- Email: [email protected]
Is fructose fuelling the obesity epidemic?
In this section ● Hawking’s “flexiverse” returns, page 10 ● Olympic start-gun technology is unfair, page 12 ● White blood cells key to longevity, page 16
opioid pills that are super-tough. In tests at the New York State Psychiatric Institute, 40 OxyContin addicts were given a placebo version of Grünenthal’s pill and asked what they would like to use to crush it. “They asked for razors, knives, hammers, paperweights, pliers,” says Sandra Comer, who helped run the tests. Each received their instrument of choice. Some were able to break the pill into a few smaller pieces, but none could crush it. “Someone asked for a blender,” adds Comer. “The pill just spun around.” Those safeguards should deter at least some abusers – one of the tragedies of the current problem is the number of young people abusing opioids. Arthur Lipman, a pain expert at the University of Utah in Salt Lake City, says that teenagers often steal opioids from their parents for use at parties. Surveys of American teens show that around 10 per cent have abused an opioid in the past year. But if teenagers cannot easily get a high, they are likely to find the drugs less attractive. “That could be life-saving,” says Lipman. More-experienced addicts pose a greater challenge. Comer’s work suggests that a hard pill prevents casual abuse, but it won’t be so easy to defeat determined addicts. They may find a way of dissolving Grünenthal’s pill, while methods for tampering with the rubbery Remoxy pills are already being A BITTER PILL TO SWALLOW Number of admissions into opioid abuse programmes in the US 70 60
Thousands
50 40 30 20
0 1995 1997 1999 2001 2003 2005 The two most popular opioids, hydrocodone and oxycodone, were prescribed almost 300 million times last year
www.newscientist.com
SOURCE: SAMHSA, VERISPAN
10
discussed on internet chatrooms devoted to opioid abuse. So Alpharma of Bridgewater, New Jersey, has created Embeda, a morphine pill that might prove harder to abuse. Like OxyContin, its active ingredient morphine tends to come as a slow-release pill that is commonly crushed by addicts. But Embeda has a core made of a substance called naltrexone, which binds to opioid receptors in the brain, preventing the morphine from reaching the same receptors. The core is coated to prevent the naltrexone from being absorbed into the body if the pill is simply swallowed. If crushed, the naltrexone is released and mixes with the morphine, so if the powder is then snorted, the morphine won’t have any effect. Alpharma plans to apply for FDA approval next month. No one is under any illusion that the tamper-resistant pills will deter everyone. “I don’t know if addicts have better imagination than our people,” says Jack Howard of Alpharma. “But they are pretty smart.” Some even think the drugs could make things worse. Labelling them as abuse-resistant could make doctors less likely to monitor patients for signs of abuse or even make patients think the drugs are safer. Partly because of these fears, members of an FDA advisory panel in May voted against approving another tamper-resistant opioid developed by Purdue Pharma of Stamford, Connecticut, which makes OxyContin. “You want to ensure that the problem you’re trying to solve doesn’t become worse,” says Frank Vocci of the National Institute on Drug Abuse in Bethesda, Maryland, who voted against approval. However, Purdue could gain approval if the labelling on the new opioid was cautious enough to prevent doctors assuming the product was safe, he says. Experts say the other tamper-resistant opioids have a good chance of getting approval if they are labelled appropriately. ●
Watch out for the wrong kind of sugar WE KNOW about good and bad fats. Now suspicion is growing that not all sugars are created equal either. Overweight adults who consume large amounts of fructose have been found to experience alarming changes in body fat and insulin sensitivity that do not occur after eating glucose. Pure fructose is found in fresh fruit, fruit juice and preserves. But much of it sneaks into our diets though highfructose corn syrup (HFCS) in soft drinks – which gets broken down into 55 per cent fructose and 45 per cent glucose in the body – or via sucrose (ordinary sugar), which is broken down into the same two sugars. Fears that fructose and HFCS are fuelling the obesity epidemic and triggering insulin resistance and
“People at risk of metabolic syndrome should avoid drinking too many fructosecontaining beverages” diabetes have been circulating for years (New Scientist, 1 September 2001, p 26), but there have been few direct investigations in humans. So Peter Havel at the University of California, Davis, persuaded 33 overweight and obese adults to go on a diet that was 30 per cent fat, 55 per cent complex carbohydrates and 15 per cent protein for two weeks. For a further 10 weeks, they switched to a diet in which 25 per cent of their energy came from either fructose or glucose. In those given fructose there was an increase in the amount of intraabdominal fat, which wraps around internal organs, causes a pot belly and has been linked to an increased risk of diabetes and cardiovascular disease. This did not happen with the group who consumed glucose instead, even though both gained an average 1.5 kilograms in weight. Those who consumed fructose also had raised levels of fatty triglycerides, which get deposited as
intra-abdominal fat, and cholesterol. Their insulin sensitivity also fell by 20 per cent. Glucose appeared to have no effect on these measures. Havel presented the results at a meeting of the Endocrine Society in San Francisco last week. Because Havel’s test looked only at pure fructose, not HFCS or sucrose, it is not yet clear whether these substances are to blame for obesity and diabetes. “The question is, what is the amount of HFCS or normal sugar you need to consume to get these effects?” says Havel, who is planning a long-term study to find out. But he says it’s not too soon for people with metabolic syndrome – the blend of conditions including belly fat and insulin resistance that raise the risk of diabetes and cardiovascular disease – to avoid drinking too many fructose-containing beverages. PepsiCo, which sponsored Havel’s research, disagrees. “This is a very interesting and important study,” says a spokeswoman. “But it does not reflect a real-world situation nor is it applicable to PepsiCo since pure fructose is not an ingredient in any of our food and beverage products.” In a separate study, Havel’s team compared the immediate effects of consuming a meal in which 25 per cent of the energy came from one of HFCS, sucrose, fructose or glucose. Blood triglyceride levels were all elevated to a similar level 24 hours after consuming fructose, sucrose or HFCS, but not glucose (The American Journal of Clinical Nutrition, vol 87, p 1194), suggesting that all three substances may have similar, negative health impacts. Longer-term studies are needed to confirm whether the triglycerides produced by sucrose or HFCS have similar effects to fructose on abdominal fat and insulin resistance. “It adds to what we have known for a long time,” says Francine Kaufman at the Keck School of Medicine in Los Angeles. “It’s probably not a good idea to consume too much sugar.” Linda Geddes, San Francisco ● 28 June 2008 | NewScientist | 9
opioid pills that are super-tough. In tests at the New York State Psychiatric Institute, 40 OxyContin addicts were given a placebo version of Grünenthal’s pill and asked what they would like to use to crush it. “They asked for razors, knives, hammers, paperweights, pliers,” says Sandra Comer, who helped run the tests. Each received their instrument of choice. Some were able to break the pill into a few smaller pieces, but none could crush it. “Someone asked for a blender,” adds Comer. “The pill just spun around.” Those safeguards should deter at least some abusers – one of the tragedies of the current problem is the number of young people abusing opioids. Arthur Lipman, a pain expert at the University of Utah in Salt Lake City, says that teenagers often steal opioids from their parents for use at parties. Surveys of American teens show that around 10 per cent have abused an opioid in the past year. But if teenagers cannot easily get a high, they are likely to find the drugs less attractive. “That could be life-saving,” says Lipman. More-experienced addicts pose a greater challenge. Comer’s work suggests that a hard pill prevents casual abuse, but it won’t be so easy to defeat determined addicts. They may find a way of dissolving Grünenthal’s pill, while methods for tampering with the rubbery Remoxy pills are already being A BITTER PILL TO SWALLOW Number of admissions into opioid abuse programmes in the US 70 60
Thousands
50 40 30 20
0 1995 1997 1999 2001 2003 2005 The two most popular opioids, hydrocodone and oxycodone, were prescribed almost 300 million times last year
www.newscientist.com
SOURCE: SAMHSA, VERISPAN
10
discussed on internet chatrooms devoted to opioid abuse. So Alpharma of Bridgewater, New Jersey, has created Embeda, a morphine pill that might prove harder to abuse. Like OxyContin, its active ingredient morphine tends to come as a slow-release pill that is commonly crushed by addicts. But Embeda has a core made of a substance called naltrexone, which binds to opioid receptors in the brain, preventing the morphine from reaching the same receptors. The core is coated to prevent the naltrexone from being absorbed into the body if the pill is simply swallowed. If crushed, the naltrexone is released and mixes with the morphine, so if the powder is then snorted, the morphine won’t have any effect. Alpharma plans to apply for FDA approval next month. No one is under any illusion that the tamper-resistant pills will deter everyone. “I don’t know if addicts have better imagination than our people,” says Jack Howard of Alpharma. “But they are pretty smart.” Some even think the drugs could make things worse. Labelling them as abuse-resistant could make doctors less likely to monitor patients for signs of abuse or even make patients think the drugs are safer. Partly because of these fears, members of an FDA advisory panel in May voted against approving another tamper-resistant opioid developed by Purdue Pharma of Stamford, Connecticut, which makes OxyContin. “You want to ensure that the problem you’re trying to solve doesn’t become worse,” says Frank Vocci of the National Institute on Drug Abuse in Bethesda, Maryland, who voted against approval. However, Purdue could gain approval if the labelling on the new opioid was cautious enough to prevent doctors assuming the product was safe, he says. Experts say the other tamper-resistant opioids have a good chance of getting approval if they are labelled appropriately. ●
Watch out for the wrong kind of sugar WE KNOW about good and bad fats. Now suspicion is growing that not all sugars are created equal either. Overweight adults who consume large amounts of fructose have been found to experience alarming changes in body fat and insulin sensitivity that do not occur after eating glucose. Pure fructose is found in fresh fruit, fruit juice and preserves. But much of it sneaks into our diets though highfructose corn syrup (HFCS) in soft drinks – which gets broken down into 55 per cent fructose and 45 per cent glucose in the body – or via sucrose (ordinary sugar), which is broken down into the same two sugars. Fears that fructose and HFCS are fuelling the obesity epidemic and triggering insulin resistance and
“People at risk of metabolic syndrome should avoid drinking too many fructosecontaining beverages” diabetes have been circulating for years (New Scientist, 1 September 2001, p 26), but there have been few direct investigations in humans. So Peter Havel at the University of California, Davis, persuaded 33 overweight and obese adults to go on a diet that was 30 per cent fat, 55 per cent complex carbohydrates and 15 per cent protein for two weeks. For a further 10 weeks, they switched to a diet in which 25 per cent of their energy came from either fructose or glucose. In those given fructose there was an increase in the amount of intraabdominal fat, which wraps around internal organs, causes a pot belly and has been linked to an increased risk of diabetes and cardiovascular disease. This did not happen with the group who consumed glucose instead, even though both gained an average 1.5 kilograms in weight. Those who consumed fructose also had raised levels of fatty triglycerides, which get deposited as
intra-abdominal fat, and cholesterol. Their insulin sensitivity also fell by 20 per cent. Glucose appeared to have no effect on these measures. Havel presented the results at a meeting of the Endocrine Society in San Francisco last week. Because Havel’s test looked only at pure fructose, not HFCS or sucrose, it is not yet clear whether these substances are to blame for obesity and diabetes. “The question is, what is the amount of HFCS or normal sugar you need to consume to get these effects?” says Havel, who is planning a long-term study to find out. But he says it’s not too soon for people with metabolic syndrome – the blend of conditions including belly fat and insulin resistance that raise the risk of diabetes and cardiovascular disease – to avoid drinking too many fructose-containing beverages. PepsiCo, which sponsored Havel’s research, disagrees. “This is a very interesting and important study,” says a spokeswoman. “But it does not reflect a real-world situation nor is it applicable to PepsiCo since pure fructose is not an ingredient in any of our food and beverage products.” In a separate study, Havel’s team compared the immediate effects of consuming a meal in which 25 per cent of the energy came from one of HFCS, sucrose, fructose or glucose. Blood triglyceride levels were all elevated to a similar level 24 hours after consuming fructose, sucrose or HFCS, but not glucose (The American Journal of Clinical Nutrition, vol 87, p 1194), suggesting that all three substances may have similar, negative health impacts. Longer-term studies are needed to confirm whether the triglycerides produced by sucrose or HFCS have similar effects to fructose on abdominal fat and insulin resistance. “It adds to what we have known for a long time,” says Francine Kaufman at the Keck School of Medicine in Los Angeles. “It’s probably not a good idea to consume too much sugar.” Linda Geddes, San Francisco ● 28 June 2008 | NewScientist | 9