- This week on The Checkup ` Shawn overloads on secret salt. - My results ` three times the recommended daily intake. - Should we believe our eyes? It's obviously white and gold, so why are others seeing it differently? The life-saving potential of organ donation. - Almost all of us can be donors, so why aren't we? - But first, I discover why teens time out. (CURIOUS MUSIC) In societies all over the world, teenagers are blamed for staying up late, and then struggling to wake up in the morning. - Morning, Jawan. It's time to get up, mate. - Are teens just lazy with bad bedtime habits? - Jawan, get up, mate. Get up! - Or is there more to it? In 2006 the staff and pupils at Wellington High School decided to find out. To give senior students the benefit of more kip in the mornings, the school introduced some unconventional start times. Most high schools start between 8 and 9am, but it's now quarter to 10, and the older students are only just arriving. There'll be no detention, though, cos they'll be right on time. (SCHOOL BELL RINGS) - Teenagers weren't necessarily coping with the traditional model of schooling that starts school at about 8.30, 8.45, 9 o'clock because they were going to bed late, still trying to get up and go to school as normal, and therefore only getting probably six hours sleep a night in some cases. - None of us are at our best when we're sleep-deprived. And worldwide studies have revealed few teens are getting their recommended eight to 10 hours. Inadequate sleep in this age group is associated with weight gain, substance abuse, motor vehicle accidents, low self-esteem, depression and poor academic outcomes. For many parents, the problem is simple ` bad bedtime habits. The ratbags stay up far too late, are constantly on their devices, and won't turn out the light. Technology use and stimulating light sources are related to delayed bedtimes and sleep loss. But these bad habits aren't the whole story. During puberty, there's a shift in our body's biological clock. Changing hormones means teenagers naturally become more awake and alert in the afternoon and evenings. Body clocks may keep them awake until 11pm or later, no matter how hard they try to get more shut-eye. To get enough sleep, these night owls therefore become late risers. Not a problem on a weekend, but life generally doesn't work that way on a school day. When Wellington High School decided to hit the snooze button on morning classes, a team from the Sleep/Wake Research Centre recorded the results. So, what changes have you noticed in the year 12 students? - I think one of the main things is when they shifted the school start times from 9 till 10.30, what they noticed was nearly an increase of two hours in average sleep of those students. So they went from reporting about seven to eight hours sleep per night to between nine to 10 hours sleep per night. For teenagers between 14 to 17 years of age, it's recommended they get between eight to 10 hours' sleep per night. So with the change in the school start time, the students are now sitting within that ideal sleep range. As well as getting more total sleep, they were reporting being less sleepy during the day. - I find it easier to concentrate once I get to school, cos I've had that chance to wake up, and there's not that blurry period in between. - Having that time to, kind of, take for myself and to just get myself in order is actually really, really nice. - I'm not as late any more, so that's always a good benefit. - They've done similar experiments overseas; what results have they found? - So, in the big US studies, what they've found is a significant benefit for the academic performance of students. And that's not surprising. Sleep is incredibly important for learning, in terms of helping us retain and store memories; that happens when we are asleep. Sleep prior to learning and sleep after learning is both really important. It's also really important in mental health. Sleep is like emotional first aid. It's absolutely fundamental to our emotional well-being, and we know from those big studies overseas that teens who get sufficient sleep are less likely to become depressed. So there's enormous advantages for understanding the importance of sleep in this age group. And give those teens a little bit more flexibility and control over their sleep, so that they can get as much sleep as they need and then be functional in everyday life. - What we've learned over time is just to be flexible. Whatever is going to work best for students ` that's what we should be doing. That's the reason for our existence. - There are numerous reasons for sleepy teens. And in those early morning hours, science is on their side. Daily timetables and schedules that we consider natural aren't always the best fit for our nature. (FUNKY MUSIC) - Former US press secretary and Dancing with the Stars contestant Sean Spicer reportedly chews and swallows 35 pieces of gum every day. Apart from wondering where he finds the time, has he not heard the old wives' tale that swallowing gum can stay in your system for up to seven years or can block up your intestines? I'm gonna get to the bottom of this sticky situation. Children have chewed gum since the Stone Age. Tooth marks and black lumps of prehistoric tar have been found dating back from 7000 BC to 2000 BC. The ancient Greeks and Native North Americans continued the tradition, but their chewing choice was tree gum. These days, chewing gum is big business, and is most often synthetic, with added colours, flavours and sweeteners. In the workplace, chewing gum has been associated with higher productivity and alertness. In our mouths, chewing increases saliva flow. This helps neutralise and wash away acids on our teeth. But what about our stomachs? Are we going to clog them up by swallowing the sticky stuff? Gum is not easily broken down, but like any other foreign object our body can't digest, it will excrete it quite rapidly. The answer to this urban myth is it's very unlikely that swallowing the occasional gob of gum is going to do you any damage. But as with all good myths, there is an element of truth behind it. Just because gum can pass through doesn't mean we should make a habit of swallowing it. Chronic massive consumption of gum can spell trouble. 10 points if you know what this is. It may look like a rock or a stone, but it's actually a bezoar. A bezoar is a tightly-packed collection of partially digested or undigested material that can become stuck in the stomach or intestines. They are most commonly made up of undigested fruit and veg, seeds, hair, medication, or milk proteins. But there have been a few cases caused by swallowing excessive amounts of this sticky stuff, particularly in children. Because children's intestines are narrower than adults, a bezoar is more likely to get stuck. This can lead to intestinal problems and will have to be removed. These cases are rare, and the kids were, on average, swallowing five to seven pieces of gum each day. For most of us, swallowing the occasional piece isn't going to do any real harm, and it's definitely not going to stick around for seven years in your body. (GROANS) Chewing gum does, however, make a horrible mess of the footpath... and your feet. So even if you're not chewing 35 pieces a day, please consider where you put it when you're done. - Only 1% of deaths occur in a way where organ donation can become an option. - I'm very pleased to give other people a better quality of life. Hey, man. Oh, hey. Come to check out the car? BOTH: Yeah. - Josh. - Jen. Hi. She's in pretty good nick. Only done 110,000 K's. WOF and rego. You know, full service history. (OMINOUS MUSIC) What is this? This is a one-star safety-rated car. Yeah. Try and get in. (HORN TOOTS) My body's, like, folded in half. I don't understand what's going on. People don't often think about how a car will crash and how it will protect you. That's what a star safety rating tells you. Just can't imagine` If we crashed in a car like this, there's no way we would survive. (OMINOUS MUSIC) * (GENTLE PIANO MUSIC) - Currently more than 550 people are waiting for a organ or tissue transplant in New Zealand. Donation offers valuable second chances and can dramatically change lives. Almost all of us can be donors, so why aren't we? - I think that when it comes to things like talking about death... is not a favourite subject that people want to talk about. - In 2012 Wikitoria experienced the worst thing a mother could go through. Her son Clifford was killed in a motorcycle accident. - The day that he died, I was sitting on the couch and writing, and then the breeze picked up the curtain and fluttered in front of me, and I sat there and I thought, 'Hmm,... wonder what that's about.' And I just ignored it. And then in the afternoon, my niece came to tell me that he had been in an accident, and I just I remember asking her, 'Bad?' And she said, 'I think so, Auntie.' - Sitting in the waiting room at Middlemore Hospital, Wikitoria learnt her son wouldn't recover and was asked a life-changing question. - I heard a voice at my shoulder asking about organ donation. When the approach was made, it was very gentle. And, um... And then it was a seed that was planted to give consideration to, cos I'm also mindful that time was of the essence, and it's not something that you could take days or weeks to consider. - It's organ donor coordinators like Lauren Sprenger who approach families at this incredibly difficult time. First they need to get the family to come to terms with the fact that their family member or their loved one is not going to survive. And then once they're confident that they have understood the gravity of that reality, then there would be a very separate conversation about end-of-life care, where to from here. And a part of that is offering the option of organ and/or tissue donation. - I remember the last... the last farewell that I gave to him, and looking out through from his room, and there were big windows looking out into the passage, and then I saw, I guess, there was the organ donation team, medical team, that were all standing all gowned up. (POIGNANT PIANO MUSIC) - I... Yeah, I was emotional when I saw that. Very emotional. I really, really wanted to run out there and say to them, 'No, you're not taking him.' And then I just stopped myself and said, 'Mo te aha,' meaning, 'Why?' Why? - But Wikitoria knew why, and that it was the right decision. - Knowing the type of person that he was, and such a giving person, that I believe truly in my heart that he'd be OK with it. - Wikitoria could only guess Clifford's wishes, as she had never discussed organ donation with him. - A lot of us know within ourselves whether or not we would like to be an organ or tissue donor. But the important thing to do is make sure your families and your loved ones around you know that. Because even though we may have made that decision within ourselves and even potentially indicated that on our driver's licence, that is not legally binding. We obtain informed medical consent from family members at the time of death. - Wikitoria not only considered Clifford's wishes, but also her Maori heritage. The concept of organ donation does not always align with cultural beliefs around death. - As Maori, we believe that there are things that are sacred and... holding on to that belief of the tapu side, the sacred side. But I see that today it's starting to change ` tikanga. Tikanga being tika, the way that we do things, and doing the right thing. - Organ donation is something that transcends culture, lifestyle, gender, age. You know, it's such an important thing to offer these families, and we shouldn't go in and, sort of, cherry-pick, as it were, who we ask or who we don't ask. - So you offer it to all cultures? - Absolutely. - When it comes to organ donation, the coordination team can't afford to leave any stone unturned. - It's important to understand that only 1% of deaths occur in a way where organ donation can become an option. And those are people who are in the intensive care unit setting, who are on a ventilator. - Blood group compatibility, tissue type, and the size of the organs themselves are also considerations. (REFLECTIVE PIANO MUSIC) - Despite the overwhelming sadness of losing her beloved son, to this day Wikitoria finds solace in the fact that his donated organs could have helped up to 10 grateful recipients. - Very pleased that, um,... his life had meaning. I'm gonna cry. His... Yeah, his life had meaning. That it wasn't, um,... not so much wasted, but to be able to... give other people a better quality of life. - Within each of us, we have incredible life-saving potential. If you want to help out, the best way to do that is to turn to your loved ones right now and start having the conversation. - Pour out how much salt you eat per day. - 7g? That's a lot of salt. - But it's tasty. - (LAUGHS) Yeah. - An optical illusion is when our eyes and brain play tricks on us. * (FUNKY MUSIC) - A pinch here, a shake there. These precious grains are a universal flavour enhancer. I love my salt, and I'm pretty sure I'm not the only one. - Would you say you're a salt fan, man? - I am, yep. - Yeah? - With my chips, yes, definitely. Fish and chips. - Love salt. Cooking, and on my tomatoes on toast, and eggs, and, yeah, pretty much everything. - How much do you like salt? - Quite a bit. - Yeah? - Nothing tastes good without it. - (CHUCKLES) - Can you take this for me... - Yep. - ...and pour out on to the scales for me, roughly how much salt you think you eat per day? - Max you'd eat? - I reckon. - Perfect. OK, so you put 2g on there. - Maybe that much. - That much? - I want to say. - That was less than a gram that you've just put on there. - You've put about 2g on there. - Whoa! - So, you've put 7g up there. - Yeah. - 7g? That's a lot of salt. - But it's tasty. - (LAUGHS) Yeah. - OK, so, you put probably less than a gram here. - Yep. It might surprise you to see that the average New Zealander eats that amount. - Wow. That's a lot. - That's a heck of a lot more than you've put on there, isn't it? - Yeah, definitely. Yep. - Yeah. - So that's 8g or 9g for one person per day. - For one person? - Wow, that's a lot. - That's a lot, right? - The average person each day? Wow. OK. No, that's a surprise. - Ooh, that's a lot. - So, how much should we be eating per day? This is 4g, which is just less than a teaspoon. - Wow. OK. - New Zealanders are eating more than twice that. - I may have underestimated my salt intake. - He's not alone. We are salt-loving nation. But a little salt isn't a bad thing. It helps with fluid balance, nerve transmission and muscle function. But high salt intake is linked with high blood pressure, and this is a major risk factor for cardiovascular diseases, our country's biggest killer. High salt intake is also linked to stomach cancer, osteoporosis and kidney disease. Our love affair with salt comes at quite a cost. The problem is, salt is hidden in everyday foods we may think of as healthy. I've decided to find out just how much salt I've been unwittingly eating. The most accurate way to do this is by measuring the amount of sodium in my urine for 24 hours. (JAUNTY PIANO MUSIC) Over this time, I ate what I thought was a pretty healthy diet. My results came to 14g of salt. That's nearly three times the recommended daily intake. 75% of our salt comes from processed food. I'm gonna have to watch what I eat. The first step in reducing our salt intake is identifying just how much is in our diet. Reading the ingredient list and nutritional information panel on your food is your best bet. But here's a tip ` some foods list the sodium content and some the salt content. To understand how much salt we are actually eating, we need to multiply the sodium number by 2.5. Low salt doesn't have to mean low taste. Try alternatives like lemon juice, herbs and spices, or tomato to pep up your plate. Our taste buds may not notice, but our hearts sure will. (FUNKY MUSIC) (SPOOKY MUSIC) - From an early age, we're fascinated by illusions and their ability to mess with our brains. Flip books, Magic Eye images and mirror mazes are just a few of my favourite illusions. An optical illusion is when our eyes and brain play tricks on us and see something that disagrees with actual physical reality. The optical illusion that got the whole world talking was of course the dress. This dress ` the one that divided the internet masses into two camps. What started out as a private convo between mother and daughter about her outfit erupted into a massive viral debate. Do you see a blue dress with a black lace fringe or a white dress with a gold lace fringe? To me, it's obviously white and gold, so why are others seeing it differently? (CONTEMPLATIVE MUSIC) Optical illusions are caused by the way the brain and the eyes communicate. Our optic nerve carries signals to the brain's visual cortex, where information is processed and interpreted. But sometimes there's a breakdown in communication, and our brain fills in the gaps. An optical illusion is sort of like the brain using autocorrect but misinterpreting the information. This can mean the brain thinks things are moving when they're actually still. Or our sense of depth and scale is misled, or it might see shapes that aren't there, or colours that aren't really there. In the controversial dress photo, the colour illusion is caused by the way our brains perceive light sources on coloured objects. Colours don't exist in a vacuum. An object's colour can be perceived differently if it's in sunlight or in shadow. It can depend on contrasting colours around it, the light temperature shining on it, and your personal understanding of colour. The dress colour controversy is a result of how people's brains interpreted these light sources. Was the dress in direct sunlight, in shade, lit from the front or back? In reality, the dress was blue and black. It's thought that the varying light sources around and on the dress made some people's brains discount the light's blue tones, in which case they saw gold and white, while other brains discounted the light's gold tones, and they saw a black and blue dress. The dress is just one illusion that got everybody talking. Illusions challenge us, fool us, and for some crazy reason, we love it.