Study links insufficient sleep, unhealthy lifestyle in kids

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.

Washington D.C., Apr 4: While consuming a high-diet salt can result in high blood pressure, a recent study has revealed a link between salt-rich diet and weaker immune system.

The study was conducted under the leadership of the University Hospital Bonn, and the results were published in the journal Science Translational Medicine.

The research was conducted on mice that were fed a high-salt diet. Later, they were found to suffer from much more severe bacterial infections.

Human volunteers who consumed an additional six grams of salt per day also showed pronounced immune deficiencies.

The World Health Organization (WHO) has recommended a maximum amount of five grams of salt a day.

It corresponds approximately to one level teaspoon. In reality, however, many Germans exceed this limit considerably. 

Figures from the Robert Koch Institute suggest that on average men consume ten, and women more than eight grams a day.

This means that we reach for the salt shaker much more than is good for us. After all, sodium chloride, which is its chemical name, raises blood pressure and thereby increases the risk of heart attack or stroke.

"We have now been able to prove for the first time that excessive salt intake also significantly weakens an important arm of the immune system," said Prof. Dr. Christian Kurts from the Institute of Experimental Immunology at the University of Bonn.

This finding is unexpected, as some studies point in the opposite direction. For example, infections with certain skin parasites in laboratory animals heal significantly faster if these consume a high-salt diet.

The study also sheds light on the fact that the skin serves as a salt reservoir.

"Our results show that this generalization is not accurate," emphasized Katarzyna Jobin, lead author of the study.

The body keeps the salt concentration in the blood and in the various organs largely constant. Otherwise important biological processes would be impaired. The only major exception is the skin which functions as a salt reservoir of the body. This is why the additional intake of sodium chloride works so well for some skin diseases.

However, other parts of the body are not exposed to the additional salt consumed with food. Instead, it is filtered out by the kidneys and excreted in the urine.

"We examined volunteers who consumed six grams of salt in addition to their daily intake," said Prof. Kurts. This is roughly the amount contained in two fast-food meals, i.e. two burgers and two portions of French fries.

After one week, from the results, it showed that the immune cells coped much worse with bacteria after the test subjects had started to eat a high-salt diet.

In human volunteers, excessive salt intake also resulted in increased glucocorticoid levels.