Karen Iris Tucker is a Brooklyn-based journalist who writes primarily about genetics, health and cultural politics.

When the actress Angelina Jolie told the world that she underwent a preventive double mastectomy because of her pervasive family history of breast and ovarian cancer, her words were laudable and responsible. In a 2013 New York Times piece, Jolie highlighted her reason for having the surgery: She had inherited a faulty BRCA1 gene, which significantly increased her cancer risk.

Though she perceptively elevated the public’s interest in BRCA mutations, a potentially life-saving thing, Jolie’s moving story, involving complex genetics minutiae, also inspired anxiety and confusion. Often lost amid the general discussion surrounding her missive was an essential fact: Most women do not have a BRCA1 mutation and are at average risk for breast cancer.

If Paul A. Offit had his way, scientists would be much more nimble in filling these types of medical-information voids. In his most recent book, “Bad Advice: Or Why Celebrities, Politicians, and Activists Aren’t Your Best Source of Health Information,” Offit, a pediatrician, scientific researcher and director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, argues that scientists should immerse themselves much more proactively into our popular discourse to help educate the public.

While “Bad Advice” is a quick read, its goal is weighty: to defend science as a vital beacon in the public sphere. Offit lays a compelling — and sometimes disturbing — foundation for why we need to protect its honor, and he calls for scientists to “become an army of science advocates out to educate the country. Because science is losing its rightful status as a source of truth, now is the time.”

In breezy and deceptively conversational prose that often winks with humor, “Bad Advice” breaks down complex scientific subjects that have been distorted through several cultural lenses. Offit takes to task actors, network news anchors, quack scientists and even politicians who, unlike Jolie in her thoughtful article, have opined on scientific subjects in ways that misinform the public, on occasion to a potentially dangerous degree.

Offit himself has spent years navigating media appearances as a medical and scientific expert. A co-inventor of RotaTeq, a vaccine against rotavirus, which can cause life-threatening vomiting and diarrhea, most commonly in infants and young children, Offit has become a high-profile voice on vaccine safety and, in particular, an ardent defender of the scientific community’s consensus that vaccines have no association with autism. He dedicates a chapter of the book to how his role in bringing RotaTeq to the market has been used by anti-vaccine activists to discredit him as a shill for pharmaceutical companies. The impulse to include this information is certainly understandable: Offit has been harassed and even sued for taking on the anti-vaxxers. He ultimately leaves it to the reader to trust the compassion and sincerity in his profession he displays in these pages.

“Bad Advice” homes in on the consequences of the failure of clear and overwhelming scientific evidence regarding vaccines to win the day. Offit examines, for example, the root causes of the reemergent debate about whether they cause autism. He cites several recent outbreaks of measles and mumps that swept across the nation because some Americans are choosing to withhold vaccines from their children.

Beyond the sizable list of celebrity activists such as Jim Carrey, Charlie Sheen, Robert De Niro and Jenny McCarthy who have questioned the safety of vaccines, Offit says the current political climate bears some culpability for what he calls “science denialism.” He points out that before being elected, President Trump posited the idea that vaccines may have an association with autism. Offit also says evolution denialists were probably heartened by Trump’s choice of Mike Pence as vice president since Pence doesn’t exactly support evolution as a concept.

Across the aisle, Offit says, “liberals have waged their own war on science, holding the unshakeable beliefs that all things natural are good; anything with a chemical name is bad.” He points to the fallacy of going “GMO free” — in the mistaken belief that genetically modified organisms are dangerous. Health organizations worldwide have consistently issued statements to the contrary. Offit says these so-called “Frankenfoods” are no more dangerous than non-GMO foods. Similarly, the misguided fear of genetic modification in medicines (a technology, for example, that led to the creation of insulin for people with diabetes), inspired a Democratic member of the New York State Senate, Thomas J. Abinanti, to introduce a bill in 2015 banning genetically modified vaccines. It rightfully failed to win support.

In addition to misconceptions about GMOs, Offit tackles the current gluten hysteria, citing the ever-expanding array of gluten-free items on our supermarket shelves, from hair products to pet food. “If you really want to watch science denialism at work, just walk into a Whole Foods store,” Offit half-jokes. He says only about 1 percent of the U.S. population would benefit from avoiding gluten. It is nevertheless a billion-dollar industry here.

Offit contends that although scientists are probably in the best position to explain science to the public, there are several factors working against them. One, he says, is the very underpinning of their training, which teaches that the scientific method does not allow for absolute certainty — something people tend to understandably crave in the face of public health scares.

There’s also the ingrained image of scientists as socially awkward toilers in white, windowless rooms. By way of illustration, Offit cites the brutal pickup line by mathematician John Nash in the 2001 movie “A Beautiful Mind”: “I don’t exactly know what I’m required to say in order for you to have intercourse with me.” Offit shows how such depictions have persisted, including in the hit television show “The Big Bang Theory” (which actually features real-life high-profile scientists).

Like the nerds in those cultural touchstones, Offit admits in “Bad Advice,” which chronicles many of his media appearances, that it took some time for him to master the art of distilling vital medical information into on-air sound bites.

For one network television appearance in his younger days, Offit recalls teetering on a high, wobbly chair, with an ill-fitting earpiece, waiting to answer questions about vaccines. A segment on “Ally McBeal,” a comedy-drama of the time, was slated to air after his appearance. The TV crew laughed and conversed loudly; models who were showcasing the new series’ short skirts strode around him. Suddenly, his earpiece fell out, and when he reinserted it, a news anchor was asking a multipronged query about what vaccines children get, how many they get and when they get them. Offit, then a newbie to on-air interviews, recalls trying valiantly, and failing, to answer it successfully. “In fact, it was so pathetic that even the models stopped talking and stared at me sadly.”

Despite its liberal use of such lighthearted anecdotes, “Bad Advice” does not let us forget its weighty contention: Science is under siege. Offit closes his book with recollections of a speech he gave at the March for Science in Philadelphia in 2017. In it, he implored his fellow scientists to be better advocates and educators. Failing that, he says, “I worry that in this age of anti-enlightenment, when science seems to be losing its place as a source of truth, we won’t be able to do it for much longer.”

Bad Advice

Or Why Celebrities, Politicians, and Activists Aren't Your Best Source of Health Information

By Paul A. Offit

Columbia. 251 pp. $24.95