HOW TO PREVENT CANCERS

by Claudine Ryan

Your kids might not like it, but new guidelines recommend keeping children in car restraints for longer, which would see many in booster seats until 12.

Most parents will do anything to keep their children safe. But when it comes to what is possibly the most dangerous thing we do with our children – drive with them in a car – we could to be putting them at risk of injury almost every day.

Car accidents are the most common cause of death and injury for children under 14. Every year, 80 children die and another 3000 are left with serious injuries. At greatest risk of serious injury are children between the ages of seven and 12, who no longer use child restraints such as car seats or boosters when travelling in a car.

This is why new guidelines on child restraints when travelling in cars, developed by Neuroscience Research Australia and Kidsafe, are recommending children under 12, unless they reach a minimum height, use booster seats and sit only in the back seat.

The guidelines, approved by the National Health and Medical Research Council, are the first national recommendations to outline consistent evidence-based advice on child restraints. Other recommendations include:

keeping infants in rear-facing car restraints for as long as possible,ensuring children using booster seats or adult seats use only lap-sash belts,ensuring all child restraints are installed properly and regulary checked. (The guidelines include 10 essential steps.)

Professor Lynne Bilston is based at Neuroscience Research Australia and is lead author of the guidelines. She studies car crashes and the injuries they cause in young passengers, and says many parents are confused about what types of restraints children need to use at different ages and stages.

"There are certainly various things that people are told to do at times by different people that certainly have no evidence behind them or they are direct contradiction of what the evidence actually says," Bilston says.

Laws vary between states and territories but in most places, children are legally required to use booster seats until the age of seven. This means the majority of children move out of a booster into an adult seat around seven, even though children at this age aren't physically big enough to use adult seat belts safely.

"Because their legs aren't long enough they slouch down until their knees bend in front of the seat, and that means that their back is not upright against the back of the seat and the seat belt – the lap belt – instead of sitting over the hip bones, it actually rides up and sits across the abdomen," Bilston says.

"So in a crash they go further underneath that seat belt and most of the force of the crash ends up in their abdomen and they end up with serious abdominal injuries, and in more severe crashes they end up with spinal injuries as well."

It's also recommended that children younger than 12 sit only in the back seat due to the risks posed by airbags.

"The issue with air bags is that they come out at 160 to 200 kilometres an hour," Bilston says, "With an adult, the seat belt and the air bag are designed to work together. But with a child, because they are shorter, think of the arc that the head goes through, they can actually be in the line of the airbag... and so you can get the air bag inflate under the chin and force the head back. And you want to make sure that doesn't happen."

Bilston says if you cannot avoid having a younger child in the front seat, then ensure the seat is as far back as possible so the child is further away from the airbag.

The guidelines, suggest children remain in a booster seat until around the age of 12, but it depends more on their size.

To determine whether your child is ready to sit in an adult seat, you can check the following:

Can the child sit with their back against the back of the seat?Do the child's knees bend in front of the edge of the seat?Does the sash belt sit across the middle of the shoulder?Is the lap belt sitting low across the hips touching the thighs?Can the child stay seated like this for the whole trip?

Parents are also being encouraged to keep their younger children in rear-facing car seats for as long as they can, although there's a limited range of these available in Australia.

Many parents use capsules for their infants, but these usually only last for about six to 12 months. After that, the child needs to move into a forward-facing restraint.

Convertible restraints, which can face either the front or back of the car, are popular, but Bilston says evidence shows many people don't properly install these in their car.

"The convertible restraints are much more likely to be misused, [as] it's more difficult for parents to use them correctly. Unfortunately the market has moved towards these convertible restraints so there are fewer single-purpose restraints on the market."

Bilston suggests getting these restraints fitted and checked by someone who knows how to fit them properly to ensure they are safe.

The reality of trying to fit all your children in your car in the seats they require can be difficult. Many cars simply don't fit three car restraints across the back seat, while others may not have the points for the tether straps or the correct seat belt to use with a booster seat in the right place.

"It is still a little bit of a juggling act, but what we're trying to do is set out all the factors that need to be considered and try and work out how best you can juggle those."

She also understands some children may be unimpressed about having to stay in a booster seat when their friends aren't using them, or want to ride in the front seat before it is safe to do so, but says parents can influence this.

"In my experience often children can be taught the right thing to do. If you can get the message across to the child – at least one over the age of a toddler – they understand why you are making such a fuss, and why it is so important."

by Claudine Ryan

As smoke from bushfires in New South Wales spreads, how can people protect themselves from its health effects?

It's not just those living in the areas directly affected by the bushfires in New South Wales who need to be aware of the dangers of bushfire smoke.

As the smoke can travel considerable distances, people living hundreds of kilometres away from a bushfire can be affected – especially if they have a pre-existing heart or lung condition.

Dr Martine Dennekamp from the Department of Epidemiology and Preventive Medicine at Monash University in Victoria says bushfire smoke can cover large areas, including major cities, and has the potential to affect millions of people.

Research has shown extreme air pollution events – such as bushfires – lead to an increase in the number of deaths and hospital admissions for people with lung disease.

"Our recent 2011 review found that there is an association between Emergency Department presentations for respiratory conditions like asthma and COPD and bushfire smoke events," Dennekamp says.

In addition, Dennekamp says other data suggests there was an increase in out-of-hospital cardiac arrests during the 2006-2007 bushfire season. These cardiac arrests occurred in Melbourne where air quality was affected by bushfires burning several hundred kilometres away in the Victorian Alps.

Bushfire smoke is a mixture of water vapour, small particles and gases, which may include carbon monoxide, carbon dioxide and nitrogen oxides.

These gases travel and are known to irritate your respiratory system, but evidence suggests it's the particles that damage people's health, says Dr Fay Johnston from Menzies Research Institute in Tasmania.

Dennekamp says it's the very small particles – those with an aerodynamic diameter smaller than 2.5 micrometres – that are likely to cause the most significant concern.

"And in particular the very small particles that can penetrate deep into the lungs," she says.

Symptoms caused by these particles can continue for days after they are inhaled.

Those most likely to be affected by bushfire smoke include:

people with existing heart or lung conditions – such as asthma, chronic obstructive pulmonary disease, and chronic bronchitis;older people;young children.

Johnston says it's important for all of these people, especially those with heart and lung conditions, to monitor their symptoms when exposed to smoke and for some days after.

Those in the high risk groups are going to feel any effects of bushfire smoke more than the general population.

"If you can see it or smell it then that means there is a significant amount in the air and people in high risk groups would be advised to try and minimise their exposure," Johnson says.

For instance, people with asthma may experience wheezing, coughing, chest tightness, and difficulty breathing while the smoke is around and for some days after.

She says healthy people tend to tolerate being exposed to this type of pollution, although it can cause itchy or burning eyes, throat irritation, runny nose and some coughing. But these symptoms usually pass when once the person is no longer exposed to the smoke.

Johnston does say it's a good idea to avoid exercising outside if you can see smoke in the air.

"If you run or do physical activity you breathe in a lot more because you need to get a lot more oxygen in, so your ventilation increases ten-fold and that means you are increasing your pollution exposure ten-fold."

For those in areas affected by bushfire smoke, but not under direct threat from the fires, experts recommended the following precautions to reduce the smoke's health effects.

Stay indoors – The best way to avoid breathing in bushfire smoke is stay inside with the windows and doors closed, preferably in an air-conditioned building. Professor Wayne Smith, director Environmental Health Branch, NSW Health, says "particle levels are likely to be higher outdoors than indoors, so people sensitive to fine particles should limit the time they spend outside".

Set air conditioning on recycle – Avoid bringing smoky air into your house. If you have the option of adding a filter to your air conditioner, do so.

Avoid physical activity outside – "Fine particles can also irritate the lungs of healthy adults, so it is best to avoid any prolonged outdoor exercise," Smith says.

Keep medication on hand and follow a treatment plan – People with asthma – and other health conditions – need to make sure they have any medication they need on hand at all times. Victorian Health Department recommends having five days of medication. Those an Asthma Action Plan – or other treatment plan – should continue to follow it and if their symptoms get worse, they should seek medical advice.

Wear a mask – NSW Health Department says wearing a P1 or P2 mask(these are available from hardware stores) properly fitted over your mouth and nose will filter fine particles and minimise the effects of bushfire smoke. But Johnson says there's no good evidence to show masks work in the community, "for general public precautions, I wouldn't recommend it".

Leave the area – If the smoke continues for some weeks, or if a person's health puts them at risk of smoke, then it might be necessary to stay friends or relatives who are living outside the smoke-affected area.

Published 21/10/2013

Our expert: Dr Therese O'Sullivan

You've probably heard it all of your life – breakfast is the most important meal of the day.

And research shows eating something before you bolt out the door in the morning – be it porridge, poached eggs or peanut butter on toast – can help to boost your concentration, energy levels and set you up for better eating throughout the day.

You've probably also been told eating breakfast will help kickstart your metabolism – helping you burn energy efficiently and avoid weight gain.

But is eating breakfast really necessary to get your metabolism going? (And what does this mean anyway?)

There is no clear evidence breakfast can significantly affect your metabolism, says Dr Therese O'Sullivan, senior lecturer in nutrition and dietetics at Edith Cowan University.

But what is clear is breakfast has other benefits.

"From observational studies what we see is people who eat breakfast also tend to eat a healthier overall diet, one that is more nutritious and higher in fibre. People who skip breakfast are more likely to miss out on important nutrients," O'Sullivan says.

Your metabolism involves all the chemical processes going on inside your body that keep you alive and functioning. These processes include breaking down the food you eat into nutrients as well as those necessary for the building and repairing your body.

The food you eat provides your metabolism with the energey it requires to carry out these processes, take in more than you need and your body stores it. But your metabolism also affects the amount of energy your body needs at any given point.

Your metabolism can be divided into three components:

basal metabolic rate (BMR), which is the amount of kilojoules your body burns to maintain functioning at rest. This accounts for 50 to 80 per cent of your overall energy requirements.the energy you use when physically active, this accounts for 20 per cent of your daily energy use, and contributes to your metabolism in terms of the amount of energy the body needs to burn.thermic effect of food, which is the energy you need in order to eat, digest and metabolise your food.

One possible explanation for why so many of us believe breakfast affects our metabolism is due to the way our metabolism responds when we go long periods without food.

O'Sullivan says randomised controlled trials have shown the metabolisms of people on starvation or crash diets slow down to conserve energy, which means their BMR can drop by up to about 15 per cent.

As well, when people lose weight quickly during long periods without food they also lose lean muscle tissue or muscle mass, which can also contribute to a reduced metabolism. Most of your basal metabolic rate is determined by the amount of muscle you have, so the more muscle you have the faster your metabolism is.

However, O'Sullivan says, studies looking at the effects of reduced food consumption on your metabolism were conducted over a period of 10 days to a month. So while it is possible a shorter fast – such as that we do every night when we sleep – may have a similar impact, there is no solid evidence at the moment to support this, she says.

As well as the amount of muscle mass you have, there are a range of other factors that will affect your metabolism.

Age – As you get older your metabolism generally slows, this is thought to be because of a loss of muscle tissue, and also hormonal and neurological changes. When babies and children go through periods of growth, their metabolism speeds up.

Gender – As men are usually larger than women, they generally have faster metabolisms.

Body size – People with bigger bodies tend to have a larger BMR.

Genetics – This can also play a role in whether you have a slower or faster metabolism, and some genetic metabolic disorders can also affect your metabolism.

Physical activity – Regular exercise increases muscle mass and encourages your body to burn kilojoules at a faster rate, even when at rest.

Hormonal factors – Hormonal imbalances caused by certain conditions, including hypo- and hyperthyroidism, can affect your metabolism.

Environmental factors – The weather can also have an effect on your metabolism – if it is very cold or very hot, your body has to work harder to maintain its normal temperature and that increases the metabolic rate.

Drugs – Caffeine and nicotine can increase your metabolic rate, while medications including some antidepressants and anabolic steroids can contribute to weight-gain regardless of what you eat.

Diet – Certain aspects of your diet can also affect the metabolism, for instance if you don't have enough iodine for optimal thyroid function it can slow down your metabolism.

While none of the factors known to affect your metabolism appear to be strongly linked to breakfast, it doesn't mean you should skip it.

People who don't eat breakfast may miss important nutrients needed for the day, and are less likely to make up for it later on, says O'Sullivan.

"If you don't have any breakfast you may be hungrier than usual around mid-morning, and the hungrier people are, the more likely they are to go for energy dense snacks," she says.

"When you're really hungry you're more likely to make choices that are more energy dense, and that may be foods that are less nutritious," O'Sullivan says. "It's important to keep a range of healthy snack options on hand like nuts, fruit and yoghurt."

Dr Therese O'Sullivan is a senior lecturer in nutrition and dietetics at Edith Cowan University, she spoke to Jenny Pogson.

Published 25/11/2013