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Put that muffin down! And that cup of coffee! Are you joking with all that . . . that . . . food? Are you trying to kill yourself?
Anybody who has ever read anything knows that baked goods, processed foods, animal fats, carbs and even certain vegetables will give you cancer. They will. Science says so.
Same holds true for expensive gel manicures, underarm deodorant and many shampoos and cosmetic products. Oh, and the foam in your couch. And your rugs. And curtains. Actually, your whole den is really just a den of carcinogens.
But don’t go outside! Do you know how many airborne heavy metals are floating around just waiting to give you cancer? Well, researchers do, and just about every week there is a new study published seemingly aimed to scare the bejeezus out of anybody with a mouth, a circulatory system or an interest in personal hygiene.
Don’t bother trying to parse these studies — some of which contradict each other. In order to do so, you’d either have to spend time in front of your computer or call someone on your cellphone, and either one of those insidious devices will give you cancer. They will. Again, science.
A thinking person might ask: Can all these claims be true? Should we give up all food, water and air in order to live a cancer-free (albeit short) life? Amidst the proliferation of alarmist studies, some researchers have started to turn a critical eye to their own fields and colleagues, uncovering some dubious findings and just plain bad science.
“Researchers often test many different foods at once in their studies and then choose which findings to highlight after the fact, which exaggerates the significance of their findings,” said Dr. Jonathan D. Schoenfeld, of the Harvard School of Public Health.
Schoenfeld co-authored a study in the American Journal of Clinical Nutrition titled, “Is everything we eat associated with cancer?”
The short answer: No. But you wouldn’t know that from reading the medical journals.
Randomly selecting 50 ingredients from “The Boston Cooking-School Cook Book,” Schoenfeld and colleague Dr. John Ioannidis of Stanford scoured scientific literature for articles evaluating the cancer risk of everything from mustard to orange juice.
They found that other researchers had published papers touting either cancer risk or prevention benefits for 40 of these randomly selected ingredients (bay leaves and thyme have, as of yet, evaded scrutiny). But when Schoenfeld and Ioannidis looked more carefully, many of the studies “spuriously highlight results that barely achieve statistical significance.”
“Associations with cancer risk or benefit have been claimed for most food ingredients. Many single studies highlight implausibly large effects, even though evidence is weak,” the authors wrote.
That doesn’t stop the public from being fed promises of death by way of breakfast. Many of the fad stories about what causes or prevents cancer comes out of the field of nutritional epidemiology, leading some researchers to question whether the publication of studies from this field does more harm than good.
Schoenfeld takes a measured approach.
“I think nutritional epidemiology has the potential to do a lot of good. More proven associations such as the links between excessive alcohol use and obesity and diseases such as cancer and cardiovascular disease are good examples,” he said. “But these important messages can get lost when the public is inundated with results from poorly conducted studies that are never repeated and ultimately disproven.”
When bad studies get big attention, the media often gets the blame for the public’s misconceptions.
“The media often take individual studies out of context and focus on what is new and exciting instead of what is more proven,” Schoenfeld said.
Another researcher said reporters have been too quick to publish preliminary findings.
“Many stories that appear in the media are early research findings presented at big scientific meetings. It’s too early. A lot of the things that get published on front page of the paper, half that stuff never appears in the medical journals,” said Dr. Steven Woloshin, professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice.
Woloshin co-authored “Know Your Chances,” a book aimed at helping reporters and consumers sift through statistics to understand the real risks and benefits associated with claims found in the media and in research studies.
Among the most important thing to keep in mind when vetting the latest findings about hairspray or orange juice is to look at the numbers and the type of study being conducted. If it’s a randomized trial of thousands of people, published in a peer-reviewed journal, take note. If it’s an opinion piece based on an observational study of a dozen school kids in Cambodia, it probably doesn’t apply to you.
And if it’s an animal study, read no further, Woloshin said.
“The road to hell is littered with animal studies that don’t pan out,” he said. “People aren’t rats.”
Schoenfeld and Woloshin warn, if something is too good (or bad) to be true, it probably is. Among the biggest doozies:
YOUR NAIL SALON WILL GIVE YOU CANCER
Recently women were warned that the UV light used to dry gel manicures causes skin cancer.
“Women who frequently get gel manicures should consider their skin-cancer risk because the UV light needed to cure the gel manicure is a risk factor for skin cancer,” Dr. Chris Adigun of the NYU School of Medicine wrote in an article in the Journal of the American Academy of Dermatology.
The nail driers were compared to tanning beds, which also emit lengthy doses of cancer-causing UV light.
Wait a minute: Except the study wasn’t a study. Adigun’s article was an opinion piece that cited a 2009 observational study of only two women, hardly the kind of science that would make most oncologists bite their nails.
Even Adigun was tempered in her opinion, saying in interviews that the cancer risk from gel manicures was “low. Not zero, but low.”
It comes down to level of exposure. Because the levels of UV exposure were not studied in either articles, it’s difficult for oncologists to determine how many manicures it would take to do real damage.
“We definitely know that UV exposure in tanning salons is a risk factor for skin cancers like melanoma,” said Greg Angstreich, an oncologist at Hoag Hospital in Newport Beach, Calif. “The amount of radiation you get from tanning salons is a magnitude higher than from nail salons.”
Instead of jettisoning the gels, Adigun and others recommend applying sunscreen before sticking your hands under the UV light, a service many nail salons already offer.
YOUR HOT DOG WILL GIVE YOU CANCER
Recent studies have suggested that eating the equivalent of one hot dog a day increases your risk of developing colorectal cancer by 21% over your lifetime.
Wait a minute: Who eats a hot dog a day? And what is your individual starting risk? If you maintain a balanced diet, stay physically active and have no family history of cancer, you’re not likely to be brought down by a brat, oncologists said.
There is also a question of how bad “bad” really is. The nitrates found in hot dogs and other cured meats are classified as “probable carcinogens,” meaning that they haven’t been proven to cause cancer in humans, but they’re likely not great for you, either.
Keeping in mind that nitrates are also found in fruits and vegetables and even occurs naturally in your own saliva, trying to avoid this food additive entirely is impossible. So, as with everything, experts advise moderation. And mustard.
YOUR TOAST WILL GIVE YOU CANCER
One of the most surprising culinary villains of last year was burnt toast.
Food cooked at high temperatures, such as barbecue, potato chips and even burnt toast are known to contain the chemical acrylamide, which researchers have associated with an increase in cancer risk in animal studies.
Wait a minute: The emphasis on the “animal study” part was largely overlooked and toast started getting blamed for breast cancer. Fortunately for crunchy toast-munchers everywhere, acrylamide’s role in human cancer development has not been validated.
Researchers often start with animal studies to test safety and efficacy before moving on to bigger game: Humans. Unfortunately, even with the most promising drug treatment animal findings, only a third typically translate to humans. Before evaluating whether what’s good for the goose is good for you, dosage, biology and other lifestyle factors have to be taken into account, information lab animals simply can’t provide.
YOUR COFFEE WILL GIVE YOU CANCER
Next to red wine and chocolate, nothing gets more attention than a study about coffee. Evil, evil coffee. In 1981 a study was published out of Harvard that suggested 50% of all pancreatic cancer cases were attributable to coffee and tea consumption, and the beverage has been demonized ever since. Coffee got blamed for breast cancer, bladder cancer and colorectal cancer, too.
When one of the researchers associated with the pancreatic cancer study publicly gave up his daily cup of Joe, coffee’s place as the devil’s elixir seemed cemented.
Wait a minute: But even the non-caffeinated pancreatic cancer researchers noted the data was incomplete and that “the positive association with coffee consumption that we observed must be evaluated with other data before serious consideration is given to the possibility of a causal relation.”
So, 32 years later, has that link been satisfactorily established? Nope.
In fact, a 2011 analysis of several studies suggests the opposite might be true. Plus, coffee is now being linked to a reduction in risk of Parkinson’s disease and a whole host of other benefits.
Does that mean coffee is now really, really good for you? Again, just as coffee’s place as a carcinogen should have been suspect, researchers warn not to put too much stock in coffee as a cure-all.
YOUR ARTIFICIAL
SWEETENER WILL GIVE
YOU CANCER
Like the coffee it dissolves so sweetly into, artificial sweeteners have been bearing a badge of shame for decades.
In the 1970s, lab rats developed bladder cancer during a saccharine trial, and the sweetener was put on the federal government’s list of carcinogens.
Wait a minute: But in 1997, the National Toxicology Program finally removed it. No case of cancer in a human has been linked to the sweet stuff.
As a result of the 20-year bad rap, other artificial sweeteners are also considered suspect by association. The National Cancer Institute has said there is no known association between any artificial sweeteners and cancer, but that won’t stop the person next to you at the Starbucks condiment station from telling you otherwise.
YOUR DEODORANT WILL GIVE YOU CANCER
According to that e-mail your mother has sent you 1,000 times, the aluminum in antiperspirant causes breast cancer.
The claim makes sense: aluminum-based compounds can cause estrogen-like effects, and estrogen has the ability to promote the growth of breast-cancer cells. Plus, many clinical studies show a disproportionately high incidence of breast cancer in the upper outer quadrant of the breast, where deodorant is normally applied.
Wait a minute: But when researchers dug deep, they found no scientific evidence to support the link, and at least one analysis of research that has been done concluded “no validated hypothesis appears likely to open the way to interesting avenues of research.”
As with so many other would-be culprits on the supermarket shelves, the persistent belief that deodorant causes cancer is based on unscientific evidence that, frankly, stinks.