are a number of phytochemicals, the most predominate being chlorogenic acid, that provide coffee’s disease-protecting punch. Of interest is the additional ability of coffee polyphenols to exert direct biological actions on cells. For instance, daily coffee intake may modify key enzymes that improve intracellular signaling, which can protect against diabetes, cancer, and many other diseases.
The benefit is dose-related. Drinking just one cup of coffee a day – caffeinated or decaffeinated – can decrease the risk of developing diabetes by 13%. But 12 cups a day slashes the risk of developing diabetes by 67%.
While traditional medicine fights an impossible battle against a tidal wave of diabetes, cancer, Alzheimer’s, and other age-related diseases, extensive research suggests that coffee – far from being a guilty pleasure that should be limited – is an all-natural and inexpensive elixir. With the availability of new “polyphenol-retaining” coffees, moderate coffee drinkers can now obtain the myriad benefits that were once reserved only for so-called “heavy” coffee users.
There remain, however, a significant percentage of people who are sensitive to caffeine’s stimulating effects on the central nervous system, or find they encounter heartburn and other digestive problems in response to ingesting even a cup of coffee. The new polyphenol-retaining coffee bean beverages are less likely to induce gastric upset.
For those who don’t want to drink any coffee, there are now standardized chlorogenic acid supplements available that provide the high potencies of beneficial coffee compounds with only tiny amounts of caffeine.
By Michael Downey at LifeExtension.com