Dear Doctor: I saw on TV that someone who’s allergic to fish actually died just from smelling it. Is that really possible?

Dear Reader: You’re referring to a news story about an 11-year-old boy who died on New Year’s Day after visiting relatives in whose home fish was cooking. The boy, who was allergic to both seafood and peanuts, did not eat or touch the fish. When he told his parents he felt ill and was having trouble breathing, they treated him with the nebulizer he carried because he also suffered from asthma. At first the treatment appeared to be successful. Soon, however, the boy’s condition worsened and paramedics were called. The boy, who became unconscious and unresponsive, was transported to a local hospital where he was pronounced dead.

The circumstances were so unusual that a definitive cause of death was not immediately announced, and the case was referred to the medical examiner’s office. However, authorities believe that vapors from the cooking process contained fish proteins, which activated the child’s immune system when he inhaled them. This triggered an allergic response, which, in combination with his asthma, proved to be fatal.

A food allergy is a chronic overreaction by the immune system to even a minute amount of a specific food. The most common allergies are to the proteins found in peanuts, tree nuts, cow’s milk, fish and shellfish, eggs, wheat and soy. Although these proteins are not actually dangerous, the immune system of an allergic person will flag them as a threat. It will then mount an attack that produces physical symptoms that range from mild to dangerous. These include digestive problems, tingling, itching, rash, flushing, hives and swelling of the lips, tongue, face, throat or other parts of the body.

The most severe allergic reaction is anaphylaxis, which is life-threatening. When this occurs, the airways can become so swollen it becomes difficult or impossible to breathe. Other symptoms of anaphylaxis include rapid pulse, loss of consciousness and a severe drop in blood pressure. Immediate medical treatment for anaphylaxis is crucial. Reaction to a food allergen begins anywhere from several minutes to several hours after eating the trigger food.

It’s estimated that of the 15 million Americans with food allergies, about 6 million are children younger than 18. Close to one-third of those are allergic to more than one food. Although it is not known why, food allergies are on the rise. Between 1997 and 2008, peanut and tree nut allergies in children tripled. All-cause food allergies in children increased by 50 percent between 1997 and 2011. Not only does this result in tens of thousands of health emergencies in children each year, there’s a financial cost as well. It’s estimated that families spend upwards of $25 billion annually caring for children with food allergies. Recent spikes in the cost of epinephrine auto-injectors have angered families and health professionals alike and made headline news.

Although the hypersensitivity in this case is rare, it is becoming an increasingly recognized problem. The American College of Allergy, Asthma and Immunology warns anyone with a fish or seafood allergy to avoid any area where these foods are being cooked.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Help! I just saw on TV that half of all Americans now have heart disease. How did this happen? How do I know if I'm one of the 50 percent?

Dear Reader: You're referring to a new report from the American Heart Association, which was published at the start of this year. The statistical update concluded that at least 48 percent of American adults have some sort of cardiovascular disease. Individuals under the age of 18 were not included in the report, so it's not actually half of all Americans. The update, which is released at the start of each new year, is compiled in collaboration with a number of government agencies, including the National Institutes of Health.

To understand why this number is suddenly so high, we need to rewind to 2017. That's when the joint American Heart Association-American College of Cardiology hypertension guidelines got an update. At that time, the definition of high blood pressure was lowered from 140/90 mm Hg to 130/80 mm Hg. In one fell swoop, millions of Americans who thought they had normal blood pressure the day before were suddenly in the hypertensive category.

Some of you may remember that this change to the definition of high blood pressure proved to be controversial. The lower benchmark was based on a medical trial in which the method of measuring blood pressure was markedly different from what you'll typically undergo in a medical setting. Participants were allowed to sit quietly for several minutes before an automated device was used to measure their blood pressure. The final reading was derived from the average of up to three separate measurements. This all led to some robust debate in the medical community.

Another factor in the new heart disease estimates is the definition of cardiovascular disease itself. It includes heart failure, stroke, coronary heart disease, and yes, high blood pressure. That means anyone with a blood pressure reading of 130/80 mm Hg or higher now meets the definition of heart disease. But when you exclude high blood pressure and focus solely on the other three conditions, the prevalence of cardiovascular disease among American adults drops to 9 percent overall.

Still, high blood pressure is dangerous. Not only is it the most common risk factor for stroke and heart disease, it plays a role in a number of other serious health conditions. The challenge is that high blood pressure is a silent condition. You can't feel it. But inside the body, all sorts of bad things are happening. Over time, uncontrolled high blood pressure can damage and weaken arteries, the heart and blood vessels in the brain. The blood vessels in the eyes and kidneys are also at risk. Research continues to show a connection between high blood pressure and certain types of cognitive impairment and dementia. That's why, through lifestyle changes, medication or both, controlling blood pressure is important to good health.

As for learning about the status of your own heart health, the best way is to see your primary care physician. Through a physical examination and certain tests, including a blood pressure reading and a lipid profile, you'll learn where you stand.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Our mom, who's running for president of the food police, just heard about a study that says any amount of fried food is basically death on a fork. Now my brothers and I are afraid we'll never see another french fry. Please. She's fallen for a conspiracy theory, right?

Dear Reader: You may be too young to know this, but the debate about fried foods has been raging for decades. For many of us, that means fried chicken and fish, fried seafood, potato or corn chips, doughnuts and french fries, to name just a few. Frying makes food deliciously rich and crispy, and each culture throughout the world has its own specialties that rely on the technique. And as anyone who has walked the midway of a state or county fair knows, pretty much anything (fried Oreos, fried ice cream, fried butter) is fair game for the fryer.

Unfortunately, although we humans love fried foods, they don't return the favor. Depending on the specific study, fried foods have been linked to cardiovascular disease, elevated blood pressure, obesity, Type 2 diabetes and certain cancers.

Now the results of research published in January in the British Medical Journal have linked the consumption of fried foods to overall mortality, which means death from any cause. Researchers used 20 years of health data from about 106,000 women who were taking part in the Women's Health Initiative, a long-term national health study.

For this particular research, done at the University of Iowa's College of Public Health, scientists drew from dietary questionnaires filled out by women aged between 50 and 79. The upshot was that those who ate a single serving of fried food per day had an 8 percent higher chance of dying early as compared to those who reported that they ate no fried food. Interestingly, while the study found a correlation between fried food consumption and heart disease, it didn't find a connection to cancer.

That said, the study has limitations. The dietary information was self-reported. So were details about smoking status, exercise habits, alcohol and drug use, and diagnoses of cardiovascular disease, cancer or diabetes, each of which can have a bearing on outcomes.

Whether the fried foods were home-cooked or commercially prepared also wasn't known. That's important because, unlike steaming, boiling, baking or broiling, frying is a complex cooking process. Not only does it change the food, the high heat that frying requires also alters the cooking medium itself. Commercial establishments often use oils that are high in omega-6 fats and saturated fats, none of which are part of a healthful diet. They also reuse their cooking oil, which breaks down in high heat to form unhealthful oxidation products that wind up in the food.

A similar study done in Spain, where frying took place with mainly olive or sunflower oil, did not find the same correlation between fried foods and coronary heart disease and death.

Still, there's no getting around that fact that fried foods are significantly higher in fat, calories and often salt than foods cooked by other methods. Because fried foods are so crunchy and tasty, it's easy to overeat. Our feeling is that rather than a regular dietary staple, fried foods should be an occasional treat.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)