Good Sleep Quality and Good Mood Lead to Good Working Memory with Age

A team of psychologists has found strong associations between working memory — a fundamental building block of a functioning mind — and three health-related factors: sleep, age, and depressed mood. The team also reports that each of these factors is associated with different aspects of working memory.

Working memory is the part of short-term memory that temporarily stores and manages information required for cognitive tasks such as learning, reasoning, and comprehension. Working memory is critically involved in many higher cognitive functions, including intelligence, creative problem-solving, language, and action-planning. It plays a major role in how we process, use, and remember information.

The researchers, led by Weiwei Zhang, an assistant professor of psychology at the University of California, Riverside, found that age is negatively related to the “qualitative” aspect of working memory–that is, how strong or how accurate the memory is. In other words, the older the person, the weaker and less precise the person’s memory. In contrast, poor sleep quality and depressed mood are linked to a reduced likelihood of remembering a previously experienced event — the “quantitative” aspect of working memory.

“Other researchers have already linked each of these factors separately to overall working memory function, but our work looked at how these factors are associated with memory quality and quantity – the first time this has been done,” Zhang said. “All three factors are interrelated. For example, seniors are more likely to experience negative mood than younger adults. Poor sleep quality is also often associated with depressed mood. The piecemeal approach used in previous investigations on these relationships — examining the relationship between one of these health-related factors and working memory — could open up the possibility that an observed effect may be influenced by other factors.”

The researchers are the first to statistically isolate the effects of the three factors on working memory quantity and quality. Although all three factors contribute to a common complaint about foggy memory, they seem to behave in different ways and may result from potentially independent mechanisms in the brain. These findings could lead to future interventions and treatments to counteract the negative impacts of these factors on working memory.

Research results appear in the Journal of the International Neuropsychological Society.

The researchers performed two studies. In the first study, they sampled 110 college students for self-reported measures of sleep quality and depressed mood and their independent relationship to experimental measures of working memory. In the second study, the researchers sampled 31 members of a community ranging in age from 21 to 77 years. In this study, the researchers investigated age and its relationship to working memory.

“We are more confident now about how each one of these factors impacts working memory,” Zhang said. “This could give us a better understanding of the underlying mechanism in age-related dementia. For the mind to work at its best, it is important that senior citizens ensure they have good sleep quality and be in a good mood.”

Source: EurekAlert!


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Study: Smiling Does Bring a Mood Boost

Here’s something to make you smile: Turning that frown upside down does make folks feel a little happier, researchers conclude.

While most of us might know this instinctively, academics have not always been sure.

“Conventional wisdom tells us that we can feel a little happier if we simply smile. Or that we can get ourselves in a more serious mood if we scowl,” said lead researcher Nicholas Coles, a graduate student in social psychology at the University of Tennessee, Knoxville.

“But psychologists have actually disagreed about this idea for over 100 years,” Coles noted in a school news release.

The controversy over the theory was heightened in 2016 when 17 teams of researchers weren’t able to replicate a well-known experiment that claimed to show that smiling can make people feel happier.

A much bigger pool of data was needed, Coles said.

“Some studies have not found evidence that facial expressions can influence emotional feelings,” he said. “But we can’t focus on the results of any one study. Psychologists have been testing this idea since the early 1970s, so we wanted to look at all the evidence.”

So Coles and his colleagues analyzed nearly 50 years of data from 138 studies that tried to determine whether facial expressions can affect people’s moods. The studies included more than 11,000 people worldwide.

The researchers’ conclusion: Facial expressions do have a small effect on feelings: Smiling makes people feel happier, scowling makes them feel angrier, and frowning makes them feel sadder.

The study was published in the journal Psychological Bulletin.

Coles stressed that no one should toss their antidepressants and just start grinning instead.

“We don’t think that people can smile their way to happiness,” he said. “But these findings are exciting because they provide a clue about how the mind and the body interact to shape our conscious experience of emotion. We still have a lot to learn about these facial feedback effects, but this meta-analysis put us a little closer to understanding how emotions work.”

Source: HealthDay


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Study: Curcumin Improves Memory and Mood

Leigh Hopper wrote . . . . . . .

Lovers of Indian food, give yourselves a second helping: Daily consumption of a certain form of curcumin — the substance that gives Indian curry its bright color — improved memory and mood in people with mild, age-related memory loss, according to the results of a study conducted by UCLA researchers.

The research, published online in the American Journal of Geriatric Psychiatry, examined the effects of an easily absorbed curcumin supplement on memory performance in people without dementia, as well as curcumin’s potential impact on the microscopic plaques and tangles in the brains of people with Alzheimer’s disease.

Found in turmeric, curcumin has previously been shown to have anti-inflammatory and antioxidant properties in lab studies. It also has been suggested as a possible reason that senior citizens in India, where curcumin is a dietary staple, have a lower prevalence of Alzheimer’s disease and better cognitive performance.

“Exactly how curcumin exerts its effects is not certain, but it may be due to its ability to reduce brain inflammation, which has been linked to both Alzheimer’s disease and major depression,” said Dr. Gary Small, director of geriatric psychiatry at UCLA’s Longevity Center and of the geriatric psychiatry division at the Semel Institute for Neuroscience and Human Behavior at UCLA, and the study’s first author.

The double-blind, placebo-controlled study involved 40 adults between the ages of 50 and 90 years who had mild memory complaints. Participants were randomly assigned to receive either a placebo or 90 milligrams of curcumin twice daily for 18 months.

All 40 subjects received standardized cognitive assessments at the start of the study and at six-month intervals, and monitoring of curcumin levels in their blood at the start of the study and after 18 months. Thirty of the volunteers underwent positron emission tomography, or PET scans, to determine the levels of amyloid and tau in their brains at the start of the study and after 18 months.

The people who took curcumin experienced significant improvements in their memory and attention abilities, while the subjects who received placebo did not, Small said. In memory tests, the people taking curcumin improved by 28 percent over the 18 months. Those taking curcumin also had mild improvements in mood, and their brain PET scans showed significantly less amyloid and tau signals in the amygdala and hypothalamus than those who took placebos.

The amygdala and hypothalamus are regions of the brain that control several memory and emotional functions.

Four people taking curcumin, and two taking placebos, experienced mild side effects such as abdominal pain and nausea.

The researchers plan to conduct a follow-up study with a larger number of people. That study will include some people with mild depression so the scientists can explore whether curcumin also has antidepressant effects. The larger sample also would allow them to analyze whether curcumin’s memory-enhancing effects vary according to people’s genetic risk for Alzheimer’s, their age or the extent of their cognitive problems.

“These results suggest that taking this relatively safe form of curcumin could provide meaningful cognitive benefits over the years,” said Small, UCLA’s Parlow–Solomon Professor on Aging.

Source: UCLA


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Does Sugar Make You Sad? New Science Suggests So

Anika Knüppel wrote . . . . . . . .

The thought of a cupcake, skillfully frosted with fluffy vanilla icing, may put a smile on your face, but research suggests that, in the long term, a sweet tooth may turn that smile into a frown – but not for the reasons you think. In a new study, published in Scientific Reports, my colleagues and I found a link between a diet high in sugar and common mental disorders.

The World Health Organisation recommends that people reduce their daily intake of added sugars (that is, all sugar, excluding the sugar that is naturally found in fruit, vegetables and milk) to less than 5% of their total energy intake. However, people in the UK consume double – in the US, triple – that amount of sugar. Three-quarters of these added sugars come from sweet food and beverages, such as cakes and soft drinks. The rest come from other processed foods, such as ketchup.

At the same time, one in six people worldwide suffers from a common mental disorder, such as a mood or anxiety disorder. Could there be a link between high sugar consumption and common mental disorders?

Earlier research, published in 2002, examined the link between depression and sugar consumption in six countries. The researchers, from Baylor College in the US, found that higher rates of refined sugar consumption were associated with higher rates of depression.

Since then, a handful of studies have investigated the link between added sugar consumption and subsequent depression. In 2011, researchers in Spain found that when they grouped participants based on their commercial baked food consumption, those who ate the most baked food had a 38% increased chance of developing depression compared with those in the group with the lowest intake. The association remained even after accounting for health consciousness and employment status.

In 2014, researchers studied the association between sweetened beverages in a large US group. They found that sugar-sweetened and artificially sweetened drinks (diet drinks) could increase a person’s risk of developing depression. And, more recently, a 2015 study, including nearly 70,000 women, found higher chances of depression in those with a high added sugar intake, but not in those with a high intake of naturally occurring sugars, such as those found in fruit.

Trying to explain the link

We are still not sure what causes depression, but some researchers believe that biological changes are at the root of it. Some of these changes could be influenced by sugar and sweet taste. For example, a study in rats found that diets high in sugar and fat can reduce a protein called BDNF that influences the growth and development of nerve cells in the brain. This protein is thought to be involved in the development of depression and anxiety.

Another possible biological cause is inflammation. High sugar diets can increase inflammation – a protective reaction of the body, normally directed against microorganisms or foreign substances. While common signs of inflammation, such as redness, are far from a mood disorder, the symptoms that keep us in bed with a cold are much closer, such as low energy and being unable to concentrate. Ongoing research suggests that mood disorders could be linked with inflammation, at least in some cases.

Dopamine is another possible culprit. A study using rats earned headlines for suggesting sweet foods could be as addictive as cocaine. This might be due to affects on dopamine, a brain chemical involved in the reward system. Dopamine is also thought to influence mood. And addiction is itself associated with a higher risk of developing a mood disorder.

Finally, sugar intake could be associated with other factors, such as obesity, which itself is related to mood.

But these associations could also reflect a reverse phenomenon: low mood could make people change their diet. Sweet foods could be used to soothe bad feelings by providing a short-term mood boost. And low mood and anxiety could make simple tasks, such as grocery shopping or cooking, so difficult and exhausting for the sufferer that they might start to avoid them. Instead, they might opt for junk food, takeaways and ready meals – all of which have a high sugar content.

What our study adds to the debate

For our latest study, my colleagues and I put the reverse association idea to the test. We used sugar intake from sweet food and drinks to predict new and recurrent mood disorders in a group of British civil servants. We also investigated whether having a mood disorder would make people more inclined to choose sweet foods and drinks.

We found that men without a mood disorder who consumed over 67g of sugar had a 23% increased risk of suffering from a mood disorder five years later, compared with those who ate less than 40g. This effect was independent of the men’s socioeconomic status, physical activity, drinking, smoking, other eating habits, body fatness and physical health.

We also found that men and women with a mood disorder and a high intake of sugar from sweet food and drinks were at higher risk of becoming depressed again five years later, compared with those who consumed less sugar. But this association was partly explained by their overall diet.

We found no evidence for a potential reverse effect: participants did not change their sugar intake after suffering from mood disorders.

Despite our findings, a number of questions remain about whether sugar makes us sad, whether it affects men more than women, and whether it is sweetness, rather than sugar itself, that explains the observed associations. What is certain, though, is that sugar is associated with a number of health problems, including tooth decay, type 2 diabetes and obesity. So cutting down on sugar is probably a good idea, regardless of whether it causes mood disorders or not.

Source: The Conversation


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The Key to A Better Mood for Young Men is A Nut

College can be a stressful time for young adults as they figure out how to manage intense daily routines that include work, study and play. Eat well, exercise and get plenty of sleep is a familiar mantra to alleviate this stress, but now with the results of his latest study, UNM Nutrition Professor Peter Pribis is able to tell college students that walnuts could be a key to a happier state-of-mind.

In this first intervention study in humans, Pribis measured the effect of walnut consumption on mood.

“In the past, studies on walnuts have shown beneficial effects on many health outcomes like heart disease, diabetes and obesity,” said Pribis. “Our study was different because we focused on cognition, and in this controlled randomized trial (CRT) we measured mood outcomes in males and females.”

The participants of the study were 64 students between the ages of 18-25. They represented most ethnic groups: Caucasian, African American, Hispanic and Asian.

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),” says Pribis. “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). The lower the TMD score the better the mood.”

In this double-blind, randomized, placebo controlled, cross-over feeding trial with walnuts for eight weeks, Pribis observed a significant improvement in mood in young, healthy males.

“There was a meaningful, 28 percent improvement of mood in young men,” said Pribis. “However we did not observe any improvement of mood in females. Why this is we do not know.”

There are several nutrients in walnuts that could be responsible for the improved mood like alpha-Linolenic acid, vitamin E, folate, polyphenols or melatonin. However, this was a whole food study, so in the end it was the synergy and interaction of all the nutrients in the walnuts combined.

For Pribis, the lesson learned from this food study is clear, “Eat more walnuts. This is an easy intervention. They’re not only good for your mood, but overall health as well. The recommended amount is one handful per day.”

With this knowledge in hand–and hopefully walnuts in the other–young men can happily tackle life’s daily stress.

Source: EurekAlert!