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30 October 2009

Why 'Sleeping on It' Helps

We're often told, "You should sleep on it" before you make an important decision. Why is that? How does "sleeping on it" help your decision-making process?

Conventional wisdom suggests that by "sleeping on it," we clear our minds and relieve ourselves of the immediacy (and accompanying stress) of making a decision. Sleep also helps organize our memories, process the information of the day, and solve problems. Such wisdom also suggests that conscious deliberation helps decision making in general. But new research (Dijksterhuis et al., 2009) suggests something else might also be at work — our unconscious.

Previous research suggests that sometimes the more consciously we think about a decision, the worse the decision made. Sometimes what's needed is a period of unconscious thought — equivalent to "sleeping on it" according to the researchers — in order to make better decisions. Here's how they study this phenomenon:

"[... In a] typical experiment demonstrating this effect, participants choose between a few objects (e.g., apartments), each described by multiple aspects. The objects differ in desirability, and after reading the descriptions, participants are asked to make their choice following an additional period of conscious thought or unconscious thought. In the original experiments, unconscious thinkers made better decisions than conscious thinkers when the decisions were complex."

The researchers suggest that unconscious thought, contrary to the way many of us think about it, is an active, goal-directed thought process. The primary difference is that in unconscious thought, the usual biases that are a part of our conscious thinking are absent. In unconscious thought, we weigh the importance of the components that make up our decision more equally, leaving our preconceptions at the door of consciousness.

So this is all fine and good, but how you do take laboratory findings and adapt them to a real-world experience to show that unconscious thinkers think better (e.g., with less distortions or biases)? One way to do this is to look at sports, because our weighting of different components is done beforehand and individually — not as an artificial variable manipulated by the researchers.

Each week over a period of 6 weeks, the researchers took 352 undergraduates from the University of Amsterdam and asked them to predict the outcome of four different upcoming soccer matches. Participants expertise about soccer was measured, and then they were asked to predict the result of each of the four upcoming soccer matches.

"[Then] participants were divided into three experimental conditions. In the immediate condition, participants saw the four matches on the computer screen and were asked to provide their answers in 20 s[econds].

"In both the conscious-thought and the unconscious-thought conditions, participants saw the four matches on the computer screen for 20 s[econds] and were told they would have to predict the outcomes later on.

"Conscious-thought participants were told they had an additional 2 min to think about the matches. Unconscious-thought participants were told they would do something else for 2 min and performed a two-back task designed to occupy conscious processing."

A second experiment was conducted on another group of undergraduates to replicate the findings and understand more about the underlying process.

What did they find?

"These experiments demonstrate that among experts, unconscious thought leads to better predictions of soccer results than either conscious thought or quick, immediate guesses.

"Experiment 2 sheds light on why this may be so: Unconscious thinkers seem to be better at using the appropriate information to arrive at their estimates. Unconscious thinkers who had more accurate knowledge about the single best prediction criterion (world ranking) made better predictions. This was not true for conscious thinkers or for immediate decision makers."

Just to emphasize this finding — if you're an expert and you had extra time to think about your decision in the area of your expertise (conscious thinker) or had to make a quick decision, you made worse decisions than those who were unconscious thinkers. The researcher hypothesize that conscious thought can lead to poor weighting in decision-making — the more you think about something, the more your biases interfere with good decision-making.

Unconscious thinkers in this experiment appear to weight the relative importance of diagnostic information more accurately than conscious thinkers did.

As always, these results must be taken with a grain of salt. The experiment was conducted only on undergraduates and may not generalize to other age groups or people with different educational backgrounds. Furthermore, other research has not found a significant performance difference between unconscious thinkers and conscious thinkers, and unconscious thought is not always the mode to rely on when faced with a complex decision (e.g., you can't use this for gambling and certain kinds of information).

But for certain kinds of decisions — those that are complex and where you have some expertise — "sleeping on it" may be more helpful than spending minutes or hours of conscious thought on it. The brain makes good unconscious decisions, when we let it.

Curry spice 'kills cancer cells'

An extract found in the bright yellow curry spice turmeric can kill off cancer cells, scientists have shown.

The chemical - curcumin - has long been thought to have healing powers and is already being tested as a treatment for arthritis and even dementia.

Now tests by a team at the Cork Cancer Research Centre show it can destroy gullet cancer cells in the lab.

Cancer experts said the findings in the British Journal of Cancer could help doctors find new treatments.

Dr Sharon McKenna and her team found that curcumin started to kill cancer cells within 24 hours.

'Natural' remedy

The cells also began to digest themselves, after the curcumin triggered lethal cell death signals.

Dr McKenna said: "Scientists have known for a long time that natural compounds have the potential to treat faulty cells that have become cancerous and we suspected that curcumin might have therapeutic value."

Dr Lesley Walker, director of cancer information at Cancer Research UK, said: "This is interesting research which opens up the possibility that natural chemicals found in turmeric could be developed into new treatments for oesophageal cancer.

"Rates of oesophageal cancer have gone up by more than a half since the 70s and this is thought to be linked to rising rates of obesity, alcohol intake and reflux disease so finding ways to prevent this disease is important too."

Each year around 7,800 people are diagnosed with oesophageal cancer in the UK. It is the sixth most common cause of cancer death and accounts for around five percent of all UK cancer deaths.

Exercise is good medicine for lymphoma patients

A healthy dose of exercise is good medicine, even for lymphoma patients receiving chemotherapy, University of Alberta researchers have found.

The Healthy Exercise for Lymphoma Patients (HELP) trial, a three-year study led by Kerry Courneya, Canada Research Chair in physical activity and cancer in the Faculty of Physical Education and Recreation, found that a regimen of aerobic exercise training produced significant improvements in physical functioning and overall quality of life benefits in patients with lymphoma.

Researchers recruited 122 patients with Hodgkin's and non-Hodgkin's lymphoma, then stratified participants by disease type and treatment status; whether they were undergoing chemotherapy at the time or receiving no treatments. Participants were randomly assigned to an exercise program designed to maximize cardiovascular fitness or to usual care, which did not include an exercise component.

Exercisers trained three times a week for 12 weeks and were encouraged to stay the course with behavioural support techniques that included perks like free parking, a well-equipped gym, flexible exercise schedules, variation in exercises, follow-up phone calls reminders and positive reinforcement by staff.

Lymphoma patients who received the exercise intervention reported significantly improved physical functioning, overall quality of life, less fatigue, increased happiness, less depression and an improvement in lean body mass. Cardiovascular fitness in the exercise group improved by over 20 per cent. The group receiving chemotherapy benefited as much as the group that was off treatments.

Perhaps most importantly, says Courneya, was that the vigorous intensity exercise program did not interfere with lymphoma patients' ability to complete their chemotherapy treatments or benefit from the treatments. He found that 46.4 per cent of patients in the exercise group had a complete response to their treatment (no evidence of disease) compared to only 30.8 per cent in the usual care group. Courneya cautions that the trial was not designed to look at this issue, but it at least suggests that lymphoma patients can achieve important health and quality of life benefits from exercise during treatment without worrying about compromising their treatment outcomes.

29 October 2009

Krill oil safe, well tolerated and effective, says study

Daily supplements of omega-3-rich krill oil is a safe and effective way of increasing levels of EPA and DHA, says a new study from Aker Biomarine.

Four weeks of krill oil supplementation raised levels of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in overweight and obese men and women with “no indication of adverse effects on safety parameters”, report researches in Nutrition Research.

The study is an important support of the safety and efficacy of an ingredient increasingly used to enrich food and supplements with omega-3 fatty acids. The research used Aker Biomarine’s Superba krill oil ingredient, and the study was financed by the Norwegian company.

Demand for krill oil, rich in omega-3, phospholipids and antioxidants, is reportedly increasing. The overall European market for omega-3 from all sources is growing at 24 per cent and forecast to be valued at $1.6bn by 2014, according to some market estimates. Another player, Enzymotec, recently announced a capacity expansion for its krill oil in order to meet growing customer demand for the product.

Krill, which means 'whale food' in Norwegian, are small shrimp-like marine crustaceans eaten by fish, birds and, in particular, whales.

Krill are considered to have the largest biomass of any multi-cellular animal in the world - between 100 and 800 million tones. Despite this, the population has reduced in the past 30 years, resulting in some concern over its harvesting.

Safe and bioavailable

Led by Kevin Maki from Provident Clinical Research, the researchers recruited 76 overweight and obese men and women to take part in their randomized, double-blind parallel arm trial.

Participants were randomly assigned to receive capsules containing 2 grams per day of krill oil, fish oil (menhaden), or control oil (olive) for four weeks.

At the end of the time, the researchers report that levels of EPA and DHA concentrations increased significantly more following krill oil supplementation than following menhaden or olive oil supplementation. Indeed, EPA and DHA levels rose by an average 178 and 90 micromoles per litre of plasma, respectively, in the krill oil group, compared to 132 and 150 micromoles per litre of plasma in the menhaden group, and only 3 and -1.1 micromoles in the olive oil group.

Regular exercise may help battle the flu

NEW YORK (Reuters Health) - Regular exercise may help reduce the misery of the flu by boosting the immune system's response to the virus, a study in mice hints.

Studies have suggested that people who exercise moderately suffer fewer and less severe colds and flu infections than couch potatoes do -- while exhausting workouts may increase a person's vulnerability to these infections.

In theory, the benefits of moderate exercise may stem from its effects on immune defenses. Research has found that exercise boosts activity in various parts of the immune system that help limit a viral attack or help clear an invading virus from the body more quickly.

In the new study, researchers found that when they had a group of mice regularly run on a treadmill over 3.5 months, the animals developed less-severe symptoms when infected with the flu virus, as compared with mice not subjected to the rodent workouts.

In addition, mice that exercised right before flu infection, but not regularly over the preceding months, also showed some protection against severe symptoms -- which in mice means dampened appetite and weight loss.

Those benefits, however, were only apparent in the couple days after infection, whereas regular long-term exercise reduced flu symptoms over the whole course of infection.

Dr. Marian L. Kohut and colleagues at Iowa State University in Ames report the findings in the Journal of Infectious Diseases.

Whether the findings translate to humans is unknown. But they offer possible clues as to why regular exercisers have been found to suffer fewer or at least less-severe respiratory infections.

Compared with their non-exercising counterparts, mice that exercised showed lower levels of various inflammatory substances in their lungs soon after being infected with the flu virus. Those levels stayed lower in mice that exercised regularly, whereas they rose over the next several days in mice subjected to just one workout.

The regularly exercising mice also showed lower concentrations of virus in their lungs early on.

These findings, Kohut's team writes, suggest that exercise boosts "early innate antiviral defenses" -- though the exact mechanisms remain unclear.

For now, the results offer one more potential reason to get regular moderate exercise.

27 October 2009

Eating Right -- Not Supplements -- Is Best At Keeping Your Good Bacteria Healthy, Dietitian Says

Healthy eating, not supplements, is the best way to keep the good bacteria in your gut healthy, says a dietitian and researcher.

As with vitamins, it's best to get the bacteria you need from healthy food rather than taking often expensive and potentially ineffective supplements, says Gail Cresci, Medical College of Georgia dietitian and researcher.

"Consumers are buying stuff like crazy that is probably not even helping them and could potentially hurt them," says Ms. Cresci, assistant professor of surgery at the MCG School of Medicine and winner of the 2009 Excellence in Practice Award for Clinical Nutrition by the American Dietetic Association.

Increasing awareness of the benefit some of these organisms play in sickness and in health has resulted in an explosion of prebiotic and probiotic additives and products marketed directly to consumers. It's also created confusion -- even among nutrition and other health care experts -- about how best to use them, says Ms. Cresci, who prescribes them to help surgery patients recover and works in the lab to learn more about their potential. She discussed the latest findings about their implications for clinical practice at the association's 2009 Food & Nutrition Conference & Expo in Denver, Oct. 17-20.

She equates the good bacterium in your gastrointestinal tract to another living being inside that helps keep you healthy. "If you do good by your bacteria, they will do good by you," Ms. Cresci says.

There are about 800 bacterial species with more than 7,000 strains inhabiting the average gut and even though many sound similar they likely aren't: a little Lactobacillus acidophilus combined with some Lactobacillus bifidus, for example, has been shown extremely beneficial in preventing antibiotic-induced diarrhea while Lactobacillus bulgaricus with some Streptococcus thermophilus is useless.

"You need to be careful," Ms. Cresci says. "You don't just give the same probiotic to try and treat everybody." That's why she lectures to dietitians, physicians and anyone interested in how to make good use of these front-line protectors that attack invaders that enter the body via the mouth and help the immune system keep a more global watch over the body, as well.

There is even mounting evidence that a healthy gut microbiota helps maintain a healthy weight. Studies have shown, for example, that when bacteria from a genetically fat mouse are placed in a lean germ-free mouse, it gains weight without changing its food intake.

Unfortunately poor diets are hurting the bacteria in many of us and the overuse of antibiotics is taking its toll as well, she says, particularly the common, broad spectrum antibiotics that wipe out anything in their path, good and bad bacteria included.

Diarrhea is an extremely common consequence of disturbing the natural balance of your gut's microbiota. In generally healthy individuals, a good diet, rich in fiber, protein and low in fat, will quickly help restore good bacteria. But in older individuals or those with an underlying condition, probiotics may be needed to avoid potentially deadly problems such as overgrowth of bad bacterium like Clostridium difficile. When that bacteria starts to thrive, it can result in an extremely enlarged colon that must be removed and, even then, about 80 percent of patients die.

To avoid such havoc, it's important that you pull the right live bugs off the shelf and that they survive to reach the lower gut, Ms. Cresci says of fragile bacteria that can be lambasted by gastric juices or killed off by even a short-term exposure to ambient heat.

The right combination is essential as well. "A lot of these probiotics have only one bacterium but we have trillions of colony forming units in our gut," she says. There is mounting evidence that one of the best ways to quickly restore the complex gut complement is by using feces from healthy individuals. It's called fecal bacteriotherapy, when feces mixed with a little saline, is given typically via a rectal enema or a nasogastric tube.

The good news is, if you eat right, you likely won't need such extremes.

26 October 2009

Promising novel treatment for human cancer -- Chrysanthemum indicum extract

A series of studies have demonstrated that Chrysanthemum indicum possesses antimicrobial, antiinflammatory, immunomodulatory, and neuroprotective effects. Recently, much attention has been devoted to the anticancer activity of Chrysanthemum indicum, especially in hepatocellular carcinoma (HCC). However, its anticancer mechanism of action is still not clear and needs further investigation.

A research article to be published on September 28, 2009 in the World Journal of Gastroenterology addresses this question. The research team, led by Prof. Zong-fang Li from the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, investigated the effects of Chrysanthemum indicum extract (CIE) on inhibition of proliferation and on apoptosis, and the underlying mechanisms, in a human HCC MHCC97H cell line.

They examined viable rat hepatocytes and human endothelial ECV304 cells by trypan blue exclusion and MTT assay, respectively, as normal controls. The proliferation of MHCC97H cells was determined by MTT assay. The cellular morphology of MHCC97H cells was observed by phase contrast microscopy. Flow cytometry was performed to analyze cell apoptosis with annexin V/propidium iodide (PI), mitochondrial membrane potential with rhodamine 123 and cell cycle with PI in MHCC97H cells. Apoptotic proteins such as cytochrome C, caspase-9, caspase-3 and cell cycle proteins, including P21 and CDK4, were measured by Western blotting.

The results showed CIE inhibited proliferation of MHCC97H cells in a time- and dose-dependent manner without cytotoxicity in rat hepatocytes and human endothelial cells. CIE induced apoptosis of MHCC97H cells in a concentration-dependent manner, as determined by flow cytometry. The apoptosis was accompanied by a decrease in mitochondrial membrane potential, release of cytochrome C and activation of caspase-9 and caspase-3. CIE arrested the cell cycle in the S phase by increasing P21 and decreasing CDK4 protein expression.

The researchers drew a conclusion that CIE exerted a significant apoptotic effect through a mitochondrial pathway and arrested the cell cycle by regulation of cell cycle-related proteins in MHCC97H cells without an effect on normal cells. The cancer-specific selectivity shown in their study suggests that the plant extract could be a promising novel treatment for human cancer.

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