9 health facts you've known all your life that are actually wrong

Barely a day goes by where you don't see a health-related headline that makes you do a double take.

There are so many opinions and myths out there to do with health, nutrition, exercise and wellness that you often don't know who to believe.

With this in mind, here are 9 health myths that are completely false and you should ignore immediately.

1. The flu shot can give you the flu

It sounds like the premise of a bad sci-fi movie, but there is a belief that flu shot or a vaccination can only lead to more illness.

A shot can potentially cause you to suffer from aches and have a minor fever - but those are just side effects and shouldn't be considered major problems.

Vaccinations do contain viruses, but they have already been made inactive and won't cause you to be ill.

Pharmacist Jeremy Blais is quoted by Reader's Digest as saying:

These side effects begin soon after the shot and usually last one to two days.

Almost all people who receive the influenza vaccine have no serious problems as a result of receiving it.

2. Catching up on sleep doesn't work

The temptation to lie in on the weekend in an attempt to catch up on the sleep that you missed during the week is awfully appealing.

However, those extra few hours of sleep can actually damage your sleeping patterns for the rest of the week and completely throw your schedule off.

This results in you being unable to get to sleep properly on Sunday evening thus starting the same routine all over again.

Sleep expert Chris Branter is quoted by IFL Science as saying:

The result is that you have a harder time to get to sleep on Sunday evening, which sets you up for a terrible Monday, not to mention for a totally messed up sleep schedule during the week.

3. Going outside with wet hair will make you ill

Picture: Getty Images/iStockphoto

You know what it's like in the morning after you've jumped out of the shower: you've only got 10 minutes to get dressed and find something to eat. Drying your hair is the last thing on your mind.

Yet you may be conscious that going outside, especially in the cold, with wet hair will make you ill. It's probably something your mother told you but it couldn't be further from the truth.

The fact is that if you already have a virus in your system you will get ill - whether your hair is wet or dry . Nothing to do with your hair or the temperature outdoors.

4. Eating carbohydrates will cause you to gain more weight

Carbs are everywhere and in nearly every type of food. They may have been demonised in recent years but they are an essential part of any balanced diet.

They help your brain, heart, nervous system and your muscles and are a great source of fibre and nutrition.

Of course, you shouldn't exclusively eat them but completely cutting them out of your diet can have a huge impact on your overall mood, performance and recovery.

5. Creative people use the right of their brain, logical people use the left

This one has been doing the rounds for years and you probably believed it for a long time.

However, it is a really old myth that first gained popularity during early surgeries on patients who had suffered seizures.

Neurosurgeon Abhishiek Sharma explains:

The myth is based on early surgeries in seizure patients where, in an attempt to attribute different functions to different parts of the brain, it was found that visuospatial information was processed better in the right hemisphere while verbal information was processed better in the left hemisphere.

But brain scans of healthy people have found that both creative and logical activities cause widespread activation of neural networks on the left and right hemispheres of the brain

6. You should drink eight cups of water a day

Picture: Getty Images/iStockphoto

Drinking water is great for your health, but you should only be consuming it in order to quench your first and not meet a grand total.

There is also the belief that your skin benefits greatly from consuming but, as long as you are drinking a sensible amount of liquid a day, then your skin will be fine.

Dry skin is often caused by low humidity and moisture from the elements and not from what is going on inside of you.

7. Not eating fatty food will cause you to lose fat

This isn't a call to completely binge of burgers and chips but having a diet entirely of fat-free food won't help you lose any more weight.

Keeping a close eye on the size of your portions and maintaining a staple diet is important as is burning calories.

Eating more calories than what you burn will actually cause you to gain weight so try to include unsaturated fats in your diet which should improve your energy, mind and heart health

8. Cracking joints will give you arthritis

If you enjoy the odd satisfaction of cracking your fingers or knuckles, but fear that it will cause you problems in later life, then don't worry.

There is no research linking arthritis and the cracking of joints - and the ailment is just something that is inevitable with age.

Matthew Amsden, an expert in research protocol and analysis for Proof Pilot, explains.

Most early studies on this topic rely on participants self-evaluating their knuckle-cracking habit over many years, and then correlating that with reports of arthritis.

Studies based on people's memories are not very accurate, and the risk of arthritis naturally increases as we age

9. Sit up straight to avoid having a bad back

This is both true and not true. Slouching over all day and not sitting up straight isn't good for you.

Then again neither is maintaining a straight back throughout the entire day, which can cause a strain up yourself.

Neel Anand, MD, clinical professor of surgery and director of spine trauma at Cedars-Sinai Spine Center in Los Angeles says:

Sitting up straight for too long without a break can also cause strain.

If you work in an office setting, make sure your chair is at a height where your knees are at a 90 degree angle, your feet can rest flat on the floor, and you have proper lower back support.

Make sure to stand up, stretch, and take a quick walk several times a day to keep from getting stiff or causing injury.

HT Reader's Digest, IFL Science

More: The commonly believed sex myth people need to know isn't true