Monthly Archives: March 2021

How Exercise Enhances Aging Brains

How Exercise Enhances Aging Brains

Sedentary, older adults who took aerobic dance classes twice a week showed improvements in brain areas critical for memory and thinking. Article from The New York Times.

Volunteers who participated in pre-pandemic dance classes in Newark, N.J., showed improvements in memory centers in the brain.
Volunteers who participated in pre-pandemic dance classes in Newark, N.J., showed improvements in memory centers in the brain.Credit…Rutgers University
Gretchen Reynolds

By Gretchen Reynolds

  • March 3, 2021, 5:00 a.m. ET

Exercise can change how crucial portions of our brain communicate as we age, improving aspects of thinking and remembering, according to a fascinating new study of aging brains and aerobic workouts. The study, which involved older African-Americans, finds that unconnected portions of the brain’s memory center start interacting in complex and healthier new ways after regular exercise, sharpening memory function.

The findings expand our understanding of how moving molds thinking and also underscore the importance of staying active, whatever our age.

The idea that physical activity improves brain health is well established by now. Experiments involving animals and people show exercise increases neurons in the hippocampus, which is essential for memory creation and storage, while also improving thinking skills. In older people, regular physical activity helps slow the usual loss of brain volume, which may help to prevent age-related memory loss and possibly lower the risk of dementia.

There have been hints, too, that exercise can alter how far-flung parts of the brain talk among themselves. In a 2016 M.R.I. study, for instance, researchers found that disparate parts of the brain light up at the same time among collegiate runners but less so among sedentary students. This paired brain activity is believed to be a form of communication, allowing parts of the brain to work together and improve thinking skills, despite not sharing a physical connection. In the runners, the synchronized portions related to attention, decision making and working memory, suggesting that running and fitness might have contributed to keener minds.

But those students were young and healthy, facing scant imminent threat of memory loss. Little was known yet about whether and how exercise might alter the communications systems of creakier, older brains and what effects, if any, the rewiring would have on thinking.

So, for the new study, which was published in January in Neurobiology of Learning and Memory, Mark Gluck, a professor of neuroscience at Rutgers University in Newark, N.J., and his colleagues decided to see what happened inside the brains and minds of much older people if they began to work out.

In particular, he wondered about their medial temporal lobes. This portion of the brain contains the hippocampus and is the core of our memory center. Unfortunately, its inner workings often begin to sputter with age, leading to declines in thinking and memory. But Dr. Gluck suspected that exercise might alter that trajectory.

Helpfully, as the director of the Aging & Brain Health Alliance at Rutgers, he already was leading an ongoing exercise experiment. Working with local churches and community centers, he and his collaborators previously had recruited sedentary, older African-American men and women from the Newark area. The volunteers, most of them in their 60s, visited Dr. Gluck’s lab for checks of their health and fitness, along with cognitive testing. A few also agreed to have their brain activity scanned.

Some then started working out, while others opted to be a sedentary control group. All shared similar fitness and memory function at the start. The exercise group attended hourlong aerobic dance classes twice a week at a church or community center for 20 weeks.

Now, Dr. Gluck and his research associate Neha Sinha, along with other colleagues, invited 34 of those volunteers who had completed an earlier brain scan to return for another. Seventeen of them had been exercising in the meantime; the rest had not. The groups also repeated the cognitive tests.

Then the scientists started comparing and quickly noticed subtle differences in how the exercisers’ brains operated. Their scans showed more-synchronized activity throughout their medial temporal lobes than among the sedentary group, and this activity was more dynamic. Portions of the exercisers’ lobes would light up together and then, within seconds, realign and light up with other sections of the lobe. Such promiscuous synchronizing indicates a kind of youthful flexibility in the brain, Dr. Gluck says, as if the circuits were smoothly trading dance partners at a ball. The exercisers’ brains would “flexibly rearrange their connections,” he says, in a way that the sedentary group’s brains could not.

Just as important, those changes played out in people’s thinking and memories. The exercisers performed better than before on a test of their ability to learn and retain information and apply it logically in new situations. This kind of agile thinking involves the medial temporal lobe, Dr. Gluck says, and tends to decline with age. But the older exercisers scored higher than at the start, and those whose brains displayed the most new interconnections now outperformed the rest.

This study involved older African-Americans, though, a group that is underrepresented in health research but may not be representative of all aging people. Still, even with that caveat, “it seems that neural flexibility” gained by exercising a few times a week “leads directly to memory flexibility,” Dr. Gluck says.

Thinking about trying collagen supplements for your skin? A healthy diet is better value for money

Thinking about trying collagen supplements for your skin? A healthy diet is better value for money

March 5, 2021 12.51pm AEDT

Author

  1. Clare Collins Laureate Professor in Nutrition and Dietetics, University of Newcastle

Disclosure statement

Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She has received research grants from NHMRC, ARC, MRFF, Hunter Medical Research Institute, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation, Rijk Zwaan Australia, WA Dept. Health, Meat and Livestock Australia, and Greater Charitable Foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers, the Sax Institute and the ABC. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and the Heart Foundation evidence reviews on meat and dietary patterns.

Partners

University of Newcastle

University of Newcastle provides funding as a member of The Conversation AU.

View all partners

CC BY NDWe believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
  • Celebrity testimonials abound for pills, potions and creams that purport to make you look younger.

This time collagen supplements are in the spotlight, after Jennifer Aniston became the face of one wellness brand’s collagen campaign in late 2020.

While some research has found benefits of collagen supplementation for some aspects of skin health, it’s a case of buyer beware. The evidence is generally weak, with many of the studies claiming to find positive effects from collagen supplementation funded mostly by industries that manufacture these products. Therefore, the results need to be interpreted with caution.

When you’re reading articles promoting these products, be especially wary of phrases such as “we may receive compensation for some links to products and services”. These statements often mean the publication has negotiated some kind of payment for featuring products in its editorial coverage. Therefore, what you’re reading isn’t necessarily an independent evaluation of the product’s effectiveness.

Get news that’s free, independent and based on evidence.

Rather than spending a lot of money on collagen supplements that promise to defy signs of ageing, smooth wrinkles and renew your skin, spend it on healthy food. You will get better value in terms of your health and well-being in the long-term.


Read more: What is a balanced diet anyway?


What does the science say?

Normal ageing is associated with loss of connective tissues within the skin, leading to a reduction in elasticity and development of wrinkles and creases.

A 2019 review of collagen supplements, conducted by US university researchers, found four of the five studies included had reported some degree of improvement in some skin variables.

This included improvements in: skin moisture and collagen density; skin hydration, wrinkling and elasticity; skin elasticity but not moisture content; and skin moisture, elasticity, wrinkles and roughness.


Read more: Wrinkles, liver spots, crows’ feet: what happens to our skin as we age?


Across the studies, closer scrutiny of the methods by the reviewers found many were rated as being of low methodological quality. The reviewers flagged a number of limitations of the studies. These included that the supplements differed across the trials, as did the types of people included in the studies, meaning you can’t compare results between trials.

It also wasn’t clear how the results translated to actual changes in skin appearance and whether this was noticeable to other people.

Amino acids needed to make collagen can be found in other foods containing protein. There’s no reliable evidence amino acids in collagen supplements speed up the process by which the body makes collagen.

What’s more, most of the studies were either fully or partly funded by cosmetic or supplement companies. This means the results of the research should be interpreted with caution, especially when the affiliation statement shows the study authors were also employed by the supplement manufacturer. Further high quality, independent research studies are needed.

What is collagen and where does it come from?

Collagen is the major structural protein in skin and other connective tissues such as cartilage, bone, tendons and ligaments.

It has a triple helix structure. Imagine three slinkies coiled around each other, and that’s roughly what collagen looks like.

Artistic depiction of collagen triple helix structure
An artistic depiction of the collagen triple helix structure. Collagen is the human body’s main structural protein. Shutterstock

The triple helix shape makes it very strong and flexible.

Vitamin C is essential for the chemical pathway that makes collagen in the body. Without adequate vitamin C, the collagen would be unstable, meaning the coils would unfurl, and you would develop scurvy.

Before you grab a bottle of collagen supplements, you may want to consider where it came from. Rich sources of collagen include pig skin, cattle hide, pork and cattle bones, tendons and cartilage, chicken cartilage and fish scales.


Read more: The skin is a very important (and our largest) organ: what does it do?


A complete diet is better value for money

A 2019 survey reported 37% of Australians spent up to A$20 a month on cosmetics and personal care, with 26% spending between $21-50 and 15% spending $51-200 a month.

A bottle of collagen supplements costs anywhere between roughly A$15-20 to over $100. Each capsule, or per serve, contains roughly between half a gram up to five grams of collagen.

By comparison, you can get better value for money by eating foods rich in protein like meat, chicken, fish, eggs, milk, cheese, nuts, tofu, dried beans and legumes. This will provide the amino acids your body needs to make collagen.

Because collagen would be unstable without vitamin C, it’s also important to regularly eat foods rich in it. Good sources include broccoli, Brussels sprouts, capsicum, tomatoes, spinach, kiwifruit, lemons and oranges.

Also aim to regularly eat foods rich in other nutrients needed to help keep skin healthy. This includes:

If you’re interested in recipes that are fast, inexpensive and designed to help promote healthier skin, check our No Money No Time website, which we developed at The University of Newcastle.

I asked hundreds of people about their biggest life decisions. Here’s what I learned

I asked hundreds of people about their biggest life decisions. Here’s what I learned

March 1, 2021 12.31pm AEDT

Author

  1. Adrian R. Camilleri Senior Lecturer in Marketing, University of Technology Sydney

Disclosure statement

Adrian R. Camilleri does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Partners

University of Technology Sydney

University of Technology Sydney provides funding as a founding partner of The Conversation AU.

View all partners

CC BY NDWe believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.

You make decisions all the time. Most are small. However, some are really big: they have ramifications for years or even decades. In your final moments, you might well think back on these decisions — and some you may regret.

Part of what makes big decisions so significant is how rare they are. You don’t get an opportunity to learn from your mistakes. If you want to make big decisions you won’t regret, it’s important you learn from others who have been there before.

There is a good deal of existing research into what people regret in their lives. In my current project, I decided to approach the problem from the other end and ask people about their life’s biggest decisions.

What are life’s biggest decisions?

I have spent most of my career studying what you might call small decisions: what product to buy, which portfolio to invest in, and who to hire. But none of this research was very helpful when, a few years ago, I found myself having to make some big life decisions.

Join 130,000 people who subscribe to free evidence-based news.

To better understand what life’s biggest decisions are, I recruited 657 Americans aged between 20 and 80 years old to tell me about the 10 biggest decisions in their lives so far.

Each decision was classified into one of nine categories and 58 subcategories. At the end of the survey, respondents ranked the 10 decisions from biggest to smallest. You can take the survey yourself here. (If you do, your answers may help develop my research further.)

Other fairly common big life decisions include starting a new job and perusing a degree. Less common, but among the highest ranked life decisions, include ending a life – such as that of an unborn child or a dying parent – and engaging in self-harm.

Of course, the results depend on who you ask. Men in their 70s have different answers than women in their 30s. To explore this data more deeply, I’ve built a tool that allows you to filter these results down to specific types of respondents.


Read more: How to help take control of your brain and make better decisions


What are life’s biggest regrets?

Much can also be learned about how to make good life decisions by asking people what their biggest regrets are. Regret is a negative emotion you feel when reflecting on past decisions and wishing you had done something differently.

In 2012, Australian caregiver Bronnie Ware wrote a book about her experiences in palliative care. There were five regrets that dying people told her about most often:

  • I wish I’d had the courage to live a life true to myself, not the life others expected of me
  • I wish I hadn’t worked so hard
  • I wish I’d had the courage to express my feelings
  • I wish I’d stayed in touch with my friends
  • I wish I had let myself be happier.

This anecdotal evidence has received support from more rigorous academic research. For example, a 2011 study asked a nationally representative sample of 270 Americans to describe one significant life regret. The six most commonly reported regrets involved romance (19.3%), family (16.9%), education (14.0%), career (13.8%), finance (9.9%), and parenting (9.0%).

Although lost loves and unfulfilling relationships were the most common regrets, there was an interesting gender difference. For women, regrets about love (romance/family) were more common than regrets about work (career/education), while the reverse was true for men.

What causes regret?

Several factors increase the chances you will feel regret.

In the long run it is inaction — deciding not to pursue something — that generates more regret. This is particularly true for males, especially when it comes to romantic relationships. If only I had asked her out, we might now be happily married.

Poor decisions produce greater regret when it is harder to justify those decisions in retrospect. I really value my friends and family so why did I leave them all behind to take up that overseas job?

Given that we are social beings, poor decisions in domains relevant to our sense of social belonging — such as romantic and family contexts — are more often regretted. Why did I break up my family by having a fling?

Regrets tend to be strongest for lost opportunities: that is, when undesirable outcomes that could have been prevented in the past can no longer be affected. I could have had a better relationship with my daughter if I had been there more often when she was growing up.

The most enduring regrets in life result from decisions that move you further from the ideal person that you want to be. I wanted to be a role model but I couldn’t put the wine bottle down.

Making big life decisions without regrets

These findings provide valuable lessons for those with big life decisions ahead, which is nearly everyone. You’re likely to have to keep making big decisions over the whole course of your life.

The most important decisions in life relate to family and friends. Spend the time getting these decisions right and then don’t let other distractions — particularly those at work — undermine these relationships.

Seize opportunities. You can apologise or change course later but you can’t time travel. Your education and experience can never be lost.


Read more: Running the risk: why experience matters when making decisions


Avoid making decisions that violate your personal values and move you away from your aspirational self. If you have good justifications for a decision now, no matter what happens, you’ll at least not regret it later.

I continue to ask people to tell me about their biggest life decisions. It’s a great way to learn about someone. Once I have collected enough stories, I hope to write a book so that we can all learn from the collective wisdom of those who have been there before.

Dieting may slow metabolism – but it doesn’t ruin it

Dieting may slow metabolism – but it doesn’t ruin it

February 17, 2021 12.38am AEDT

Authors

  1. Adam Collins Principal Teaching Fellow, Nutrition, University of Surrey
  2. Aoife Egan PhD Researcher, Mathematical Modelling of Weight-loss, University of Surrey

Disclosure statement

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

Partners

University of Surrey

University of Surrey provides funding as a founding partner of The Conversation UK.

View all partners

CC BY NDWe believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
Healthy fruits and vegetables on a scale with a knife and fork on either side.
The body slows your metabolism on purpose to prevent weight loss. Gts/ Shutterstock

When it comes to dieting, research shows the majority of people will regain some – if not most – of the weight they’ve lost. While there are many reasons why this weight regain may happen, some popular claims online are that it’s because dieting permanently wrecks your metabolism. But while it’s true that dieting slows your metabolism, it also improves your metabolism in many positive ways.

When we talk about metabolism, we’re typically referring to your metabolic rate. This is the number of calories your body burns at rest. Of course, the more activity we do, the more calories we burn. In order to lose weight through dieting, you need to consume fewer calories than you’re using. This forces the body to use its energy stores – like fat – to meet the shortfall. Your metabolic rate will also change as a result.

The loss of lean tissue (muscle) when you diet – which burns around 15-25 calories per kilogram each day – lowers resting metabolic rate, meaning you need fewer calories than you previously did. But the body also deliberately slows down metabolism to preserve energy stores and minimise weight loss.

When the body senses depleted fat stores it triggers adaptive thermogenesis, a process which further reduces resting metabolic rate – and may stunt weight loss despite strict dieting. Adaptive thermogenesis can kick in within three days of starting a diet, and is suggested to persist way beyond dieting – even hampering weight maintenance and favouring weight regain.

Get your news from people who know what they’re talking about.

One example of adaptive thermogenesis’s effect was seen in a widely publicised 2016 study which looked at former contestants of US reality TV show “The Biggest Loser”. It showed that participants had a significant decrease in their metabolic rate, even several years after initial weight loss. Participants needed to eat up to 500 calories less than expected daily.

Other studies have also shown metabolic slowing with weight loss, but with much smaller decreases (around 100 calories fewer a day to maintain weight). However, there’s less certainty whether this slowing persists once people are weight stable.

A man fills out a diet plan.
Adaptive thermogenesis may stunt weight loss – even if you follow a strict diet. Rawpixel.com

Research seems to show that most adaptive thermogenesis happens in the actual dieting phase as a temporary response to the amount of weight being lost. Overall, we don’t have conclusive evidence to support the notion that metabolic rate remains slowed over the long term (over a year post-diet).

It’s worth noting many factors can affect metabolic rate, so changes to it after dieting may vary between people. For example, one study on fasting diets showed metabolic rate indeed decreases as a result – but those who had the the greatest decrease in metabolic rate already had a higher metabolic rate to begin with. Overestimaing metabolic rates at the start of a study or errors in predicting metabolic rate after weight loss could both also affect study results.

It’s agreed that metabolic rate slows because of weight loss, due to both decreasing body size, and as a way of preserving key tissues and fuel reserves. But there’s currently no consensus on how much it slows by. Quantifying and predicting this slowing is something we’re currently researching at the University of Surrey.

Metabolic changes

A decrease in metabolic rate is just one change that occurs with weight loss, however.

When we lose weight, the main change we see is a decrease in body fat. This decrease is actually our fat cells shrinking in size – they don’t actually disappear. This shrinking of fat cells signals the body’s fuel stores are emptying, causing a drop in the hormone leptin. Ordinarily leptin inhibits appetite and increases metabolic rate – but when leptin levels plumment, metabolic rate slow and hunger increases.

The gut also releases fewer incretins (hormones which regulate appetite) when we lose weight, which could persist beyond dieting. Less leptin and fewer incretins may make us feel hungrier and can lead to over eating.

When fat cells shrink, they’re able to take up glucose and store fat more efficiently to help restore lost fuel. Your body also creates more fat cells so that you can store more fat in the future to better cope with this calorie “crisis” the next time it happens.

But as contradictory as it sounds, all these changes actually result in a more efficient and ultimately healthier metabolism. For example, smaller fat cells are better for our health, as over-inflated “sick” fat cells don’t work as well in getting rid of surplus sugar and fat. This can lead to high levels of sugar and fat in the blood, increasing risk of insulin resistance, diabetes, and cardiovascular disease.

So dieting doesn’t technically ruin your metabolism but rather improves it by helping it work better. But without care, this metabolic improvement can conspire against you to regain the weight, and even overshoot your original weight.

Studies show exercise (or simply physical activity) may be one way to prevent weight regain, by improving our ability to maintain our weight and can potentially minimise metabolic slowing. Exercise can also help regulate appetite and fuel burning in the short term, and may make weight loss more sustainable in the long term.

Having trouble sleeping? Here’s the science on 3 traditional bedtime remedies

Shutterstock

Having trouble sleeping? Here’s the science on 3 traditional bedtime remedies

February 23, 2021 5.31pm AEDT

Authors

  1. Nenad Naumovski Associate Professor in Food Science and Human Nutrition, University of Canberra
  2. Amanda Bulman PhD Candidate, University of Canberra
  3. Nathan M D’Cunha PhD Candidate, University of Canberra
  4. Wolfgang Marx Postdoctoral research fellow, Deakin University

Disclosure statement

Nenad Naumovski has received a funding from Capitol Chilled Foods Australia (Canberra Milk) that was registered with the University of Canberra (Reg: UC:R00140).

Wolfgang Marx is currently funded by an Alfred Deakin Postdoctoral Research Fellowship and a Multiple Sclerosis Research Australia early-career fellowship. Wolfgang has previously received funding from the NHMRC, Clifford Craig Foundation, Cancer Council Queensland and university grants/fellowships from La Trobe University, Deakin University, University of Queensland, and Bond University, received industry funding and has attended events funded by Cobram Estate Pty. Ltd, received travel funding from Nutrition Society of Australia, received consultancy funding from Nutrition Research Australia, and has received speakers honoraria from The Cancer Council Queensland and the Princess Alexandra Research Foundation. The Food & Mood Centre has received Grant/Research support from the Fernwood Foundation, Wilson Foundation, the A2 Milk Company, and Be Fit Foods

Amanda Bulman and Nathan M D’Cunha do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

Partners

Deakin University
University of Canberra

Deakin University and University of Canberra provide funding as members of The Conversation AU.

View all partners

CC BY NDWe believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.

Sleep is essential for good health. Poor sleep quality, or not enough sleep, can negatively affect our mood, cognitive function, and immune system.

Stress can impact our sleep, and stress and anxiety associated with the COVID pandemic have meant many of us are not sleeping as well as we used to. A survey of 2,555 people across 63 countries found 47% of people were experiencing poorer sleep than usual during the pandemic, compared with 25% before COVID hit.

We also know stress is associated with poor dietary habits. People who are feeling stressed and tired may be more likely to reach for energy drinks and caffeinated beverages. But a high intake of caffeine as well as sugar-sweetened and energy drinks can keep us awake. So it’s something of a vicious cycle.

Similarly, people who are feeling stressed may be more likely to drink alcohol. Alcohol before bed, especially in excess, can also disrupt our sleep.

Forget Facebook and get your news straight from experts.

So what can you drink to improve your sleep?

Chamomile

Chamomile tea has been used in traditional medicine for centuries to treat a range of sleep ailments, such as insomnia.

The plant extract contains apigenin, a chemical compound that binds to the same receptors in the brain as benzodiazepines (drugs used to treat anxiety and insomnia), producing a sedative effect.


Read more: Can’t sleep and feeling anxious about coronavirus? You’re not alone


Studies have shown chamomile (consumed in the form of an extract or a tea) leads to significant improvement in sleep quality.

However, although the evidence is positive, these studies were relatively small and we need larger, well-designed clinical trials to reinforce these observations.

A pot of chamomile tea.
If you’re having trouble sleeping, it might be worth trying a cup of chamomile tea before bed. Irene Ivantsova/Unsplash

Milk

A warm cup of cow’s milk is a popular bedtime beverage in Western cultures, particularly for children.

Milk is a source of the essential amino acid tryptophan, which our bodies need to produce compounds including serotonin and melatonin in the brain. These compounds are involved in the sleep-wake cycle, which could explain why milk helps us sleep better — if indeed it does.

Scientists have studied the effects of milk and milk products (such as yogurt and cheese) on sleep quality for decades, but the evidence is still inconclusive.

It may simply be the ritual of drinking warm milk before bedtime that relaxes the brain and body, rather than the effects of compounds present in the milk itself. We’ll need more research evidence before we can be confident one way or the other.


Read more: Get headaches? Here’s five things to eat or avoid


Cocoa

Hot cocoa (commonly dissolved in milk) is also regarded as a sleep-promoting drink. The cocoa bean is a rich source of many beneficial chemicals, including compounds called flavonoids.

Flavonoids have a range of potential health benefits, and may be used to treat some neurodegenerative disorders.

There’s limited research on the effects of cocoa on sleep quality. But a study in mice suggested natural cocoa may improve stress-induced insomnia.

In humans, consuming cocoa is associated with a reduction in blood pressure (in healthy people and those with high blood pressure). This lowering of blood pressure, which relaxes the smooth muscles that line our arteries, could produce a calming effect, making it easier to go to sleep.

A man sits on the couch reading a newspaper, with a mug in hand.
Some people like to drink a glass of milk or a cup of cocoa before bed. Shutterstock

While these sleep remedies are unlikely to be harmful, the overall evidence on improvement in quality of sleep is weak. You may like to try them, but you shouldn’t see any of them as a quick fix.

At the end of the day, several lifestyle factors can influence our sleep quality, including screen time, physical activity, stress and diet.

If you are consistently struggling to sleep, it’s best to consult with your general practitioner.