SEOUL—Kim Min-koo has an easy reply to new American research that hits South Korea where it hurts—in the noodles. Drunk and hungry just after dawn, he rips the lid off a bowl of his beloved fast food, wobbling on his feet but still defiant over a report that links instant noodles to health hazards.

“There’s no way any study is going to stop me from eating this,” Kim says, his red face beaded with sweat as he adds hot water to his noodles in a Seoul convenience store. His mouth waters, wooden chopsticks poised above the softening strands, his glasses fogged by steam. At last, he spears a slippery heap, lets forth a mighty, noodle-cooling blast of air and starts slurping.

“This is the best moment—the first bite,” Kim, a freelance film editor who indulges about five times a week, says between gulps. “The taste, the smell, the chewiness—it’s just perfect.”

Instant noodles carry a broke college student aura in America, but they are an essential, even passionate, part of life for many in South Korea and across Asia.

Hence the emotional heartburn caused by a Baylor Heart and Vascular Hospital study in the United States that linked instant noodles consumption by South Koreans to some risks for heart disease.

Wounded pride

The study has provoked feelings of wounded pride, mild guilt, stubborn resistance, even nationalism among South Koreans, who eat more instant noodles per capita than anyone in the world. Many of those interviewed vowed, like Kim, not to quit.

Other noodle lovers offered up techniques they swore kept them healthy: taking Omega-3, adding vegetables, using less seasoning, avoiding the soup.

Some, however, dismissed the study because the hospital involved is based in cheeseburger-gobbling America.

The heated reaction is partly explained by the omnipresence here of instant noodles, which, for South Koreans, usually mean the spicy, salty “ramyeon” that costs less than a dollar a package.

Individually wrapped disposable bowls and cups are everywhere: Internet cafes, libraries, trains, ice-skating rinks. Even at the halfway point of a trail snaking up South Korea’s highest mountain, hikers can refresh themselves with cup noodles.

Deep nostalgia

Elderly South Koreans often feel deep nostalgia for instant noodles, which entered the local market in the 1960s as the country began clawing its way out of the poverty and destruction of the Korean War into what’s now Asia’s fourth-biggest economy.

Many vividly remember their first taste of the once-exotic treat, and hard-drinking South Koreans consider instant noodles an ideal remedy for aching, alcohol-laden bellies and subsequent hangovers.

Some people won’t leave the country without them, worried they’ll have to eat inferior noodles abroad. What could be better at relieving homesickness than a salty shot of ramyeon?

“Ramyeon is like kimchi to Koreans,” Ko Dong-ryun, 36, an engineer from Seoul, says in reference to the spicy, fermented vegetable dish that graces most Korean meals. “The smell and taste create an instant sense of home.”

Ko fills half his luggage with instant noodles for his international business travels, a lesson he learned after assuming on his first trip that three packages would suffice for six days. “Man, was I wrong. Since then, I always make sure I pack enough.”

US study

The US study was based on South Korean surveys from 2007 to 2009 of more than 10,700 adults aged 19-64, about half of them women.

The study found that people who ate a diet rich in meat, soda and fried and fast foods, including instant noodles, were associated with an increase in abdominal obesity and low-density lipoprotein (LDL), or “bad,” cholesterol.

Eating instant noodles more than twice a week was associated with a higher prevalence of metabolic syndrome, another heart risk factor, in women but not in men.

The study raises important questions, but it can’t prove that instant noodles are to blame rather than the overall diets of people who eat lots of them, cautions Alice Lichtenstein, director of the cardiovascular nutrition lab at Tufts University in Boston.

“What’s jumping out is the sodium (intake) is higher in those who are consuming ramen noodles,” she says. “What we don’t know is whether it’s coming from the ramen noodles or what they are consuming with the ramen noodles.”

Produced safely

There’s certainly a lot of sodium in those little cups. A serving of the top-selling instant ramyeon provides more than 90 percent of South Korea’s recommended daily sodium intake.

Still, it’s tough to expect much nutrition from a meal that costs around 80 cents, says Choi Yong-min, 44, marketing director for Paldo, a South Korean food company. “I can’t say it’s good for your health, but it is produced safely.”

By value, instant noodles were the top-selling manufactured food in South Korea in 2012, the most recent year figures are available, with about 1.85 trillion won ($1.8 billion) worth sold, according to South Korea’s Ministry of Food and Drug Safety.

China is the world’s largest instant noodle market, according to the World Instant Noodles Association, although its per capita consumption pales next to South Korea’s. The food is often a low-end option for Chinese people short of money, time or cooking facilities.

Japan, considered the spiritual home of instant noodles, boasts a dazzling array. Masaya “Instant” Oyama, 55, who says he eats more than 400 packages of instant noodles a year, rattles off a sampling: Hello Kitty instant noodles, polar bear instant noodles developed by a zoo, black squid ink instant noodles.

In Tokyo, 33-year-old Miyuki Ogata considers instant noodles a godsend because of her busy schedule and contempt for cooking.

Instant noodles also bring her back to the days when she was a poor student learning to become a filmmaker, and she would buy two cup noodles at the 100 yen shop. Every time she eats a cup now, she is celebrating what she calls “that eternal hungry spirit.”

Speed, cost, flavor

In South Korea, it’s all about speed, cost and flavor.

Thousands of convenience stores have corners devoted to noodles: Tear off the top, add hot water from a dispenser, wait a couple minutes and it’s ready to eat, often at a nearby counter.

Some even skip the water, pounding on the package to break up the dry noodles, adding the seasoning, then shaking everything up.

“It’s toasty, chewy, much better than most other snacks out there,” Byon Sarah, 28, who owns a consulting company, says of a technique she discovered in middle school. “And the seasoning is so addictive—sweet, salty and spicy.”

Food for the lazy

Cheap electric pots that boil water for instant noodles in one minute are popular with single people. Making an “instant” meal even faster, however, isn’t always appreciated.

At the comic book store she runs in Seoul, Lim Eun-jung, 42, says she noticed a lot more belly fat about six months after she installed a fast-cooking instant noodle machine for customers.

“It’s obvious that it’s not good for my body,” Lim says. “But I’m lazy, and ramyeon is the perfect fast food for lazy people.”

Why I love canned goods, instant noodles, processed products