You may still follow the same trendy beauty and health advice you and your friends have believed for decades. Your grandmother probably shared her secrets on how to live a long, healthy life, but it’s possible that she got a few things wrong. We’ve researched five superstitions that we were raised on; here's the truth behind these common beliefs.

Wait an hour after eating to swim: FALSE

You’ve heard it your whole life: wait one hour after eating to swim, unless you want to get a stomach ache and drown. Well, sorry mom, it’s just not true. You might feel a little lethargic, according to Jim Sears, a pediatrician in San Clemente, California, but that won't pose much of a danger.

“You might have less energy to swim vigorously, but it shouldn’t inhibit your ability to tread water or play,” Sears told Real Simple.

Shaving makes your hair grow back darker and thicker: FALSE

For decades, women have blindly believed that shaving makes their hair grow back darker and thicker. But does shaving actually make it more difficult the next time you grab your razor? No, it won’t

"Hair that hasn't been cut grows to a point," Heather Woolery-Lloyd, a dermatologist in Miami, told Real Simple. "It's widest at the base and narrowest at the tip."

When you shave a hair, you cut it at the base — therefore shaving doesn't change the width, density, or color of hair.

Apple cider vinegar skin benefits: TRUE

Apple cider vinegar has been gaining prominence in the beauty market recently. The hype is real; this healing ingredient acts as a great natural toner that can leave your skin looking healthier. As Medical Daily previously reported, the acidity of apple cider vinegar helps change the pH of your scalp and prevent dandruff.

It’s also a great teeth whitener. It is the astringent, highly acidic nature of the vinegar that provides the teeth-whitening benefit.

Avocado helps with hair growth and health: TRUE

The oil in the avocado can help to moisturize brittle hair and prevent split ends, New Health Guide reported. Avocado also adds shine and luster to hair, and it also prevents future hair loss and promotes hair growth.

Additionally, avocado oil contains proteins and vitamins including A,D, E and B6 as well as magnesium, folic acid, amino acids, copper and iron. All of these can help with both hair growth and nourishment.

Coffee stunts kids’ growth: FALSE

Ah, another age-old myth. In truth, there is absolutely no evidence that drinking coffee at a young age stunts kids' growth.

"It's 'common knowledge,' so to speak — but a lot of common knowledge doesn't turn out to be true," author Mark Pendergrast told Smithsonian Magazine.

But, the long-term effects of coffee on children haven't been thoroughly studied. Are there still health risks for younger people who consume a lot of coffee?

"My biggest concern is that caffeine is addictive," Pendergrast said. "And there is a lot of evidence that if you're addicted, and you don't get your caffeine, you suffer quite exquisite headaches, among other symptoms.”

Read more:

What Are The Most Common Weight Loss Myths?

5 Things That Don’t Kill Your Brain Cells, Despite The Myths