Tuesday, 25th Jul 2017

Category Archive: Health News

‘Buying time’ and not just things may increase life satisfaction

“Using money to free-up time is linked to increased happiness,” BBC News reports. Researchers surveyed people from a number of developed countries and found those who reported using money to free up time, such as hiring a cleaner, tended to report higher life satisfaction.

Researchers surveyed more than 6,000 participants from the US, Canada, Denmark and The Netherlands, including around 800 Dutch millionaires, about “buying time” – which was defined as paying people to do chores that participants personally found unenjoyable. Researchers found that, regardless of income, people who bought time reported better life satisfaction.

A further small experiment found that spending money on time-saving purchases rather than material goods such as wine and clothes was associated with increased happiness and positive feelings and reduced feelings of “time stress”.

However, due to the complex web of factors that affect our wellbeing, it is difficult to say that this study proves that “buying time” makes you more satisfied with your life.

Prioritising time over money and material goods may well be one route to happiness, but it may not work for everyone.

Of course not everyone can afford to hire a cleaner (or in the case of a Dutch millionaire, a butler). However there are techniques you can use that may help you manage your time more effectively.

Read more advice about time management.

 

Where did the story come from?

The study was carried out by researchers from Harvard Business School in the US, University of British Columbia in Canada, and Maastricht University and Vrije Universiteit Amsterdam, both in The Netherlands.

The study was funded by Public Scholars Initiative at the University of British Columbia, the Social Sciences and Humanities Research Council of Canada, the Society for Personality and Social Psychology Heritage Foundation, and the Society for Personality and Social Psychology Q&pAy Initiative.

The study was published in the peer-reviewed medical journal PNAS on an open-access basis, meaning it is freely available online.

The UK media’s reporting of the study’s findings wasn’t accurate, as it failed to point out that the study is not able to prove cause and effect. There could have been multiple other reasons why some people reported greater life satisfaction.

For example, the headline in the print edition of the Daily Mail: “The secret behind true happiness? Hire a cleaner” is not representative of the findings of the study.

 

What kind of research was this?

This research involved multiple cross-sectional studies using questionnaires. There was also a small experimental study, randomising people to spend $40 (around £30 at time of writing) on material goods one weekend and time-saving purchases another weekend and then asking them about their level of stress and happiness.

Using a questionnaire is a good way of including a lot of people and in this case allowed researchers to easily look at participants’ answers from four countries. However, this can only tell us what their levels of perceived happiness and satisfaction are in relation to the “ladder of life rung” they are on at one time point. It is likely other factors such as job, relationships and health status would have more of an effect on these perceptions, but none of these were taken into account.

The additional experimental component added little weight to their argument as again they did not take into account any other potential confounding factors.

 

What did the research involve?

Researchers carried out questionnaires with 6,271 participants from the US, Canada, The Netherlands (including a sample of 800 millionaires) and Denmark to investigate the effect of buying time on life satisfaction. They also conducted an experimental study to test the results of the questionnaire.

The researchers firstly carried out surveys involving questions about how much money, if any, people spend every month to free up their time by paying someone else to complete daily tasks they do not find enjoyable. They were also asked about their satisfaction with life through two questions: “Taking all things together, how happy would you say you are?”, and where they currently stand on a ladder spanning from the worst possible to best possible life imaginable.

Participants also answered questions on potentially confounding factors, including:

  • annual household income
  • number of hours worked each week
  • age
  • marital status
  • number of children living at home
  • the amount spent on groceries, material and experiential purchases (buying an “experience” such as a night out at the theatre), to account for the fact that decisions to spend money on time-saving purchases might be a reflection of income

In the Canadian and Dutch surveys, participants also reported a measure of “time stress”. This includes stating how much they agreed with statements such as “I feel pressed for time today”, “Compared to yesterday, I feel more stressed out about my time”, and “Time is my scarcest resource”.

The researchers then carried out an experiment on 60 Canadian working adults. They were asked to spend the equivalent of £30 on two consecutive weekends; on one weekend they were randomly assigned to purchase something that would save them time and on the other weekend, a material purchase.

After making each purchase, participants received a phone call at 5pm to report their feelings of positive or negative mood and time stress on that particular day.

 

What were the basic results?

Across samples from all included countries, 28.2% of participants spent money to buy themselves time each month with a mean spend of $147.95 US dollars per month in those who “bought time”.

When controlling for variables, those who spent money in this way reported slightly better life satisfaction than those who did not. This effect was not altered by wealth or income.

The researchers then considered a broader definition of time-saving purchases, to cover any way a respondent might spend money to provide more free time.

Of a sample of 1,802 US working adults, 50% reported spending money in this way, with most buying their way out of cooking, shopping and household maintenance.

Again, when controlling for variables, those who spent money in this way reported slightly better life satisfaction, when controlling for the amount spent on groceries, material goods and experiences.

In the experiment phase of the research:

  • Participants reported a greater end of the day positive mood on a 12-item scale after making a time-saving purchase versus material purchase.
  • Participants reported a lower end of the day negative mood on a 12-item scale after making a time-saving purchase versus material purchase.
  • Participants reported lower feelings of time stress after making a time-saving purchase versus material purchase.

 

How did the researchers interpret the results?

The researchers concluded that “across several distinct samples, including adults from Canada, the United States, Denmark, The Netherlands, and a large sample of Dutch millionaires, buying time was linked to greater life satisfaction. These results held controlling for a wide range of demographics, as well as for the amount that respondents spent on groceries and material and experiential purchases each month. These results were not moderated by income, suggesting that people from various socioeconomic backgrounds benefit from making time-saving purchases.”

 

Conclusion

This large multi-country study on adults of various incomes found that buying time was linked to greater life satisfaction, even when considering a wide range of demographics and spend on other items each month. It also seemed to show that people were in a better mood when buying something that saved them time versus buying something material.

These results are interesting in the busy, time-pressured culture many of us face today. The researchers suggest using money to buy time may reduce feelings of time pressure and buffer against negative effects of time pressure on life satisfaction.

While this may be the case, before you start giving up all household chores, you might want to consider some limitations to the research:

  • These were mainly cross-sectional studies with responses given at one time point. This means they cannot show that paying people to do tasks for you improves life satisfaction or happiness. Both will be dependent on a variety of factors that were not taken into account, such as employment, work/life balance, social situation, family life, personality and health status.
  • For the small experimental study, the researchers did not look at what other activities or events were occurring on those two particular weekends that may have affected mood and stress levels rather than what they had purchased. In addition, the participants knew what the money was being spent on, which could have biased the results.
  • Participants self-reported their activities. It might be that not all wanted to admit that they pay other people for housework.
  • Participants also self-reported life satisfaction. People might want to seem like they are happier with their life to justify paying someone to do housework, which might not necessarily be the case.
  • As the results showed, the question around paying money to free up time is subjective – some people might include paying for a ready-made lunch in this category whereas others might just think of paying other people to do housework as fitting into this definition.
  • The median age in the millionaires category was 68 compared with 30 in one of the US samples. This variation in age, as well as other factors such as number of children in the household, might mean people have different amounts of time to spend doing household chores so might be more or less stressed at the prospect of doing such activities.

If you are feeling “time stressed” there are time management techniques that can help as well as ways to help relieve feelings of stress.

Links To The Headlines

Time, not material goods, ‘raises happiness’. BBC News, July 25 2017

Money CAN buy you happiness, as long as you spend it on time-saving luxuries: Forget trying to ‘do it all’ and spend cash on a cleaner or cook as it will give you greater life satisfaction. Mail Online, July 24 2017

Money can buy you happiness, claim researchers. The Independent, July 24 2017

Links To Science

Whillans AV, Dunn EW, Smeets P, et al. Buying time promotes happiness. PNAS. Published online June 24 2017

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Snoring link to Alzheimer’s disease unproven

“Snoring linked to Alzheimer’s,” the Mail Online reports. A US study reported an association between sleep-disorder breathing and Alzheimer’s disease in later life. But no definitive link between the two has been proven.

Sleep-disordered breathing is a general term to describe pauses in breathing during sleep that restrict oxygen supply to the body. At the most severe end of the spectrum is obstructive sleep apnoea, which can itself range in severity.

In this latest study, researchers looked at data regarding sleep in 1,750 middle aged and older adults. They then looked at whether problems with sleep breathing were associated with their performance in cognitive testing.

Researchers in the current study found a link between certain measures of sleep-disorder breathing and worse attention, short term memory and information processing speed. However, there was no link with overall cognitive function (which also includes aspects such as language, judgement, fluency of speech and visual thinking). The reason for this was unclear but it suggests the evidence of any link is inconclusive.

Some of the links were stronger in people who carried a form of a gene called APOE-e4, which is a known genetic risk factor for Alzheimer’s.

In conclusion, this study does not prove that sleep-disorder breathing is a risk factor for Alzheimer’s disease. This study did not specifically look at whether people developed dementia or not. It only looked at their performance on cognitive tests at a single point in time.

These limitations aside, it is important to see your GP for a diagnosis if you suspect you may have sleep apnoea. Left untreated, sleep apnoea may increase the risk of more serious conditions, such as heart attack and stroke.

 

Where did the story come from?

The study was carried out by researchers from Brigham and Women’s Hospital (Boston), Harvard Medical School, Beth Israel Deaconess Medical Center (Boston), University of Washington, Wake Forest School of Medicine, US Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, and Stanford University School of Medicine. It was funded by the National Heart, Lung, and Blood Institute in the US.

The study was published in the peer-reviewed medical journal Annals of the American Thoracic Society. Both the Mail and The Sun suggest a link between snoring and Alzheimer’s has been found, but this is not the case. A cohort study analysis, where people are assessed for dementia over the course of many years, would be a better way to look at the question.

Also, while it looked at performance on cognitive tests it did not investigate whether people went on to develop dementia. The media also did not mention that it’s not possible to say from this type of study whether the breathing problems during sleep are actually the cause of the problems with brain function, because both were measured at around the same time. They also didn’t mention that the size of the effect of sleep problems on brain function was small.

 

What kind of research was this?

This was a cross-sectional analysis of data from the ongoing Multi-Ethnic Study of Atherosclerosis (MESA) cohort study in the US. The main goal of MESA is to look at how various lifestyle factors impact on the risk of developing atherosclerosis (hardening of the arteries).

The researchers aimed to see if breathing problems during sleep (sleep-disordered breathing or SDB) were associated with problems in brain functions such as attention and memory. The researchers say that previous studies examining this question have had mixed findings – some showing a link and others not.

They also looked at whether the presence of a variant of the apolipoprotein-E gene called e4 (APOE-e4) also affected the risk of developing problems with brain function. The APOE-e4 variant is a known risk factor for Alzheimer’s disease. The Alzheimer’s Society report that people with one copy of the variant gene have twice the risk of developing Alzheimer’s disease compared to the population at large.

While a cross-sectional analysis can identify a link between two different factors, it cannot prove that one causes the other, as we can’t be sure which factor came first. Links identified using this type of study need to be followed up by studies that can identify the sequence of events.

 

What did the research involve?

Researchers analysed sleep and brain function data from participants of the MESA study They looked at whether people with breathing problems during sleep had poorer performance on cognitive tests.

The MESA study involved adults aged between 45 and 84 years old. Study participants underwent a sleep study at home. This involved attaching various monitors to their body overnight to record:

  • episodes of shallow breathing (called hypopneas)
  • episodes of stopping breathing completely (called apnoeas)
  • the levels of oxygen in the blood (oxygen saturation) – as sleep breathing problems can reduce these levels
  • the total time of sleeping
  • the timing of the different stages of sleep

The participants also filled out the Epworth Sleepiness Scale (ESS) questionnaire, which asks various questions to assess whether someone has excessive sleepiness during the day. The minimum score is 0 (no daytime sleepiness) and the maximum score is 24 (most daytime sleepiness).

For each participant the researchers calculated the:

  • apnoea-hypopnea index (AHI) – a measure of how many apnoea and hypopnea episodes a person has per hour of sleep
  • percentage of time during sleep when the oxygen levels in their blood were under 90%

Participants with an AHI score of 15 or more were considered to have moderate to severe sleep disordered breathing. People with an AHI of five or more, and an ESS score of more than 10 were considered to have sleep apnoea.

The cognitive assessment involved three tests that assessed:

  • overall brain function, including areas such as attention, concentration, short and long-term memory and language using the Cognitive Abilities Screening Instrument
  • how quickly the brain could perform tasks (processing speed) and attention using the Digit Symbol-Coding test
  • memory and attention using the Digit Span Test (DST)

The researchers also carried out genetic testing to identify participants with at least one APOE-e4 gene variant (an Alzheimer’s “risk gene”).

They then compared the cognitive performance of people with the quality of breathing during sleep. They looked at whether results were any different for those people with the APOE-e4 variant. The researchers took into account a number of factors that could affect the results (potential confounders) in their analysis, including:

  • race
  • age
  • body mass index (BMI)
  • level of education
  • smoking
  • high blood pressure
  • depression
  • use of benzodiazepines (a class of drugs used as sleeping pills and tranquilisers)
  • diabetes

 

What were the basic results?

The sleep studies showed that 9.7% of the participants had sleep apnoea, and 33.4% had moderate to severe sleep disordered breathing.

There was no association between AHI score and any of the cognitive outcomes. There was also no link between any of the sleep breathing measures and one of the more challenging cognitive tests used (The DST Backward), or with the test of overall brain function.

Lower oxygen levels in the blood and being more sleepy during the daytime were associated with a small reduction in attention and short-term memory on one cognitive test (the DST Forward). Having sleep apnoea and greater daytime sleepiness were also associated with small reductions in attention and the speed that the brain could process simple mental tasks on another cognitive test.

Some – but not all – of these links were stronger in people carrying at least one copy of the e4 form of the APOE gene (the links were between having lower levels of oxygen in the blood and poorer attention and memory, and between greater daytime sleepiness and poorer attention and speed of brain processing).

 

How did the researchers interpret the results?

The researchers concluded that their results “suggest that more severe overnight [low blood oxygen levels] and sleepiness may be related to poorer cognitive function, especially attention, concentration, and process speed in middle-aged to older adults, and that the risk is greater among carriers of the APOE-ε4 alleles, a known risk factor for Alzheimer’s disease.”

 

Conclusion

This relatively large cross-sectional analysis has found a link between certain measures of breathing problems during sleep and poorer cognitive function in middle-aged to older adults.

The strengths of this study include its size and use of a prospective sleep study to assess whether people had sleep apnoea or other problems with breathing during sleep. The use of standard cognitive tests is also a strength.

However, the study does have its limitations:

  • The study did have mixed findings – while certain measures of problems with breathing during sleep (e.g. oxygen levels) were associated with cognitive outcomes, others (e.g. Apnea-Hypopnea Index) were not. This suggests that findings are not conclusive. In addition, previous studies have also had mixed results. This suggests that a systematic review which brings together all of the available evidence on this question would be helpful to assess whether, on balance, the research suggests a true link.
  • It’s not possible from this type of cross-sectional analysis to prove that breathing problems during sleep cause the differences in brain function seen. This is largely because it’s not possible to establish whether participants only developed problems with brain function after they experienced sleep breathing problems. It’s also difficult to be sure that the effect of all potential confounders has been removed.
  • The study measured brain function at one time point and did not assess whether people had (or went on to develop) dementia. Therefore we don’t know if the brain function differences were temporary or long lasting, whether it had any impact on the participants’ lives, or whether there is a link between problems with breathing during sleep and dementia.
  • Sleep was only assessed on one night and may not be indicative of longer term sleep breathing problems.
  • The participants were older and middle aged adults so it may not be possible to generalise these results to younger adults.

Some of the risk factors for sleep apnoea are similar to some of those for dementia. These include being overweight or obese, smoking, and drinking excessive amounts of alcohol.

So maintaining a healthy weight, giving up smoking, and limiting your alcohol intake are likely to reduce both your risk of developing sleep apnoea and dementia.

Links To The Headlines

Snoring linked to Alzheimer’s: Difficulty breathing while asleep accelerates memory decline in people at-risk of the condition, reveals study. Mail Online, July 21 2017

Snoring can increase the chances of getting dementia in later life, new study reveals. The Sun, July 21 2017

Links To Science

Johnson DA, Lane J, Wang R, et al. Greater Cognitive Deficits with Sleep-Disordered Breathing among Individuals with Genetic Susceptibility to Alzheimer’s Disease: The Multi-Ethnic Study of Atherosclerosis. Annals of the American Thoracic Society. Published online July 21 2017

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Could cows be the clue that leads to an HIV vaccine?

“Cows have shown an ‘insane’ and ‘mind-blowing’ ability to tackle HIV which will help develop a vaccine, say US researchers,” BBC News reports.

The report is based on new research in cows that were immunised against HIV before having their immune response to HIV assessed. There’s currently no vaccine for HIV because the virus mutates so easily.

Scientists aim to develop a vaccine that is not only potent (produces a strong immune system response), but also causes the immune system to make “broadly neutralising antibodies” (able to protect against many different strains of virus).

The four cows in this study were immunised against HIV with a specially developed vaccine to test both strength and “breadth”. Some cows developed a weak response with reasonable breadth (20% – or it helped protect against 1 in 5 strains tested in the lab) at 42 days. One cow in particular showed an impressive immune response to most of the lab strains of HIV (“96% breadth”) 381 days after being vaccinated.

This research, done in a small number of cows, may help scientists work out if immune proteins made in cows could potentially be used to protect humans against a range of HIV strains.

While this is certainly welcome news, it doesn’t mean an effective HIV vaccine is guaranteed to appear in the future. The most effective way to protect yourself from HIV is to always use a condom during sex, including oral and anal sex. Men who have sex with other men are particularly at risk if they don’t practise safe sex.

Read more advice about HIV and gay health.

 

Where did the story come from?

The study was carried out by researchers from The Scripps Research Institute the International AIDS Vaccine Initiative, Texas A&M University, Kansas State University, and Ragon Institute of MGH, MIT and Harvard, all in the US.

The research was funded by various grants from the International AIDS Vaccine Initiative, the National Institutes of Health, the Centre for HIV/AIDS Vaccine Immunology and Immunogen Discovery and the US Department of Agriculture. The study was published in the peer-reviewed medical journal Nature.

The UK media reporting was generally accurate and made clear the research was carried out in cows and not humans. However, the Mail Online’s claim that “An injection may soon be available that prevents the virus spreading and could rid sufferers of the infection” is incredibly optimistic.

This research is at a very early stage and will need to be repeated and refined before testing in humans is considered. There is no imminent vaccine for HIV.

 

What kind of research was this?

This was an investigational laboratory study carried out using cows. Researchers attempted to immunise cows against HIV and assessed their response to the vaccine.

HIV infects the body’s immune system, causing progressive damage that eventually stops the body’s ability to fight off infection. The virus attaches itself to immune cells that protect the body against bacteria, viruses and other germs. Once HIV has attached itself, it enters the cell and uses it to create thousands of copies of itself. The copies then leave the original immune cell and kill it in the process.

The process continues until the number of immune cells is so low, the immune system stops working. This process can take as long as 10 years, during which time the person may feel and appear to be well.

Thankfully, due to medical advances, antiretroviral drugs are now available that help protect the immune system from further damage and prevent secondary infections.

 

What did the research involve?

Researchers aimed to immunise cows with a substance called an immunogen, which are designed to provoke an immune response.

In this study the researchers used an immunogen called BG505 SOSIP. This mimics the outside of the HIV virus to produce an immune response. Researchers were able to see if the immunogens were “broad” (could neutralise many different viral strains) and potent by measuring how long it took for the immune response to occur; the quicker the response the more potent a vaccine tends to be.

Researchers chose to look at cows because, unlike most animals, they have longer amino acid chains.  Amino acids are the “building blocks” of proteins. Previous research has found that a small proportion of people with HIV who develop a level of natural immunity to the virus also have similarly long amino acid chains.

Four six-month-old calves were immunised with the BG505 SOSIP immunogen and the researchers looked at the subsequent immune response.
 

What were the basic results?

All cows developed immune cells to HIV 35 to 50 days following two injections. One cow showed an immune response that could neutralise 20% of HIV strains tested in the lab in 42 days and another neutralised 96% of HIV strains in 381 days.

When analysing the proteins created as part of the immune response, the researchers found that one in particular binds to a key HIV site that the virus uses to infect cells.

 

How did the researchers interpret the results?

The researchers conclude that they “have shown that immunization with a well-ordered immunogen in cows reliably and rapidly elicits broad and potent neutralizing serum responses in contrast to previous experiments in other animals.”

 

Conclusion

This early stage research on cows indicates that they had a broad and quick immune response to HIV infection when given a specific vaccine. Because the immune proteins produced in cows are able to neutralise many different strains of HIV virus, the authors suggest this potentially gives them an edge over the human proteins that have been looked at so far.

As always with animal studies it is important to remember that what works in cows might not work in the same way in humans. Many drug studies that appear promising at first, fall at the first hurdle once humans are involved.

The study was also carried out on just four cows and the most promising finding – neutralisation of 96% of HIV strains in 381 days – was found in just one cow. It is therefore best seen as promising early research, rather than a proven cure.

While we all hope an HIV vaccine or cure may be on the horizon, until that time, using a condom during penetrative, oral and anal sex is the most effective method of preventing infection with HIV.

Links To The Headlines

‘Mind-blowing’ cows hold clue to beating HIV. BBC News, July 21 2017

Scientists may be one step closer to a cure for HIV: Injection prevents the virus spreading and could rid sufferers of the disease. Mail Online, July 21 2017

Links To Science

Sok D, Le KM. Vadnais M, et al. Rapid elicitation of broadly neutralizing antibodies to HIV by immunization in cows. Nature. Published online July 20 2017

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Nine lifestyle changes may reduce risk of dementia

“Nine lifestyle changes can reduce dementia risk,” BBC News reports. A major review by The Lancet has identified nine potentially modifiable risk factors linked to dementia.

The risk factors were:

  • low levels of education
  • midlife hearing loss
  • physical inactivity
  • high blood pressure (hypertension)
  • type 2 diabetes
  • obesity
  • smoking
  • depression
  • social isolation

However, it’s important to note that even if you add up the percentage risk of all of these factors, they only account for about 35% of the overall risk of getting dementia. This means about 65% of the risk is still due to factors you can’t control, such as ageing and family history.

Although not guaranteed to prevent dementia, acting on the risk factors above should improve your physical and mental wellbeing.

What is dementia?

Dementia refers to a group of symptoms associated with the gradual decline of the brain and its abilities. Symptoms include problems with memory loss, language and thinking speed.

The most common cause of dementia is Alzheimer’s disease. Vascular dementia is the next most common, followed by dementia with Lewy bodies.

For more information, visit the NHS Choices Dementia Guide.

Where did the review come from?

This review was written by the Lancet Commission on Dementia Prevention, Intervention and Care (LCDPIC). The commission is established by convening experts in the field to consolidate current and emerging evidence on preventing and managing dementia. It generates evidence-based recommendations on how to address risk factors and dementia symptoms. These are presented in this review.

The LCDPIC endeavoured to use the best possible evidence to make the recommendations. However, in cases where the evidence was incomplete, it summarised the balance of the evidence, drawing attention to the strengths and limitations.

The media in general has covered the review responsibly and accurately, with helpful comments from experts in the field.

What does the review say?

The review examines aspects of how better to manage the burden of dementia: the risk factors, interventions for prevention and interventions for treatment.

Risk factors

The LCDPIC discusses the effects of several different risk factors potentially linked to dementia.

The review reported population attributable fractions (PAFs). PAFs are an estimate of the proportion of cases of a certain outcome (in this case, dementia) that could be avoided if exposure to specific risk factors were eliminated – for example, how many lung cancer cases would be prevented if nobody smoked.

Using the available evidence, researchers calculated PAFs for the following risk factors.

Education

Less time in education – specifically, no secondary school education – was responsible for 7.5% of the risk of developing dementia.

Hearing loss

The relationship between hearing loss and the onset of dementia is fairly new. It’s thought that hearing loss may add stress to an already vulnerable brain with regard to the changes that occur. Hearing loss may also increase feelings of social isolation. However, it’s also possible that old age could have a role to play in this association.

The LCDPIC analysis found that hearing loss could be responsible for 9.1% of the risk of developing dementia.

Exercise and physical activity

A lack of physical activity was shown to be responsible for 2.6% of the risk of dementia onset. Older adults who do not exercise are less likely to maintain higher levels of cognition than those who do engage in physical activity.

Hypertension, type 2 diabetes and obesity

These three risk factors are somewhat interlinked; however, all had PAFs lower than 5%, with hypertension contributing the greatest risk of the three:

  • hypertension – 2%
  • type 2 diabetes – 1.2%
  • obesity – 0.8%

Smoking

Smoking was found to contribute to 5.5% of the risk of dementia onset. This is a combination of smoking being more widespread in older generations, and there being a link between smoking and cardiovascular conditions.

Depression

It’s possible that depressive symptoms increase dementia risk due to their effect on stress hormones and hippocampal volume. However, it’s not clear whether depression is a cause or a symptom of dementia. It was found to be responsible for 4% of the risk of developing dementia.

Lack of social contact

Social isolation is increasingly thought to be a risk factor for dementia as it also increases the risk of hypertension, heart conditions and depression. However, as with depression, it remains unclear whether social isolation is a result of the development of dementia.

It was found to contribute to 2.3% of the risk of developing dementia.

Prevention of dementia

The review highlights that although there are potentially modifiable risk factors for dementia, this does not mean dementia as a condition is preventable or easy to treat. It is evident that there are multiple risk factors contributing to the onset of the disease. However, some interventions that could prevent onset include:

  • Using antihypertensive drugs, such as ACE inhibitors, in people with hypertension.
  • Encouraging people to switch to a Mediterranean diet, which is largely based on vegetables, fruit, nuts, beans, cereal grains, olive oil and fish. This has been proven to improve cardiovascular health, and may help with the symptoms of type 2 diabetes, obesity and hypertension.
  • Encouraging people to meet the recommended physical activity levels for adults. Again, regular exercise may help with the symptoms of type 2 diabetes, obesity and hypertension.
  • Using cognitive interventions, such as cognitive training, which involves a series of tests and tasks to improve memory, attention and reasoning skills. The review points out, however, that the clinical effectiveness of most commercially available brain-training tools and apps is unproven.
  • Encouraging people to become more socially active. This could be by organising social activities – book clubs, for example – for older adults. 
  • Continuing to provide support to smokers who want to quit.

Read more about ways to reduce your dementia risk.

Links To The Headlines

Nine lifestyle changes can reduce dementia risk, study says. BBC News, July 20 2017

Lifestyle changes could prevent a third of dementia cases, report suggests. The Guardian, July 20 2017

Third of dementia cases are preventable through nine lifestyle changes, say researchers. The Independent, July 20 2017

The nine lifestyle changes that could save you from dementia. The Daily Telegraph, July 20 2017

A third of dementia cases are ‘preventable’ – with lifestyle choices a key factor, experts say. Daily Mirror, July 20 2017

These nine lifestyle changes could PREVENT dementia – ‘stopping a third of Alzheimer’s cases’. The Sun, July 20 2017

From hearing loss to loneliness, the NINE dementia risk factors: One in three cases could be prevented by changes to lifestyle. Mail Online, July 20 2017

Links To Science

Livingston G, Sommerlad A, Orgeta V, et al. Dementia prevention, intervention, and care. The Lancet. Published online July 19 2017

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High-dose vitamin D ‘doesn’t prevent colds and flu in kids’

“Vitamin D will not protect your child from a cold: myth-busting study says ‘more isn’t always better’ to help toddlers stay healthy,” says the Mail Online.

The story is based on a study that looked at whether giving healthy young children high doses of vitamin D in the winter protects them from colds and flu better than the standard recommended lower dose.

It found children taking the high dose were just as likely to get ill as children taking the standard dose – both groups got an average of about one case of cold or flu during the winter.

There was a reduction in flu cases with the high dose, but flu cases were uncommon and therefore the reduction was small (four fewer infections per 100 children over the winter season).

Current UK advice is that children aged one to four years old should be given a daily supplement containing 10 micrograms (mcg) of vitamin D – the same as the standard dose in this study.

Giving children the higher dose used in the study (50mcg) seems unlikely to offer much benefit for winter colds and flu if they’re generally healthy.

Where did the story come from?

The study was carried out by a large group of researchers at various centres in Canada who were part of the TARGet Kids! Collaboration. This group is studying the health of Canadian children and the impact of early health in later life.

It was funded by the Canadian Institutes of Health Research Institutes of Human Development, Child and Youth Health and Nutrition, Metabolism and Diabetes, and the Thrasher Research Fund.

The vitamin D used in the study was provided for free by the manufacturer Ddrops.

The study was published in the peer-reviewed Journal of the American Medical Association (JAMA).

The Mail Online provides good coverage of this story, making it clear that the study isn’t challenging the usefulness of the recommended vitamin D dosage, but saying more isn’t better for colds.

What kind of research was this?

This randomised controlled trial (RCT) compared the effect of high- and standard-dose vitamin D on the risk of children catching a cold or flu in winter.

Observational studies have suggested that people with low vitamin D levels are at greater risk of getting viral infections affecting their upper airways – essentially colds or the flu.

Young children in the US and the UK are advised to take a daily dose of around 10mcg (400 international units, IU) of vitamin D.

The researchers wanted to see if taking five times as much (50mcg or 2,000 IU) during the winter might be even better for preventing colds and flu.

We get most of our vitamin D from sunlight and some food sources, such as eggs and oily fish like tuna.

Winter is when our vitamin D levels tend to be lower because there’s less sunshine, and is also when we tend to get more upper airway infections. It’s plausible that giving more vitamin D might be helpful at this time of year.

Assigning children to receive either the standard or high dose of vitamin D at random makes sure the groups are as similar as possible before the study starts.

This means that any difference between the groups in how many times they got ill would be directly caused by what vitamin D dose they were taking.

What did the research involve?

The researchers enrolled 703 healthy children aged between one and five years old.

They randomly assigned the children to receive either 10mcg or 50mcg of vitamin D by mouth each day during winter. They then compared how often the children got colds or flu over this time.

The children were all from Toronto in Canada and were recruited at “well-child visits” to paediatric or family medicine practices between September and November 2015.

Children with any chronic illnesses (other than asthma) and those born prematurely weren’t eligible to take part. The vitamin D3 given to both groups was given as a drop a day of identical-looking and tasting liquid.

Parents and children didn’t know what dose they were taking. The parents were told not to give their children any other supplements containing vitamin D during the study.

The children took the drops for between four and eight months.

Whenever the children got symptoms of a cold, their parents filled in a checklist to record what symptoms they had.

Parents were also trained to take a swab of the inside of their child’s nose and send it to the lab. The researchers then tested the swab for viruses.

The main outcome the researchers were interested in was how often the children got colds or flu that could be confirmed as being viral infections by laboratory tests.

The researchers also compared how often the parents reported their child as having a cold or the flu.

Children went to the clinic to have blood samples taken to measure vitamin D levels at the four and eight-month mark.

Almost all (99.4%) of the children who started the study remained in it until the end and could be included in the analyses.

What were the basic results?

At the end of the study, children in the high-dose group had higher levels of vitamin D in their blood than those taking the low dose.

The parents didn’t report noticing that their children had any side effects from taking the vitamin D drops.

But high-dose vitamin D didn’t reduce the number of colds and flu the children got over the winter.

On average there were:

  • 1.97 cases in the high-dose group and 1.91 cases in the standard-dose group of parent-reported cases of cold and flu
  • 1.05 cases in the high-dose group and 1.03 in the standard-dose group of laboratory-confirmed cases of cold and flu

The differences between the groups were very small and not large enough to be statistically significant.

The higher dose of vitamin D did halve the risk of flu compared with the standard dose (incidence rate ratio [iRR] 0.50, 95% confidence interval [CI] 0.28 to 0.89).

But there were very few cases of flu – only 16 in the 349 children in the high-dose group and 31 in the 354 children in the low-dose group – so the difference of four fewer cases per 100 children (CI 1-8 fewer cases per 100 children) over the winter season wasn’t considered to be an important reduction.

How did the researchers interpret the results?

The researchers concluded that giving 50mcg of vitamin D a day to healthy young children in the winter didn’t reduce the number of upper airway infections overall compared with the standard dose of 10mcg a day.

They said: “These findings do not support the routine use of high-dose vitamin D supplementation in children for the prevention of viral upper respiratory tract infections.” 

Conclusion

This study found giving a high dose of vitamin D to healthy children in the winter doesn’t reduce their overall risk of upper airway infections compared with the standard recommended dose.

This well-designed study used several measures to ensure the results were robust. For example, researchers:

  • used randomisation to split the children into groups
  • blinded parents as to which treatment the child was receiving to make sure this knowledge couldn’t affect their perception of their child’s health
  • used laboratory tests to confirm that the child did have a viral infection

There was a reduction in flu with high-dose vitamin D, but the number of cases was very small, so this finding needs to be treated cautiously. The researchers have called for this to be looked at in further studies to see if this finding can be confirmed.

But there are some other important points to bear in mind. The study only included healthy children – it can’t rule out possible benefits for children with chronic conditions or in specific subgroups, such as children who have asthma or particularly low vitamin D levels.

And researchers only looked at upper airway infections, so the study doesn’t tell us about other outcomes that may be affected by vitamin D.

On balance, this study suggests that if your child is generally healthy, they aren’t likely to get much extra cold and flu protection from taking more than the recommended dose of vitamin D in winter.

Flu is normally more serious than a cold – the NHS offers a free flu vaccine to children of certain ages and with certain conditions to reduce this risk. Check if your child is eligible for the children’s flu vaccine.

Links To The Headlines

Vitamin D will not protect your child from a cold: myth-busting study says ‘more isn’t always better’ to help toddlers stay healthy. Mail Online, July 18 2017

Links To Science

Aglipay M, Birken CS, Parkin PC. Effect of High-Dose vs Standard-Dose Wintertime Vitamin D Supplementation on Viral Upper Respiratory Tract Infections in Young Healthy Children. JAMA. Published online July 18 2017

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Benefits of artificial sweeteners unclear

“Artificial sweeteners linked to risk of weight gain,” the Daily Mirror reports. Researchers looking at data gathered in previous studies reported a link between artificial sweeteners – ironically often associated with diet drinks – and weight gain. They also found a link with type 2 diabetes, high blood pressure and stroke.

However, the results of this review should be treated with caution. They are based on seven small, low-quality trials, and 30 cohort studies, which cannot show cause and effect. There was such a wide difference in the results and methods between the trials that pooling them increases the risk the results could have occurred by chance.

The best way to achieve and maintain a healthy weight and prevent type 2 diabetes is through a combination of a healthy diet, including at least five portions of fruit or vegetables a day, and regular exercise. And the ultimate diet drink? Water.

Where did the story come from?

The study was carried out by researchers from various hospitals and institutions in Canada, including the University of Manitoba. It did not receive any specific funding. The study was published in the peer-reviewed Canadian Medical Association Journal.

Neither The Independent nor the Daily Mirror explained any of the limitations in the underlying studies or recognised that pooling the results of such different types of studies increases the possibility that the results occur by chance.

The Mirror’s claim that the study found artificial sweeteners could affect gut bacteria and appetite is inaccurate. Researchers speculated along these lines, but these factors were not included in the research.

What kind of research was this?

This was a systematic review of published research on the effect of artificial sweeteners on body mass index (BMI) and a range of medical conditions. The results of any relevant randomised controlled trials and cohort studies were pooled in a meta-analysis. This type of review is useful for collating a large amount of information, but the findings rely on the quality and strength of the underlying evidence.

What did the research involve?

The researchers searched three medical databases for relevant trials and cohort studies. After sifting through more than 11,000 article titles, they found seven randomised controlled trials and 30 cohort studies that looked at the consumption of artificial sweeteners and various outcome measures.

The trials included adults who were overweight, obese or had high blood pressure. They were randomised to consume either a non-nutritive sweetener, such as aspartame, taken as a capsule or in ‘diet drinks’, or placebo or water daily for 6 to 24 months.

The cohort studies included between 347 and 97,991 adults whose weight ranged from healthy to obese. The researchers grouped adults into highest and lowest sweetener consumption, mostly from fizzy drinks. They then compared any change in weight or BMI, or development of type 2 diabetes or cardiovascular disease over a follow-up period ranging from 9 months to 38 years.

What were the basic results?

According to the randomised controlled trials:

  • Sweeteners did not have any effect on BMI (mean difference 0.37kg/m2, 95% confidence interval [CI] 1.10 to 0.36). This was based on three similar trials with 242 people.
  • Sweeteners did not have an effect on weight change (mean difference 0.17kg, 95% CI 0.54 to 0.21). Five studies of 791 adults were included, though there were major differences between the studies.

The cohort studies found that compared with those whose consumed the least sweetener, those who consumed the most had a:

  • 14% increased risk of type 2 diabetes (relative risk [RR] 1.14, 95% CI 1.05 to 1.25; nine trials, 400,571 people)
  • 14% increased risk of stroke (RR 1.14, 95% CI 1.04 to 1.26; two trials, 128,176 people)
  • 12% increased risk of high blood pressure (RR 1.12, 95% CI 1.08 to 1.13; five trials, 232,630 people)
  • 31% increased risk of metabolic syndrome – a combination of high blood pressure, abdominal obesity and diabetes (RR 1.31, 95% CI 1.23 to 1.40; five trials, 27,914 people)

The cohort studies also found that compared with those who did not consume sweeteners at all, high consumers of sweeteners had a slight increase in BMI, obesity and waist circumference.

How did the researchers interpret the results?

The researchers concluded that evidence from the trials “does not clearly support the intended benefits of non-nutritive sweeteners for weight management”, and the cohort studies suggest “routine consumption of non-nutritive sweeteners may be associated with a long-term increase in BMI and elevated risk of cardiometabolic disease”. However, they say these results are tentative and need to be confirmed in higher-quality trials.

Conclusion

The study authors suggest artificial sweeteners may not aid weight loss, despite marketing claims to the contrary, and could actually increase the risk of type 2 diabetes. However, the results need to be treated with caution, as this review had numerous limitations:

  • The randomised controlled trials had great variability and few participants, increasing the possibility of the results occurring by chance. They were also judged to be at a high risk of bias – for example, the participants could not be blinded to the intervention, and adherence (drop-out) rates were not provided.
  • We do not know whether there were any other interventions, such as change in diet or exercise, in either group over the course of the trials. Some trials involved consuming an artificial sweetener capsule, but we do not know what other drinks – “diet”, sugary or alcoholic – were also being consumed. It is unlikely that changing one dietary factor would result in major weight reduction.
  • The cohort studies relied on food-frequency questionnaires. Poor recall can make these inaccurate, and they may not adequately account for changes in people’s diet over time.
  • Cohort studies can be useful for looking at trends in large groups, but they cannot account for all possible confounding factors. Most of the studies only controlled for age, sex, smoking and physical activity level.
  • The majority of cohort studies were from the US, with only one cohort study from the UK, so the results may not be generalisable to the UK population.
  • There was too much variability between the cohort studies – such as different outcome measures, type of sweetener and length of study – to pool the results.

In summary, although this was a reasonably thorough review, it does not provide firm conclusions as to the beneficial or potentially harmful effects of artificial sweeteners. This is not the fault of the researchers but is down to the lack and poor quality of available evidence.

If you are overweight or obese, the best way to lose weight is by combining dietary changes with more exercise.

There are plenty of tips on our Weight loss page.

Links To The Headlines

Diet coke could be making you FAT: Artificial sweeteners linked to risk of weight gain. Daily Mirror, July 17 2017

Artificial sweeteners linked to weight gain, finds new research. The Independent, July 17 2017

Links To Science

Azad MB, Abou-Setta AM, Chauhan BF, et al. Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. CMAJ. Published online July 17 2017

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Site last updated July 25, 2017 @ 6:30 pm