Wednesday, 12 October 2005
Head way to a healthy heart
article, entitled "The Good Heart
", adds to the notion that psychology is an important aspect of health.
The article reports that at a meeting of the American Heart Association last year, Debra Moser, a professor of nursing at the University of Kentucky in Lexington, presented the results of a study heart-attack patients with high anxiety levels were more likely to suffer complications than those low anxiety levels.
The article also cites Dr. Michael Frenneaux, professor of cardiovascular medicine at the University of Birmingham in England, as saying that depression doubles an otherwise healthy person's heart-attack risk, while for people who have suffered a heart attack in the past, depression quadruples or quintuples the risk of a second one.
Other factors in heart attack risk mentioned in the article include levels of hostility, depression, stress and childhood trauma. These seem to affect the body negatively through the release of stress hormones like cortisol and epinephrine (adrenaline), which lead to high blood pressure and blood-glucose levels. Stress hormones also cause inflammation, which is believed to promote heart disease through several stages, from plaque formation to heart attack.
The opposite of these negative emotions appears to help prevent or ameliorate heart disease. Psychologist Karen Matthews at the University of Pittsburgh found that optimism helped reduce thickening in the carotid arteries of postmenopausal women while Dr. Michael Miller of the University of Maryland School of Medicine found that laughter relaxed people's peripheral arteries and increased blood flow.
The findings reported in the article are interesting. They show that one way to a healthy heart is through the head.
However, the article probably does not cover the full range of mechanisms through which psychology affects heart health. For example, it does not mention the effect of stress on telomere shortening
, an important ageing mechanism and therefore, surely an important factor in the development of heart disease.
Monday, 10 October 2005
China grows old
As some people say, China will get old before it gets rich.
A report from Xinhuatnet
says that more than seven percent of China's total population is 65 years old or above. "The aging problem has come around not only somewhat earlier but also developed rapidly," the report cited Hui Liangyu, vice premier of the State Council, as saying. He also said that currently, the number of Chinese age 60 or above accounts for more than 10 percent of the total Chinese population.
China's ageing population is largely the result of its one-child policy. However, even without this policy, the greying of China appears inevitable.
According to the CIA World Factbook -- updated on 20 September 2005 -- in rankings of countries by birth rates
and fertility rates
, the countries at the bottom are almost all either European -- including formerly communist East European countries -- or Asian countries dominated by Confucian cultures.
For all the talk of the uniqueness of Asian values that was in vogue in the 1990s, European and Confucian cultures clearly share certain common traits that manifest themselves in areas like economic performance and demographic trends.
Monday, 29 August 2005
Coffee with antioxidants
This is good news for coffee-lovers.
In its report entitled "Another Coffee Perk: Antioxidants
", HealthCentral.com says:
By measuring the amount of antioxidants contained in the most common foods and beverages, and comparing them to U.S. government data on food consumption, researchers found that coffee far outpaced any other beverage or food as the main source of antioxidants in the American diet.
... [T]he average American received more than four times the amount of antioxidants from coffee daily than from black tea, which was second on the list. Bananas, dry beans and corn were the top three foods on the list.
However, Joe Vinson, the University of Scranton chemist who presented the results of his analysis yesterday at the annual meeting of the American Chemical Society, in Washington, DC, was also quoted in the report as saying that coffee has been linked to increased risk of cardiovascular disease and high blood pressure.
So the recommendation in mainstream health circles to rely more on fruits and vegetables for antioxidants still seems to be the more prudent one.
Tuesday, 2 August 2005
American interest in Chinese rises with China's rising economic power
AFP had a story recently entitled "China's rapid rise spurs Americans to learn Chinese
". An excerpt:
China is casting such a huge shadow on the United States that many Americans are scrambling to learn the Chinese language in a bid to retain their competitive edge.
"Interest in learning Chinese among American youth and their parents has grown dramatically in the past five years," said Vivien Stewart, vice president at the Asia Society, a US group trying to bridge the gap between Americans and the peoples of Asia and the Pacific.
China's dramatic rise to near superpower status and its telling effects politically, economically and culturally are driving the interest to learn the language, experts say.
The report also mentioned the following:
[In US schools] Japanese is the most-sought-after Asian language.
"Our nation's schools are locked in a time warp," said Charles E.M. Kolb, president of the Committee for Economic Development, a pro-business think tank in Washington. "By ignoring critical languages such as Chinese and the essential cultural knowledge needed to succeed, our school systems are out of step with new global realities," he said.
I have been struck for some time by how ordinary Americans seem to know much more about Japanese culture and history than about Chinese culture and history, despite the fact that the latter are obviously richer. Clearly, Japan's economic power counts here. Cultural power comes from economic power.
However, as Mr Kolb said, there are new global realities, and Americans have to learn to adjust to them or find themselves at an increasing disadvantage in the global political and economic spheres.
Wednesday, 27 July 2005
Exercise cannot halt age-related effects on fitness
A new study published in the American Heart Association journal Circulation
shows that exercise cannot ward off the effects of ageing. Excerpt from the Associated Press report
A treadmill test given to different age groups showed that as people aged, their aerobic capacity -- the amount of oxygen consumed while exercising -- declined at higher rates with each passing decade whether they exercised or not.
The researchers knew the rate of decline would worsen with age, but they were surprised by the magnitude, said Dr. Jerome L. Fleg, a cardiologist who is lead author of the study and a medical officer at the National Heart, Lung and Blood Institute in Maryland.
"I guess we were a little disappointed that regular exercise didn't make a difference in the rate of decline," he said.
However, he pointed out that those who exercise still end up ahead because their aerobic capacity was higher to begin with.
"If I start higher, I'm going to end higher," Fleg said. "Having a higher aerobic capacity translates into being more fit."
In my opinion, there is too much hope and hype involved in exercise. As the report points out, exercise can improve a person's health and fitness, but the deterioration in the body associated with ageing is an intrinsic process. It affects the body at a cellular and even genetic level -- see, for example, my previous posts on telomeres and ageing "Stress and ageing
" and "Obesity and smoking affect biological age
". While exercise causes the body to adapt closer to its capacity -- that is, it causes the body to become fitter -- that capacity -- the maximum fitness that the body can attain -- itself declines with age.
The idea in some that exercise can arrest or reverse that age-related decline in fitness capacity was always a bit of wishful thinking.
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.
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