Health File

Finding Bacteria’s Sweet Tooth

Employing nanotechnology, which uses particles one billionth of a metre in size, researchers at the University of Toledo in Ohio have devised a new means of capturing bacteria—by catering to their “sweet tooth.”

Many bacteria launch their infections after latching onto carbohydrates (sugars) on human cell surfaces. Dr. Xuefei Huang, an associate professor of chemistry, and colleagues from the department of civil engineering, coated some magnetic nanoparticles with a sugar that is particularly attractive to E. coli, the bacteria responsible for many cases of food poisoning. The ‘bugs’ just ate it up.

Within five minutes researchers, using a magnetic field, had captured 65 per cent of the bacteria in the lab sample, and were able to remove 88 per cent of the pathogens in 45 minutes. “We can use this technique to get quick answers to identify suspicious substances and bacteria,” Huang said in an interview with Legion Magazine. In the future, he said, it’s possible this technology could be used to clean up foods contaminated with deadly E. coli, like the spinach crops that caused a nationwide outbreak in the United States in 2006 that killed three and sickened more than 100. Closer to home, E. coli contaminated the water supply in Walkerton, Ont., killing seven people and sickening hundreds of others.

Faster identification and decontamination techniques are big news for agencies that fight food and water-borne illnesses. Health Canada estimates 30 Canadians die and two million get sick from bacteria in food each year. Security agencies will also be interested, for this technology could be used to identify suspicious substances like the white powder—which turned out to be laced with anthrax—that was delivered through the mail in the U.S. and claimed five lives in 2001, said Huang.

Identifying the type of bacteria, distinguishing the strain so as to determine the best treatment, then eliminating the contamination can be a frustratingly slow process. Once someone develops symptoms of food poisoning—typically diarrhea or vomiting—a stool sample is sent to a laboratory where it is used to grow new colonies of the pathogen, or agent of disease, in a process that can take upwards of two days. The type and/or strain of pathogen is then identified so effective treatment can be started.

The magnetic nanoparticle process promises to greatly shorten the amount of time needed to detect, differentiate and decontaminate samples because all three procedures can be done at the same time. Identifying type and strain of bacteria becomes easier because each has a unique response to sugars, Huang explains. Removal is quicker, too. The procedure is akin to picking spilled straight pins up from a carpet individually by hand, versus passing a magnet over the whole area. In addition, many nanoparticles can attach to one bacterium, increasing its “magnetic personality.”

Now Huang’s team is moving on to enlarge the number of pathogens that can be identified using nanotechnology, and investigate whether it might be used to detect cancer cells. Nanomagnets offer rich ground for research, with promises that magnetic fields can move nanomagnets coated with drugs right where they’re needed in the body or heat-absorbing nanomagnets can be concentrated in a tumour, which can then be destroyed with heat.

Since it’s not expensive technology, applications should be quick to develop. Huang is particularly excited about using similar technology in the future for early detection of cancer. “It would be a non-invasive diagnosis,” he said, and would lead to much earlier, and thus more successful, treatment of the disease.

Fasting Makes The Heart Go Stronger

Regularly skipping a couple of meals may be good for our health, promoting heart health and delivering some protection from diseases associated with aging, some new U.S. studies suggest.

Monthly fasting may lower risk of heart attack, according to results of a recent U.S. study that linked religious fasting to less cardiovascular disease.

Researchers from Intermountain Healthcare in Utah studied habits of two groups of people with an average age of 64, and found those surveyed who fast regularly, mostly Mormons who fast one day each month, had a 39 per cent lower risk of being diagnosed with heart disease.

Short periods of fasting might remind the body to use stored nutrients for energy rather than relying on food intake, according to lead researcher Dr. Benjamin Horne, director of cardiovascular and genetic epidemiology at the center, in Salt Lake City. It also reduces the body’s constant exposure to foods and glucose. This might have an effect on metabolic syndrome, in which cells that produce insulin become desensitized, which can result in diabetes, which in turn can lead to heart disease. Skipping a few meals might allow these cells to “reset” so they remain sensitive. Or perhaps those who fast also have other heart-healthy habits, he suggests.

There is much research about the benefits of fasting. Proponents say short fasts detoxify the body in otherwise healthy individuals. (Those with chronic health conditions or acute diseases should consult a doctor before fasting.) Many toxins, such as chemicals absorbed from the environment, are stored in body fat. During fasting the body turns to fat as an energy source, breaking it down and releasing the stored toxins, which then can be eliminated.

Fasting is also believed to promote healing because energy that would normally be used in the digestion process can be diverted for use by the metabolic and immune systems.

Other recent research shows fasting also seems to provide the same life-lengthening benefits of a low calorie diet. Researchers at the National Institute on Aging in the U.S. found that mice who ate only every other day not only lived longer, but had lower blood glucose and insulin levels than either those allowed to eat whenever they wanted, or those on a diet with 30 per cent fewer calories.

Lead researcher Dr. Mark Mattson, noting skipping meals might provide protection against diabetes, postulated going without food mildly stresses cells, increasing their ability to cope with more severe stress later, much like the stress of exercise strengthens muscles. Or, fasting may reduce free radicals, atoms that can attack, damage and kill cells in the body.

Mattson, chief of the National Institute on Aging’s neurosciences laboratory, also found low-calorie diets or fasting delays the onset of Hungtington’s disease symptoms in mice and prolongs their lives.

Institute researchers are now looking to see if fasting works as well for people as for those longer-lived—but quite possibly hungry—mice.

The Benefits Of Being Conscientious

Keeping the mind agile by doing crosswords and puzzles has long been advocated as a means to keep the brain healthier—but now it seems keeping the nose to the grindstone is also effective for staving off Alzheimer’s disease. Researchers at the Rush University Medical Center in Chicago have found that self-disciplined, goal-oriented people—conscientious people, in other words—are less likely to develop Alzheimer’s disease.

Between 1994 and 2006, the research team annually tested 997 older Catholic nuns, priests and brothers with no signs of dementia for conscientiousness, rating such things as productivity and determination to complete a task. Over that time, 176 of those interviewed developed Alzheimer’s disease—with the least conscientious most likely to succumb. The most conscientious were also slower to lose cognitive abilities or show signs of dementia.

Conscientiousness might protect people against Alzheimer’s disease in several ways, the researchers reported in the Archives of General Psychiatry.

Conscientious people are more likely to have a good education and succeed at work, two factors associated with lower risk of the disease. As well, they are more resilient and able to cope better with life’s difficulties, lowering their stress levels. High stress is associated with risk of dementia in old age.

Understanding why being conscientious helps maintain cognition in old age may help develop strategies to delay symptoms of Alzheimer’s, the team says.