Demi
Tue, Oct-08-13, 02:19
Not low per se, but an interesting article by Michael Mosley, author of The Fast Diet, the secret of 5:2 intermittent fasting, and also presenter of the BBC2 Horizon documentary Eat, Fast & Live Longer, the BBC documentary The Truth About Exercise, both of which were featured in this forum, and the new BBC2 programme, Trust Me I'm A Doctor (http://www.bbc.co.uk/programmes/p01dgd9c), which starts on Thursday evening.
From The Times
London, UK
7 September, 2013
The sunshine is bad for you - and other health myths
1. Drinking coffee is bad for you
There have been numerous claims down the years that drinking coffee will increase your risk of succumbing to a whole range of terrible things. These claims, like the ones about the benefits of fruit and vegetables, have been based largely on retrospective case studies.
When scientists observed 130,000 men and women for more than 20 years they found something altogether more surprising. The report, The Relationship of Coffee Consumption with Mortality, which was published in the Annals of Internal Medicine, concluded that “regular coffee consumption was not associated with an increased mortality rate in either men or women”. In fact, what they found was that moderate coffee consumption appears to be mildly protective.
Based on this and other studies the most effective “dose” is two to five cups a day. More than that and any benefits drop off. What it is in coffee that helps, we simply don’t know.
The amount of coffee you can drink without side effects such as insomnia may be down to how much of the liver enzyme CYP1A2 you have. The speed with which caffeine is cleared from your body is dependent on levels of CYP1A2 and that is largely down to your genes. Which could explain why I can drink coffee in the evening without any problems, while a single cup in the afternoon keeps my wife twitching.
2. There’s no such thing as a healthy tan
The leathery, mahogany look is out of fashion, but is it also true, as some health messages claim, that there is no such thing as a healthy tan? It’s certainly true that ultraviolet light causes skin damage, skin ageing and can lead to skin cancer, but the most lethal form, melanoma, is not straightforwardly related to ultraviolet exposure. Melanoma is more common in people who work indoors than in people who work outdoors. An Australian office worker is more likely to get a melanoma than an Australian farmer.
Although it is not a good idea to binge on sunshine, there is increasing evidence of a huge range of benefits to be got from regular exposure to the sun. The link is vitamin D, most of which we manufacture in our skin. Recent studies have shown that low levels of vitamin D are strongly associated with increased risk of heart disease, stroke, schizophrenia, multiple sclerosis, asthma and at least a dozen cancers. S unshine is not just good for your body, it’s good for your mood. As the poet Walt Whitman put it, “Keep your face always toward the sunshine — and shadows will fall behind you.” Time, I think, to get into the garden.
3. Being overweight is unhealthy
The accepted wisdom is that if you have a body mass index (BMI) of between 25 and 30, then you are overweight and this will shorten your life.
So a recent review in the Journal of the American Medical Association caused a stir because the scientists involved claimed to have found evidence, based on 97 studies involving nearly 2.9 million people, that people with a BMI of between 25 and 30 were actually 6 per cent less likely to die than people considered to have a healthy BMI, ie, 18.5 to 25.
The criticisms were vigorous and in some cases vitriolic. Dr Walter Willett of the Harvard School of Public Health said “this is an even greater pile of rubbish” than a study conducted by the same group in 2005.
So who is right? Well, one of the problems with defining obesity by using BMI is that it is an extremely crude measure. Your BMI is calculated by dividing your weight in kilograms by your height in metres squared. If you have a lot of muscle or are tall then the results of BMI will be misleading.
Also being fit and overweight is likely to be a healthier option than being unfit yet within the guidelines. So being slim is good, being fit is better.
4. A couple of glasses of red wine a day are good for you
You can’t open a newspaper without reading a story about a glass of wine being good or bad for you or making no difference at all. So is it true? Well, if you like a drink there is some good news, but it might not be in the quantities you would hope. The upside of drinking modest amounts of alcohol is that it may protect you against heart disease. The downsides of drinking alcohol are the increased risk of liver disease and cancer. Dr Peter Scarborough of the University of Oxford says that the downside swiftly displaces the upside and that half a unit (about a quarter of a glass of wine a day) is the optimum amount from a health perspective. “If you’re drinking any more than that then you are not at the best level for reduced risk,” he says.
5. Eating “five a day” cuts your risk of cancer
The five-a-day campaign was dreamt up in the fields of California in 1988 and was launched on the back of claims that eating more fruit and vegetables would cut your risk of developing cancer.
Yet when Professor Tim Key of the Cancer Epidemiology Unit at the University of Oxford wrote a review in the British Journal of Cancer, he concluded: “The possibility that fruit and vegetables may help to reduce the risk of cancer has been studied for over 30 years, but no protective effects have been firmly established.”
The original claims were based on case-control studies in which people with cancer were compared with those without it and were asked to look back at their lifestyle for an explanation. A better way is to do a cohort study, where you collect data about a group of healthy people then follow them for many years. This approach has produced very different results.
In the Nurses’ Health Study and the Health Professionals Follow-Up Study, for example, it was found that men and women with the highest intake of fruit and vegetables (eight or more servings a day) were no less likely to develop cancer than those who ate the least.
It is possible that these studies have design flaws, but more likely that some fruit and vegetables protect against some cancers. A report by the World Cancer Research Fund suggests that non-starchy vegetables such as broccoli, cabbage and onions will “probably” protect against cancers of the mouth, oesophagus and stomach. Tomato and tomato-based products “may” reduce the incidence of prostate cancer.
That said, eating fruit and vegetables does seem to protect against heart disease and other chronic diseases, and is certainly better than eating junk food.
6. Drinking two litres of water a day will do wonders for your body and mind
This is a myth, but where did this figure of two litres come from? It probably dates back to the 1940s when researchers calculated that this was how much water someone’s body used in 24 hours. But the researchers also said (and this gets ignored) that we obtain much of the water we need each day from our food. Drinks such as coffee and tea also count, despite what many people believe.
Drinking eight glasses of water a day could help you lose weight if you drink it very cold. Drinking ice-cold water burns through a few calories simply because you have to raise that water to body temperature. In fact doing so adds up to a quite impressive 70 calories.
Apart from that, the claim that drinking two litres of water a day is good for us has absolutely no evidence to back it up. The boring truth is: just drink when you’re thirsty and you’ll be fine.
7. Cracking your knuckles causes arthritis
A delightful piece of research was done some years ago by a doctor Donald Unger. For 50 years he cracked the fingers of his left hand and left the right totally free. And what did he find? No arthritis in either hand. So what makes that cracking noise? Its probably just the sound of gases in our joints filling a vacuum as we stretch them.
8. Eating eggs will raise your cholesterol
We used to be told not to eat more than a few eggs every week on the ground that eggs contain cholesterol and cholesterol is bad for you. At the time it was widely believed that elevated cholesterol in our blood was caused by large amounts of cholesterol in our food.
We now know that’s not true and that most of the excess cholesterol in our blood is actually produced by our livers and is a direct response to eating too much saturated fat, not cholesterol.
When scrambled, boiled, poached or in a healthy omelette eggs are a superb source of protein, are rich in vitamins and minerals and make a great start to the day.
9. Listening to Mozart can make you more intelligent
This is the sort of story we love — a short cut to genius. It’s based on a study made in 1993 in which a team from the University of California exposed people to Mozart’s music. Surprisingly enough, they did seem to get better at solving simple puzzles.
Naturally, a lucrative industry was made from selling “Mozart will make you clever” CDs. But what is less reported is that the IQ-enhancing effects were short-lived. Only 15 minutes. And Mozart doesn’t seem to be that special. Follow-up studies have produced confusing and contradictory results. All sorts of music — or even listening to a story — have been claimed to result in better performance, but often the effect can’t be repeated. It probably depends less on what you hear and more on whether you like what you hear. In the short term, music can help you to be more alert, more focused, and to concentrate. It won’t make you more intelligent, however.
10. Smoothies are a health drink?
Smoothies have a reputation for being healthy because they are based on fruit, but unfortunately by the time you get rid of the fibre and the peel you have lost many of the potential health benefits. What you are left with is a big sugar hit.
In fact,in a survey published early this year researchers revealed that out of 52 commercial smoothies, 41 had more sugar than cola and all had more calories. They are also acidic and the bits cling to your teeth, so dentists are not enthusiastic. An apple a day may keep the doctor away, but not when it’s been peeled, blended, mashed and packaged. http://www.thetimes.co.uk/tto/health/article3888976.ece
From The Times
London, UK
7 September, 2013
The sunshine is bad for you - and other health myths
1. Drinking coffee is bad for you
There have been numerous claims down the years that drinking coffee will increase your risk of succumbing to a whole range of terrible things. These claims, like the ones about the benefits of fruit and vegetables, have been based largely on retrospective case studies.
When scientists observed 130,000 men and women for more than 20 years they found something altogether more surprising. The report, The Relationship of Coffee Consumption with Mortality, which was published in the Annals of Internal Medicine, concluded that “regular coffee consumption was not associated with an increased mortality rate in either men or women”. In fact, what they found was that moderate coffee consumption appears to be mildly protective.
Based on this and other studies the most effective “dose” is two to five cups a day. More than that and any benefits drop off. What it is in coffee that helps, we simply don’t know.
The amount of coffee you can drink without side effects such as insomnia may be down to how much of the liver enzyme CYP1A2 you have. The speed with which caffeine is cleared from your body is dependent on levels of CYP1A2 and that is largely down to your genes. Which could explain why I can drink coffee in the evening without any problems, while a single cup in the afternoon keeps my wife twitching.
2. There’s no such thing as a healthy tan
The leathery, mahogany look is out of fashion, but is it also true, as some health messages claim, that there is no such thing as a healthy tan? It’s certainly true that ultraviolet light causes skin damage, skin ageing and can lead to skin cancer, but the most lethal form, melanoma, is not straightforwardly related to ultraviolet exposure. Melanoma is more common in people who work indoors than in people who work outdoors. An Australian office worker is more likely to get a melanoma than an Australian farmer.
Although it is not a good idea to binge on sunshine, there is increasing evidence of a huge range of benefits to be got from regular exposure to the sun. The link is vitamin D, most of which we manufacture in our skin. Recent studies have shown that low levels of vitamin D are strongly associated with increased risk of heart disease, stroke, schizophrenia, multiple sclerosis, asthma and at least a dozen cancers. S unshine is not just good for your body, it’s good for your mood. As the poet Walt Whitman put it, “Keep your face always toward the sunshine — and shadows will fall behind you.” Time, I think, to get into the garden.
3. Being overweight is unhealthy
The accepted wisdom is that if you have a body mass index (BMI) of between 25 and 30, then you are overweight and this will shorten your life.
So a recent review in the Journal of the American Medical Association caused a stir because the scientists involved claimed to have found evidence, based on 97 studies involving nearly 2.9 million people, that people with a BMI of between 25 and 30 were actually 6 per cent less likely to die than people considered to have a healthy BMI, ie, 18.5 to 25.
The criticisms were vigorous and in some cases vitriolic. Dr Walter Willett of the Harvard School of Public Health said “this is an even greater pile of rubbish” than a study conducted by the same group in 2005.
So who is right? Well, one of the problems with defining obesity by using BMI is that it is an extremely crude measure. Your BMI is calculated by dividing your weight in kilograms by your height in metres squared. If you have a lot of muscle or are tall then the results of BMI will be misleading.
Also being fit and overweight is likely to be a healthier option than being unfit yet within the guidelines. So being slim is good, being fit is better.
4. A couple of glasses of red wine a day are good for you
You can’t open a newspaper without reading a story about a glass of wine being good or bad for you or making no difference at all. So is it true? Well, if you like a drink there is some good news, but it might not be in the quantities you would hope. The upside of drinking modest amounts of alcohol is that it may protect you against heart disease. The downsides of drinking alcohol are the increased risk of liver disease and cancer. Dr Peter Scarborough of the University of Oxford says that the downside swiftly displaces the upside and that half a unit (about a quarter of a glass of wine a day) is the optimum amount from a health perspective. “If you’re drinking any more than that then you are not at the best level for reduced risk,” he says.
5. Eating “five a day” cuts your risk of cancer
The five-a-day campaign was dreamt up in the fields of California in 1988 and was launched on the back of claims that eating more fruit and vegetables would cut your risk of developing cancer.
Yet when Professor Tim Key of the Cancer Epidemiology Unit at the University of Oxford wrote a review in the British Journal of Cancer, he concluded: “The possibility that fruit and vegetables may help to reduce the risk of cancer has been studied for over 30 years, but no protective effects have been firmly established.”
The original claims were based on case-control studies in which people with cancer were compared with those without it and were asked to look back at their lifestyle for an explanation. A better way is to do a cohort study, where you collect data about a group of healthy people then follow them for many years. This approach has produced very different results.
In the Nurses’ Health Study and the Health Professionals Follow-Up Study, for example, it was found that men and women with the highest intake of fruit and vegetables (eight or more servings a day) were no less likely to develop cancer than those who ate the least.
It is possible that these studies have design flaws, but more likely that some fruit and vegetables protect against some cancers. A report by the World Cancer Research Fund suggests that non-starchy vegetables such as broccoli, cabbage and onions will “probably” protect against cancers of the mouth, oesophagus and stomach. Tomato and tomato-based products “may” reduce the incidence of prostate cancer.
That said, eating fruit and vegetables does seem to protect against heart disease and other chronic diseases, and is certainly better than eating junk food.
6. Drinking two litres of water a day will do wonders for your body and mind
This is a myth, but where did this figure of two litres come from? It probably dates back to the 1940s when researchers calculated that this was how much water someone’s body used in 24 hours. But the researchers also said (and this gets ignored) that we obtain much of the water we need each day from our food. Drinks such as coffee and tea also count, despite what many people believe.
Drinking eight glasses of water a day could help you lose weight if you drink it very cold. Drinking ice-cold water burns through a few calories simply because you have to raise that water to body temperature. In fact doing so adds up to a quite impressive 70 calories.
Apart from that, the claim that drinking two litres of water a day is good for us has absolutely no evidence to back it up. The boring truth is: just drink when you’re thirsty and you’ll be fine.
7. Cracking your knuckles causes arthritis
A delightful piece of research was done some years ago by a doctor Donald Unger. For 50 years he cracked the fingers of his left hand and left the right totally free. And what did he find? No arthritis in either hand. So what makes that cracking noise? Its probably just the sound of gases in our joints filling a vacuum as we stretch them.
8. Eating eggs will raise your cholesterol
We used to be told not to eat more than a few eggs every week on the ground that eggs contain cholesterol and cholesterol is bad for you. At the time it was widely believed that elevated cholesterol in our blood was caused by large amounts of cholesterol in our food.
We now know that’s not true and that most of the excess cholesterol in our blood is actually produced by our livers and is a direct response to eating too much saturated fat, not cholesterol.
When scrambled, boiled, poached or in a healthy omelette eggs are a superb source of protein, are rich in vitamins and minerals and make a great start to the day.
9. Listening to Mozart can make you more intelligent
This is the sort of story we love — a short cut to genius. It’s based on a study made in 1993 in which a team from the University of California exposed people to Mozart’s music. Surprisingly enough, they did seem to get better at solving simple puzzles.
Naturally, a lucrative industry was made from selling “Mozart will make you clever” CDs. But what is less reported is that the IQ-enhancing effects were short-lived. Only 15 minutes. And Mozart doesn’t seem to be that special. Follow-up studies have produced confusing and contradictory results. All sorts of music — or even listening to a story — have been claimed to result in better performance, but often the effect can’t be repeated. It probably depends less on what you hear and more on whether you like what you hear. In the short term, music can help you to be more alert, more focused, and to concentrate. It won’t make you more intelligent, however.
10. Smoothies are a health drink?
Smoothies have a reputation for being healthy because they are based on fruit, but unfortunately by the time you get rid of the fibre and the peel you have lost many of the potential health benefits. What you are left with is a big sugar hit.
In fact,in a survey published early this year researchers revealed that out of 52 commercial smoothies, 41 had more sugar than cola and all had more calories. They are also acidic and the bits cling to your teeth, so dentists are not enthusiastic. An apple a day may keep the doctor away, but not when it’s been peeled, blended, mashed and packaged. http://www.thetimes.co.uk/tto/health/article3888976.ece