What a year 2017 was for health news.
We saw major advances in gene therapy for leukemia, we learned how the sugar industry misled the public on the link between the sweet stuff and heart disease, and Canada's opioid crisis opened our eyes to a grim epidemic.
But there was also some... other stuff. Lighter stuff. Weirder stuff.
Specifically, health experts in 2017 spent a lot of time telling us to stop doing things. Some of the cautions might seem kind of obvious, while others are more surprising and downright upsetting. Is nothing safe in this world?!
Here are the 15 oddest things experts told us to stop doing this year.
1. Having doggy-style sex
Why? It could cause men to "break" their penis. A small study published in the Journal of Impotence found that doggy style was the most likely position to cause penile fractures during heterosexual sex. The researchers blamed the angle and "vigour."
2. Taking selfies
Why? It could spread head lice. Leaning in close to take a family photo or a selfie gives lice the opportunity to crawl from one scalp to another when heads touch, according to lice-removal service Ottawa Lice Squad.
3. Sleeping with the door shut
Why? Keeping a door open increases the ventilation in your room, which can help you get a good night's sleep, researchers said. Opening a window can help, too.
4. Having oral sex with a lot of people
Why? A study published in Annals of Oncology journal found that men who have oral sex with a high number of partners could increase their risk of head and neck cancer. The risk among men ages 20-69 who had been tested for oral human papillomavirus infection (HPV) was more than double for men who had a lot of oral sex partners.
5. Eating too much with your partner
Why? Mealtimes have become a central part of relationships, leading to relationship weight gain (newlyweds can gain an average of four to five pounds during their first year of marriage), said Dr. Catherine Hankey, a nutritionist at the University of Glasgow. This trend, coupled with being less physically active, is problematic, she added.
6. Trying vaginal seeding
Why? The trend, where an infant born by caesarean section is swabbed with fluids from a mother's vagina, could pass potentially-dangerous bacteria and illnesses such as sexually transmitted infections to the newborn. The American College of Obstetricians and Gynecologists are cautioning against the practice.
7. Dyeing your hair frequently
Why? It could increase your risk of breast cancer. A study found that women who frequently dye their hair increase their risk of developing breast cancer by about 14 per cent. Carcinogens in the hair products could be causing the increased risk.
8. Drinking in front of your kids
Why? Kids notice a change in their parents' behaviour even if they've only had a moderate amount of alcohol, a U.K. study revealed. And the kids reported feeling anxious, embarrassed, and worried as a result.
9. Being a teen mom
Why? A study found that being a teen mom might have a negative impact on the heart. The study, published in the Journal of the American Heart Association, found that those who gave birth for the first time before they were 20 years old had a higher risk of heart disease and stroke later in life.
10. Storing eggs in the fridge door
Why? It will expose the eggs to sudden temperature changes each time the door opens and closes, which will make them go rotten faster, food storage expert Vlatka Lake said.
11. Saying "I love you" to show how you feel
Why? A study said it's not the best way to show someone you love them. Researchers found that small, non-romantic gestures such as compassion or snuggling can make people feel more loved than hearing "I love you."
12. Eating food flies have landed on
Why? A study found that flies carry more bacteria and disease than previously thought. Common houseflies carry more than 351 types of bacteria, such as salmonella and e-coli, according to the study. And those bacteria are carried onto any surfaces they land on.
13. Eating your placenta
Why? There's "little to no" health benefit, according to a recent study. And in October, the American Journal of Obstetrics and Gynecology warned that not only are there no documented benefits, but that eating your placenta can actually cause harm, including the potential for transmission of serious bacterial infections to newborns.
14. Going on slides with your kids
Why? You could break your kid's leg. A study presented at the 2017 American Academy of Pediatrics National Conference & Exhibition cautioned that the weight of a parent sliding behind their kid could cause little bones to snap if a kid's leg gets caught or bends at a weird angle.
15. Blowing out birthday candles
Also on HuffPost: