I bet that you must have heard this news 
A California judge ruled on March 29 that Starbucks (SBUX) and other coffee companies in California should have to post warnings because the brew may contain an ingredient that's been linked to cancer, a judge has ruled.
Coffee has been part of the human diet for centuries, but scientists have oscillated between warning against over-consumption and advising that a cup a day (or more) may have protective effects.
At the heart of the cancer debate is a chemical called acrylamide, which can be found in a number of foods and drinks, including both coffee and french fries.
Coffee is a hot commodity with controversial benefits and risks
Around the world, people drink an estimated 2.25 billion cups of coffee every day, a daily ritual that makes coffee the second most valuable trading commodity in the world.
The fruit itself is rarely eaten now and, while the beans have only very small quantities of nutrients, some research has linked its contents to better heart, bowel and liver.
The very thing that makes us love coffee so much — the natural stimulant, caffeine — can be overwhelming to the body, causing anxiety and disrupting our sleep patterns.
But beyond this, for every part of the body that one study says coffee is beneficial for, another says the drink is harmful.
Though raw coffee beans themselves are safe, some studies have hinted that roasting them to reach the bold, rich flavors we enjoy in our morning cups may come at a cost.
What’s Acrylamide exactly?
There is a common carcinogen
in many other foods
A chemical called acrylamide can form as a byproduct of cooking foods at high temperatures. The same chemical is used to make plastics, but, in the case of coffee, it is formed when many carbohydrates are cooked.
In 2002, Swedish scientists discovered that a number of baked, roasted and fried foods contained acrylamide, which is a genotoxin, meaning that it corrupts DNA.
In experiments, rats whose mouths were exposed to the chemical were significantly to develop cancers of various parts and systems of their bodies.
These tumors of their mammary glands, central nervous systems, thyroids, uteruses and scrotums, though the same has not been observed in humans.
You cannot drink enough coffee
to give you cancer
Based on the studies in rats, the Environmental Protection Agency calculated that the risk of developing a cancer due to acrylamide exposure would be increased if you drank 4.5 mg of the chemical per every 2.2 lbs you weigh every day.
In other words, someone who weighs 150 lbs would have to ingest 307 mg of acrylamide in order for it to increase their cancer risks.
For comparison, 307 mg is less than one tenth of a teaspoon. That isn't much, but it is much more than scientists found in even the most acrylamide-laced coffee product samples.
In 2013, researchers found that a single cup contained 0.45 micrograms of acrylamide. That is one 100th as much as the EPA says would make you no more than a one-in-a-million increased chance of developing cancer as a direct result of acrylamide.
The World Health Organization took coffee off its list of possible carcinogens in 2016, but the presence of a carcinogen at all seems to be sufficient for California to warn against the beverage.
"There is really not strong evidence that coffee does cause cancer," says Dr Kathryn Wilson, who served on the committee of the World Health Organization that decided to downgrade coffee to an unlikely carcinogen.
Different content of acrylamide in food
What kind of food contain the highest levels of acrylamide?
Coffee and its similar products, such as instant coffee
High temperature processing of potato products
Breakfast cereal
A cup of coffee a day may keep cancer away — and three will not kill you
Dr Wilson has studied the links between cancer and acrylamide itself as well as between coffee and cancer. Her research has found more evidence of positive links than negative ones.
"There is actually pretty strong evidence that coffee is associate with lower risks of endometrial and liver cancers," she says.
Even in the top percentile of acrylamide-consumers that she has examined, there were weak associations of heightened risks for ovarian and endometrial cancer.
Perhaps more importantly, coffee is hardly the only source of our acrylamide exposure, and acrylamide is not the only compound in coffee.
In fact, she has added research to a substantial stack of evidence that coffee can have protective effects against cancers, especially those of the liver.
Coffee also "seems to have a really positive effect on how the body handles insulin," and has been linked to reduced risks for type 2 diabetes, according to Dr Wilson.
Source | Daily Mail/Chinadaily
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