On Wednesday, as we awaken to a new year, one mumbled vow will be heard in countless households: “Never again.”

To paraphrase the holiday ditty, it’s the most hungover time of the year. If it weren’t a national holiday, New Year’s Day would likely eclipse the day after the Super Bowl for the dubious title of most people calling in sick at work.

Hangovers aren’t limited to the holidays. More than 15 percent of Americans have a hangover at least once a month, according to the Annals of Internal Medicine, and hangover-related absenteeism and poor performance have an estimated annual cost of $148 million. Nor are they new. Accounts go back to biblical times (“Woe unto them that rise up early in the morning, that they may follow strong drink” — Isaiah 5:11).

But there’s more folklore than fact about this day-after malaise. Instead of leaving you to pithy slogans (“Beer before liquor, never sicker; liquor before beer, never fear”), we took a run through the recent research to help you sort hangover myth from reality. 

Myth: You won’t get a hangover if you don’t get drunk.

Reality: Actually, many subjects in a Danish research project suffered hangover symptoms (headaches, exhaustion, dizziness, dry mouth, nausea) even if they never reached the DWI benchmark of 0.08 blood-alcohol concentration (BAC) the night before. However, a Canadian experiment found that higher BACs tend to increase the likelihood of getting a hangover.

Myth: It’s the alcohol that gets ya.

Reality: There’s truth to that, but the likelihood and degree of a hangover often are determined by the content of alternate alcohol forms called congeners, according to several studies. Drinks with high congener content (tequila, whiskey and brandy) contain more methanol, while those with low content (vodka and gin) contain more pure ethanol. Ethanol is not as toxic as methanol, and it breaks down more quickly.

Congeners have much more to do with hangover likelihood and severity than all the old urban legends about mixing types of alcoholic beverage (“Beer before wine, all is fine, wine before beer, always fear”).

Myth: Anyone who drinks heavily will get a hangover.

Reality: Extensive tests indicate that about 23 percent of the population never suffers from hangover symptoms. And many alcoholics seem to develop immunity: One study found that 50 percent of people who are addicted to alcohol hadn’t suffered a hangover in the previous year. 

Myth: Gender and ethnicity don’t play a role in hangovers.

Reality: Some East Asians have genetic differences in their ability to metabolize alcohol (the so-called “Asian flush”) that make them much more likely to suffer hangovers. Recent research indicates that they might not be alone. “There is other less well-established data that suggest that the same may be true in other ethnicities,” said John McGeary, a research psychologist at Brown University.

Dr. Jason Burke, who has treated more than 10,000 people at Las Vegas’ Hangover Heaven clinic, has noticed marked gender differences in symptoms as well. “Women tend to get much more nausea than men,” he said. “Women can have terrible, vacation-ending nausea, but no headache. On the other side of the coin, men tend to get severe headaches and little nausea.”

Overall, genetic differences are believed to be a key element in hangover experiences, and are a major focus in current research.

Myth: Having a hangover is a good deterrent to drinking to excess in the future.

Reality: That whole “never again” feeling generally is fleeting. Several studies have shown that people do not alter drinking patterns despite having hangovers.

Myth: It’s all about dehydration.

Reality: According to Danish researcher Joris Verster, considered by many the world’s foremost expert on hangovers, “drinking water takes away dry mouth and thirst but does not relieve the overall misery of having a hangover.”

Researchers still don’t know the exact physiological components of hangovers, but Verster said that “current studies on the pathology of hangover focus on the role of the immune system.” 

Myth: Having a big meal before, during or after drinking will alleviate a hangover.

Reality: Because alcohol is metabolized primarily in the liver and food in the stomach, that late-night breakfast or White Castle stop helps only a wee bit. 

Myth: Age doesn’t matter.

Reality: There is growing evidence that older drinkers get fewer hangovers than younger ones, partially because older people do less binge drinking. In a Verster-led study of 50,000 adults, published in the journal Alcoholism: Clinical and Experimental Research, both men and women report markedly fewer hangover symptoms as they get older (21 percent of women ages 18-29 suffered nausea vs. 3 percent of women older than 60; 60 percent of men in their 20s suffered exhaustion vs. 4 percent of their elders).

There also might be a little “older and wiser” factor. Brown University professor of emergency medicine Jonathan Howland, who has been involved in several alcohol studies, said that older people might learn how to “drink differently than younger people and thus are less likely to experience next-day discomfort, even if volume is comparable by age group.”

And then there is a bit of natural selection in play. “You don’t see many 60-, 70-year-old active alcoholics,” said Darren Reed, volunteer coordinator of the Southern Minnesota Recovery Center in Mankato. “You either are into recovery or you’re incarcerated or you’re dead. Younger people might get more hangovers because they’re still out there using.” 

Myth: It’s OK to drive with a morning-after hangover.

Reality: You might not be legally drunk, but your driving skills are likely to be impaired. Recent tests have shown that people with hangovers are prone to weaving, speed variability and a decline in reaction time, more than those with a 0.05 BAC.

If you go to work with a hangover, you may face a host of cognitive problems in alertness, reaction time, memory and accuracy. 

Myth: Drinking soda pop will cure a hangover.

Reality: No such luck.

A few things have been shown to alleviate the symptoms of a hangover somewhat: fruit and fruit juices, bland foods with complex carbohydrates (crackers, toast), along with antacids and aspirin (but not acetaminophen, which can have toxic effects on the liver). But, basically, only time heals hangovers.

In October, researchers at Sun Yat-Sen University in China tested 57 potential remedies and determined that Sprite does the best job of speeding up the metabolic process that alleviates hangovers. But McGeary pointed out that alcohol metabolism “is only one of several factors that seem to affect hangovers. There is much more work to be done.”

And the final word comes from Verster: “There is currently no effective hangover cure available. The best way to prevent hangovers is to consume alcohol in moderation.” 

Follow Bill on Twitter: @billward4