Even a 10-minute run is enough to have a positive effect on mood, new research shows. Photo / 123RF
Is there a right time to hit the hay? Is a low amount of booze good or bad for you? And can a quick run lift your mood? We look at new insights from eight recent studies from New Zealand and around the world.
The brain perks of caffeine
For many of us, it's a Monday morning crutch: but now scientists think caffeine may have more benefits for your brain than just helping you get through the workday.
A recent study of more than 365,000 people in the UK, aged 50 to 74, found sipping a daily combination of two to three cups of coffee, or two to three cups of tea, was linked with a 32 per cent lower risk of stroke and a 28 per cent lower risk of dementia.
Of note for latte-lovers, coffee was specifically linked to less risk of post-stroke dementia.
"Our findings suggested that moderate consumption of coffee and tea separately or in combination were associated with lower risk of stroke and dementia," said the study's authors, from China's Tianjin Medical University and Yale University in the US.
The authors point out their study suggests the links are possible, and not causal - but may still be useful for prevention.
Strokes are life-threatening events which cause around 10 per cent of deaths globally, while dementia is a general term for symptoms related to decline in brain function.
A daily dollop of yogurt is a heart helper
Whether it's a dollop on your morning cereal or a simple snack on the go, a daily dose of yoghurt could be the next go-to food for people with high blood pressure.
A new study by US and Australian researchers looked at links between yogurt intake, blood pressure and cardiovascular risk factors, finding that yogurt is associated with lower blood pressure for those with hypertension.
Globally, more than a billion people suffer from high blood pressure, putting them at greater risk of cardiovascular diseases like heart attack and stroke, and a leading cause of death here and worldwide.
"High blood pressure is the number one risk factor for cardiovascular disease, so it's important that we continue to find ways to reduce and regulate it," said study author Dr Alexandra Wade, from the University of South Australia.
"Dairy foods, especially yogurt, may be capable of reducing blood pressure."
That was because dairy foods packed a range of micronutrients, including calcium, magnesium and potassium - all of which are involved in the regulation of blood pressure.
"Yogurt is especially interesting because it also contains bacteria that promote the release of proteins which lowers blood pressure," Wade said.
The study, conducted with a sample of 915 US adults, showed for people with elevated blood pressure, even small amounts of yogurt were associated with lower blood pressure.
"And for those who consumed yoghurt regularly, the results were even stronger, with blood pressure readings nearly seven points lower than those who did not consume yoghurt."
A sunny solution for cardio health
Free from the sun, vitamin D delivers a natural source for one of the hormones essential to our bodies, especially the bones.
But when you're down on this essential nutrient, it's not only your bones that could suffer, but also your cardio health.
In the first study of its kind, researchers from the University of South Australia identified genetic evidence for a role of vitamin D deficiency in causing cardiovascular disease.
It showed that people with vitamin D deficiency were more likely to suffer from heart disease and higher blood pressure, than those with normal levels of vitamin D.
For participants with the lowest concentrations the risk of heart disease was more than double that seen for those with sufficient concentrations.
Low concentrations of vitamin D are common in many parts of the world, with data from the UK Biobank showing that 55 per cent of participants have low levels of vitamin D and 13 per cent have severe deficiency.
"Severe deficiency is relatively rare, but in settings where this does occur it is very important to be proactive and avoid negative effects on the heart," study lead author Professor Elina Hyppönen said.
"For example, deficiency can be a problem for people living in residential care who may have limited exposure to sun."
We can also get vitamin D from food, including oily fish, eggs and fortified foods and drinks.
"This said, food is unfortunately a relatively poor source of vitamin D, and even an otherwise healthy diet does not typically contain enough."
Why a quick run is a mood-booster
Taking a regular run is obviously great for physical health – but what about our mental health?
Researchers from Japan's University of Tsukuba have found that only 10 minutes of running is enough to boost blood flow to the part of the brain that plays a key part in controlling mood and executive functions.
Running has always played an important role in the well-being of humans, and is likely linked to our species' evolutionary success.
Despite this, researchers previously hadn't looked closely at the effects of running on brain regions that control mood and executive functions.
To test their hypothesis, the research team used the well-established Stroop Color-Word Test and captured data on hemodynamic changes associated with brain activity while participants were engaged in each task.
The results demonstrated that, after 10 minutes of moderate-intensity running, there was a significant boost to activity in the bilateral prefrontal cortex, and participants reported being in a better mood.
Given that many characteristics of the human prefrontal cortex were uniquely human, the study not only shedded light on the present benefits of running - but also on the possible role that these benefits may have played in the evolutionary past of humans.
Strength training can burn fat too
It's basic exercise knowledge that to gain muscles, you strength train, and to lose fat, you do cardio – right?
Not necessarily.
In fact, an Australian study – a systematic review and meta-analysis that reviewed and analysed existing evidence – shows we can lose around 1.4 per cent of our entire body fat through strength training alone, which is similar to how much we might lose through cardio or aerobics.
"A lot of people think that if you want to lose weight, you need to go out and run," said study author Dr Mandy Hagstrom, of the University of New South Wales.
"But our findings show that even when strength training is done on its own, it still causes a favourable loss of body fat without having to consciously diet or go running."
Up until now, the link between strength training and fat loss has been unclear.
Studies have investigated this link in the past, but their sample sizes tend to be small – a side effect of not many people wanting to volunteer to exercise for months on end.
In their analysis, Hagstrom and colleagues pulled together findings from 58 research papers that used highly accurate forms of body fat measurement to measure the outcomes from strength training programmes.
While the strength training programmes differed between the studies, the participants worked out for roughly 45 to 60 minutes each session for an average of 2.7 times per week.
The team found that, on average, the participants lost 1.4 per cent of their total body fat after their training programmes, which equated to roughly half a kilogram in fat mass for most participants.
While the findings are encouraging for fans of pumping iron, Hagstrom said the best approach for people aiming to lose fat was still to stick to eating nutritiously - and have an exercise routine that included both cardio and strength training.
Is there an optimal bedtime?
Going to sleep between 10pm and 11pm may come with a lower risk of developing heart disease, compared with earlier or later bedtimes.
While there have been plenty of analyses looking at the link between sleep duration and cardiovascular disease, there's still much scientists have to learn.
In a recent study, researchers from the UK's University of Exeter examined the association between objectively measured - rather than self-reported - sleep onset in a sample of more than 80,000 adults.
Data on sleep onset and waking up time were collected over seven days using a wrist-worn accelerometer, and participants completed a range of assessments and questionnaires.
They were then followed up for a new diagnosis of cardiovascular disease, which was defined as a heart attack, heart failure, chronic ischaemic heart disease, stroke, and transient ischaemic attack.
Just under six years later, around 3.6 per cent of participants developed cardiovascular disease – and incidence was highest among those with sleep times at midnight or later - and lowest in those with sleep onset from 10pm to 10.59 pm.
As an extra measure, the researchers adjusted their results for a host of factors including age, sex, physical health and sleep duration and irregularity.
Compared to sleep onset from 10pm to 10.59 pm, they found there was a 25 per cent higher risk of cardiovascular disease with a sleep onset at midnight or later, a 12 per cent greater risk for 11pm to 11.59pm - and a 24 per cent raised risk for falling asleep before 10pm.
In a further analysis by sex, the link with increased cardiovascular risk was stronger in women, with only sleep onset before 10pm remaining significant for men.
"Our study indicates that the optimum time to go to sleep is at a specific point in the body's 24-hour cycle and deviations may be detrimental to health," study author Dr David Plans said.
"The riskiest time was after midnight, potentially because it may reduce the likelihood of seeing morning light, which resets the body clock."
He concluded: "While the findings do not show causality, sleep timing has emerged as a potential cardiac risk factor – independent of other risk factors and sleep characteristics.
"If our findings are confirmed in other studies, sleep timing and basic sleep hygiene could be a low-cost public health target for lowering risk of heart disease."
The perception that low or moderate drinking can have health benefits has been grounded in studies that linked abstaining from alcohol with earlier death, compared to modest indulging.
A recent long-term study delved into the links between booze and health, using death data 20 years after the same participants were interviewed about their drinking.
"It has long been assumed that low to moderate alcohol consumption might have positive effects on health based on the finding that alcohol abstainers seemed to die earlier than low to moderate drinkers," said study author Dr Ulrich John, of Germany's University Medicine Greifswald.
The researchers used data on a random sample of 4,028 German adults who had participated in a standardised interview conducted between 1996 and 1997, when participants were 18 to 64 years old.
"We found that the majority of the abstainers had alcohol or drug problems, risky alcohol consumption, daily tobacco smoking or fair to poor health in their history, [such as] factors that predict early death."
The study authors said their results supported the view that people in the general population who currently were abstinent from alcohol didn't necessarily have a shorter survival time than the population with low to moderate alcohol consumption.
"The findings speak against recommendations to drink alcohol for health reasons."
Do deadlines work?
They say procrastination is the thief of time – but it may be that deadlines are.
Otago University researchers have found that, if you want someone to help you out with something, it's best not to set a deadline at all.
But if you do set a deadline, make it short.
In their study, Otago's Professor Stephen Knowles tested the effect of deadline length on task completion for their research published in Economic Inquiry.
Participants were invited to complete an online survey in which a donation goes to charity, and given either one week, one month, or no deadline to respond.
The study found responses to the survey were lowest for the one-month deadline, and highest when no deadline was specified.
No deadline and the one-week deadline led to many early responses, while a long deadline appeared to give people permission to procrastinate, and then forget.
Knowles wasn't surprised to find that specifying a shorter deadline increased the chances of receiving a response compared to a longer deadline.
However, he did find it interesting that they received the most responses when no deadline was specified.
"We interpret this as evidence that specifying a longer deadline, as opposed to a short deadline or no deadline at all, removes the urgency to act, which is often perceived by people when asked to help," he said.
"People therefore put off undertaking the task, and since they are inattentive or forget, postponing it results in lower response rates."