Post By Dr_Dave
Post By kopigeek
Post By Dr_Dave
Post By Dr_Dave
Coffee is GOOD for you
From NZ Herald today
I haven't seen original article yet
Some like it hot, some like it iced, and some just don't like it at all. Until recently, coffee was on the list of habits to break if you really wanted to be healthy.
Not anymore. Systematic reviews of the research - the most powerful method to weigh up scientific evidence - judge the current evidence as mostly in favour of drinking coffee. Coffee drinking is linked to a decreased risk of premature death, type 2 diabetes and some types of cancer.
However, some people will need to be cautious of the amount. Heavy coffee intake has been linked to an increased risk of lung cancer and can exacerbate heart problems.
Coffee drinkers live longer. A review of 20 studies including more than 970,000 people found those who usually drank the most coffee had a 14 per cent lower risk of dying prematurely from any cause, compared with those who drank the least.
Even drinking just one to two cups a day conferred an 8 per cent lower risk.
Decaffeinated coffee drinkers who had two to four cups a day still had a 14 per cent lower relative risk of premature death than those who didn't drink coffee at all.
Coffee drinkers, particularly men, have a lower risk of liver cancer. This is important as liver disease is the sixth-most-common cancer in the world and is more common in men.
Results from six studies, based on the total number of cups of coffee drunk per day, found the relative risk of liver cancer was 14% lower for every extra cup.
Research shows that naturally occurring coffee components, including kahweol and cafestol, have direct cancer-protection and anti-inflammatory properties. Coffee appears able to up-regulate biochemical pathways in the liver that protect the body from toxins, including aflatoxin and other carcinogenic compounds.
Type 2 diabetes
Coffee drinkers have a lower risk of type 2 diabetes. Across 28 studies of more than one million adults, those who drank three or more cups of coffee a day had a 21 per cent lower relative risk of developing type 2 diabetes compared to those who never or rarely drank it.
For those drinking six or more cups a day, the risk was lowered by 33 per cent.
Interestingly, the risk was lower for both regular and decaffeinated coffee drinkers. For each cup of regular caffeinated coffee there was an extra 9% lower relative risk of developing diabetes and a 6 per cent lower risk for each cup of decaffeinated coffee.
The active components of coffee help reduce oxidative stress, the imbalance between free radicals and antioxidants. Coffee contains chlorogenic acid, which has been shown to improve glucose metabolism and insulin sensitivity, and caffeic acid, which increases the rate muscles use up blood glucose, as well as having immune-stimulating and anti-inflammatory properties.
Coffee drinkers have a lower risk of prostate cancer. Across 13 studies that included more than 530,000 men, those who drank the most coffee had a 10 per cent lower relative risk of developing prostate cancer than those who drank the least.
For every extra two cups of coffee drunk per day, cancer risk decreased by a small extra amount of 2.5 per cent.
However, when prostate cancer grade was factored in, there was no protective effect for advanced or terminal types of prostate cancer.
Now, the reasons to watch your coffee intake.
Watch you total coffee intake to lower your risk for lung cancer.
Studies of more than 100,000 adults found those with the highest coffee intakes had a 27 per cent higher relative risk of lung cancer.
Every extra two cups of coffee per day was associated with an 11 per cent greater risk of developing lung cancer.
There were only two studies on decaffeinated coffee and they had the opposite finding: a 34 per cent lower relative risk for high decaffeinated coffee intakes.
Drinking more that one to two cups of coffee when pregnant may not as be risky as once thought, but it's worth being cautious.
The relationship between coffee and risk of miscarriage and other adverse pregnancy outcomes in older research studies was more likely to be seen in poorly designed studies, especially for outcomes like low birth weight and congenital anomalies.
Some of the risk of miscarriage was probably confounded by the fact that women with severe morning sickness, which is a sign of good implantation of the embryo, tend to cut down on coffee due to nausea.
It also appears that cigarette smoking, which tended to be associated with coffee consumption in older studies, was not always adjusted for, so some of the risk is likely to have been due to smoking.
The American College of Obstetricians and Gynecologists recommends pregnant women drink less than 200 milligrams of caffeine per day. This is equivalent to one to two cups of coffee a day (instant coffee has 50-100 mg caffeine per cup; brewed coffee about 100-150 mg).
The last caution relates to your heart. High intakes of caffeine can increase blood pressure in the short term and plasma homocysteine, another heart disease risk factor. Coffee is not associated, however, with the long-term risk of heart disease.
People with high blood pressure or heart conditions, older people, adolescents, children and those who don't usually drink coffee will be more sensitive to caffeine found in "energy" drinks, cola and coffee, and it can take longer to metabolise. Switching to decaffeinated coffee will help.
It's important to note that most of the research on coffee comes from population-based observational studies that measure association and not causation. That is partly because it would be very hard to do a randomised controlled trial of drinking more coffee and measuring health outcomes over many years. But there's a thought - anyone like to volunteer for that study?
Clare Collins is Professor in Nutrition and Dietetics at University of Newcastle.
This article was originally published on The Conversation.
Read the original article.
I sometimes wonder if the elevated heart-rate I get from coffee has any long-term negative effects given that it is an artificial (drug-induced) stimulus rather than the natural increase you get from exercise which involves other physiological processes as well. I guess alcohol is similar in that it stimulates the sympathetic nervous system in the absence of any other physical stimulus.
Whether this is a problem I wouldn't have a clue.
Better switch the machine on. I've only had 2 cups today.
How reliable is this? In past years there were many researches and in general results are inconclusive on wheter coffee is beneficial or not...
I just got told by my brother that there is some people have a gene that makes them tired when they have coffee? Has anyone read any research supporting this?
i have my doubts about legitimacy of internet tabloid doctors period, coffee related or otherwise. Some articles do reference research, but are few and far between...
Originally Posted by stephan
A similar and equally interesting article:
You spit out a half-formed expletive as you bury your head into the pillow, desperately pleading with an invisible force for an extra 10 minutes of sleep before you give in to the bleep and switch the alarm off.
At this point there's only one thing that might wipe the frown off your face and make the morning drudgery more bearable: a steaming hot cup of coffee.
But don't be surprised if your morning brew does more than wake you up. There's more to this magical elixir than you might think.
Coffee has been said to boost your immune system, reduce inflammation and even cut the risk of some cancers.
So if you like your tidbits served with a helping of science, I thought I'd summarise just what coffee is – and isn't – capable of doing.
COFFEE'S SUITE OF COMPOUNDS
Coffee contains hundreds of biologically active compounds with unpronounceable chemical names. So if you're one of those "if you can't pronounce it, don't eat it" kind of people, at this point I should inform you that if you're a coffee consumer, you break this rule every morning.
Actually, we all break this rule every day because even the most organic wholesome apple is made up of chemicals with unpronounceable names, because nature is the most ingenious, sagacious chemist of them all.
Coffee's most interesting compounds are caffeine, theophylline, theobromine, and chlorogenic acids (I won't bore you with the chemical nomenclature for these).
Caffeine, theophylline and theobromine are all central nervous system stimulants, key to coffee being such a popular psychoactive drug.
Caffeine and theophylline are also bronchodilators, which help relax the smooth muscle in our airways and are used to treat asthma. They also stimulate lipolysis or the breakdown of fat.
Caffeine and theophyline bring about their effects by reducing a small compound known as cyclic adenosine monophosphate – a small messenger inside cells that plays a role in many biological processes. When adenosine levels are reduced, there is a stimulation of the release of neurotransmitters such as glutamate, dopamine and acetylcholine.
This little bit of information may be the clue to understanding many of the suggested benefits of coffee consumption. For instance, Parkinson's disease is characterised by a marked decrease in dopamine levels in the brain, and as mentioned, caffeine stimulates dopamine secretion.
Another compound, trigenolline, has been shown to promote regeneration and repair of neurons and improve memory (pre-exam cram must-have), and is being investigated for therapeutic roles in Alzheimer's disease.
COFFEE'S ROLE IN DIABETES
An estimated 1.5 million deaths worldwide were directly caused by diabetes in 2012 according to the World Health Organization (WHO). Type-2 diabetes is characterised by a resistance to insulin, a hormone that regulates uptake of sugar from the bloodstream into cells.
Again the influence of coffee on Type-2 diabetes has been widely researched. Chlorogenic acids found in coffee have been shown to inhibit an enzyme in the liver that plays a role in increasing blood glucose levels.
When roasted, chlorogenic acid in coffee forms compounds called quinides, which have been experimentally shown to enhance insulin action in rats. Research has shown that consumption of six cups of coffee a day over 20 years could prevent the development of glucose intolerance, and the antioxidant effects of certain coffee compounds may also help guard against diabetes.
COFFEE AND CORONARY HEART DISEASE
Another major killer in both developed and developing nations is coronary heart disease (think heart attacks).
Antioxidants found in coffee may reduce inflammation, reducing dysfunction of certain cells that line blood vessels, preventing heart attacks and strokes.
Caffeine has also been shown to reduce calcification (calcium deposits leading to hardening) of coronary arteries in women.
COFFEE AND CANCER
There is also debate on the effects of coffee on cancer. Coffee consumption has been shown to decrease the risk of developing certain cancers, such as ovarian, endometrial, pancreas, pharyngeal and colorectal cancer, the most common cancer in the western world.
The lipid (scientific name for fat) fraction of coffee contains two interesting compounds – cafestol and kahweol – which have been shown in the laboratory to safeguard against malignant cells by modulating detoxifying enzymes.
The effects of these lipids on serum cholesterol levels is under investigation, but there is no evidence that these lipids are oxidised in the human body, which suggests that any negative effects may be negligible at best.
There are always two sides to a coin however, so before you make a bee-line to your nearest cafe, I should mention some of the risks associated with coffee consumption (no such thing as free lunch).
Consumption of more than eight cups of coffee a day may cause anomalies in cardiac rhythm due to the action of caffeine on muscle cells.
There is also some research that exists, linking coffee to increased rates of certain cancers. However, further investigation in relation to gender correlation, smoking and other risk factors is mandated.
Caffeine has been shown to interact with xenobiotics, or compounds synthesised to mimic naturally-occurring biological compounds in the body, such as hormones. Caffeine has also been linked to decreased effectiveness of the contraceptive pill (yikes!) and certain drugs, such as anti-epileptics.
The psycho-stimulant effects of coffee can also cause addiction and associated withdrawal symptoms, such as headaches and muscle fatigue when you stop drinking it.
So, what's the deal with this beverage that has reached an almost revered status?
Well, the jury is out; coffee in moderation does appear to have scientifically proven benefits to the human body, but as the literature suggests, there are also some negative effects, and these warrant further investigation.
Maybe make up your own mind by further investigating the studies, perhaps at your local cafe while sipping on a cappuccino.
Auckland-based Chrislyn Jeyaprakash has a BSc (Honours) in biomedical science with a special interest in genetics and nutrition. Her new blog, moleculesandthings.wordpress.com, hopes to combat mass science phobia.
A report by WHO published in Lancet this week:
If you're like many around the world who enjoy a cup of coffee in the morning, you'll be happy to know that the World Health Organisation has released its long-anticipated report on the drink, and its findings bode well for your health.
In reviewing the most recent scientific evidence over the 25 years since its last analysis on coffee, the WHO concluded that coffee should no longer be considered a carcinogen and that it may actually have positive effects for your body when it comes to liver and uterine cancers.
Now before you start ordering that second steaming cup, it's important to know that the WHO report wasn't all good news. There was another significant finding: "Very hot" beverages "probably" cause cancer. This is mostly based on studies related to the consumption of a traditional drink called mate or cimarron in South America where the tea can be taken at temperatures around 70C. That's significantly hotter than people in North America or Europe usually consume their drinks.
The findings were published in The Lancet Oncology on Wednesday.
"These results suggest that drinking very hot beverages is one probable cause of esophageal cancer and that it is the temperature, rather than the drinks, that appears to be responsible," said Christopher Wild, director of the International Agency for Research on Cancer (IARC).
Wild and other officials were unable to quantify the risk - "We can't put a number on it at this stage," they said - but they had some practical advice for people who consume hot beverages.
"Certainly wait a few minutes more before drinking," the IARC said.
The decision to reclassify coffee is a major victory for the industry, which has been aggressively lobbying for such an action. For organisations, such as the WHO, that are charged with protecting the public's health, it's often politically trickier to say a product causes no harm than to say a product causes harm - even for one as beloved as coffee. In the United States, when a federal advisory committee issued recommendations regarding the Dietary Guidelines for Americans last year and said coffee could be part of a "healthy diet", there was a significant backlash. The new US recommendations, officially issued in January, say that up to five 240ml cups a day is fine.
The National Coffee Association cheered the WHO finding, pointing out that it's the first time scientists have positively reclassified a foodstuff or beverage.
"Coffee drinkers have known for a long time that their go-to beverage is a super food," said association president Bill Murray. "Today we can brew or buy a cup with even more confidence, thanks to science."
"More confidence" are the key words here as science is a moving target, especially in terms of food, as bodies making recommendations about what people consume have tended to flip-flop in recent years.
The WHO working group said that it reviewed more than 1000 studies in humans and animals in making its decision, and that there was "inadequate evidence" for the carcinogenicity of coffee drinking. It noted that epidemiological studies mentioned no impact of coffee drinking, specifically on cancers of the pancreas, prostate and female breast. Reduced risks were seen for cancers of the liver and uterine endometrium. For more than 20 other types of cancer, the evidence was inconclusive.
Although the WHO's coffee decision was carefully thought out and involved countless hours of research by some of the top minds in nutrition science, it's just a snapshot in time in terms of what we know. Meat was once thought to be good and important for your health, but the WHO told us last year that it now thinks hot dogs and bacon cause cancer and red meat "probably does", too. Many other changes have taken place over just the past few months: cholesterol, the boogieman of our diets since the 1960s, suddenly became less harmful in January when the new Dietary Guidelines for Americans came out - as did salt.
The coffee issue is also far from definitively resolved. Early work shows that there may be at least one place in your genes that may determine whether you process caffeine quickly or slowly, and that there is a roughly 50-50 split among humans. That has led some experts to wonder whether a general rule about the good or ill effects of a food means anything to individuals.
"A one-size-fits-all recommendation for coffee won't work. Some people just can't tolerate it," Marilyn Cornelis, a Northwestern medical school professor, said at the time.
More interesting news! cheers Dr Dave
Caffeine may counter age-related inflammation
A chronic inflammatory process that occurs in some, but not all, older people may trigger cardiovascular problems, a new Stanford study shows. Part of the solution might be found in a cup of coffee.
JAN 16 2017
Mark Davis and his colleagues studied blood samples and a variety of data from more than 100 clinical trial participants and found a link between chronic inflammation and the chronic diseases that accompany aging.
Stanford University School of Medicine scientists have unearthed a connection between advancing age, systemic inflammation, cardiovascular disease and caffeine consumption.
Extensive analysis of blood samples, survey data and medical and family histories obtained from more than 100 human participants in a multiyear study has revealed a fundamental inflammatory mechanism associated with human aging and the chronic diseases that come with it.
The study, published online Jan. 16 in Nature Medicine, implicates this inflammatory process as a driver of cardiovascular disease and increased rates of mortality overall. Metabolites, or breakdown products, of nucleic acids — the molecules that serve as building blocks for our genes — circulating in the blood can trigger this inflammatory process, the study found.
The study also provides evidence that caffeine and its own metabolites may counter the action of these circulating nucleic-acid metabolites, possibly explaining why coffee drinkers tend to live longer than abstainers.
“More than 90 percent of all noncommunicable diseases of aging are associated with chronic inflammation,” said the study’s lead author, David Furman, PhD, a consulting associate professor at the Stanford Institute for Immunity, Transplantation and Infection. More than 1,000 papers have provided evidence that chronic inflammation contributes to many cancers, Alzheimer’s disease and other dementias, cardiovascular disease, osteoarthritis and even depression, he said.
“It’s also well-known that caffeine intake is associated with longevity,” Furman said. “Many studies have shown this association. We’ve found a possible reason for why this may be so.”
Mark Davis, PhD, a professor of microbiology and immunology and the director of the Stanford Institute for Immunity, Transplantation and Infection, shares senior authorship of the study with Benjamin Faustin, PhD, a cell biologist at the University of Bordeaux in France. Davis is also a Howard Hughes Medical Institute investigator.
“Our findings show that an underlying inflammatory process, which is associated with aging, is not only driving cardiovascular disease but is, in turn, driven by molecular events that we may be able to target and combat,” said Davis, who holds the Burt and Marion Avery Family Professorship.
Notably, this inflammatory mechanism was found to be activated only in some, but not all, of the older study participants. Those in whom it was relatively quiescent tended to drink more caffeinated beverages. Laboratory experiments revealed that the mechanism was directly countered by caffeine and associated compounds.
Coffee cup in the midst of coffee beans
The researchers also found that the inflammatory mechanism was dampened among older participants who tended to drink more caffeinated beverages, such as coffee.
The investigators made this discovery using data gathered from the Stanford-Ellison cohort, a long-term program begun 10 years ago by Davis and study co-author Cornelia Dekker, MD, professor of pediatric infectious diseases, to study the immunology of aging. In that program, healthy participants ages 20-30 and another group older than 60 were monitored annually via surveys, blood draws and reviews of their medical histories.
For the new study, the researchers compared blood drawn from older versus younger study participants to see which genes tended to be more highly activated in older people. They zeroed in on two clusters of genes whose activity was associated with the production of a potent circulating inflammatory protein called IL-1-beta. The genes within each cluster appeared to work in coordination with one another.
The researchers also looked at two particular groups of older participants: One with high activation of one or both inflammatory gene clusters, and the other with one or both clusters exhibiting low activation. On reviewing these individuals’ medical histories, the scientists learned that nine of the 12 subjects with high cluster activity had high blood pressure, compared with only one of the 11 subjects with low cluster activity. Follow-up studies by study co-author Francois Haddad, MD, a clinical associate professor of cardiovascular medicine, revealed that individuals in the “high” group were much more likely to have stiff arteries — a risk factor for cardiovascular complications — than those in the “low” group.
Furthermore, those in the low group were eight times as likely as those in the high group to report having at least one close family member who had lived to age 90 or older. Not only that, but participants in the high group who were older than 85 in 2008 were substantially more likely to have died by 2016 than were those in the low group. The high group’s blood also showed signs of increased activity of free radicals, which can harm cells, compared with the low group’s blood. The high group also had elevated concentrations of IL-1-beta, as well as of several nucleic-acid breakdown products that can be produced by free-radical action.
The researchers found that incubating a type of immune cell with two of those nucleic-acid metabolites boosted activity in one of the gene clusters, resulting in increased IL-1-beta production. When injected into mice, the substances triggered massive systemic inflammation, along with high blood pressure. In addition, immune cells infiltrated and clogged the animals’ kidneys, increasing renal pressure substantially.
How caffeine may affect longevity
Intrigued by the correlation between older participants’ health, gene-cluster activation and self-reported rates of caffeine consumption, the researchers followed up and verified that blood from the group with low cluster activity was enriched for caffeine and a number of its metabolites, compared with blood from the group with high cluster activity. (Examples of these metabolites are theophylline, also found in tea, and theobromine, which abounds in chocolate.)
Incubating immune cells with caffeine and its breakdown products along with the inflammation-triggering nucleic acid metabolites substantially prevented the latter from exerting their powerful inflammatory effect on the cells.
What we’ve shown is a correlation between caffeine consumption and longevity.
“That something many people drink — and actually like to drink — might have a direct benefit came as a surprise to us,” said Davis, who noted that the study did not prove a causal link. “We didn’t give some of the mice coffee and the others decaf. What we’ve shown is a correlation between caffeine consumption and longevity. And we’ve shown more rigorously, in laboratory tests, a very plausible mechanism for why this might be so.”
Other Stanford co-authors are postdoctoral scholars Junlei Chang, PhD, Christopher Bohlen, PhD, and Gabriela Fragiadakis, PhD; former graduate student Matthew Spitzer, PhD; life science research associate Edward Ganio; assistant professor of anesthesia, perioperative and pain medicine Brice Gaudilliere, MD, PhD; professor of microbiology and immunology Garry Nolan, PhD; and professor of hematology Calvin Kuo, MD, PhD.
Researchers from the Sidra Medical and Research Center in Qatar, the French National Institute of Health and Medical Research and the University of North Carolina also co-authored the study.
The study was funded by the National Institute of Allergy and Infectious Diseases (grant U19AI090019) and the Ellison Medical Foundation.
Stanford’s Department of Microbiology and Immunology also supported the work.
I might just go and have another coffee...with impunity!
Thanks Dr Dave...
Reading articles about the health effects of coffee like...