The California judge is wrong: Coffee is not a cancer risk

[David Baxter PhD]

Here's what science says about coffee and cancer risks
CBC News
April 1, 2018

'If anything, coffee is protective for some types of cancer,' says public health expert

Trouble is brewing for coffee lovers in California, where a judge ruled that sellers must post scary warnings about cancer risks. But how frightened should we be of a daily cup of joe?

Scientific concerns about coffee have eased in recent years, and many studies even suggest it can help health.

"At the minimum, coffee is neutral. If anything, there is fairly good evidence of the benefit of coffee on cancer," said Dr. Edward Giovannucci, a nutrition expert at the Harvard School of Public Health.

The World Health Organization's cancer agency moved coffee off the "possible carcinogen" list two years ago, though it says evidence is insufficient to rule out any possible role.
The current flap isn't about coffee itself, but a chemical called acrylamide that's made when the beans are roasted. Government agencies call it a probable or likely carcinogen, based on animal research, and a group sued to require coffee sellers to warn of that under a California law passed by voters in 1986.

The problem: No one knows what levels are safe or risky for people. The U.S. Environmental Protection Agency sets acrylamide limits for drinking water, but there aren't any for food.
"A cup of coffee a day, exposure probably is not that high," and probably should not change your habit, said Dr. Bruce Y. Lee of Johns Hopkins Bloomberg School of Public Health. "If you drink a lot of cups a day, this is one of the reasons you might consider cutting that down."

Here's what's known about the risks.

The chemical
Start with the biggest known risk factor for cancer — smoking — which generates acrylamide. In the diet, French fries, potato chips, crackers, cookies, cereal and other high-carbohydrate foods contain it as a byproduct of roasting, baking, toasting or frying.

U.S. Food and Drug Administration tests of acrylamide levels found they ranged from 175 to 351 parts per billion (a measure of concentration for a contaminant) for six brands of coffee tested; the highest was for one type of decaf coffee crystals. By comparison, French fries at one fast food chain ranged from 117 to 313 parts per billion, depending on the location tested. Some commercial fries had more than 1,000.

Even some baby foods contain acrylamide, such as teething biscuits and crackers. One brand of organic sweet potatoes tested as having 121 parts per billion.

What's the risk?
The "probable" or "likely" carcinogen label is based on studies of animals given high levels of acrylamide in drinking water. But people and rodents absorb the chemical at different rates and metabolize it differently, so its relevance to human health is unknown.

A group of 23 scientists convened by the WHO's cancer agency in 2016 looked at coffee — not acrylamide directly — and decided coffee was unlikely to cause breast, prostate or pancreatic cancer, and that it seemed to lower the risks for liver and uterine cancers. Evidence was inadequate to determine its effect on dozens of other cancer types.

California law
Since 1986, businesses have been required to post warnings about chemicals known to cause cancer or other health risks — more than 900 substances are on the state's list today — but what's a "significant" risk is arguable.

Coffee sellers and other defendants in the lawsuit that spurred Thursday's ruling have a couple weeks to challenge it or appeal.

The law "has potential to do much more harm than good to public health," by confusing people into thinking risks from something like coffee are similar to those from smoking, Giovannucci said.

The International Food Information Council and Foundation, an organization funded mostly by the food and beverage industry, says the law is confusing the public because it doesn't note levels of risk, and adds that U.S. dietary guidelines say up to five cups of coffee a day can be part of a healthy diet.

Dr. Otis Brawley, the American Cancer Society's chief medical officer, said, "The issue here is dose, and the amount of acrylamide that would be included in coffee, which is really very small, compared to the amount from smoking tobacco. I don't think we should be worried about a cup of coffee."

Amy Trenton-Dietz, public health specialist at the University of Wisconsin-Madison, said the California ruling contrasts with what science shows.

"Studies in humans suggest that if anything, coffee is protective for some types of cancer," she said. "As long as people are not putting a lot of sugar or sweeteners in, coffee, tea and water are the best things for people to be drinking."

 

[David Baxter PhD]

Should You Worry About Acrylamide in Your Coffee?

Should You Worry About Acrylamide in Your Coffee?
Berkeley Wellness
April 23, 2018

In March 2018, a judge in Los Angeles ruled that coffee sold in California must carry a warning label, based on Proposition 65, which requires companies to alert consumers about products containing any of a growing list of chemicals (now more than 850) that could possibly cause cancer or birth defects. The coffee industry is fighting the decision. The chemical in coffee is acrylamide, which we first wrote about in 2002. That was when Swedish researchers caused an uproar by reporting that fried or baked starchy foods like French fries, crackers, potato chips, and even bread and breakfast cereals contain the compound, which they said may cause cancer.

For those of you who don’t live in California, Prop 65 (formally called the Safe Drinking Water and Toxic Enforcement Act of 1986) has been controversial from day one. Countless products carry the warning label, which overall has helped consumers make safer choices, though the ubiquity of the warnings makes it hard to distinguish genuine risks from trivial ones. For some labeled compounds, including acrylamide, the evidence of carcinogenicity for humans is open to debate. Prop 65 lawsuits are a big business. And what happens in California often affects the rest of the nation, as companies try to reformulate their products to avoid having to add a Prop 65 warning.

Acrylamide forms during frying, grilling, baking, roasting, and toasting, when the amino acid asparagine (notably in potatoes and grains) reacts with naturally occurring sugars, a reaction that gives the foods their brown color, crusty texture, and distinctive taste.

Potato chips, French fries, and other fried potato products have the most acrylamide. (The darker the color, the more acrylamide.) Lower levels are found in some presumably healthier foods — namely breakfast cereals, crackers, and bread, which we tend to consume a lot of. Roasted nuts, peanut butter, olives, some dried fruit, and, yes, coffee also contain low levels. By one estimate, nearly 40 percent of calories in the U.S. come from acrylamide-containing foods. Nonfood sources include cigarette smoke and, to a much lesser extent, drinking water.

Putting this brewhaha in perspective
How risky is acrylamide? The U.S. National Toxicology Program and the International Agency for Research on Cancer (part of the World Health Organization) have deemed acrylamide a likely or probable human carcinogen, based on studies of animals fed very high amounts. But studies in people have had mixed results, with some showing no increased risk in those with the highest dietary intakes. According to the National Cancer Institute, “a large number of epidemiologic studies (both case-control and cohort studies) in humans have found no consistent evidence that dietary acrylamide exposure is associated with the risk of any type of cancer.”

The potential health risks of acrylamide for humans are hard to study, largely because its levels vary tremendously within the same types of foods, not only from brand to brand, but even from batch to batch. And since acrylamide is so prevalent in the food supply, there’s not much difference between low-intake and high-intake groups in observational studies.

Because of Prop 65 lawsuits and consumer concerns, the food industry has been devising strategies to reduce acrylamide in order to avoid labeling—for example, by altering cooking times, temperature, and methods and by using ingredients that help block the formation of acrylamide.

Back to coffee. Like many plant-derived foods, coffee naturally contains thousands of chemicals, plus others, like acrylamide, that are formed during roasting. Research suggests that many of these compounds have potential anti-cancer and other beneficial effects, while others may promote cancer and pose additional risks (some may have both good and bad effects). Of course, as the saying goes, “the dose makes the poison,” and the amounts of various compounds (including acrylamide) in even a whole pot of coffee are truly minuscule.

The good news is that observational studies have consistently linked coffee to a host of potential health benefits, sometimes even a reduced risk of certain cancers, such as prostate, colon, and endometrial cancer, as well as reduced mortality rates. The latest Dietary Guidelines for Americans state that moderate coffee intake has potential health benefits.

If you want to minimize your intake of acrylamide, limit or avoid French fries, chips, cookies, pastries, biscuits, and pies, which tend to have the most acrylamide. Don’t roast potatoes or toast bread until they are dark brown. Above all, don’t smoke: You’ll get much more acrylamide from tobacco smoke than from food.

 

[Daniel E.]

Survey Data on Acrylamide in Food: Individual Food Products

 

[David Baxter PhD]

Coffee & Your Health: What the Research Says

Coffee & Your Health: What the Research Says
Berkeley Wellness
August 06, 2013

Not too long ago, coffee drinking was considered a bad habit and many people avoided it for health reasons. But now, as with chocolate and wine, the pendulum has swung so far in the other direction that we have to remind readers that moderation is still a good idea.

Coffee, the world’s most popular beverage after water and tea, used to be blamed for everything from high blood pressure and high cholesterol (and thus heart disease) to pancreatic cancer, fibrocystic breasts and bone loss. But early research linking coffee or caffeine to health problems has almost always been refuted by better studies. In recent years, most research has suggested that coffee actually has health benefits.

How can coffee be healthful?
Like all plant foods, coffee beans contain many naturally occurring chemicals—more than 1,000 have been identified so far, many formed during the roasting process. Some are potentially harmful for coffee drinkers, while others are potentially healthful, according to lab studies. Many of the beneficial substances are polyphenols that are antioxidants; these contribute to the bitter and acidic taste of the beverage. In fact, coffee is the No.1 source of antioxidants in the U.S. and many other countries, largely because we drink so much of it.

For most people, coffee means caffeine, which is one of the most studied substances in food. Caffeine is a natural pesticide that helps protect coffee plants from predators. Brewed coffee typically contains anywhere from 60 to 120 milligrams of caffeine in six ounces. Caffeine is a mild psychoactive substance that stimulates the central nervous system. Thus, it improves reaction time, mental acuity, alertness and mood; wards off drowsiness; and helps people wake up and feel better in the morning. So it’s no surprise that a recent Australian study of long-distance truck drivers, published in BMJ, found that caffeine greatly reduced the risk of crashes.

What’s more, caffeine is classified as an “ergogenic aid” because it can improve some aspects of athletic performance. It also enhances the analgesic effect of pain relievers, which is why it’s in some over-the-counter formulations.

Coffee's potential health benefits
Every month or two another study on coffee comes out. Most research has focused on regular coffee, but some has included decaf. Here’s a sampling of recent findings:

Diabetes. Research, including two large studies in the American Journal of Clinical Nutrition in 2012 and 2013, has fairly consistently linked long-term coffee consumption (regular or decaf) to a reduced risk of type 2 diabetes. Some of coffee’s polyphenols may enhance insulin sensitivity and slow the release of glucose into the bloodstream. Most studies on people who already have diabetes have not found a benefit from coffee, however.

Heart disease. Compounds in coffee have positive and negative effects on coronary risk. Overall, coffee does not affect the risk of heart attacks (or strokes), according to a large German study last year as well as previous research. One way coffee may be good for the heart is by reducing the risk of diabetes. One way it can be bad is if it is unfiltered and raises blood cholesterol.

Blood pressure and stroke. There has long been a concern about caffeine’s effect on blood pressure. However, a 2011 review of studies concluded that it’s okay for people with controlled hypertension to drink caffeinated coffee. The studies on the acute effects found that in people with hypertension who had abstained from caffeine for 9 to 48 hours, two cups of coffee raised blood pressure (7 points, on average) for up to three hours. But in studies lasting two weeks, daily coffee intake did not increase blood pressure, probably because tolerance to caffeine develops in about a week. And longer observational studies in the review found no link between habitual coffee consumption and the risk of cardiovascular disease.

Even better news, a Swedish analysis published in the American Journal of Epidemiology in 2011 found that moderate coffee consumption was associated with a modest reduction in stroke risk. Other studies have also shown this.

Colon cancer. An analysis from the large NIH-AARP Diet and Health Study last year found that people who drank at least four cups of coffee (regular or decaf) a day were 15 percent less likely to develop colon cancer than nondrinkers. Previous studies have been inconsistent; different coffee types and methods of preparation may have different effects on cancer risk.

Prostate cancer. A British study published in the Nutrition Journallast year found a reduced risk of aggressive prostate cancer in coffee drinkers, though the overall risk for prostate cancer was not affected. That confirms the conclusions of a large 2011 study in the Journal of the National Cancer Institute, which found that men who regularly consumed the most coffee (including decaf) had a 60 percent lower risk of advanced or lethal prostate cancer than nondrinkers. Even drinking one to three cups per day was linked to a 30 percent lower risk. This potential benefit is “biologically plausible,” according to the Harvard researchers, since coffee improves blood sugar control, has anti-inflammatory and antioxidant effects and affects sex hormone levels, all of which play a role in prostate cancer progression.

Endometrial cancer. In 2011 two large studies of women linked coffee to a decreased risk of endometrial cancer. This was especially true of obese women, who are at increased risk for the disease.

Parkinson’s disease. Many observational studies have suggested that coffee helps protect against Parkinson’s, according to a review paper in Experimental Neurobiology last year. It noted that caffeine appears to have neuroprotective effects, though this may depend on a genetic variable involved in caffeine metabolism.

Depression. Women who drank two to three cups of regular coffee a day over a 10-year period were 15 percent less likely to develop depression than those who drank little or no coffee, according to a 2011 analysis from the Nurses’ Health Study. The authors theorized that coffee can positively affect serotonin and other brain chemicals.

Cognitive decline. In a study in the Journal of Alzheimer’s Disease in 2011, older women (but not men) who drank coffee had a reduced rate of cognitive decline over an eight-year period. Another paper in the same journal last year linked higher levels of caffeine in the blood to reduced progression from mild cognitive impairment to dementia in people over 65.

Liver disease. Several recent studies suggest that regular coffee may protect against the development or progression of non-alcoholic fatty liver disease.

Life expectancy. People who drank at least two cups of coffee (regular or decaf) a day were 10 to 15 percent less likely to die over a 14-year period than nondrinkers, according to a large study in the New England Journal of Medicine in 2012. Smoking and other factors that influence health and longevity were taken into account. Reductions were seen in deaths from diabetes, heart and respiratory disease, strokes, infections and accidents.

Bottom line: There’s no health reason to deprive yourself of coffee if you like the lift it gives and the sociability it affords, unless it affects you adversely. On the other hand, we can’t recommend that anyone start drinking coffee for its potential benefits, since most are still too uncertain. Notably, all the long-term studies have been observational, so they do not prove cause and effect. Keep in mind that tea also contains an array of potentially beneficial compounds and has been linked to many health benefits.

Nervous About Coffee's Effects?
It's easy to see why some people would worry about coffee. First of all, because caffeine is a stimulant, it can cause jitters and insomnia. It can boost heart rate temporarily, which is why people with certain heart problems are sometimes advised to avoid it. Coffee, regular or decaf, can also cause stomach upset and heartburn.

Moreover, the effects of coffee and caffeine can vary from person to person, depending on genetic and other factors. For instance, caffeine's transient effect on blood pressure and heart rate depends largely on whether you are used to caffeine or not. For most people, any such boost isn't a danger. However, in people with multiple cardiac risk factors who rarely consume it, caffeine may increase the risk of a heart attack during the hour or two after drinking coffee.

The stimulant effects vary as well. In fact, a 2010 British study suggested that caffeine isn't stimulating for people who drink coffee regularly. For them, caffeinated beverages merely counter the effects of caffeine withdrawal (such as headaches and a decreased ability to pay attention) and only help restore or maintain a normal state of alertness. In contrast, infrequent coffee drinkers get more of a stimulant effect from the caffeine. The more caffeine you consume regularly, the more you build up a tolerance for it.

Coffee's effects also depend on the amount of caffeine and other compounds in it. This, in turn, depends on the type of bean, how the beans were processed, and how the beverage is prepared. For instance, it has long been known that large quantities of unfiltered coffee—notably espresso or that made in a French press, regular or decaf — can boost blood cholesterol. The likely culprits are cafestol and kahweol, which are diterpenes in the coffee's oil that are trapped in paper filters. (Interestingly, though, these compounds have anti-cancer properties.) If you have undesirable cholesterol levels and regularly drink large quantities of unfiltered coffee, try cutting down or switching to filtered coffee. Single-serving coffee pods, by the way, contain a filter.

Note for pregnant women: Some research suggests that high doses of caffeine raise the risk of miscarriage and birth defects. While the evidence for this is not consistent, to be safe, pregnant women should drink no more than one or two cups a day.

 

[David Baxter PhD]

California moves to declare coffee safe from cancer risk
CBC News
June 15, 2018

Proposal would counter recent court ruling requiring warning labels

California health officials proposed a regulation change on Friday that would declare coffee does not present a significant cancer risk.

The proposal would counter a recent state court ruling that found coffee should carry warning labels because of a carcinogen found in every cup of brew.

The Office of Environmental Health Hazard Assessment says that a review of more than 1,000 studies published this week by the World Health Organization found inadequate evidence that coffee causes cancer.

The agency implements a law passed by voters in 1986 that requires warnings of chemicals known to cause cancer and birth defects. One of those chemicals is acrylamide, which is found in many things and, as a byproduct of coffee roasting and brewing, is present in every cup.

If the regulation is adopted, it would be a huge win for the coffee industry which faces potentially massive civil penalties after losing an eight-year-old lawsuit in Los Angeles Superior Court over the issue and could have to post scary warnings on all coffee packaging sold in California.
Judge Elihu Berle said the companies failed to show that benefits from drinking coffee outweighed any risks. He ruled in an earlier phase of trial that companies hadn't shown the threat from the chemical was insignificant.

The state's action rejects that ruling.

"The proposed regulation would state that drinking coffee does not pose a significant cancer risk, despite the presence of chemicals created during the roasting and brewing process that are listed under Proposition 65 as known carcinogens," the agency said in a statement.

"The proposed regulation is based on extensive scientific evidence that drinking coffee has not been shown to increase the risk of cancer and may reduce the risk of some types of cancer."

Lawyer 'shocked' by proposal
Attorney Raphael Metzger, who won the court case on behalf of the Council for Education and Research on Toxics, said the agency had essentially nullified the decision.

"I'm shocked. I'm just shocked," he said. "The whole thing stinks to high hell."

The National Coffee Association had no comment on the proposed change. In the past, the organization has said coffee has health benefits and that the lawsuit made a mockery of the state law intended to protect people from toxic substances.

Scientific evidence on coffee has gone back and forth many years, but concerns have eased recently about possible dangers, with some studies finding health benefits.

The coffee association didn't deny that acrylamide was found in coffee, but argued it was only found at low levels and was outweighed by other benefits such as antioxidants that reduce cancer risk.