Systematic Solutions

Weight loss is great for your health - even if it's just a little. This is the conclusion from a recent systematic review and meta-analysis from Aberdeen, Scotland.
The authors looked at 54 randomised controlled trials (RCTs) involving 30,206 people. Most trials analysed the effects of low-fat diets aiming to reduce obesity (weight-loss diets).
Losing weight resulted in a reduction in all-cause mortality (dying for any reason) of 18%, even though most trials were of a relati...vely short duration (around 2 years).
Impressively, the average weight loss in the studies was only 3.4 kg, meaning that this substantial risk reduction was associated with a reduction in weight of only about 5%.
So if you ever feel disheartened about your weight loss, just remember that every bit helps.
You can see the whole study here: http://www.bmj.com/content/359/bmj.j4849< br> See More

Can low-energy sweeteners (LES) help you lose weight? Or do you end up eating more? This was the question asked by researchers from Europe. They looked at the evidence for energy intake and body weight from both human and animal studies.
They found that in animal studies, consumption of low-energy sweeteners reduced body weight in 22 of 47 studies (47%). There was no difference in body weight in 21 studies, and an increase in body weight in 4 studies. At high doses, body weig...ht was decreased in 18 studies (53%), with 13 showing no difference and three showing an increase.
HOWEVER, when the animals are allowed to eat as much as they want, in some studies there is no difference in food intake, whereas in other studies the addition of LES to food leads to an increase in food intake and body weight.
The authors also looked at observational studies (cohort studies). In these studies, groups of people who have different lifestyles or take different medications (or other factors) are compared. Importantly, they are not randomised to different groups, so you can never be sure if the effects you see are due to factors other than your area of interest.
In the cohort studies, there was no difference in body mass index (BMI) between those consuming LES and those who did not consume LES. This was true for both adults and children.
Finally, we have randomised controlled trials (RCTs). These are the gold standard in research - as long as they are well-conducted. The first set of RCTs looked at how much food people consume if given foods and drinks with LES. In these studies, there was very little or no difference in energy intake.
In longer-term studies (1.25 to 40 months), adults consuming LES-sweetened beverages lost 1.4 kg more than those consuming sugar-sweetened beverages. The results were similar for children (1.35 kg). People consuming LES-sweetened beverages lost on average 1.24 kg more than those consuming plain water.
In conclusion: the highest quality evidence suggests that LES-sweetened beverages can aid in weight loss. The increase in weight loss, however, is moderate (1.2 - 1.4 kg).
You can read the study for yourselves here! http://www.nature.com/…/journal/v40/n3/ full/ijo2015177a.html
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Our meta-analyses and reviews were among the most read articles in August - feeling proud!
http://ajcn.nutrition.org/reports/most-re ad

We have not updated this page for a month while I was on holiday, but now it's time for a new update!
Topical treatments for inflammatory causes of dandruff
Dandruff is caused by a number of different things. Most dandruff is simply caused by dry skin (which means it’s often worse in winter), or can be caused by conditions such as seborrhoeic dermatitis or psoriasis. Almost 50% of people have dandruff, so it’s nothing to be ashamed of. It is self-limiting and does not require... treatment.
If, however, you have an inflammatory or autoimmune condition, it is important to treat the symptoms of dandruff. One group of scientists has examined the evidence for both anti-inflammatory and antifungal treatments for seborrhoeic dermatitis.
In the first study, Kastarinen and coworkers looked the efficacy of topic anti-inflammatory agents. They found 36 randomised controlled trials, but because these trials looked at many different treatments and outcomes, these was little evidence for most of their scientific questions.
They found that steroids are possibly as effective as calcineurin inhibitors (low quality of evidence) at achieving total clearance of symptoms. They could show with a moderate degree of certainty that steroids are equally effective as azoles at achieving total clearance of symptoms. A single study suggested that lithium is more effective than azoles, but this should be interpreted with caution. In any case, moderate evidence shows that the use of strong steroids is better than placebo in achieving total clearance of symptoms.
You can find the original paper in the Cochrane Database of Systematic Reviews: http://onlinelibrary.wiley.com/…/146518 58.CD009446.pub2/full
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Screen time and depression. For this week's review of a meta-analysis, we're finishing up our examination of screen time and adverse outcomes in children.
The only other meta-analysis I could find on the adverse effects of screen time on children was the work of Mingli Liu et al (2016). They analysed studies looking at screen time in children and adolescents and depression.
Overall they found a small but significant increase in the risk of having depression with increased sc...reen time. However, their subgroup analysis found that this effect was found only Australian children, only in boys, only in children under 14, and only when children used computers for non-gaming activities (e.g. social media).
The studies used for this meta-analysis were cross-sectional and longitudinal. Therefore, any associations between differences between the groups and negative or positive outcomes are simply that - associations (correlation is not causation).
The take-home message from this study is that, if we are to take the associations as causative, protecting children under 14 from online computer use, just as social media, may reduce the incidence of depression in this group.
http://bjsm.bmj.com/content/50/20/1252.lo ng
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Screen time and adverse outcomes in children. For this week's review of a meta-analysis, I have taken the advice of Rachel Wilkinson and looked for evidence for an association or causal relationship between screen time and adverse outcomes in children.
There is surprisingly little systematic evidence looking at this question. I did, however, find two meta-analyses, one on sedentary behaviour and obesity, and the other on screen time and depression.
In the first study, van Ekr...is and coworkers looked at the evidence for increased BMI associated with increased sedentary behaviour. In a meta-analysis of studies looking at TV watching and BMI, they a small increase in body weight (0.12 kg), but this relationship disappeared when adjusted for diet and/or physical activity. This suggests that TV watching per se does not result in obesity - it is increased calorie intake and/or reduced activity.
They also found no association between computer use and BMI, even when the data were adjusted for diet and/or physical activity.
The take-home message here is that TV watching is associated with an increase in body weight if the child has in increased calorie intake or reduced physical activity. Also, there does not appear to be any relationship between computer use and obesity.
http://onlinelibrary.wiley.com/…/abstra ct;jsessionid=4B370F…
— Products shown: Systematic Review Starter Course.
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I'm looking for requests for topics of interest for tomorrow's systematic review post. Does anyone have a burning issue they'd like to know the evidence for?

The other meta-analysis on fructose metabolism is today's focus. This is also one of mine - and follows on from our paper on the postprandial effects of fructose consumption.
In this review, we looked at studies that were double-blind or at least provided the participants with all food, or checked their diets regularly.
Our meta-analysis involved studies of two weeks or longer, where the participants were given equal amounts of fructose, sucrose or glucose, in food or beverag...es. We found that this longer-term consumption of fructose lowered fasting blood glucose by a small amount (0.14 mmol/L), but that in people with impaired glucose tolerance or type 2 diabetes, this effect was much larger (0.61 and 0.80 mmol/L).
We found that this glucose lowering was not at the expense of fasting insulin, and that fructose consumption was also associated with a small reduction in body weight (1.40 kg). We found no effect on fasting blood triglycerides, contrary to the dogma surrounding fructose. Nor did we find any effects on other blood lipids.
These data suggest that, given its lack of harms, replacement of sucrose or glucose in foods by fructose may be of benefit, especially in those with diabetes.
However, as always, sugar consumption in general should be reduced. Don't waste your calories on foods without other nutrients like vitamins and dietary fibre!
And don't forget you can learn how to do a systematic review and analysis just like this one - by trying my online course: http://systematic-solutions.teachable.com /
http://ajcn.nutrition.org/…/2017/06/07/ ajcn.116.145169.abst…
— Products shown: Systematic Review Starter Course.
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For this week's systematic review, I'm going to show you something close to my heart. This one is my own meta-analysis on the immediate effects of fructose on blood glucose, insulin and triglycerides.
We searched for studies that compared consumption of fructose with consumption of glucose or sucrose. Sucrose is what we normally use as table sugar. We were careful only to include studies that used the same amount of each sugar.
We found that people who consumed fructose had ...markedly reduced peak blood glucose and insulin in the short period after taking the sugar. This was particularly noticeable in people with impaired glucose tolerance ("pre-diabetes") or with type 1 or type 2 diabetes.
In contrast to the prevailing wisdom, we found no difference in the peak levels of triglycerides between those consuming fructose and those consuming glucose or sucrose.
This meta-analysis breaks with the dogma that says that there is something about fructose that has a particularly bad effect on health. Because it is important for people to reduce their peak blood glucose and insulin, particularly in people with diabetes, we have provided medical and nutrition professionals with evidence for the efficacy and safety of replacing table sugar or glucose with fructose.
However, it is really important that you don't change your diet without first consulting a registered dietician or your general practitioner. There might be a good reason why fructose is not for you.
A link to the study can be found here: http://ajcn.nutrition.org/…/…/06/07/a jcn.116.145151.abstract
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Tobacco packaging design for reducing tobacco use
For this week's systematic review, we're going to be looking at a very recent Cochrane Collaboration review on standardised packaging for reducing tobacco use.
This review, by Ann McNeill and colleagues, from the UK Centre for Tobacco and Alcohol Studies, sought to answer the following question: does standardised packaging have an effect on tobacco use uptake, cessation or reduction?
... The authors found 51 studies meeting their criteria, which involved around 800,000 participants. The authors were unable to perform a meta-analysis, as only one country (Australia) had actually introduced plain packaging at the time of the analysis.
However, their qualitative analysis found that the single study on 700,000 people, looking at smoking prevalence reported a 4% reduction in the the odds of smoking prevalence compared with the time before the packaging was introduced. Because of the type of study and the data relying on a single study, the quality of the evidence was rated as low.
Four studies on 9394 people found that people exposed to standardised packaging might reduce the number of cigarettes smoked each day, but it's also possible there is no change in the number of cigarettes smoked. The quality of the evidence was rated very low.
Two observational studies in 5441 people found that more people attempted to quit smoking after standardised packaging was introduced. The quit rate rose from 20% to 26% one year after the packaging was introduced. Given the small number of studies and the observational nature of the studies, the quality of the evidence was rated as low.
Conclusions: The authors conclude that, given that standardised packaging is very recent, the evidence supports a possible relationship between standardised packaging and a reduced smoking prevalence. Data should be collected as more countries introduce this form of smoking harm minimisation.
The systematic review can be found at the following link:
http://onlinelibrary.wiley.com/…/146518 58.CD011244.pub2/full
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For this Friday's systematic review presentation, I'd like to share a review on a topic of interest to you! Let me know what area of evidence you're most interested in - education, surgery, public health - any topic you'd like to hear about is interesting to me!

Every Friday we'll be sharing a new systematic review or meta-analysis. If you have any articles you'd like us to look at, let us know in the comments!