7 health myths debunked in 2018

If your New Year’s resolution is to get healthy in 2019, that’s great. Eating better and exercising more are goals many people set for themselves each January.

But don’t fall for some of these health fads that have no science to support their claims.

1. Ketogenic diet

The ketogenic — or keto — diet involves nearly eliminating carbs and replacing them with fat. The lack of carbohydrates puts your body in a metabolic state called ketosis. The lack of carbs forces your body to burn fat for energy. Weight loss is definitely a benefit of the keto diet, but there is no research suggesting it's a long-term solution. In fact, it can have some adverse side-effects, including:

» What you need to know before starting the keto diet

2. Exercising in 30-minute intervals is best

Google "30-minute workout" and you'll get pages of results. But new government guidelines issued in November stress the total time spent exercising, not how long you work out each session. According to the Physical Activity Guidelines for Americans, adults "should do at least 150 minutes to 300 minutes a week of moderate-intensity, or 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity."

» Hate exercising? Skipping workouts worse for health than smoking, diabetes and heart disease, study says

3. Going gluten-free is good for you

For those with celiac disease, avoiding gluten — a protein in wheat, rye and barley — is necessary to be healthy. For everyone else, avoiding gluten is unnecessary. "People who are sensitive to gluten may feel better, but a larger portion will derive no significant benefit from the practice. They'll simply waste their money, because these products are expensive," Dr. Daniel A. Leffler, director of clinical research at the Celiac Center at Beth Israel Deaconess Medical Center in Boston and an assistant professor of medicine at Harvard Medical School, told Harvard Health Publishing. Recent studies have found that a gluten-free, low-carb diet could pose a health risk to unborn babies, and that gluten-free diets could increase heart attack risk for non-celiacs.

» Gluten free, low-carb diets could pose serious health risks to unborn babies
» Gluten-free diets could increase heart attack risk for non-celiacs, study finds

4. Americans are living longer

According to the Centers for Disease and Prevention in Atlanta, the life expectancy in the United States declined for the second year in a row. The latest report from the CDC says the overall life expectancy in the U.S. was 78.6 years, down .1 from the previous year. Men can expect to live 76.1 years, down from 76.3. Women held steady at 81.1 years. During the 20th century, advances in medications and other treatments were responsible for dramatic increases in how long people lived. But deaths from drug overdoses, chronic liver disease, suicide, Alzheimer's and blood infections (septicemia) have all gone up, resulting in a shortened average life span.

» CDC: Life expectancy in US declines for second year in a row

5. Glasses block blue light

In July, researchers at the University of Toledo in Ohio warned that prolonged exposure to blue light — a high-intensity 445-nanometer shortwave emitted from digital screens, the sun and other electronic devices — can accelerate blindness and increase risk of eye disease. Ads for glasses that block this blue light are plentiful. According to the American Academy of Ophthalmology, however, those glasses are useless. "People are very worried that we're looking at our screens more than we ever did," Academy spokesman Rahul Khurana, told Business Insider. "Everyone is very concerned that it may be harmful to the eye, and it's a valid concern, but there's no evidence it may be causing any irreversible damage." The academy states it "does not recommend any special eye wear for computer use."

» Is the blue light from your computer, phone screen slowly blinding you?

6. E-cigarettes are a safe alternative to tobacco

Using electronic cigarettes, or vaping, is marketed as a less-addictive alternative to tobacco products. But that doesn't mean they are safe. Studies this year have found that not only are teens who vape more likely to start smoking, but also they might be inhaling cancer-causing chemicals. The U.S. Food and Drug Administration says using e-cigarettes, which contain nicotine, can "prime the brain's reward system, putting vapers at risk for addiction to other drugs." And in an advisory Tuesday, the Associated Press reported, Surgeon General Jerome Adams said parents, teachers, health professionals and government officials must take "aggressive steps" to keep children from using e-cigarettes. Federal law bars the sale of e-cigarettes to those under 18.

» Teens who smoke hookah, e-cigarettes are more likely to try cigarettes, study says

7. You “need” superfoods

Kale, quinoa — even cockroach milk — have been touted as "superfoods," those nutrient-rich foods that are supposed to be especially beneficial for good health. But do you really need them? Registered dietician K. Anita Mirchandani, spokeswoman for the New York State Dietetic Association, told healthline.com that people can get enough nutrients "by eating any variety of fruits, vegetables, eggs, walnuts, and yogurt. Antioxidant-rich foods include a variety of peppers, berries, and anything rich in vitamin C, such as oranges, grapefruits, and papaya; or rich in vitamin A, like carrots." Mirchandani also recommends yogurt. "You are getting an excellent source of calcium, fat, and protein, and it fills you up," she said.

» Cockroach milk may have more nutrients than regular milk, study says

» The sudden collapse of coconut oil, 2015's favorite superfood