Science:-How much exercise do we need to live longer

Science:-How much exercise do we need to live longer?

To increase our chances for a long life, we probably should take at least 7,000 steps a day or play sports such as tennis, cycling, swimming, jogging or badminton for more than 2 1/2 hours per week, according to two large-scale new studies of the relationship between physical activity and longevity. The two studies, which together followed more than 10,000 men and women for decades, show that the right types and amounts of physical activity reduce the risk of premature death by as much as 70 per cent. But they also suggest that there can be an upper limit to the longevity benefits of being active, and pushing beyond that ceiling is unlikely to add years to our life spans and, in extreme cases, might be detrimental.
Plenty of research already suggests that people who are active outlive those who seldom move. A 2018 study by the Centers for Disease Control and Prevention, for instance, concluded that about 10 per cent of all deaths among Americans 40 to 70 years old are a result of too little exercise. A 2019 European study found that two decades of inactivity doubled Norwegian people’s risk of dying young. But scientists have not yet pinned down precisely how much — or little — movement might be most strongly associated with greater longevity. Nor is it clear whether we can overdo exercise, potentially contributing to a shorter life. Those issues lie at the heart of the two new studies, which look at the links between activity and longevity from distinct but intersecting angles. The first of the studies, published this month in JAMA Network Open, centered on steps.
Most of us are familiar with daily step counts as an activity goal, since our phones, smart watches and other activity trackers typically prompt us to take a certain number of steps every day, often 10,000. But as I have written before, current science does not show that we require 10,000 steps for health or longevity. Researchers from the University of Massachusetts at Amherst, the CDC and other institutions wondered if, instead, smaller step totals might be related to longer lives. So they turned to data gathered in recent years for a large, ongoing study of health and heart disease in middleaged men and women. Most of the participants had joined the study about 10 years earlier, when theywere in their 40s. At the time, they completed medical tests and wore an activity tracker to count their steps every day for a week. Now, the researchers pulled records for 2,110 of the participants and checked their names against death registries.
They found that 72 had died in the intervening decade, a relatively small number but not surprising given the people’s relative youth. But the scientists also noticed a strong association with step counts and mortality. Those men and women accumulating at least 7,000 daily steps when they joined the study were about 50% less likely to have died than those who took fewer than 7,000 steps, and the mortality risks continued to drop as people’s step totals rose, reaching as high as 70% less chance of early death among those taking more than 9,000 steps. But at 10,000 steps, the benefits leveled off. “There was a point of diminishing returns,” said Amanda Paluch, an assistant professor of kinesiology at the University of Massachusetts Amherst, who led the new study. People taking more than 10,000 steps per day, even plenty more, rarely outlived those taking at least 7,000.
Helpfully, the second study, which was published in August in Mayo Clinic Proceedings, settled on broadly similar activity levels as best bets for long life. This study involved data from the decades long Copenhagen City Heart Study, which has recruited tens of thousands of Danish adults since the 1970s and asked them how many hours each week they play sports or exercise, including cycling wildly popular in Copenhagen), tennis, jogging, swimming, handball, weightlifting, badminton and soccer.
The researchers focused on 8,697 of the study’s Danes who had joined in the 1990s, noted their activity habits then, and checked their names against death records. In the 25 years or so since most had joined, about half had died. But those who reported exercising, in some way, between 2.6 and 4 1/2 hours per week when they joined were 40% or so less likely to have died in the in terim than less active people. Translating those hours of exercise into step counts is not an exact science, but the researchers estimate that people exercising for 2.6 hours a week, or about 30 minutes most days, likely would accumulate around 7,000 to 8,000 steps most days,

Elevated stress hormones linked to higher blood pressure risk: Study
Washington [US]: In a study of more than 400 adults with normal blood pressure, those who had high levels of stress hormones detected in their urine were more likely to develop high blood pressure over the next 6-7 years. The findings of the study were published in the journal ‘Hypertension’. Higher levels of the stress hormonecortisol were also linked to an increased risk of cardiovascular events, including heart attack and stroke. Studies have shown that cumulative exposure to daily stressors and exposure to traumatic stress can increase cardiovascular disease risk. A growing body of research refers to the mind-heart-body connection, which suggests a person’s mind can positively or negatively affect cardiovascular health, cardiovascular risk factors and risk for cardiovascular disease events, as well as cardiovascular prognosis over time.
“The stress hormones norepinephrine, epinephrine, dopamine and cortisol can increase with stress from life events, work, relationships, finances and more. And we confirmed that stress is a key factor contributing to the risk of hypertension and cardiovascular events,” said study author Kosuke Inoue, MD, PhD, assistant professor of social epidemiology at Kyoto University in Kyoto, Japan. Inoue also is affiliated with the department of epidemiology at the Fielding School of Public Health at the University of California, Los Angeles. “Previous research focused on the relationship between stress hormone levels and hypertension or cardiovascular events in patients with existing hypertension. However, studies looking at adults without hypertension were lacking,” Inoue said. “It is important to examine he impact of stress on adults in the general population because it provides new information about whether routine measurement of stress hormones needs to be considered to prevent hypertension and CVD events,”
Inoue added. Study subjects were part of the MESA Stress 1 study, a substudy of the MultiEthnic Study of Atherosclerosis (MESA), a large study of atherosclerosis risk factors among more than 6,000 men and women from six US communities.
As part of MESA exams, 3 and 4 (conducted between July 2004 and October 2006), white, Black and Hispanic participants with normal blood pressure from the New York and Los Angeles sites were invited to participate in the substudy MESA Stress 1. In this substudy, researchers analysed levels of norepinephrine, epinephrine, dopamine and cortisol — hormones that respond to stress levels. Hormone levels were measured in a 12- hour overnight urine test. The substudy included 412 adults ages 48 to 87 years. About half were female, 54 per cent were Hispanic, 22 per cent were Black and 24 per cent were white. Participants were followed for three more visits (between September 2005 and June 2018) for the development of hypertension and cardiovascular events such as chest pain, the need for an artery-opening procedure, or having a heart attack or stroke.
Norepinephrine, epinephrine and dopamine are molecules known as catecholamines that maintain stability throughout the autonomic nervous system — the system that regulates involuntary body functions such as heart rate,

Pregnant women at a higher risk of novel coronavirus infection: ICMR study
New Delhi: The novel coronavirus may infect a higher proportion of pregnant women and they can develop moderate-to-severe diseases, an ICMR study has said, underlining the need for them to seek immediate medical attention.
According to the study published in the Indian Journal of Medical Research, the most common complications were preterm delivery and hypertensive disorders in pregnancy. Comorbidities such as anaemia, tuberculosis and diabetes mellitus were associated with an increased risk of maternal death in pregnant and post-partum women with COVID-19, the study said. It analysed clinical characteristics and pregnancy outcomes of women with COVID-19 enrolled during the first wave of the pandemic in Maharashtra.
The analysis was based on the data from the PregCovid registry, a study of pregnant women and women in the post-partum period with a confirmed diagnosis of COVID-19. The PregCovid registry collected information on a nearreal-time basis on pregnant and post-partum women with a laboratory-confirmed coronavirus infection from 19 medical colleges across Maharashtra. The data of 4,203 pregnant women collected during the first wave (March 2020-January 2021) was analysed.
“There were 3213 live births, 77 miscarriages and 834 undelivered pregnancies. The proportion of pregnancy/foetal loss including stillbirths was six per cent. Five hundred and thirty-four women (13%) were symptomatic, of which 382 (72%) had mild, 112 (21%) had moderate, and 40 (7.5 %) had severe disease. The most common complication was preterm delivery (528, 16.3%) and hypertensive disorders in pregnancy (328, 10.1%). A total of 158 (3.8%) pregnant and postpartum women required intensive care, of which 152 (96%) were due to COVID-19 related complications,” the findings of the study stated.

Green tea: Know when and how much you should consume
New Delhi: Green tea, which is one of the least processed teas made from unoxidised leaves, often finds mention in talks about weight loss. While many restrict it to one or two cups a day, some others even consume up to five cups. But what is the ideal quantity that one should consume for weight loss, among other benefits? Today, on green tea researcher and chemist Michiyo Tsujimura‘s 133rd birth anniversary which also finds mention on Google Doodle, we have experts decoding the beverage for you. According to a National Center for Biotechnology Information (NCBI) literature review, to produce green tea, freshly harvested leaves are immediately steamed to prevent fermentation, yielding a dry, stable product.
This steaming process destroys the enzymes responsible for breaking down the colour pigments in the leaves and allows the tea to maintain its green colour during the subsequent rolling and drying processes, it reads. Origin of green tea Dolly Kumar, founder and director, Gaia, mentioned in an earlier interaction with indianexpress.com that “the tea got popularised in Japan around 1190 when a Zen priest visiting and studying in China’s Buddhist monasteries and temples returned to Japan with tea plant seeds and bushes”.
“He popularised the tea as a meditation ritual within his own community of Buddhist monks, eventually spreading the custom of tea drinking throughout the rest of Japan,” she said. Benefits of green tea Green tea consumption has also been linked to the prevention of many types of cancer, including lung, colon, esophagus, mouth, stomach, small intestine, kidney, pancreas, and mammary glands, as per the 2010 NCBI review. As an anti-bacterial tea, it is rich in antioxidants, minerals and vitamins, and has innumerable benefits including helping in weight loss, improving body’s metabolism, promoting oral health, exhibiting antiageing properties and aiding in reducing the risk of heart diseases too. According to Dr Parmeet Kaur, senior dietician, Narayana Superspeciality Hospital, Gurugram, green tea also helps increase good cholesterol levels; and the high amount of antioxidants improve brain function and reduce risk of cancer, type-2 diabetes, and cardiovascular diseases.
In fact, some studies indicate that people who drink green tea are less likely to develop several types of cancer than those who do not. Cancers that green tea can help protect against include bladder and breast cancer, two common cancers in men and women, respectively, with specific studies showing health benefits for people who drink one cup a day, said Neha Pathania, Chief- Dietitian, Paras Hospital Gurugram. Dr Pooja Thacker, Head of Department Dietetic, Bhatia Hospital Mumbai told indianexpress.com that since green tea is a good source of catechin (71mg in 100ml), epigallocatchingallate (126 mg /100ml), and some vitamins compared to wine and berries, it is known to prevent ageing and is also neuroprotective, helping lower chances of Alzheimer’s and dementia, due to the presence of phytochemicals and polyphenols.

Is stress always bad?
Study at University of Rochester suggests otherwise

New Delhi: When the term ‘stress’ comes to mind, it is rarely ever associated with something positive. People believe that nothing good can ever come out of a situation by being stressed about it. However, does the statement always hold true in every situation? A recent study led by the University of Rochester says otherwise.
The study titled “Reappraising stressarousal improves affective, neuroendocrine, and academic performance outcomes in community college classrooms”, is published in the Journal of Experimental Psychology: General says that it’s all about perception. Stress and its perception Much like anxiety, stress is one of the most common emotions experienced by people. Due to the prolonged periods of isolation and lack of social activity, the COVID-19 pandemic has increased incidents of such emotions that can easily put a person through episodes of panic attacks, hyperventilation, trembling sensations, and more.
The pandemic aside, stress is not a new phenomenon. It is the body’s response to certain events, be it good or bad. From appearing in job interviews to going out on a first date and from moving to a new country to losing a loved one, it is not possible to evade stressful situations because it is natural.
As obvious as it sounds, how a person perceives a situation can indicate a lot about how they will act upon it and the probable outcomes of the same. “I work better under stress” – is a common statement by numerous working professionals. If stress is inherently negative, how can it benefit them to work better? This can be achieved by a perspective-based approach. Jeremy Jamieson, a Rochester associate professor of psychology, the principal investigator at the University’s Social Stress Lab and the lead author of the study said,
“We use a type of ‘saying is believing’ approach whereby participants learn about the adaptive benefits of stress and they are prompted to write about how it can help them achieve.” Stress reappraisal Stress reappraisal aims at a re-evaluation of the stressful situation and using it at an advantage. A positive individual approach will result in a positive outcome. This will result in favourable results with channelled efforts towards achieving focused goals with optimal utilization of resources. Altered cortisol and testosterone levels were found after stress reappraisal. Cortisol and testosterone indicate stress and optimal performance, respectively. The study observed an increase in testosterone levels and a decrease in cortisol levels in subjects which indicated enhanced performance.
More about the study Students from a community college were trained for the purpose of the study through writing and reading exercises to enhance their comprehension of stress. The aim was to alter the perception of stress as a driving force rather than a hindrance. Tools such as undertaking tests were used to evaluate how stress can influence their performance. As a result, the following was observed: Enhanced performance levels of procrastination Improved problem handling abilities.

Drug targets for memory enhancement – Here is what a recent study suggests

Bristol: Specific drug targets within the neural circuits that encode memories and pave the way for significant advances in the treatment of a broad spectrum of brain disorders have been identified by a new University of Bristol-led research.
Loss of memory is a core feature of many neurological and psychiatric disorders including Alzheimer’s disease and schizophrenia. Current treatment options for memory loss are very limited and the search for safe and effective drug therapies has, until now, had limited success. The study was published in Nature Communications.
The research was done in collaboration with colleagues at the international biopharmaceutical company Sosei Heptares. The findings identify specific receptors for the neurotransmitter acetylcholine that re-route information flowing through memory circuits in the hippocampus. Acetylcholine is released in the brain during learning and is critical for the acquisition of new memories. Until now, the only effective treatment for the symptoms of cognitive or memory impairment seen in diseases such as Alzheimer’s is using drugs that broadly boost acetylcholine.
However, this leads to multiple adverse side effects. The discovery of specific receptor targets that have the potential to provide positive effects whilst avoiding negative ones is promising. Lead author, Professor Jack Mellor, from the University of Bristol’s Centre for Synaptic Plasticity, said:
“These findings are about the fundamental processes that occur in the brain during the encoding of memory and how they may be regulated by brain state or drugs targeting specific receptor proteins. In the long term, the discovery of these specific targets opens up avenues and opportunities for the development of new treatments for the symptoms of Alzheimer’s disease.