If you're pregnant, the pollution can seriously harm your baby

Washington, Feb 12: People who are optimistic may contribute to the health of their partners, staving off the risk factors leading to Alzheimer's disease, dementia and cognitive decline as they grow old together, according to a study.

The research, published in the Journal of Personality, followed nearly 4,500 heterosexual couples from the US Health and Retirement Study for up to eight years.

The researchers found a potential link between being married to an optimistic person and preventing the onset of cognitive decline, due to a healthier environment at home.

"We spend a lot of time with our partners.They might encourage us to exercise, eat healthier or remind us to take our medicine," said William Chopik, an assistant professor at the Michigan State University in the US.

"When your partner is optimistic and healthy, it can translate to similar outcomes in your own life. You actually do experience a rosier future by living longer and staving off cognitive illnesses," Chopik said.

An optimistic partner may encourage eating healthy foods, or working out together to develop healthier lifestyles, the researchers said.

For example, if a person quits smoking or starts exercising, their partner is close to following suit, they said.

"We found that when you look at the risk factors for what predicts things like Alzheimer's disease or dementia, a lot of them are things like living a healthy lifestyle," Chopik said.

"Maintaining a healthy weight and physical activity are large predictors.There are some physiological markers as well. It looks like people who are married to optimists tend to score better on all of those metrics," he said.

The researchers said there is a sense where optimists lead by example, and their partners follow their lead.

They also suggest that when couples recall shared experiences together, richer details from the memories emerge.

Chopik noted while there is a heritable component to optimism, there is some evidence to suggest that it's a trainable quality.

"There are studies that show people have the power to change their personalities, as long as they engage in things that make them change," Chopik said.

"Part of it is wanting to change. There are also intervention programs that suggest you can build up optimism," he added.

The record levels of new daily COVID-19 cases are due to the fact that the pandemic is peaking in a number of big countries at the same time and reflect a change in the virus' global activity, the World Health Organisation said.

At a media briefing on Monday, WHO's emergencies chief Dr Michael Ryan said that the numbers are increasing because the epidemic is developing in a number of populous countries at the same time.

Some countries have attributed their increased caseload to more testing, including India and the US But Ryan dismissed that explanation.

We do not believe this is a testing phenomenon, he said, noting that numerous countries have also noted marked increases in hospital admissions and deaths neither of which cannot be explained by increased testing.

There definitely is a shift in that the virus is now very well established, Ryan said. The epidemic is now peaking or moving towards a peak in a number of large countries.

He added the situation was definitely accelerating in a number of countries, including the US and others in South Asia, the Middle East and Africa.

Washington D.C, Feb 10: Children's vulnerability towards depression, anxiety, impulsive behaviour, and poor cognitive performance could be determined by considering the hours of sleep they manage to get.

Sleep states are active processes that support the reorganisation of brain circuitry. This makes sleep especially important for children, whose brains are developing and reorganising rapidly.

In a study by researchers from the University of Warwick -- recently published in the journal Molecular Psychiatry -- cases of 11,000 children aged between 9 and 11 years from the Adolescent Brain Cognitive Development dataset were analyzed to find out the relationship between sleep duration and brain structure.

The study was carried out by researchers Professor Jianfeng Feng, Professor Edmund Rolls, Dr. Wei Cheng and colleagues from the University of Warwick's Department of Computer Science and Fudan University.

Measures of depression, anxiety, impulsive behaviour and poor cognitive performance in the children were associated with shorter sleep duration. Moreover, the depressive problems were associated with short sleep duration one year later.

The reduced brain volume of areas such as orbitofrontal cortex, prefrontal, and temporal cortex, precuneus, and supramarginal gyrus was found to be associated with the shorter sleep duration.

Professor Jianfeng Feng, from the University of Warwick's Department of Computer Science, comments: "The recommended amount of sleep for children 6 to 12 years of age is 9-12 hours. However, sleep disturbances are common among children and adolescents around the world due to the increasing demand on their time from school, increased screen time use, and sports and social activities."

A previous study showed that about 60 per cent of adolescents in the United States receive less than eight hours of sleep on school nights.

Professor Jianfeng Feng further added: "Our findings showed that the total score for behavior problems in children with less than 7 hours sleep was 53 per cent higher on average and the cognitive total score was 7.8 per cent lower on average than for children with 9-11 hours of sleep. It highlights the importance of enough sleep in both cognition and mental health in children."

Professor Edmund Rolls from the University of Warwick's Department of Computer Science also commented: "These are important associations that have been identified between sleep duration in children, brain structure, and cognitive and mental health measures, but further research is needed to discover the underlying reasons for these relationships."