“Sugar is so harmful that it should be controlled and taxed in the same way as tobacco and alcohol,” according to health experts quoted in today’s Daily Express. The researchers say that sugar indirectly contributes to 35 million deaths a year worldwide.

The news is based on a comment article by US health scientists, who argue that there has been a massive rise in diseases such as heart disease, cancer and diabetes since we began eating more sugar contained in processed food. The researchers argue that many of the health effects of excess sugar consumption are similar to those of alcohol, and that sugar should, therefore, be controlled and taxed in a similar way. They advocate introducing a tax on processed foods with added sugar, limiting sales during school hours and placing age limits on purchase. Interestingly, the authors rate sugar as more dangerous to health than saturated fat and salt, which they call dietary “bogeymen”.

It is important to highlight that the researchers’ article is a comment piece and, therefore, primarily reflects their views and opinions, rather than presenting direct research on the issue. While it is certainly an interesting concept, there is still a lack of evidence supporting the effectiveness of such measures and, crucially, whether the public would actually accept them.

 

Where did the story come from?

The article was written by researchers from the University of California. There is no information about any external funding. It was published in the comment section of the peer-reviewed scientific journal Nature.

The article was covered fairly by the papers, many of which included comments from UK experts including the UK Food and Drink Federation, which represents food manufacturers. The BBC also quoted an expert from the British Heart Foundation, who reportedly said that taxing salt and fat alongside sugar should also be considered.

 

What kind of article was this?

This was a comment piece in which experts discuss the global burden of general chronic disease related to sugar consumption and the need to regulate certain dietary items. In particular, the authors draw parallels between the health effects of sugar and the use of alcohol and tobacco, arguing that sugar should be regulated in a similar manner.

It is important to highlight that this was a comment piece only and, as such, it primarily reflects the views and opinions of the authors. A formal systematic review of the literature does not appear to have been conducted and, as such, it is not certain whether all relevant evidence and resources related to sugar consumption and its health effects will have been consulted.

Also, the short piece looks at the issue from a global perspective and, therefore, is not a direct commentary on sugar consumption in the UK. In fact, a map showing average added sugar consumption per day across different nations shows that people in the UK consume a relatively low amount of sugar, at least compared with the rest of the world. Much of the article’s content may be focused on policies suited to the US, which has by far the greatest per-head sugar consumption, at more than 600 calories worth of sugar per day.

 

What does the article say?

The article points out that, for the first time in human history, non-communicable diseases such as heart disease, cancer and diabetes, pose a greater health burden worldwide than infectious disease. While alcohol, tobacco and diet are all targeted as risk factors for these diseases by policymakers, only the first two – alcohol and cigarettes – are regulated by governments to protect public health. (Although, as it points out, Denmark taxes food high in saturated fats and is now considering taxing added sugar.) The authors argue that fat and salt have become the current “dietary bogeymen” in the US and Europe, but that most doctors no longer believe that fat is the “primary culprit” of such disease. Doctors are apparently calling for attention to be turned towards the dangers of excess sugar consumption.

The authors estimate that over the past 50 years sugar consumption has tripled worldwide, mainly as a result of it being added to cheap processed foods. While excess sugar is thought to be a key cause of the obesity epidemic, they argue that obesity itself is not the root cause of disease but that its presence is a marker for metabolic damage. This, they say, could explain why 40% of those with metabolic syndrome (a collection of the key metabolic changes that lead to heart disease and diabetes) are not obese.

 

Why do they think sugar is dangerous?

The authors say that although sugar is described as “empty calories”, a growing body of evidence suggests that fructose (one component of table sugar) can trigger processes that lead to liver toxicity and a host of other chronic diseases. “A little is not a problem but a lot kills – slowly,” they say.

The authors argue that sugar meets all the four criteria used by health policy makers to justify the regulation of alcohol. These are:

• Unavoidability. While sugar was only available as fruit and honey at certain times of the year to our ancestors, it is now present in nearly all processed foods. In some parts of the world people are consuming more than 500 calories worth of sugar per day.
• Toxicity. There is growing evidence that excess sugar has an effect on human health beyond simply adding calories and can cause many of the same problems as alcohol, including high blood pressure, high blood fats, insulin resistance and diabetes.
• Potential for abuse. The authors argue that, like tobacco and alcohol, sugar acts on the brain to encourage dependence. Specifically, it interferes with the workings of a hormone called ghrelin (which signals hunger to the brain) and it also affects the action of other important compounds.
• Negative impact on society. The economic and human costs of these diseases place excess consumption of sugar in the same category as smoking and drinking.

 

What do they think should be done?

While the authors accept that sugar is “natural” and a “pleasure”, they argue that, like alcohol, too much of a good thing is toxic. Strategies to reduce consumption of alcohol and tobacco show that government controls, such as taxation and imposing age limits, work better than educating people. They make several proposals for controlling sugar, including:

• taxing any processed foods with added sugar, including drinks
• reducing the hours during which retailers can sell food containing added sugar
• tightening the licensing requirements on vending machines and snack bars selling sugary products
• controlling the numbers of fast food outlets and convenience stores
• limiting sales during school hours or imposing an age limit for drinks with added sugar

Finally, they argue that regulating sugar will not be easy, but it can be done with enough pressure for change, citing bans on smoking in public places as an example of what can be achieved.

 

What does this mean for me?

This article will be of interest to food scientists, health policy makers and the public alike, but the use of strategies to restrict the consumption of added sugar is complicated and, indeed controversial. The implications of such moves would need to be considered in both medical and societal terms. They would need both medical evidence to support their effectiveness and assurance that the public would accept drastic changes, such as age limits on buying sweets. For example, in recent years, Denmark has imposed taxes on fatty foods, a move that has divided opinions greatly.

It is generally accepted that added sugar or excessive sugar consumption is bad for health and dietitians advise restricting sugar intake to the occasional “treat”. However, to what extent sugar is directly to blame for the rise in chronic disease and how much is due to other dietary components, such as saturated fat and salt, is open to debate. The current article does not appear to be a formal systematic review of the literature, and it is not certain whether all relevant evidence and resources related to sugar consumption and its health effects have been consulted. As such, it should be considered primarily to reflect the views and opinions of the authors.

In the UK at present, policymakers generally favour encouraging healthier eating through education and the provision of healthier options. This is carried out through public health campaigns such as 5 A DAY or by introducing new food ranges to schools. Whether this approach alone is adequate and whether healthier eating patterns should be encouraged by government regulation, is a crucial area of debate.

Links To The Headlines

Sugar 'is toxic and must be regulated just like cigarettes', claim scientists. Daily Mail, February 2 2012

Sugar tax needed, say US experts. BBC News, February 2 2012

Tax harmful sugar. Daily Express, February 2 2012

Links To Science

Lustig RH, Schmidt LA, Brindis LD. Public health: The toxic truth about sugar. Nature, February 2 2012

“Mind-boggling! Science creates computer that can decode your thoughts and put them into words,” the Daily Mail’s headline exclaimed today, while The Daily Telegraph heralded an era in which a “mind-reading device could become a reality”.

You’d be forgiven for thinking famous mind readers such as Derren Brown had just produced a telepathy implant. Instead, these reports are from a small study of 15 people that culminated in researchers being able to reconstruct the sound patterns of words using brain activity alone.

This research involved attaching electrical sensors directly to brains of people undergoing brain surgery to understand how they processed individual words that were played to them. The researchers demonstrated that the brain breaks words down into complex patterns of electrical activity. They were then able to create a mathematical algorithm that decoded and translated the brain activity back into a rough version of the original sound.

But the reconstructed words were not of good enough quality to be recognised by a human listener when played. The words were only recognised when the original and reconstructed sound patterns were compared visually.

This exciting and new research does raise the prospect of brain activity one day being translated into words using an implant. Such technology could help the vast numbers of people suffering from problems affecting speech. But it is important to recognise that this research is in its very early stages and a clinically effective implant is likely to be a long way off.

 

Where did the story come from?

The study was carried out by a collaboration of North American universities led by researchers from the University of California, Berkeley. It was funded by several academic grants and was published in the peer-reviewed science journal Public Library of Science (PLoS) Biology.

The researchers report that the human brain has evolved complex mechanisms to decode highly variable sounds into meaningful elements of language, such as words. Understanding this complex decoding in humans has proved difficult, as it requires recording brain activity on the exposed brain (with the skull removed).

This study took advantage of cases of rare brain surgery for epilepsy and brain tumours that allowed researchers to measure brain activity by attaching sensors directly to the brain surface. This provided a unique opportunity to understand how the human brain recognises speech.

This study received wide media coverage due to its futuristic appeal and was often given a sci-fi angle, with some suggesting a “mind-reading device could become reality”. This research does raise the possibility of developing a device that could interpret thoughts into speech in the future. However, it is important to note the authors’ own caution - that the technology of translating thoughts into words needs to be vastly improved before such a device could become a reality.

 

What kind of research was this?

This was a small study of 15 people undergoing brain surgery for epilepsy or brain tumour. It looked at whether the complex brain activity involved in processing spoken words, such as the sound wave form and syllable rate, could be reconstructed using a computer program.

The researchers believe that the brain processes internal thoughts in a similar way to hearing sounds, and hope that this type of technology could eventually be used to help those who cannot talk, such as those in a coma or in the much-feared “locked-in syndrome”.

 

What did the research involve?

Fifteen patients undergoing brain surgery for epilepsy or brain tumour were asked to listen to 47 real or invented words and sentences from different English speakers. All patients had normal language capabilities when they were enrolled in the study.

During this process electrical signals from the brain were recorded using multiple sensors attached directly to the part of the brain called the lateral temporal cortex, which includes the superior temporal gyrus (STG), thought to be very important in the processing of speech.

To understand and mimic the brain activity involved in processing heard words, the researchers used an approach referred to as “stimulus reconstruction”. In this case, the stimulus was hearing a spoken word.

Hearing words causes a large amount of brain activity involved in recognising and processing the different aspects of the sounds of the words, for example the different sound frequencies and timing of syllables. The word reconstruction involved creating a mathematical program (like that used in computer software) capable of decoding the vast amount of brain activity in such a way that it was possible to identify the original words heard by the participant.

The reconstructed signals from different mathematical models (linear and non-linear) were compared to those detected directly from the brain surface to see how good they were at mimicking the brain’s activity when hearing spoken words. The researchers also used the models to identify the most important areas of the brain involved in processing this information and what other factors influenced the accuracy of the sound reconstructions.

 

What were the basic results?

When constructing the mathematical models they found that the STG region of the brain was important in creating an accurate prediction of the sound pattern of the original word.

The sound patterns generated by the mathematical model allowed the identification of specific words to be generated directly from the brain activity of patients listening to the words. These took the form of visual representations of the word sound pattern. A total of 47 words were presented in pairs and, on average, the model correctly identified the word in approximately nine out of every ten instances (89%). This was significantly better than 50% correct identification, which would be seen simply by guessing.

Importantly, however, the quality produced from reconstructing the words was not good enough for them to be recognised by a human listener when played. The words were only recognised when the original and reconstructed sound patterns were compared visually.

The researchers found that different types of mathematical models performed better at reconstructing the sounds of words with particular characteristics.

 

How did the researchers interpret the results?

The authors concluded that their results demonstrated that key aspects of speech signals can be reconstructed from STG activity.

 

Conclusion

This study of 15 people undergoing brain surgery has demonstrated a method of reconstructing the sound of a heard word using only the signals obtained from the brain. This study represents an important progression in the field of speech reconstruction, which has the potential to improve the lives of many who suffer from speech difficulties in the future.

But the words, when reconstructed, were not of good enough quality to be recognised by a human listener when played. The words could only be identified when the original and reconstructed sound patterns were compared visually. The researchers suggest that improving the brain sensors detecting the STG brain activity may, in the future, improve the reconstructed sound to a level that could be understood by a person listening.

The mathematical formula used to reconstruct the words is at a very early stage and would need a significant amount of improvement and development before it could be considered for use in an implant or similar device in the future. Similarly, future speech reconstruction research would need to demonstrate it was effective in a large range of words, sentence patterns and languages. Currently, the mathematical program has only been tested on a limited vocabulary of 47 English words.

This research represents an intriguing first demonstration of the potential of speech reconstruction technology to transform the lives of people with communication problems in the future.

Links To The Headlines

Science decodes 'internal voices'. BBC News, February 1 2012

Mind-reading device could become reality. The Daily Telegraph, February 1 2012

Mind-boggling! Science creates computer that can decode your thoughts and put them into words. Daily Mail, February 1 2012

Mind-reading program translates brain activity into words, The Guardian, February 1 2012

Links To Science

Pasley BN, David SV, Mesgarani N, et al. Reconstructing Speech from Human Auditory Cortex. PloS Biology. Published online January 31 2012