Tuesday, 14 June 2005
Obesity and smoking affect biological age
A new study has provided yet more evidence that telomeres play a fundamental role in translating risk factors into age-related diseases.
Telomeres are the material which cap the ends of the chromosomes in cells and protect them from damage. Every time a cell divides -- and as people age -- the telomeres get shorter.
The new study involved more than 1,100 British women aged between 18 and 76 years. The women filled out a questionnaire on their smoking history and provided blood samples, which were tested for concentrations of a body fat regulator called leptin and for telomere length.
As HealthDay News reports
, the study found that:
...telomeres of obese women and smokers were much shorter than those of lean women and those who'd never smoked. In contrast, lean women had much longer telomeres than moderately overweight women who, in turn, had longer telomeres than obese women.
The net effects:
Overall, obese women aged an additional 8.8 years -- based on telomere length -- compared to lean women, the researchers reported. A current or previous history of smoking entailed an average 4.6 year increase in aging compared to never-smokers, while those with long-term smoking habits -- a pack-a-day for 40 years -- added an additional 7.4 years of aging to their life compared to those who stayed away from cigarettes completely, the study found.
For another post on research involving telomeres, see "Stress and ageing
Saturday, 28 May 2005
The biology of psychopathy and empathy
Topic: Science & Technology
Researchers have found that psychopathy may be an inherited trait.
An article in The Economist
" reported the results of a study on twins' behaviour. Many of the twins studied had a tendency to bad behaviour and for the display of callous and unemotional traits, such as a lack of feelings of guilt after doing something wrong, or not having at least one good friend. In adults, callous and unemotional traits are symptoms of psychopathy.
The findings were reported as follows:
Based on the teachers' assessments, the researchers identified the naughtiest 10% of the individuals in their sample—in other words those with severe conduct disorder. They then subdivided these children into those with psychopathic traits and those without and asked, in each case, whether an individual's twin showed bad behaviour, psychopathy, or both.
Their analysis showed that bad behaviour without psychopathy has relatively little genetic component—less than a third. By contrast, four-fifths of the difference in behaviour between the general population and children with psychopathic traits seems to lie in the genes.
The article concluded that if there is a genetic basis for psychopathy, there is probably a selective advantage to the trait.
If it does, such an advantage probably pertains only when psychopaths are in the minority (a state of affairs known to biologists as a balanced polymorphism). But it does mean that far from being an aberrant behaviour, psychopathy may be disturbingly normal.
Callous and emotional traits are related to empathy, or more accurately, the lack of it. An earlier article in The Economist
"A mirror to the world
" discussed the biological basis of empathy.
Essentially, empathy appears to rely on a type of nerve cell known as a mirror neuron. A mirror neuron is one that is active when the individual whose brain it is in is engaged in some action or experiencing some sensation or emotion, and also when that particular action, sensation or emotion is being observed in someone else. A lack of mirror-neuron activity is considered to be at least part of the cause of autism.
The idea that traits such as empathy and psychopathy have biological and even genetic bases will inevitably be controversial to society, as most claims of genetic linkages in personality traits tend to be. However, it is the job of scientists to discover the science behind the traits, and the responsibility of society as a whole to determine what to do with the discoveries.
Friday, 27 May 2005
Innovation and age
Topic: Science & Technology
reads a working paper "Age and Great Invention
" from the National Bureau of Economic Research and concludes that "there is hope for some of us yet". From the abstract of the paper:
Great achievements in knowledge are produced by older innovators today than they were a century ago... I find that innovators are much less productive at younger ages, beginning to produce major ideas 8 years later at the end of the 20th Century than they did at the beginning. Furthermore, the later start to the career is not compensated for by increasing productivity beyond early middle age... [T]he accumulation of knowledge across generations leads innovators to seek more education over time. More generally, the results show that individual innovators are productive over a narrowing span of their life cycle, a trend that reduces -- other things equal -- the aggregate output of innovators. This drop in productivity is particularly acute if innovators' raw ability is greatest when young.
Yes, there is reason to be hopeful for some -- specifically for those who might have thought they had missed the innovation boat -- but overall, the message of a narrowing productive innovation life span is not one of optimism.
On the other hand, greater knowledge accumulation through longer education means that innovators start the most productive phase of their life spans with greater innovative capacity. In addition, the information and management sciences now have a better understanding of how information is assimilated and converted into knowledge and thence, innovation.
Improvements arising from such understanding enable organisations and individual innovators to compensate for the shorter innovation life spans of the latter with more intensively productive ones.
Wednesday, 18 May 2005
Diet affects recurrence of breast cancer
A new study has found that postmenopausal breast cancer survivors who cut down on fats in their diet can reduce their risk of tumor recurrence.WebMD
reports the following details on the study:
The study included 2,437 women aged 48 to 75. All were treated with surgery for breast cancer, followed by radiation, chemotherapy, and hormone treatment, if needed. Every three months, they received some general dietary guidance.
Nearly 1,000 of the women were also entered into an intensive nutrition program... Women who received the intensive counseling reduced the amount of fat in their diet from 51 grams per day to about 33 grams a day, or from 29% to 21% of their total daily calories.
And the results:
At five years, less than 10% of those on the low-fat diet had their cancer recur. Twelve percent of the women who continued on their usual diet had cancer recurrence during this time. This translates to about a 24% reduction in risk, [researcher Rowan T] Chlebowski says.
Most breast cancers are fueled by estrogen, and because of this several treatments are available that block hormones to the breast and reduce the risk of recurrence.
Women whose tumors were not fueled by hormones -- a high-risk group that account for about 30% of women with breast cancer -- benefited the most. Their chances of recurrence fell by about 42% when limiting dietary fats.
This study just adds to the growing body of evidence that diet has an important role in the incidence of cancer. There are two caveats, though.
First of all, although the women on the low-fat diet benefited as a group, the researchers are not clear on whether the benefit was derived from the low amount of fat consumed or from other factors -- for example, weight loss, increase in fibre consumption.
Secondly, for the study subjects a whole -- as opposed to just those women whose tumours were not fueled by hormones -- the recurrence rate dropped from 12 percent for those on their usual diet to 10 percent for those on the low-fat diet -- all of 2 percentage points.
More studies on this would certainly be helpful.
Thursday, 28 April 2005
Vitamin D, calcium supplements not helpful in osteoporosis
Two new studies carried out in the United Kingdom have found that taking vitamin D or calcium supplements does not help prevent fractures in elderly people.
In one study, researchers led by University of Aberdeen professor Adrian Grant randomly assigned 5,292 people over 70 who had already suffered a fracture either to take a dummy pill, a daily supplement of vitamin D, calcium or both supplements together. They were then tracked for between 24 and 62 months.
The researchers found that 13 percent of the patients had a new fracture. For people in the group taking calcium, the fracture rate was 12.6 percent, compared with 13.7 percent of those taking a dummy pill. For those taking vitamin D alone, the fracture rate was 13.3 percent, compared with 13.1 percent for those taking the dummy pill. And for those taking both calcium and vitamin D, the fracture rate was 12.6 percent, compared with 13.4 percent for those taking the dummy pill.
The researchers concluded that supplements do not offer protection from second fractures.
This study appears in the April 27 online issue of The Lancet
In the second study at the University of York, researchers tracked 3,314 women aged 70 and older. Half were given calcium and vitamin D tablets to take daily, the rest just received a leaflet on diet and prevention of falls. All women were monitored for an average of about two years.
The researchers found that about 1 percent of women in both groups suffered a subsequent hip fracture. The researchers concluded that there was no reduction in hip fractures with either calcium or vitamin D.
This study appears in the April 30 issue of the British Medical Journal
An expert interviewed by HealthDay
saw nothing new in The Lancet
study. "I am not surprised," said Dr. Steven J. Goldstein, a professor of obstetrics and gynecology at New York University Medical Center. "By definition, the people they studied here had osteoporosis."
"We know that vitamin D and calcium alone are not sufficient to treat osteoporosis," Goldstein added. "All this study showed is that if you take people who have already suffered a fracture, who therefore by definition have osteoporosis, and you simply treat them with calcium and vitamin D, it's not sufficient. You've already let the horse out of the barn."
Goldstein pointed out that the time to take vitamin D and calcium is when you are young.
Thursday, 21 April 2005
Obesity and mortality
A new study
has found that obesity is not as dangerous as previously thought.
Researchers from Centers for Disease Control and Prevention (CDC) have found that both obesity and being underweight are associated with excess deaths when compared with the normal weight population.
There were 112,000 more deaths than expected among obese individuals, that is, those with body mass index (BMI) of 30 or higher. Among underweight individuals -- those with BMI of less than 18.5 -- there were nearly 34,000 more deaths than expected. However, while most of the excess deaths among the underweight occurred in people age 70 or older, most of the excess deaths among the obese occurred in people younger than 70.
Being slightly overweight -- BMI of 25-29.9 -- was not associated with excess mortality. In fact, the study found 87,000 fewer deaths than expected among those in this BMI range.
Another study by researchers from CDC found that cardiovascular disease risk factors in the US have declined, regardless of BMI. The exception was diabetes, which has increased by 55 percent over the past 40 years.
These studies appear in the 20 April 2005 issue of Journal of the American Medical Association (JAMA)
Most reports on the study linking obesity and mortality have highlighted the fact that it shows that the risk of death from being overweight has been overestimated. Times Online, however, entitled its report on the study "If you want to live longer - put on weight
". This seems unwarranted.
First of all, whether putting on weight is healthy depends on your starting weight. Obesity is still associated with higher death risk.
Secondly, it may be premature to make recommendations based on this study. No one study can be conclusive. The findings need to be replicated in other studies to eliminate the possibility of flaws in the study. With so many factors affecting health and mortality rates, failure to properly account for any factor can have an impact on the overall result. After all, CDC itself had earlier put out a report that predicted a much higher mortality rate from obesity, which, in the light of the findings from the new study, is leading to some controversy in the United States (see the report "Stonewalling: Why Won’t The CDC Endorse New Obesity Deaths Figure?
In any case, as the Times Online itself wrote, quoting Nigel Hawkes, The Times
health editor: "Despite its breadth, the conclusions of the report are limited. It looked only at deaths, not at disease or disability which generally increase with weight".
Wednesday, 20 April 2005
Happiness brings health
A new study has found that happiness may bring health.
Researchers from University College London tested 116 men and 100 women who were taking part in a major study of thousands of London-based civil servants to investigate the risk factors for coronary heart disease. The researchers evaluated the level of happiness of the subjects during the course of the day.
The researchers found that levels of cortisol -- a stress hormone related to conditions including type II diabetes and high blood pressure -- were 32 percent lower in people who reported more happy moments. Happy people also had lower levels of plasma fibrinogen -- a marker for inflammation and an indication of heart disease -- when they were stressed.
The research is published in the Proceedings of the National Academy of Sciences
. The BBC
carry reports on the study.
By focusing on happiness, this study complements some others that find that psychological distress adversely affects health -- see for example "Stress and ageing
Sunday, 17 April 2005
China protests over Japan's new history textbooks
Japanese atrocities committed during World War II have not been forgotten by many people in Asia. If the Japanese need reminding of this fact, the recent protests in China over the Japanese government's approval of revamped history textbooks -- which many people think whitewashes those atrocities -- have done just that.
Thousands protest against Japan as China says relations at 'crossroads'
Thousands of people staged violent anti-Japanese rallies across China Saturday in a second weekend of protests as Beijing said relations with its neighbour were at a "crossroads". Onlookers estimated up to 10,000 people marched along Yanan Road in Shanghai towards the Japanese consulate while several thousand others rallied in the eastern city of Hangzhou and similar numbers in Tianjin, southeast of Beijing.
At the consulate in Shanghai, riot police three-deep linked arms to prevent the rowdy crowd from entering the compound as they pelted it with rocks, bottles and paint, smashing windows. Elsewhere in the city, Japanese restaurants, businesses and cars were attacked with rocks and eggs, while a restaurant was completely destroyed. Two Japanese were injured in Shanghai after being surrounded by a group of Chinese, Kyodo news reported citing the Japanese embassy.
More protests, sparked by the Japanese government's approval of revamped history textbooks which Beijing felt made light of the nation's atrocities in World War II, are expected around China Sunday.
Read the full story here
points to an eyewitness account
of the Chinese protest in Shanghai by Ian Hamet, as well as Hamet's analysis
of the protest.
While many have described the Chinese reaction as excessive, the Japanese government was surely complicit in instigating the protests by the way it handled its history textbooks even as it was opening up another potential area of dispute with its giant neighbour by preparing to let its companies drill for oil and gas in a part of the East China Sea that is also claimed by China.
Having said that, the Chinese people have tended to be nationalistic and xenophobic, traits that are at least partly fuelled by their own government. To quote from Hamet's analysis:
[The protest] was the payoff of decades of anti-Japanese propaganda in the school systems here. Pretty much anyone you ask will say he hates Japan and the Japanese, and takes personal offense at the way Japanese schools teach World War II. Even if he has Japanese friends. And a Japanese mobile phone. And digicam. And reads manga. And watches anime...
However, people here don't know, or don't care, that Japan today is vastly different than 60-70 years ago. The government there was formed under occupation, and I seriously doubt that anyone outside of China (and possibly Korea) has any fear of a renewal in Japanese military aggression. And if you try to explain that to anyone here, the pretty much discount what you say or get shriekingly angry at you for dismissing their grievances.
Furthermore, one aspect of Chinese culture you don't read much about is a nationwide inferiority complex...
And Chinese nationalism is not just directed at past imperialist transgressors. I had written about the tiff that the Chinese government had with Singapore over a visit to Taiwan -- a relatively minor issue blown out of proportion (see "Lee Hsien Loong's Taiwan visit unleashes storm from China
"). This sort of thing gets replayed again and again.
In the meantime, foreign governments can help themselves by avoiding unnecessary provocative action. Japan -- in view of its own past -- probably more so than others.
Monday, 21 March 2005
The China threat
Chalmers Johnson, president of the Japan Policy Research Institute, has written an article entitled "The real 'China threat'
". In the article, he describes how China's rise in the past few decades is being perceived in the United States as a threat to its dominance.
An important basis for Johnson's position is that historically, the United States, like Britain before it, has had difficulty adjusting to the emergence of new centres of power. In the past century, the United States, with Britain, has fought two world wars to curb the rise of Germany and Japan, and a cold war to thwart Russia.
Now, the United States has turned its attention to China. And where Britain was its close ally in opposing Germany and Russia, Japan is now being seen in the United States as its "proxy in...balancing China". Hence, its repeated requests to Japan to rearm, despite the apprehension of most other Asian countries.
Johnson thinks that President Bush's administration has been actively pursuing a strategy that is hostile towards China's rise. He quoted President Bush as saying that he would do "[w]hatever it takes to help Taiwan defend herself". During its convention in August, the Republican Party proclaimed that "America will help Taiwan defend itself". And in February, President Bush went to Europe where he urged European leaders not to lift their ban on military sales to China.
On 19 February, the United States signed a new military agreement with Japan in which the Taiwan Strait was identified as a "common strategic objective". Johnson describes this as the Bush administration's "most dangerous card".
"Japan had decisively ended six decades of official pacifism by claiming a right to intervene in the Taiwan Strait," he warned. "It is possible that, in the years to come, Taiwan itself may recede in importance to be replaced by even more direct Sino-Japanese confrontations. This would be an ominous development indeed, one that the United States would be responsible for having abetted but would certainly be unable to control."
Johnson is almost certainly correct in saying that the Taiwan issue threatens to drag China, Japan and the United States into military conflict. However, President Bush -- to be fair to him -- is not exactly oblivious to the danger.
Recall that in late 2003, in response to Taiwanese president Chen Shui-bian's proposal to hold a referendum regarding China's missile threat -- a referendum which was widely seen as an attempt to stoke independence sentiment among Taiwanese -- President Bush had reaffirmed the United States' one-China policy and said that he opposed any "unilateral decision to change...the status quo", adding that "the comments and actions made by the leader of Taiwan indicate that he may be willing to make decisions unilaterally to change the status quo -- which we oppose" (see the CNN report "Blunt Bush message for Taiwan
Nevertheless, Johnson's overall message -- that opposition to China's rise is dangerous and ill-conceived -- is an important one. He asks rhetorically: "Why should China's emergence as a rich, successful country be to the disadvantage of either Japan or the United States?" Then advises with a warning: "The world needs to adjust peacefully to its legitimate claims...while checking unreasonable Chinese efforts to impose its will on the region. Unfortunately, the trend of events in East Asia suggests we may yet see a repetition of the last Sino-Japanese conflict, only this time the US is unlikely to be on the winning side."
Friday, 18 March 2005
Topic: Science & Technology
A New Scientist
report entitled "Pay up, you are being watched
" describes a study which provides a clue as to why people behave altruistically.
[Researchers Terry Burnham] and Brian Hare pitted 96 volunteers against each other anonymously in games where they donate money or withhold it. Donating into a communal pot would yield the most money, but only if others donated too.
The researchers split the group into two. Half made their choices undisturbed at a computer screen, while the others were faced with a photo of Kismet - ostensibly not part of the experiment. The players who gazed at the cute robot gave 30 per cent more to the pot than the others. Burnham and Hare believe that at some subconscious level they were aware of being watched. Being seen to be generous might mean an increased chance of receiving gifts in future or less chance of punishment, they will report in Human Nature.
If true, this suggests that people who act altruistically may actually be doing so for deep-seated subconscious reasons, and not necessarily because they are consciously seeking favours in return.
This seems a reasonable postulate. People do not always act on purely rational grounds. The subconscious plays an important part. After all, isn't that how conscience works?
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