In our job as professional communicators, we take pride in educating the public on health issues and the best possible treatments available. As part of most campaigns there’s an element of debunking medical myths and dealing with contradictions. Sometimes old-wives’ tales don’t stack up that well against medical facts, but they can be more persistent than a winter cold!

Have a look at some of these popular “medical myths.” Have you fallen for them?

1. Makeup with SPF is just as good as sunscreen

Women tend to be wary of caking on makeup, but this means they rarely put on the amount of sunscreen-enhanced foundation, tinted-moisturizer or lipstick required to protect their skin from the sun. They also neglect to reapply the products every two to three hours, which is the amount of time it takes for any sunscreen to wear or rub off, and for the sun’s UV rays to deactivate its protective ability. This is why makeup with SPF can be 14 times less effective than sunscreen. Source

2. We only use 10 per cent of the brain

The belief that we use only 10 per cent of our brains has persisted for over a century, despite dramatic advances in neuroscience. Some sources attribute this claim to Albert Einstein, but no such reference or statement by Einstein has ever been recorded. This myth arose as early as 1907, propagated by multiple sources advocating the power of self-improvement and tapping into each person’s unrealised latent abilities. Source

3. Shaved hair grows back faster and thicker

The rate of hair growth is determined by a number of factors including genetics, nutrition and nerve function to the area of skin. The idea that hairs grow back darker and thicker is an illusion, created by the fact that hairs tend to taper towards their ends. Shaving them at the base will result in a blunt-ended hair that feels more obvious and is slightly thicker than the end of the hair that has been cut. The base of the hair has been this thickness all along. But compared with the end of a longer hair, it seems a lot thicker. Source

4. You should drink at least eight glasses of water a day

The origin of this myth is most likely the fact that a 1945 government agency said that the human body needed around 8 glasses of fluid a day. This estimation included the fluid from all of the foods we eat and drinks like tea and coffee. Somehow over time “fluid” turned to “water” and the modern water myth arose. This also lead to silly slogans like “if you are thirsty it is too late” – a concept that would seem to have been invented by water bottlers who have something to gain from excess water consumption in the population in general. So, in reality, if you are thirsty, drink some water. If you are not, don’t. Source

5. Vaccines can cause developmental disorders in children.

This remains a hotly debated issue, despite being debunked in multiple large studies. And now the United Kingdom is dealing with a serious outbreak of measles partly as a result of the large number of children who were not inoculated against the disease during the MMR vaccine scare of the early 2000s. Measles, mumps and rubella are still relatively uncommon in the United States, but there has been an increase in cases in recent years. The UK has launched a large-scale, expensive catch-up campaign to quickly vaccinate as many children as possible.

6. Eating a lot of carrots can save your failing vision.

Vitamin A is essential for good vision but you only need a small amount.
In fact one half-cup of raw carrots will provide you with 184 per cent of the recommended daily intake. An excessive amount of beta carotene, the compound in carrots that’s converted to vitamin A, can not only make your skin turn orange, but studies show it has also been associated with an increased risk of lung cancer in some people. So enjoy the crudités, but if you worry that your eyesight is failing, make an appointment with an optometrist or an eye doctor.

7. Stomach ulcers are caused by stress

“Don’t get so mad! You’ll give yourself an ulcer!” how often have you heard that statement? It’s an established idea, that stress, emotional negativity, or even spicy food can lead to stomach ulcers however, research suggests that harmful stomach bacteria, rather than “acid levels” or stress, are in fact to blame for abdominal agony attacks. The H. pylori bacteria, believed to be spread via person-to-person contact, apparently weakens the mucus lining of the stomach, paving the way for gastric acid to attack our delicate stomach lining. Source

8. Cracking your knuckles will cause arthritis in later life

The cracking sound in the knuckles is caused by the bones moving apart and forming a gas bubble – the sound is the bubble bursting. It is quite common to hear someone warning a knuckle-cracker that they will get arthritis, but the worst that can happen to a compulsive-cracker is that their finger joints may weaken over time. Arthritis is caused by a variety of things (such as crystal formations in the case of gout) – but knuckle-cracking isn’t one of them. Source