ISLAMABAD – Triglyceride lipid emulsions rich in an omega-3 fatty acid injected within a few hours of an ischemic stroke can decrease the amount of damaged brain tissue by 50 per cent or more in mice, according to a new study.
The results obtained by researchers at Columbia University Medical Centre suggest that the emulsions may be able to reduce some of the long-term neurological and behavioral problems seen in human survivors of neonatal stroke and possibly of adult stroke, as well.
Currently, clot-busting tPA (recombinant tissue-type plasminogen activator) is the only treatment shown to improve recovery from ischemic stroke. If administered soon after stroke onset, the drug can restore blood flow to the brain but may not prevent injured, but potentially salvageable, neurons from dying.
Drugs with neuroprotective qualities that can prevent the death of brain cells damaged by stroke are needed, but even after 30 years of research and more than 1000 agents tested in animals, no neuroprotectant has been found effective in people.
Omega-3 fatty acids, commonly found in marine and plant oils, may have more potential as neuroprotectants because they affect multiple biochemical processes in the brain that are disturbed by stroke, said the study`s senior author, Richard Deckelbaum, MD, director of the Institute of Human Nutrition at Columbia`s College of Physicians and Surgeons.
“The findings also may be applicable to other causes of ischemic brain injury in newborns and adults,” added co-investigator Vadim S. Ten, MD, PhD, an associate professor of pediatrics from the Department of Pediatrics at Columbia.
The effects of the omega-3 fatty acids include increasing the production of natural neuroprotectants in the brain, reducing inflammation and cell death, and activating genes that may protect brain cells. Omega-3 fatty acids also markedly reduce the release of harmful oxidants into the brain after stroke.
“In most clinical trials in the past, the compounds tested affected only one pathway. Omega-3 fatty acids, in contrast, are very bioactive molecules that target multiple mechanisms involved in brain death after stroke,” Dr. Deckelbaum said.
The study revealed that an emulsion containing only DHA (docosahexaenoic acid), but not EPA (eicosapentaenoic acid), in a triglyceride molecule reduced the area of dead brain tissue by about 50 percent or more even when administered up to two hours after the stroke.
Dr Deckelbaum noted, “Since mice have a much faster metabolism than humans, longer windows of time for therapeutic effect after stroke are likely in humans.”
Eight weeks after the stroke, much of the “saved” mouse brain tissue was still healthy, and no toxic effects were detected.
Studies are currently under way to test the emulsion in older mice and in mice with different types of stroke. The researchers are also conducting additional studies to identify more precisely how the omega-3 emulsion works and to optimize the emulsion in order to improve functional recovery after stroke.
After animal studies on dosages and timing, and if the emulsions continue to show promising results, Dr. Deckelbaum said, clinical trials could begin quickly, as such emulsions have already been shown to be safe in people.
‘Milk and sugary foods may increase acne risk’
Eating foods with a high glycaemic index (GI) like white rice and drinking milk not only aggravates acne but in some cases triggers it too, a landmark overview of study carried out over 50 years claims. The painful skin condition affects millions of teens - and increasingly adults - causing their skin to develop unsightly spots on the face, neck, chest and back.
Caused by a combination of the skin producing too much sebum and a build-up of dead cells which clogs the pores, acne cause a localised infection or spot and can lead to anxiety, low self-esteem and depression, the `Daily Mail` reported.
Since the late 19th century, researchers have linked diet to acne, with chocolate, sugar and fat singled out as the main culprits. However, studies carried out from the 1960s onwards have disassociated diet from the development of the condition.
Two important studies that are repeatedly cited in the literature and popular culture as evidence to refute the association between diet and acne,” Dr Jennifer Burris from the
Department of Nutrition, Food Studies, and Public Health, Steinhardt School of Culture, Education, and Human Development, New York University, said.
Eating High GI foods causes a spike in hormone levels including insulin which is thought to instigate sebum production, researchers said. According to a 2007 Australian study, young males who were put on a strict low GI diet noticed a significant improvement in the severity of their acne.
Milk is thought to affect acne because of the hormones it contains. The earlier study carried out by Harvard School of Public Health found that there was a clear link between those who drank milk regularly and suffered with acne.
Interestingly, those who drank skimmed milk suffered with the worst breakouts, with a 44 per cent increase in the likelihood of developing blemishes. It is thought that processing the milk increases the levels of hormones in the drink, the report said.
Sitting time influences risk of chronic diseases
Sitting for long periods can raise your risk of chronic diseases, a new study has warned. Kansas State University researcher Richard Rosenkranz, assistant professor of human nutrition, examined the associations of sitting time and chronic diseases in middle-aged Australian males.
The study’s sample included 63,048 males ages 45-65 from the Australian state of New South Wales. Study participants reported the presence or absence of various chronic diseases, along with their daily sitting time: categorized as less than four hours, four to six hours, six to eight hours, or more than eight hours.
Compared with those who reported sitting four hours or less per day, those who sat for more than four hours per day were significantly more likely to report having a chronic disease such as cancer, diabetes, heart disease and high blood pressure. The reporting of chronic diseases rose as participants indicated they sat more. Those sitting for at least six hours were significantly more likely to report having diabetes.
“We saw a steady stair-step increase in risk of chronic diseases the more participants sat,” Rosenkranz said. “The group sitting more than eight hours clearly had the highest risk.”
The study is relevant to office workers sitting at desks and those sitting for long periods of time such as truck drivers, he said. “We know that with very high confidence that more physically active people do better with regard to chronic disease compared with less physically active people, but we should also be looking at reducing sitting,” Rosenkranz said. “A lot of office jobs that require long periods of sitting may be hazardous to your health because of inactivity and the low levels of energy expenditure.”
Researchers said that although most of the current evidence is suggestive of a causal connection, they cannot be certain in this study whether volumes of sitting time led to the development of chronic diseases or whether the chronic diseases influenced sitting time. “It’s a classic case of, `Which came first: the chicken or the egg?” Rosenkranz said.