Knowledge Update

​New York, Dec 1 (IANS) Individuals with mild cognitive impairment (MCI) who took part in aerobic exercise such as brisk walking, running, jogging or swimming four times a week were found to have greater increase in brain volume as well as better cognitive functioning, researchers say. "Any type of exercise can be beneficial. But, aerobic activity may create potential benefits for higher cognitive functioning," said Jeongchul Kim from Wake Forest University in North Carolina, US. Individuals with MCI -- which affects memory and thinking skills -- are at risk of developing Alzheimer's disease (AD), the most common form of dementia, the study said. "Even over a short period of time, we saw aerobic exercise lead to a remarkable change in the brain," added Laura D Baker from Wake Forest University. For the study, the team included 35 adults with MCI. The participants were divided into two groups. Sixteen adults (average age 63 years) engaged in aerobic activity, including treadmill, stationary bike or elliptical training, four times per week for six months. A control group of 19 adults (average age 67 years) participated in stretching exercises with the same frequency. The results, based on the high-resolution MRI images taken before the intervention and after six months, revealed that for both the aerobic and stretching groups, brain volume increased in most gray matter regions, including the temporal lobe, which supports short-term memory. "Compared to the stretching group, the aerobic activity group had greater preservation of total brain volume, increased local gray matter volume and brain tissue," Kim said. The stretching group showed atrophy within the connecting fibres in the brain's white matter, which could be an early marker for neurological changes. The study was presented at the annual meeting of the Radiological Society of North America (RSNA) in Chicago, US, recently.

New York, Nov 29 (IANS) Individuals who suffer problems associated with walking such as reduced speed, imbalance, among others, can be at an significant risk of developing decline in memory and thinking, a study has found. Walking is part of the complex cognitive task known as gait that includes everything from a person's stride length to the accompanying swing of each arm. Previous studies have reported that slower gait speed might predict cognitive impairment and dementing illnesses, supporting the role of gait speed as a possible subclinical marker of cognitive impairment. In the study, researchers from Mayo Clinic in Minnesota, US, used a non-invasive computerised gait analysis test that could identify patients at high risk for cognitive decline and to target appropriate therapies. They measured gait parameters, such as stride length, ambulatory time, gait speed, step count, cadence, stance time, arm swing on each patients. The results showed that alterations in several of the gait parameters were associated with decline in memory, thinking and language skills, and visual perception of the spatial relationship of objects. "The presence of gait disturbances increases with advancing age and affects the independence of daily living, especially in the elderly," said lead author Rodolfo Savica, neurologist at Mayo Clinic. For the study, the researchers analysed 3,426 cognitively normal participants who were between ages 70 to 89. The study was published in the Journal of Alzheimer's Disease.

​New York, Nov 27 (IANS) Repeated jet lag can increase both obesity related liver disease and the risk of liver cancer, researchers warned. "Liver cancer is on the rise worldwide, and in human studies we have now seen that patients can progress from fatty liver disease to liver cancer without any middle steps such as cirrhosis," said lead author David Moore, Professor at Baylor College of Medicine in the US. The study found that chronically jet-lagged mice developed liver cancer in a very similar way as that described for obese humans. When we constantly travel through different time zones, work night shifts, or push ourselves to stay awake at the regular sleep time, our central circadian clock in the brain becomes chronically disrupted, the researchers said. "We think most people would be surprised to hear that chronic jet lag was sufficient to induce liver cancer," Moore added. In the study, the researchers changed the times the lights went on and off during the night each week to understand the effects of chronic jet lag in normal mice who were fed a healthy diet. They found that the mice gained weight and fat, and developed fatty liver disease, which progressed to chronic inflammation and eventually liver cancer in some cases. The jetlagged mice lost normal control of liver metabolism. This included not only the buildup of fat, but also increased production of bile acids -- acids produced by the liver to help us digest our food -- linked with liver cancer. Further, the jetlagged mice were also lacking in receptors -- called FXR and CAR -- that help regulate liver bile acid metabolism, which works in a similar manner in humans. Although the researchers did not directly study jetlag in humans. But as evidence have showed that sleep disruption increases both fatty liver disease and liver cancer risk in humans, they hypothesised that lifestyle changes that generate chronic jet lag can also disrupt the body's internal homeostasis and increase liver cancer risk in humans. The study appears in the journal Cancer Cell.

Sydney, Nov 27 (IANS) Dietary combination of protein and carbohydrate may help promote good gut health as such a diet encourages cooperation between ourselves and bacteria in our gut, suggests new research. "There are many different diet strategies that claim to promote gut health, and until now it has been very difficult to establish clear causality between various types of diet and their effect on the host's microbiome," said led author Andrew Holmes, Associate Professor at the University of Sydney in Australia. "This is because there are many complex factors at play, including food composition, eating pattern and genetic background," Holmes said. In this study, the researchers found that the availability of intestinal nitrogen to microbes in the gut plays a key role in regulating interactions between gut microbes and their host animal. "This research really lays the groundwork for future modelling by setting out the rules for a general model of how diet shapes the gut ecosystem," Holmes said. "The simple explanation is that when we eat in a way that encourages cooperation between ourselves and bacteria we achieve a good microbiome, but when we eat in a way that doesn't require cooperation this lets bacteria do whatever they want -- and mischief can ensue," Holmes explained. Despite the huge diversity of gut bacteria, two main response patterns emerged in the study -- microbe species either increased or decreased in their abundance depending on the animal's protein and carbohydrate intake. "The largest nutrient requirements for our gut bacteria are carbon and nitrogen in the foods we eat. As carbohydrates contain no nitrogen but protein does, the bacterial community response to the host animal's diet is strongly affected by this diets' protein-carbohydrate ratio," Holmes said. "The fact that this same pattern was seen across almost all groups of gut bacteria indicates that the makeup of the microbial ecosystem is fundamentally shaped by a need to access nitrogen in the intestinal environment," Holmes added. This new research -- published in the journal Cell Metabolism -- is the latest in a series stemming from a study in which 25 different diets composed of different amounts of protein, carbohydrates and fat were systematically varied in 858 mice. The researchers said their new model suggests that while high-carbohydrate diets were the most likely to support positive interactions in the microbiome, such benefits were relative to the protein intake of the host animal.

London, Nov 27 (IANS) If you thought cushioned footwear can protect you better during jogging, think again! Researchers have found that shoes with no cushioning, or minimal footwear, are, in fact, better at reducing risk of running injuries. Runners who wear running shoes with no cushioning and land on the ball of their foot rather than the heel put significantly less demand on their bodies, the study found. Researchers compared how quickly the force acts when runners' feet hit the ground -- known as the loading rate -- which has been shown to influence running injury risk. "This research shows that running in minimal shoes and landing on the balls of your feet reduces loading rates and may therefore reduce the risk of injury," said lead author Hannah Rice from University of Exeter in Engalnd. The study of 29 runners -- published in the journal Medicine & Science in Sports & Exercise -- found significantly lower loading rates for those who wore the so-called minimal running shoes and landed on the ball of their foot, compared to people in normal running shoes, regardless of whether the latter landed on the heel or ball of the foot. "So many people use running as a means of reducing the risk of chronic diseases, but about three quarters of runners typically get injured in a year," Rice said. "Footwear is easily modifiable but many runners are misguided when it comes to buying new running shoes," Rice noted. Running continues to grow in popularity, and research aimed at reducing the high incidence of running-related injuries has been ongoing for decades -- but injury rates have not fallen. Modern-day runners in cushioned footwear tend to land on their heel -- known as a "rearfoot strike" -- while those who run in the natural barefoot state are more likely to land on the ball of their foot -- a "forefoot strike." "Our research tells us that becoming accustomed to running with a forefoot strike in shoes that lack cushioning promotes a landing with the lowest loading rates, and this may be beneficial in reducing the risk of injury," Rice said. The researchers, however, cautioned that any transition to new footwear or to a different foot strike pattern should be undertaken gradually, and with guidance.

​New York, Nov 25 (IANS) Do you find it difficult to remember lessons despite reading them over and over again because of the stress that examinations put? If yes, this new study may provide you a solution. Researchers have found that learning by taking practice tests, a strategy known as retrieval practice, can protect memory against the negative effects of stress. "Our results suggest that it is not necessarily a matter of how much or how long someone studies, but how they study," said corresponding author on the study Amy Smith from Tufts University in Massachusetts, US. In experiments involving 120 student participants, individuals who learned a series of words and images by retrieval practice showed no impairment in memory after experiencing acute stress. Participants who used study practice, the conventional method of re-reading material to memorise it, remembered fewer items overall, particularly after stress, showed the study published in the journal Science. "Typically, people under stress are less effective at retrieving information from memory," said senior study author Ayanna Thomas, Associate Professor at Tufts University. "We now show for the first time that the right learning strategy, in this case retrieval practice or taking practice tests, results in such strong memory representations that even under high levels of stress, subjects are still able to access their memories," Thomas added. The research team asked participants to learn a set of 30 words and 30 images. These were introduced through a computer programme, which displayed one item at a time for a few seconds each. To simulate note taking, participants were given 10 seconds to type a sentence using the item immediately after seeing it. One group of participants then studied using retrieval practice, and took timed practice tests in which they freely recalled as many items as they could remember. The other group used study practice. For these participants, items were re-displayed on the computer screen, one at a time, for a few seconds each. Participants were given multiple timed periods to study. The researchers found that participants who learned through study practice remembered fewer words overall, and those who were stressed remembered even less. "Even though previous research has shown that retrieval practice is one of the best learning strategies available, we were still surprised at how effective it was for individuals under stress. It was as if stress had no effect on their memory," Smith said.

​New York, Nov 23 (IANS) Meditation can help alleviate severe depression in people who do not fully respond to drugs, reports a new study. Researchers found significant improvement in symptoms of depression and anxiety in medicated patients with major depressive disorder who participated in the yogic breathing technique. The Sudarshan Kriya yoga helped those suffering from depression and on medication when compared to those who took medicines but did not do any breathing exercise. "The study found a promising, lower-cost therapy that could potentially serve as an effective, non-drug approach for patients battling depression," said Anup Sharma, doctoral student at the University of Pennsylvania, in the US. The meditation technique, which is practiced in both groups and at home, includes a series of sequential, rhythm-specific breathing exercises that bring people into a deep, restful and meditative state. It involves slow and calm breaths alternated with fast and stimulating breaths. Patients, who practised Sudarshan Kriya yoga, also showed a significantly greater improvement in mood, interest in activities, energy levels. It also brought down suicidal thoughts and feelings of guilt among other symptoms of depression. "Sudarshan Kriya yoga gives people an active method to experience a deep meditative state that's easy to learn and incorporate in diverse settings," Sharma added. Past studies suggest that yoga and other controlled breathing techniques can potentially adjust the nervous system to reduce stress hormones. The study was published in the Journal of Clinical Psychiatry.

​New Delhi, Nov 21 (IANS) A year ago, when 28-year-old Soma Chatterjee Maiti started using mobile messaging app WhatsApp, she did not know that one day the platform would economically empower her. Living in the small town of Khorda in Bhubaneswar, Maiti is a school teacher and sells suits and sarees via her WhatsApp group during her spare time. She informed her friends about the idea and they helped her get more customers from across the country. "The group currently comprises 30 people belonging to different cities like Delhi, Bangalore and in West Bengal, among others. Moreover, it's been just six months since I started this business. Every now and then, my friends introduce me to new members to whom my products can be sold," Maiti told IANS. Creating a group is not where her job ends. Maiti has to make sure that the group remains active, for which she keeps on following up, like asking the members if the package was delivered properly. Besides, she keeps on posting the pictures of her products in the group, so that the sales do not slow down. "Whatever material I have, I click its pictures and post it in the group. If a person likes a product, she directly contacts me over phone and the deal is taken further," Maiti added. WhatsApp is a social community tool and these days it is becoming an opportunity for homemakers to earn as well as stand on their feet, while not restricting themselves to just being "homemakers". Just like Maiti, 30-year-old Pooja Srivastava, who lives in Ghaziabad, has also created a group on WhatsApp called "Bend the Trend". The name suggests breaking the general trend of shopping in the malls or via online portals, through a daily-use app, making the process easier. "With about four years of using WhatsApp, I thought of starting my own business this year. I was aware that this app is quite popular and has every feature I needed to kick-start my business," Srivastava told IANS. There are 76 members in the group who hail from various metros of India, along with some belonging to countries like Canada, Singapore and the US. Her group also exists on Facebook which helps her get customers from abroad. Srivastava sells all sorts of apparel, artificial jewellery, kids wear, fashion accessories, etc., and earns around Rs 30,000 in a month. Prior to starting her business, Srivastava was an Assistant Professor at the Sun Institute of Management and Technology in Shahjahanpur, Uttar Pradesh. "I used to teach a few years back and even before that I was an HR professional. However, after getting married, I shifted to Ghaziabad and it was difficult to find a new job here. Thus, I decided to start my own business," she added. According to Anoop Mishra, a Lucknow-based social media analyst, technology is becoming an enabler for homemakers these days. "One-touch mobile accessibility of social applications is playing a wider role in making ideas visible and viral. Easy accessibility of technology and cost-effectiveness are encouraging homemakers day by day," Mishra told IANS in an email interview. With Prime Minister Narendra Modi's schemes like "Make in India" and "Skill India" getting a push, Mishra thinks that these homemakers-turning-entrepreneurs can be recognised if they are good enough at their work. "To make their story bigger, they would have to be exceptionally different and must go beyond the limits," he asserted. Yashmalika Singh, a resident of Delhi, has also been using WhatsApp for quite some time. She has a paying guest house (Ashirwaad PG) for girls in Dwarka and whoever lives there, she easily connects with them through this app. "Whenever she has to inform or ask something, she would send a text in the group she has created on WhatsApp, instead of calling the person individually," informs Riya Singh, who lives there. It's true that technology is evolving every day and with its evolution, people are also looking for possibilities to make their lives better. In an era where we talk of gender equality, a tool like WhatsApp is helping these homemakers attain their own identity and freedom.

Tokyo, Nov 20 (IANS) Engaging in social activities like participating in hobby clubs or volunteer groups may help the elderly relieve the stress of loneliness as well as slow down the decline in their ability to manage daily activities crucial to an individuals' independence and quality of life, say researchers. The study, led by a team of researchers from the Nara Medical University in Japan, found that elderly men and women who participated in social activities were less likely to experience a decline in their ability to perform daily functions. "Participation in a variety of different types of social activities was associated with change in IADLs (instrumental activities of daily living) over the three years of this study in women, and participation in hobby clubs was associated with change in IADLs in men and women," said the study published in the Journal of the American Geriatrics Society. Losing a spouse is considered a stressful experience that may speed up an older adult's functional decline. But participating in social activities may help relieve the stress of loneliness - and that might help an older adult maintain his or her ability to function, the researchers said. Participating in social activities allows older adults to have a meaningful role in society, giving them a sense of value and belonging. This sense of value may motivate older adults to maintain their ability to function, they added. Further, the researchers found that older adults who experienced a decline in their ability to perform daily activities were more likely to use medications, describe their health status as poor, experience depression, and have trouble with memory or making decisions compared to those who maintained their ability to function well. Such people also were less likely to participate in hobby clubs or volunteer groups versus those who could still perform simple activities of daily living. When older adults begin having trouble managing these activities by themselves, their risks for falls, hospitalisation, and even death can increase. Healthcare professionals should be aware of older adults' social activity participation - or lack of it - to help lessen the likelihood of functional decline, the researchers suggested.

​New York, Nov 19 (IANS) A handful of walnuts every day can help young men happily tackle life's daily stress as this nutrient-dense snack can lead to a happier state-of-mind, suggests a new study. The researchers found a significant improvement in mood in young, healthy males who consumed walnuts every day for eight weeks. "In the past, studies on walnuts have shown beneficial effects on many health outcomes like heart disease, diabetes and obesity," said researcher Peter Pribis, Professor at University of New Mexico in the US. "Our study was different because we focused on cognition, and in this controlled randomised trial (CRT) we measured mood outcomes in males and females," Pribis added. The participants of the study were 64 students between the ages of 18-25. The participants were asked to eat three slices of banana bread every day for sixteen weeks -- eight weeks of banana bread with walnuts and eight weeks of banana bread without walnuts. The nuts were finely ground into the dough so the two banana breads were similar in taste and appearance. While eating banana bread with walnuts the participants consumed half a cup of walnuts daily. The mood of the students was measured at the end of each eight-week period. "We used a validated questionnaire called Profiles of Mood States (POMS)," Pribis said. "It is one of the most widely used and accepted mood scales in studies on cognition. The test has six mood domains: tension, depression, anger, fatigue, vigor, confusion and also provides a Total Mood Disturbance score (TMD)," Pribis explained. The researchers found that consumption of walnuts led to a significant improvement in mood in young, healthy males. "In non-depressed healthy young males, walnuts seem to have the ability to improve mood," the study, published in the journal Nutrients, said. "There was a meaningful, 28 per cent improvement of mood in young men," Pribis pointed out. There are several nutrients in walnuts that could be responsible for the improved mood like alpha-Linolenic acid, vitamin E, folate, polyphenols or melatonin, the researchers said. "However we did not observe any improvement of mood in females. Why this is we do not know," Pribis said.