Historic wisdom, modern dilemma
They are well meaning, but are health statements through the ages actually correct? Peta Rasdien takes a look.
We use only 10 per cent of our brain
A commonly held belief for more than a century, but it is untrue.
Royal Australian College of General Practitioners (WA) chairman Tim Koh said we use most, if not all, of our brain at different times.
“When speaking, you use a different part to when you are reading,” he said.
“Even when you are asleep it is still active.”
You must wait half an hour after you eat before you swim
There is no specific medical reason why you can’t swim directly after a meal.
Cramps and stitches, the thread of which are thought to be behind the advice, are not real dangers.
Dr Koh said people, particularly children, were more likely to throw up if they swallowed a lot of water when swimming straight after a meal.
You can predetermine baby’s gender
There are very clear and accurate ways to determine your baby’s gender in utero.
Whether the mother craves salty or sugary treats, or speculation about how she is carrying the baby — high or low — are not among them (sweet and high for a girl and salty and low for boys, according to the old wives tales).
Dr Koh said cravings varied from person to person and how you carry during pregnancy will also differ.
For those desperate to find out the gender of their baby, the best bet is an ultrasound at 20 weeks.
The flu shot gives you the flu
Not true, but it can cause symptoms that can be similar as the vaccine sparks an immune response.
This can include a raised temperature and feeling achy and sore.
“You can feel like that after the vaccine but not actually have the flu and indeed you don’t have an infection, you are responding to an infection,” Dr Koh said.
Drink coffee to sober up
There is no way to accelerate the sobering up process.
Your body metabolises alcohol depending on the availability of certain enzymes and caffeine does not affect how quickly those enzymes become available.
The rule of thumb is it takes about one hour to deal with the effects of one standard drink, according to Anne Finch, LiveLighter dietitian.
Rather than having a coffee to sober up before heading home after a night out, Ms Finch said people should instead catch a taxi and have a big glass of water before going to bed to ease the effects of dehydration linked to alcohol consumption
The oral contraceptive pill increases your cancer risk
Yes and no. The combined oestrogen and progesterone pill has been shown to increase the risk of some cancers but also to provide a protective effect against others.
One study estimated 105 breast and 52 cervical cancers in women younger than 49 were attributable to current use of combined oral contraceptive pill in Australia in 2010 (0.7 per cent of all breast cancers and 6.4 per cent of all cervical cancers).
Past contraceptive pill use was estimated to have prevented 1032 endometrial and 308 ovarian cancers, reducing the number of these cancers that would otherwise have occurred by 31 per cent and 19 per cent.
The pill was also known to have a protective effect against colorectal cancer, says Cancer Council WA cancer smart manager Melissa Ledger said.
Artificial sweeteners cause cancer
There is no evidence that aspartame or any of the other artificial sweeteners are linked to cancer, says Cancer Council WA nutrition and physical activity manager Steve Pratt.
Concern about a possible link came to the fore some years ago when a study was published suggesting aspartame consumption caused an increased risk of cancer in rats. However, the doses given were far in excess of what would be normal human consumption.
“It’s an area of international interest, there are constantly papers coming out about this,” Mr Pratt said.
Starve a fever, feed a cold
Rubbish. You are better off listening to what your body wants in regard to hunger.
“Generally speaking, if you are hungry it is probably reasonable to start to consume food again when you are unwell and if you are not hungry, you don’t need to force food down,” Dr Koh said.
Red wine is good for your heart
This idea was born out of investigations into the mechanisms behind the French Paradox, a phenomenon whereby French people have generally lower rates of heart disease than their European neighbours, despite drinking red wine and eating cheese, both of which were thought to be bad for heart health.
Research narrowed the search down to an antioxidant found in the skin of red grapes called resveratrol.
However there has been no consistent evidence to prove it can help prevent heart disease.
Vitamin C helps cure the common cold
Promoted by Nobel prize-winning chemist Linus Pauling in the 1970s, the idea that high doses of vitamin C could cure the common cold have since been debunked.
The theory has been studied closely and there is little to no benefit, and at high doses it could even be detrimental.
“The recommended amount of vitamin C we need in a day is quite small and we can get that from one orange, that’s about 60mg,” Ms Finch said.
Stay awake after concussion
There is a kernel or truth in this one, Dr Koh says.
“If you notice a child is becoming unrouseable or excessively drowsy or a change in their behaviour then that is a sign of concern after a head injury,” he said.
WA Health recommends waking people every four hours in the 24 hours after the concussion, if advised to do so by a medical professional.
Chocolate is good for your health
Sadly, chocolate is a sometimes food and should not be eaten for any perceived health benefits, Ms Finch said.
Thought to be high in health-improving antioxidants that could reduce risk factors for cardiovascular disease, the truth is most commercial forms of chocolate and cocoa are poor sources of antioxidants.
“It is high in sugar and fat and that is the bigger problem for the population — not a lack of antioxidants but an excess of kilojoules,” Ms Finch said.
“The Heart Foundation says raw cocoa powder can be high in polyphenols but realistically the stuff you get at the shops is not high in antioxidants and the foods that you make with your raw cocoa powder is probably going to be high in sugar and high in fat so on balance it is not a better choice than a piece of fruit.”
A nightcap will help you get a good night’s sleep
Alcohol does help you fall asleep quicker but it gives you worse quality sleep and the more you drink, the bigger the impact.
Ms Finch advised people would be better off meditating, spending time relaxing, slowing their breathing and turning off screens before bedtime if they wanted a good rest.
Plastic containers cause cancer
There is a theoretical risk that compounds found in plastics can interact with normal biological processes, but there has been no evidence to prove that this is occurring in normal doses.
Mr Pratt said there was concern about bisphenol A and as a precaution most manufacturers had voluntarily removed it from their products.
The risk lay in when the plastic container was heated, allowing the chemicals known as phthalates to leach out into food or drink.
“It’s also important people follow instructions on the container, so make sure it is microwave-safe,” Mr Pratt said.
“While there is no evidence these cause cancer, chucking a heap of plastic into your food probably isn’t great.”
Knuckle cracking causes arthritis
It sounds like it must be doing damage, the snap and pop of someone cracking their knuckles, but all the evidence points to it being a harmless but annoying habit.
Researchers believe the noise is caused by dynamic changes in pressure associated with a gas bubble in the synovial fluid around the joint.
Green snot means you need antibiotics
Not necessarily. Green mucus can indicate a virus or a bacterial infection.
“Obviously antibiotics are only going to treat a bacterial infection so green snot is actually not at all predictive of whether you need antibiotics and you just need to be paying attention to what your symptoms are,” Dr Koh said.
Its colour is caused by beta-carotene and is related to the breakdown of cells.
You have to drink eight glasses of water a day
A myth believed to date back to the early 20th century.
In fact there is no golden amount of water that we have to drink for good health.
How much water you need can vary from person to person and depend on what you are doing.
Someone who is active and working outdoors will need to drink more water than someone sitting at a computer indoors.
Experts say we use most, if not all, of our brain at different times.
Don’t believe everything you hear about health.
An ultrasound at 20 weeks is the best way to tell the gender of your unborn child.