The Complex Causes of Obesity

While the history of research into obesity and related health problems has had opposing camps for over a century, one camp came to dominate our widely held assumptions about what makes us fat. The simple and appealing concept that eating more than we use makes us fat has a grip on society and has done a great deal of damage. This so called ‘energy-balance disorder’ has led to the stereotype that fat people are weak and gluttonous but growing evidence suggests this is often unfair and a gross over-simplification. This demonisation of ‘fat’ has spawned, and been reinforced by, modern image (glossy magazines) and health empires (gyms and diet fads) where skinny and toned is worshipped at great profit to some but little benefit to most. There have been many studies in the past that have cast doubt on the simple energy-balance model and, with modern advances in genetics, neuroscience and even our increasing appreciation of the role our gut microbiome plays, more studies are backing them up. The alternate, and more complex, model for obesity points the finger at specific physiological malfunctions in individuals either due to congenital curses (genetically linked) or through a combination of diet and lifestyle with the energy-balance concept relegated to a potential exacerbator. While these explanations may appear to exonerate the overweight of responsibility, I think they should rather be viewed as a path to empowerment to effectively tackle any health problems and are likely to be incorporated by the growing field of personalised medicine.

    So first off, we need to get a rough overview of how the energy-balance model works. The concept is simple in that excess energy, in the form of calories, is stored by the body in fat cells. Thus, over time an excess of eating and a dearth of exercise will cause our fat cells to grow and multiply. It is worth pointing out that I'm not saying this process is irrelevant to the issue of obesity (it certainly doesn't help) but I will argue we've had the emphasis wrong. The power of this model is in its simplicity which has been preyed on by diet fad after diet fad, fitness gurus and even purveyors of sugary goods (‘to be enjoyed as part of a healthy/active lifestyle’!). A common associated mantra is ‘a calorie is a calorie’, which is again unhelpful, most clearly seen in the case of sugar. The alternate models try to explain the process that leads to this fat storage and how this process varies between individuals due to genetics and lifestyle. While uncomfortable as a scientist I will stray into the anecdotal to highlight a point. I am clinically underweight and have been my whole life and while I probably exercise more than the average Briton (not hard really) I certainly don’t watch my calories and usually eat three full meals a day and enjoy my calorific beer (full of alcohol and complex carbohydrates). In short, the calories just don’t stick to me and as far as I am concerned I cannot put weight on, and trust me I have tried. On the other hand, I have a number of friends who will quite normally gain (and then lose) 5kg over the festive period, prime candidates for those new years resolutions and gym memberships. The point is that there is wide variation in how people respond to their food and clearly the energy-balance model is limited at best. So why the differences? Well without going into huge detail I’d like to highlight some key examples that might well explain these differences.

    Hormones: Many studies have pointed the finger at hormone imbalances as a cause for obesity and most other factors can be thought of as feeding into and affecting these mechanisms. There are many different hormones that influence both the rate of fat deposition and general metabolism. It’s important to also remember that hormones mediate interactions between our brain and our body and this goes both ways. In fact, the ordering of this cause and effect has been suggested to mean that ‘we eat more because we are getting fat’  which is why I said earlier that energy-balance issues are relegated as secondary issues. The two key hormones in this are insulin and leptin. Insulin is released when we have sugar in the blood and it instructs various tissues to extract this sugar and store it as glycogen and, importantly, fat to be used as energy stores when needed. Type 2 diabetes is a disease in which over time our bodies become more and more resistant to insulin and so we produce more and more to try have the same effect. This rise in insulin is thought to have a knock-on effect causing leptin resistance, although this is disputed by some. Leptin, produced by fat cells, is one of two hormones, along with its antagonist ghrelin, that regulates our hunger sensation and it is leptin’s job to tell our brain when we’ve had enough food. So with resistance to leptin, our brains fail to get the message that we’ve had enough, which equates to ‘we need more, I’m starving’, and so we eat more exacerbating the problem. This is a big problem as the will-power required to eat less can be immense as we fight what is effectively a starvation signal in our brain. So according to this model our diet, e.g. high sugar, leads to fat deposition and hormonal resistance in turn leading to a behavioural change that often reinforces the problem.

    Ghrelin is another interesting example in which it can specifically go wrong in some people. Ghrelin is released by the gastrointestinal tract and relates to the size of the stomach. Normally, a full stomach means little ghrelin is released while an empty stomach induces ghrelin production. Ghrelin then acts on the same target cells in the brain as leptin but to convey hunger. Again, there is natural variation in how people produce and respond to ghrelin meaning some people habitually feel hungry and none more so than those with the genetic disorder known as ‘Prader-Willi syndrome’. These people have constantly high ghrelin levels and an insatiable appetite leading to morbid obesity alongside a suite of other mental and physiological problems. In fact, one treatment for obesity is the gastric bypass in which the stomach is effectively reduced and this means that less ghrelin is produced and so hunger is reduced. It is not hard to imagine that an unfortunate combination of these hormonal problems could lead to people having uncontrolled hunger and fat deposition.

    Diet: As alluded to above, sugar has come under the spotlight for its contribution to obesity and diabetes and one of its key modes of action appears to be through how it affects insulin and leptin. Some of the most effective diets are the ‘low-carb’ diets and while they seem to work in a number of ways, their effect on the hormonal model discussed above is likely a factor. Low carbohydrate diets effectively reduce our insulin levels and so we avoid the insulin spikes and associated leptin resistance helping us eat less. Tantalising studies have shown that, at least in the short term, a diet in which carbohydrates are swapped for fats (with their own associated health problems) can result in weight loss so watch this space as more evidence comes out! The key thing here is that it does not result from a calorie reduction but a food group swap. When fat itself was demonised a few decades ago as the leading cause of obesity, we saw people and food manufacturers avoiding it while carbohydrates and especially sugars came to fill the calorie gap. This change, more so than an increasingly sedentary life, is thought to have been a key driver in the world obesity epidemic. In view of the flaws in the calorie-balance model, exercise should be viewed as a way to keep people generally healthy, but not to lose weight. Just by way of example, if I wanted to burn off the calories from a big mac (563), I’d need to jog for an hour and a half. If I just did nothing and relied upon my resting metabolic rate at 1809 calories per day, I’d need to eat three big macs a day to sustain myself. The point is we burn a pretty large amount just by living and breathing but when we need to burn the extra on top of that we need to spend a lot of time to burn seemingly little more. Keeping active helps but is unlikely to solve a weight problem if we are putting in the wrong type of food and hoarding fat.

    Gut microbiome: A third area relating to obesity is the gut microbiome. This incredibly complex ecosystem feeds on what we eat and is even thought to interact with our brains. Studies in rodents have suggested that the whole hormonal story outlined above could also be influenced by our gut bacteria. The break down of fat by bacteria is thought to result in acetate which sends signals to our brain and instructs both ghrelin and insulin to be produced! The implication is that certain gut microbiomes produce more acetate so making this effect stronger. I.e. the make up of our gut bacteria can make certain people susceptible to becoming obese through behavioural and physiological changes. The variation in peoples gut bacteria has attracted much interest recently and studies are finding correlations between certain compositions and health. Such progress has even spawned companies offering to study your microbiome and give you insights into how to best manage general health. As we understand more, the concept could allow certain treatments and preventative measures specifically targeting our guts and what grows there. We gain our mothers bacteria first and then build up our own unique ecosystem as we grow and this is then modulated by our diet through life offering different stages to target.

    So obesity could be traced back to the bacteria we inherited, acquired and encouraged through our diet with it effecting our behaviour but it goes further than this. A fantastic twin study has found for example that the obese (human) twin had a less complex microbiome, likely due to lifestyle and diet choices, while the leaner twins had a richer mixture higher in plant fibre and starch digesting bacteria. Now, while the chicken and the egg debate might erupt, the same study then used mice to demonstrate that the microbiome does have a clear effect on obesity. Sterile twin mice were populated by the bacteria from either the obese or the lean human twin. Following an identical diet, the twin mouse with the obese humans gut bacteria got fat and the other remained lean! This final example is I think very telling, especially in my personal case, as even when the calorific intake was the same, one twin got fat and the other didn’t meaning their bodies did not treat the calories the same. In one, the food went straight into fat storage while it seemed to vanish in the other.

     It appears that due to various factors there are big variations between people in how certain food is digested and absorbed, how it is stored, how it is used and how much of it we feel we need. I look forward to a time, quite soon I hope, when those struggling with obesity, or in my case being underweight, can understand why and make the appropriate targeted changes needed to be actually effective as simply telling people to eat less and run more appears woefully inadequate. At the dawn of personalised medicine, these possibilities are almost upon us and if used properly have the potential to empower all of us to get the most out of our bodies.

Organic vs Conventional Farming: The Bogus Debate

I am a plant geneticist and I care about agriculture and food production however, after watching a highly biased and un-nuanced video clip from the New Scientist which painted organic farming as dangerous and environmentally damaging, I have become sick and tired of the organic vs ‘conventional’ farming debate; it’s a bogus debate. The debate has two vocal extremes with (for entertainment purposes only) the hippie tree-hugger on one side who distrusts science, big business and regularly uses the phrase 'mother-earth' (the ‘organic’s’) while on the other side you have the sterile white coat wearing, condescending scientist who scoffs at claims based on ‘feelings’ (the ‘conventionals’). Both loathe each other and ultimately have very different philosophies and approaches to life and are likely to never see eye to eye. While obviously few people fit these descriptions, the point in that the debate has long been highly polarised and quite damaging, in my opinion, to progress in agriculture and food production. It is my view, and I hope to convince more to think like this group, that both sides of the debate have merit and that food production requires a mix of ideas and technologies promoted by both sides to achieve sustainable agriculture. I suspect, however, that a Buddha approved ‘middle-way’ will be scorned by many on both sides, so toxic the debate has become.

    I’d first like to highlight some of the technologies, concepts and beliefs at the heart of both sides. For the conventional’s, science and industry have saved the world as technologies like plant breeding, GM, intensive animal rearing, industrially produced pesticides, herbicides and fertilisers have allowed the feeding of the 9 billion. This industrial/scientific package is what people generally refer to as ‘conventional’ farming which is a PR win for this side immediately branding the other side unconventional or abnormal. For the organic’s, ‘conventional’ farming is killing mother-nature and more ‘natural’ methods are favoured like free-range (although my caricature is of course likely to be a vegan), mixed farming (smaller to medium scale animal and crop farms), inter-cropping/polyculture, ecosystem services and composting. To summarise the debate, the conventional’s claim their approach to be the only way to feed our burgeoning population and, as in the New Scientist video, claim organic farming would never achieve this resulting in famine and/or further deforestation and they push an agenda of continued chemical use and increased use of GMOs and genetics led plant breeding as a way of squeezing greater yields out of the same land (key word: efficiency). The organics claim that conventional farming is damaging and unsustainable, that GMOs are poisoning us and nature and that organic farming can be as or indeed more productive (key word: sustainable) and even tastes better! Hopefully we can see that some claims stand and fall on both sides.

    Now rather than treat these as two sides of an apartheid, I would like you to think of the concepts and technologies from both sides as part of a technological buffet. This buffet can be carefully chosen from by individual farmers and indeed governments or policy makers to meet local needs and conditions. Indeed there is a science which concerns itself with this buffet selection process; agroecology. The point is that both sides have validity and I’ll highlight some winning ideas from both sides. Let’s face it, intensive, industrial farming requires huge energy inputs primarily in the form of fossil fuels, has created a range of environmental issues (such as nitrogen run-off and biodiversity loss), animal welfare issues and is ultimately unsustainable (although there is the term ‘sustainable intensification’ being bandied about). I am a firm believer, however, that technology and science have an important role to play in the future of agriculture. Take GMOs, the hate-symbols for the organic's, for example. Up until now, the GM plants in use have primarily brought benefits to some larger scale farmers, a little to us consumers but especially to the big agrotech companies through products such as Roundup ready crops (Roundup being Monsanto’s trademark herbicide then sold to the farmer whose just bought your seeds! One of the best business models I've come across). GM crops have become associated with big business, deforestation (e.g. GM soy) and farmer suicides which is a shame because they are nutritionally ‘safe’ and are eaten daily by a large proportion of the world right now; knowingly or not. While the first generations of GM crops have arguably been principally about making money, the research I know is going on in plant science promises to be more about boosting yields to benefit consumers (you!) by, for example, improving plants nitrogen use efficiency (reducing fertiliser requirements which will certainly hurt some businesses pockets), improving photosynthesis efficiency (so plants can convert a higher proportion of sunlight into biomass) and improving drought tolerance (improving productivity in marginal areas and reducing drought induced crop failures). The obvious problems remain that while opposition to GM exists, the only financially viable way such plants would ever make it to the fields is through the big companies who are able to fund the trials and safety tests leaving such plants in a PR limbo although this is where governments could step in to help fund these stages removing the big business connection. These, and other similar approaches (like genetics led plant breeding), can not be achieved by organic farming but by no means exclude organic farming associated concepts. It is not hard to envision such potential future plants being part of, for example, a mixed farming environment with minimal fertiliser or pesticides that employed inter-cropping. The acceptance of GM’s is unlikely to occur any time soon given the inability for many to disentangle the science with the arguable darker economic/business/social aspects and there is a general mistrust that keeps feeding this (a similar mistrust that leads to aid workers being killed for administering polio vaccines). Other promising technological examples from the organic’s camp are inter-cropping and polyculture in which multiple plants are grown in the same space such that they can be mutually beneficial or maximise the available resources and minimise the need for chemical inputs. One example is the use of the push-pull method where one plant acts to push pests away from the main crop towards the attractant (pull) plants so minimising the need for pesticides. Another example is the ancient 'Three Sisters' crop system of the native Americans in which corn was grown to provide a structure for the creeper-like beans (which in turn strengthen the corn stalks and, as legumes, return nitrogen to the soil) while squash occupied the ground level shading the soil to reduce evaporation and block out any weeds. This happy trinity demonstrates the concept well however it is not favourable to the heavily mechanised harvesting techniques widely employed in modern farming and so also demonstrates some of the limitations to many of these approaches; namely scale and labour.

     One key area of the debate is the yield gap which generally puts organic farming at 80% that of ‘conventional’ farming. This number is vaguely useful but it doesn’t tell the full story of the variation in this number which is large and significant for this discussion. One key point is that there are many experiments that have demonstrated negligible differences between the two approaches for certain crops in certain environments. There is no shortage of anecdotal evidence (always taken with a large pinch of salt) from farmers who claim they have experienced an overall yield boost after switching to organic farming. It is interesting to read that such gains are often only achieved after a few growing seasons which likely reflects not only an adaptation by the farmer but the gradual improvement in soil quality over time. A key aspect of organic farming, while shunning chemicals (unless they fall under a strangely arbitrary list of ‘natural’ chemicals, much to the mirth of many scientists, such as the insecticide pyrethin which, while industrially made, is naturally occurring in Pyrethrum’s – so is organic!?), aims to maintain soil quality through crop rotations (cycling through nitrogen fixing plants like legumes), cover cropping and minimal tillage/ploughing. Such techniques could be more widely applied to help remedy and reverse the degradation in soil quality in many conventionally farmed areas. Some conventional farmers are aware enough to employ crop rotations and lay fields to fallow (the EU even funded this before), however, perhaps not enough and degraded soils lead to more fertilizer being required to maintain those high yields keeping farmers on an unsustainable treadmill. Much evidence for the yield gaps have come from experiments where either chemicals were added (i.e. fertilizer) or not of course resulting in clear differences however, it is bad science to relate this to the debate as it ignores all the other approaches organic farming employs to boost yields like composting (check the source of your claims!). Another key aspect of the yield gap is just how much research and development has gone into each approach with billions being spent developing and optimizing many crops for intensive farming while a fraction of the money has been spent optimizing organic farming methods. I for one think far more funding and research is required to optimize, not necessarily organic farming in stricto but its associated approaches to boost its yields and minimize the requirement for inputs. The closer we can afford to move towards organic farming, the better.

    Another side of organic farming, very different to agriculture and often ignored in the debate, is how it's applied to livestock. While regional rules vary, organic meat and milk must generally be free from antibiotics (unless the animal is actually sick after which it requires a quarantine period before it becomes organic again and is especially banned for the ludicrous purpose of growth promotion) and hormones and must be fed on non-GM feed. While I am personally comfortable with a GM diet, one concern is that meat and milk are reared on crops (principally soy) in the first place which could have fed us more efficiently (whole other story here). While there is nothing saying organic meat can’t have been reared on non-GM crops, the rules surrounding organic meat and milk mean that animals generally receive far more pasture (often being free-range) than their intensive counterparts which reduces their dependency on feed. This stems not only from the overall ethos of raising animals more naturally, but from the ban on antibiotics which makes indoor crowded rearing infeasible as infections spread rapidly (often helped by the animals being stressed and unhealthy). Current intensive livestock farming has brought with it a suite of animal welfare and human health issues most people are not aware of as few of us ever visit a farm (you’d be hard pressed to even see most livestock which can spend their whole lives in sheds), however, the negative health effects from antibiotic use both in its contribution to growing antibiotic resistance and the potential effects on consumers (along with hormones) are rightly receiving considerable attention. Whether it’s on welfare or health grounds, organic meat and milk have potential benefits but these are not guaranteed by the label alone (get informed!). Some argue that intensive livestock farming can be done to high welfare standards and as the culture of ubiquitous antibiotic and hormone use is decreasing is some parts of the world (indeed banned in many) it means that, like with agriculture, ‘conventional’ approaches can be viable options in many parts of the world when weighed up against other factors.

    While not exhaustive, I hope to have at least highlighted the ridiculous nature this bogus debate has descended to. It is not one or the other. There will always be those on both sides who think exactly this, will not be reasoned with and will refuse to meet somewhere in the middle and reach not what I’d call a compromise but a solution. Food production is a complex business with many components small and large and vested interests pushing their agendas. Food production is also the cornerstone of all of our existence and its safeguarding is too important to get caught up in ideological squabbles although of course its importance means that it almost inevitably does. All too often, the embracing of ‘conventional’ farming has been the easy option of politicians with its ready made package of proven technologies and products that promises to feed the masses. The problem is it is largely unsustainable and the hard path needs to be taken to transition to sustainable food production that adopts technologies and concepts from the buffet on offer helping feed people for generations to come.

The Power In and Under the Waves

I live in the UK which is a relatively long thin island (with many smaller satellite islands) in which you are never more than 112km from the sea. The total coastline, at almost 12,500km and even more when the satellite islands are included, would take you over one quarter of the way round the world. For me, this wealth of coastline could offer so much more than blustery cliff top walks and a gateway to fishing and should play a major role in future energy supplies. Currently, the seas do play host to large wind farms but the energy potential under and in the waves is truly huge. A number of pilot plants have been developed around the world with a number of large scale plants in various stages of fruition. The energy sources in the seas can be split into three main types: Tidal, wave and ocean currents which I will discuss in turn. I will also touch on a fourth and special case of osmotic power or blue energy.

    Tidal power is particularly promising in the UK where some of the highest tidal ranges in the world are found. An important and notable project in the pipeline is the Swansea Bay tidal lagoon which will occupy a large part of the bay being encompassed by a 9.5km wall. The concept of such tidal lagoons is simple: As water fills and empties the lagoon depending on the tides it runs past and drives turbines 4 times a day (there are 2 tidal periods per day). This project is largely privately financed but benefits from government incentives which take the form of guaranteed prices for the energy eventually produced (like with nuclear in the UK). Such installations are on truly large scales but they payback with huge outputs with this plant designed to produce 320MW; enough to provide energy for 155,000 homes which is more than the 106,300 estimated households in the whole of Swansea! This lagoon, as a blueprint for future tidal lagoons, rightly aims to add to the coastline offering not only energy but recreation opportunities including a seawall walkway, rockpools, sailing and art installations if the claims are to be believed. The body behind the Swansea Bay project are planning a ‘fleet’ of tidal lagoons around the UK (4 in Wales and 2 in England) at spots particularly well suited due to high tidal ranges and have plans to expand globally. This makes the success of the Swansea Bay project so important for the future of the technology as a proof of concept allowing people to see how we can make the most of our coasts to power significant areas with minimal environmental cost, especially as this is likely to become a tourist attraction in its own right.
     A second type of tidal power plant involves the placement of turbines on the sea bed which has the advantage of being discreet, easily installed and scalable. These act much like underwater wind turbines with the movement of water due to tides flowing over the turbines to generate electricity. The Paimpol-Brehat Tidal Farm in France is currently the worlds largest such installation with an 8MW capacity from the four 22m heigh turbines which sit just below the surface. I mentioned scalable and, as such plants are modular (each module is a turbine), more can be added and hooked up to the grid as needs dictate. Their lack of a visual presence is a plus for many but a key benefit is the ease of installation with minimal disruption to the sea environment. Most construction is carried out on land with the turbines being lowered and secured to a modest platform on the sea bed. 

    Tidal is great but what about those places that have very small tidal ranges and plus tides oscillate between maximums but pass through midpoints where no energy can be generated making them predictable but intermittent. So what about some more constant sources like waves and currents? Capturing the energy from ocean currents relies on much the same approaches as the underwater tidal turbines except that rather than oscillating, the currents tend to flow in the same direction much like a river offering the potential for more constant energy production. However, suitable locations for such plants need to be close enough to land to reduce electricity transport costs while still tapping into the strong currents. One such place might be off the coast of Florida where the Gulf Stream flows close by and is being explored by a crowd funded company Crowd Energy. One area of concern for such plants, depending on this technologies success, is that they do not suck out too much energy from the currents which could affect the rhythm and circulation of the oceans affecting both marine life and the above ground climates.

     Wave energy aims to capture the energy stored in waves (formed by wind in the first place) which are limited to the waters surface requiring floating or just below the surface devices. There is a lot of energy in waves, and there is a plentiful and regular supply of them, however, the technical challenges in harnessing their power are significant. The simplest way of harnessing wave energy is by converting the vertical or horizontal movement into rotational movement to drive a generator in a wave energy converter (WEC) and these simple concepts are explained in this short video with the hinged set-up explained more here. While there are a broad range of possible WEC designs, the principals are generally shared and a steady flow of electricity can be produced by these plants and transported for use on the land. There are, however, two other common applications for WECs, the first in pumping sea water into reservoirs on land and in secondly in water desalination. These couplings aim to solve two separate issues but both maximise the coastal environment. Pumping sea water into reservoirs allows for energy storage through potential energy as discussed here meaning excess wave energy can be stored for when other sources are unavailable or during power surges. The use of WECs in desalination plants means this power hungry process can be carried out sustainably and can provide human usable water for coastal areas or small islands which often suffer from a lack of fresh water. The use in desalination also segways nicely into my last section on osmotic power. 

    Osmotic power (a.k.a blue energy) is a relatively old concept that is slowly emerging from its experimental pupae but could be another useful local energy solution. It is principally a local solution as it requires a unique environment; namely a river estuary where fresh and salt water mix. To tap this energy, a membrane must separate the fresh and salt water. This separation can then be used in a number of ways including pressure-retarded osmosis and the creation of ‘salt batteries’. The pressure approaches rely on the movement of water from fresh water to salt water across a water permeable membrane in a clever chamber system such that this movement changes the pressures of specific chambers (a change in volume=a change in pressure) and these changes can be used to drive a turbine. The salt battery, or reversed electrodialysis, set-up harnesses the chemical energy found in the gradient of ions between the salt and fresh waters to generate a voltage as explained here. This technology is an exciting prospect and is being pursued in the sea embattled Netherlands where the Afsluitdijk dam pilot plant is up and running with plans to massively up-scale. With a theoretical 1MW being derived per 1m3 fresh and salt water, they have hopes for the plant to supply energy for a whopping half a million homes! 

    I hope I’ve illustrated some of the incredibly promising ways we can harness the power of the seas in ways that are inventive but often elegantly simple, sustainable and effective on large scales. Future energy demands require a mixed energy policy and with almost 170 countries having over 100km of coastline, the potential of the untapped energy in these waters is huge. So the next time you look out over a brooding, tumultuous sea (or watch a video of one online) reflect on the power of and under the waves and how it could power your next cup of tea.

Renewable Energy Storage

Green energy technologies are often criticised on the grounds that they cannot provide a steady supply of energy, nor can they provide energy when the wind stops blowing or the sun stops shining. The primary issue here is with energy storage to overcome this intermittency. One high-tech solution in the development pipeline is the development of large and efficient chemical batteries – something being worked on by Tesla. There are however a number of drawbacks with such technologies including inefficiencies as the energy can often decay or leak over time, very high cost and their components have their own environmental problems with their extraction and disposal. Despite these issues, when these, and other, issues are cracked the potential of these batteries is great. There are, however, a number of ‘low-tech’ options which I would like to discuss which could indeed be cleaner, cheaper and often a little more off the wall than a chemical battery (literally in the case of the Tesla Powerwall).

    Many low-tech energy storage options make use of gravity allowing energy to be stored as potential energy which has the advantage of not depreciating over time. A common principal is to use excess electrical energy to raise a mass which then can then be ‘dropped’ in a controlled manner when needed to drive a motor or generator and thus regenerate electrical energy. Check out the ‘gravity light’ for a very small scale example of this idea which is summarised in three steps below.
    1) Excess electrical energy used to raise a mass.

    2) The energy input is now stored as potential energy.
    3) Dropping the mass back down converts potential energy back into electrical.
A good option for the mass, especially in wet and hilly places, is to use water, pumping it up hill into a reservoir before releasing it down through turbines. This has the advantage that dams or reservoirs can be pretty big meaning more mass and therefore are able to hold significant amounts of potential energy. Other possibilities include lifting actual solid weights however these are only really appropriate for smaller scale operations such as for individual houses. This is because you need very large masses to store and generate significant amounts of energy. However, it is not too hard to imagine a house that has an array of solar panels able to use some of the energy on a sunny day to crank up a heavy block of concrete (or other potential waste material like scrap metal) before dropping it down through a high resistance hydraulic turbine to power the lights and TV at night before raising it back up the next day.

    The concept is relatively straight forward and there are as many ways of implementing it as the imagination allows and one example in particular has caught mine and others attention. A left-field suggestion for using this concept has been cooked up which looks to reuse existing resources and infrastructure in America, namely trains and train tracks, and will work particularly well in the drier parts. The idea involves using excess energy from wind and solar plants to drive electric motors on heavily loaded trains to move them up hill. When needed, the trains rumble back down hill and now turn the electric motors the other way so acting as generators to produce electricity. This system has some advantages over vertical lifting systems of solid weights, which generally need unrealistically tall lifts to operate at such levels, as the trains on tracks act more like water being able to run along slopes rather than vertically and therefore are scalable (just strap on more loaded carriages). 

Beacons of hope?

    Another really exciting, but slightly less low-tech technology being developed for energy storage I wanted to include here is high-temperature solar thermal. The concept here is the use solar energy to directly heat a medium such as water, salt or oil and the release of heat can be used to drive steam turbines to produce electrical energy. Some of the most interesting examples of these include so called 'power towers'. Here, thousands of mirrors track the sun and concentrate its energy on a central tower where salt is heated to extremely high temperatures (over 500°C) such that it melts. This hot molten salt is stored in insulated tanks to minimise heat loss and then this heat can drive a steam turbine when power is required and especially at night. The first working commercial example of this, an 11MW plant that uses water rather than salt, was set up in the hot, sunny dry south of Spain. Morocco, another hot and dry country just across the straight of Gibraltar, has also been investing (or rather been invested in by the EU) heavily in solar and was even touted as a potential base for providing solar for west Europe (investment, not charity!). They have recently finished the first stage on a plant that aims to produce 580MW with up to 8 hours energy storage using molten salt as the storage medium but with a different design to the power towers. Despite solar energy being in plentiful supply in these locations, water is not which is a problem as a lot is required not least in cleaning the mirrors (although a dry cleaning method is being developed) to keep them shiny and effective! 

    As I hope you can see, there are alternate options out there to help make more sustainable energy sources more reliable and our slow progress should not be blamed completely on a lack of energy storage systems, it is still largely a lack of will and investment. A range of smaller scale low-tech options exist which means poorer regions can benefit from green(er) energy despite not being able to afford the expensive batteries when they arrive. Our future energy solutions will require imagination and policies that match and optimise the local conditions – one size does not fit all.

An Introduction to the Issues with Publication in Science and the Three Tier Publication System - a possible solution?

Scientists live in fear under the mantra ‘publish or perish’. This simple phrase has far reaching ramifications that many believe are harming both the reputation and integrity of science. The culture most scientists find themselves in is that their ‘value’ is measured by both the volume and ‘impact’ of their published work. Herein lie two problems. The first begins when researchers ask themselves, ‘how many papers can I get out of this?’ Most researchers, especially those in ‘un-sexy’ fields, are unlikely to ever get ‘high impact’ papers and so go for volume. At its worst, this can mean work is split up and spread thin. I’m sure many researchers are also familiar with trying to whip and fluff an otherwise stray dataset into a small paper. The second of our problems relates to ‘impact’ with high impact papers being used as an inappropriate proxy for good science. The allure of high impact journals such as Nature and Science can prove an all too tempting a carrot and has led to high profile fraud scandals but its effects can be more subtle. One major problem is the urge to overstate claims in a bid to make findings more attention grabbing and sensational. While the liberal use of bold language in abstracts and discussions may not bring about the downfall of science, it is symptomatic of an unhealthy culture where results are analysed with one eye on positive findings and the other firmly shut to anything that might mess up the ground-breaking paper. Instead of considered caution we have a culture of bold claims and superlatives.

    These issues, among others not discussed, have negative knock-on effects most notably on robustness and integrity – two words I feel make for a far more suitable mantra. Science is suffering from a well-documented reproducibility crisis as highlighted by one survey which found 70% of researchers have failed to replicate others results while half also failed to reproduce their own. In less anecdotal fashion, scientists from a biotech company tried to reproduce results from 53 ‘landmark’ papers in oncology, only succeeding in 6 (Begley and Ellis, 2012). There are a number of other such examples. While there are many reasons for low reproducibility, these findings are very worrying as they erode trust in the scientific process. They also have very tangible effects by, for example, contributing to rising cancer drug trial costs as a high proportion of pre-clinical results turn out to be no more than flashes of fools gold. The current system of publication and the evaluation of a scientists worth no doubt contributes to this worrying problem as papers are either rushed out with minimum requirements (insufficient replicates and inappropriate statistics), contain cherry picked data and are topped off with a not-so-healthy dollop of bluster and exaggeration.

    There have been no shortage of suggestions to remedy the current state of affairs but action has been lacking because the current system works just well enough and discoveries are still being made (and at least some are real!). But just well enough is not good enough as science is at risk of eroding away at its cornerstones: robustness and integrity. I’d also like to introduce another aspect of science which has long been in short supply: transparency. The current publishing system goes some way to promoting secrecy and rivalry which, while not always a bad thing, can be to the detriment of science. Collaborations have long been an integral part of science bringing together complementary teams to maximise productivity, spread ideas and even unite otherwise political enemies. To remedy the issues outlined here, many possible changes both big and small have been suggested but here I’d like to outline the skeleton of an admittedly radical alternative three tier system which could foster an all-round healthier, more connected scientific community.

    The first tier involves the publication of progress reports every few months much in the same way most (good!) scientists maintain a lab book basically including methods and data (with judicious use of censorship if appropriate). The second tier involves the publication of proto-papers every year or so when certain landmarks in a project are reached. These are intended to allow the easy digestion of results using good figures and also framed by introductions and discussions. Such proto-papers would not be traditionally peer reviewed but published in the way pre-print versions are now in repositories such as arXiv, bioRxiv, ChemRxiv and engrXiv. The final tier would be a more traditional peer reviewed publication. All three tiers would be linked using the magic of the internet under a project name and with all associated members linked to their contributions. The three tiers also allow interested readers to drill down into increasingly more detailed levels depending on their level of interest. Firstly, such a system would greatly increase transparency reducing the level of fraud, cherry picking of data and improper statistical analysis. The first tier could also greatly reduce redundancy as lab groups with overlapping interests might be encouraged to either collaborate more often or steer clear of too much overlap. The second tier of proto-papers allows the rapid dissemination of findings avoiding the frustrations of the peer review system in this regard. The proto-papers could also (again through the magic of the internet) be live documents with versions updated as new data rolls in as well as acting on suggestions and comments from peers. Such peer review-lite could be a powerful tool in increasing the robustness and integrity of research as interested readers might very well look into the first tier data and methods and spot inconsistencies or suggest improvements. The lack of any significant gap between data analysis and publication in proto-papers also means that people worried about being scooped need not as the time stamps of work are there for all to see and any ‘cheats’ can be quickly called out. What this should all mean is that the final published peer reviewed papers should both be fewer in number and higher in quality.

    A very important and intended side effect of all this is to alter the way we assess scientists. This system could be used to more accurately assess the contributions of individual researchers through their work output and ability to develop ideas and projects, all easily accessed at the click of a button. Potential employers would then have a tool to measure far more than just the number of papers a candidate has either sweated their way, or ‘networked’ their way, onto to. Of course this proposed system is far from perfect, but science is in need of a shake up or it risks becoming irrelevant through a loss of power in what it can achieve and, importantly, a loss of the general public’s trust. A dynamic and open system would also be greatly conducive to collaborations allowing the greater flow of ideas and knowledge, a science environment I know I want to be part of.

Can Coca-cola Stop the Tide?

There has been a growing consensus over the years that our ever increasing sugar intake is strongly linked to obesity, type II diabetes and heart disease. Sugar is everywhere being an almost ubiquitous component of processed foods (just check the ingredients of almost anything in your cupboard) and a major constituent of fizzy drinks, supposed ‘sports drinks’ (e.g. lucozade) and fruit juices. Standard coke contains a whopping 11% sugar which amounts to 35g in a single 330ml can which is already over the recommended daily allowances of the NHS (30g), the WHO (25g) and the American Heart Association (AHA) (37.5g). This all before you've consumed anything else that contains sugar or indeed is broken down into sugar like starch. Studies suggest that UK children and teenagers are on average consuming closer to 70g per day with adults only cutting down to around 55g. Those guidelines are even a little conservative (especially the AHA!) and many experts believe the guidelines could be slashed further and avoiding sugar completely is a perfectly reasonable approach.

    I don’t want to go much into the science behind why sugar is bad for you here, maybe in another post, but I’ll summarise two principal mechanisms by which it causes harm. First it's important to know that what we know of as table sugar is sucrose. This is the most common sugar in plants found in fruits, sugar cane and sugar beet and is a composite made up of equal parts glucose and fructose. Glucose is the primary energy source of our body and is also derived from breaking down complex carbohydrates such as starch as found in bread, pasta and other grains like rice. Too much glucose in our blood causes spikes in insulin. Insulins job is to mediate the uptake of glucose from our blood into tissues and to convert it into glycogen in the liver for storage. Abusing this system by flooding ourselves with sugar over years can lead to insulin resistance whereby insulin becomes less and less effective meaning you lose control of blood sugar levels leading to type II diabetes. The other dark side of our sugar addiction is the harmful effects of fructose. The thing with fructose is our bodies do not treat it like glucose. It can only be metabolised in the liver where it, for example, feeds into fat synthesis, is associated with what is known as metabolic syndrome and does not induce leptin production which tells our brains we have eaten. It is not particularly good stuff. Check out this website for more information.

     So given this little background, I wanted to talk a little about the ways some big players in the sugar world have been trying to hide these things from us. Diet and health are complex fields with so many external factors such as lifestyle and our genetic predispositions playing big roles. This complexity gives wriggle room for countless diet fads and questionable claims. Getting reliable data either supporting or rejecting various claims can often take a long time which also means a lot of money. The situation with sugar is in many ways similar to climate change where the science is complex and, while a consensus has emerged in both situations among experts, powerful vested interests exert their influences to muddle the debate by spreading doubt and confusion. You only need to look at the list of climate deniers and where their funding comes from to see how clear this conflict of interest is. Like oil, sugar is huge business and the big companies can flex their financial muscles to exert significant influence. For example, Coca-cola have been shown to have influenced research by funding work that seeks to blame lifestyle rather than diet. You can see from this paper an example of research biased by funding from the Coca-cola company and as such sugar is not discussed, only lifestyle and exercise. This is bad scientific practice and flies in the face of genuine unbiased research which should ideally be free from such blatant conflicts of interest. See this interesting article which gives some insight into the authors of the paper in which they defend their work. 

    Whether or not their work is good or bad science, this highlights the cynical approach by Coca-cola which funds anything that looks into alternate causes of obesity and diabetes besides sugar. The idea with this highly cynical approach is to say to people that lifestyle or other dietary factors (like fat) are to blame, not the sugar. Yes, people in general should exercise more and eat less in many parts of the world but exercise is not the main route to weight loss (diet is the key) and nor is simply eating less necessarily a solution – it’s what you eat less of. The different food types (e.g. sugar, fat and protein) are not equal and are not treated equally by our bodies and what has become clear is that it is in fact sugar, and in particular fructose, that is disproportionally to blame for obesity. The misdirection by vested interests has translated into the idea that all these ‘treats’ can be enjoyed as part of a healthy lifestyle. Think how often you see various big brands (like Coco-cola, McDonald's or Mars) sponsoring sports events which both serves to promote a brand image associated with active healthy lifestyles but this is also part of this multifaceted approach to distract from the real problem – diet. 

    The influence of the Coca-cola company is immense with millions spent on lobbying the American Government each year. Interestingly, this expenditure sky-rocketed in 2009 which was (not) coincidentally when the famous you-tube video, Sugar: The Bitter Truth, came out and more generally the spotlight was shifted to sugar and its harmful effects. Yes yes, we all know that companies lobby (and often more directly bribe) governments all round the world and it’s a largely accepted part of politics but the influence of Coca-cola also spread to charities. In 2010, the charity Save the Children were embarking on a sugar tax campaign in light of the fast emerging strong evidence that it was a leading cause of childhood obesity and health problems. This charity was then the beneficiary of multi-million dollar donations from Coca-cola and PepsiCo and low and behold, their campaigns shifted away from sugar tax and onto promoting healthy lifestyle and exercise (are you seeing a trend yet?)! Thankfully, however, the idea of a sugar tax has gained more traction in the intervening years and has come (or  will be very soon) into effect in many countries (South Africa, the UK, France, Denmark, Mexico (who have a huge sugar problem), Norway and the USA including others). The UK’s sugar tax, due to come in in 2018, is being fought tooth and nail by soft drinks companies who are now, rather than flat out denying the effects of sugar, are using the language of collective guilt (it’s not just the drinks fault, what about the chocolates!) and casting doubt on the effectiveness of a sugar tax in actually cutting obesity. Now these companies and pressure groups are not against this tax because it will hurt sales by increasing the cost of each drink although it might. A far more damaging side effect of this tax is the psychological effect a tax will have. Far more than simply being a financial disincentive, this tax legitimises the findings that sugar is generally bad for you. It is a major step to changing public opinion on sugar whereby the negative health effects will be more widely recognised as people think ‘well it’s being regulated, so it must be bad’. This is what the food and beverage companies are so afraid of happening and what will really harm sales.

    Even if the evidence behind an issue is confusing and not accessible for a non-expert (which most of us are), when a company with very clear vested/financial interests in one outcome or the other gets heavily involved to direct the argument, alarm bells should start ringing. For the same reason that the tobacco industry so blatantly denied, discredited and lied about the now obvious health impacts of smoking, the food and drink industries are throwing shadows across an important modern health issue that continues to wreck havoc on peoples health. Diabetes and obesity continue to rise with huge impacts on individuals lives as well as health services. Just like the bad effects of smoking became accepted, one day we will look back and think how naive we were about sugar. Just like tobacco is addictive, so too is sugar. Just like the tobacco industries were forced to pay out huge sums in lawsuits for lying about sending countless smokers to early graves following an undeniable body of evidence and shift in public opinion, so too will there be lawsuits against the food and beverages industry. However, just like the tobacco industry survived these ‘sticky’ patches, so too will Coca-cola, PepsiCo and the like as they are just too big to collapse and their delay tactics mean that public (i.e. consumer) opinion is slow to change allowing them time to adapt and probably tuck some money away for the rainy days to come. They cannot stop the tide, but they are doing a good job of slowing it.

    I’d recommend people to read up more on the effects of sugar and find the easiest way to cut it down in your diet. You don’t need it, we can get plenty of energy from other food sources, and too much is almost certainly doing you harm. Eating plenty of fibre with sugars and carbohydrates in general (including starch) helps moderate our bodies uptake of sugar reducing insulin spikes and reducing the chance of developing diabetes.

EXTRA READING: A longer but excellent article putting this subject into the wider context of our growing modern health epidemic relating to sugar. Crucially, it explains why obesity (and the related diabetes) is not an 'energy-balance disorder'.

An Uncomfortable Scenario

As a follow on from the previous blog about human evolution and cultural buffering, I wanted to play out some hypothetical, and possibly uncomfortable, future scenarios. One question I asked myself, as others have like Isaac Asimov in ‘A Choice of Catastrophes’, is what if we ‘buffer’ ourselves too much from nature? Are there any risks? Specifically, I am referring to the build up potentially deleterious mutations in a world where negative selection and so called purifying selection is significantly reduced. 

    To help explore this scenario I would like to introduce an analogy: Each successive mildly deleterious mutation adds another small item of baggage to the pack on someone’s back (this represents our genetic mutation load). As this pack grows in weight, another helium balloon is tied to it so masking the weight for the person and allowing him/her to go about their business (these balloons represent our clever cultural buffering). Now in this scenario I’m sure you can envisage a few things that could go wrong, besides having difficulty fitting through doors.

    Scenario 1: There is the dramatic case of a number of balloons being burst at once. In this case, people are quickly overloaded and are at risk of being crushed. Now selection would get to work and many people would find it all too much and collapse under the weight of their pack whereas a lucky few will by chance be better adapted to cope with the extra weight, will survive and reproduce children also able to cope. Now this scenario is frighteningly a distinct possibility with the rise of antibiotic resistant super bugs and the potential ‘post-antibiotic era’. Antibiotics have played a HUGE role in extending life expectancies and helping people fight off infections for the last 100 years or so. In our analogy, we are flying a model helicopter blindfolded around our balloons. Given our current reckless use of antibiotics in both medicine and agriculture, it is only a matter of time before we crash into our bunch of balloons unless we remove the blindfold and carefully land that helicopter safely on the ground.

    Scenario 2: A less dramatic scenario, but perhaps more insidious, is if we consider what happens when the production of new helium starts being outstripped by the weight we add. In this case we will reach the carrying capacity of our balloons and not be able to support any more baggage. One possibility here is if the pace of medical progress falters possibly because there is finite headroom into which to advance. One thing about humans, however, is that we have a knack of pulling the rabbit out of the hat with seismic advances in technology and understanding. Another angle is if the mutation rates increase which has been predicted to happen given our increasing exposure to mutagens and even our increasing age of parenthood. This scenario is harder to predict but something like the excellent film ‘Children of Men’ is a possibility. For example our increasing load may reduce fertility levels as the development from egg and sperm to baby is incredibly complex and genetically finely tuned. The increasing levels of infertility may be allowed to grow if families tend to have less children (already the case in many European countries). This would prevent any more ‘fertile’ people having more fertile children to re-populate as they would simply have children younger (or conceive easier) and stop there (using increasingly effective contraceptives, male pills coming soon!) while those less fertile would take longer to conceive, possibly having children later but would also just about reach their quota of one or two. Over time this precess would get harder and harder.

     So what are the possible solutions for our increasingly burdened descendants? Well assuming we navigate global disasters for long enough we might need to fight this hypothetical monster created by our technological advances with… more technological advances! A not too distant reality will be precise and simple genome editing (it is already possible and being carried out in human cells for research purposes in China and the UK with, suitably enough, a view to understanding infertility). Combined with a deeper understanding of what genes do, we could simply correct serious faults. Now I know this is a can of worms with enough ethical dilemmas and many obvious problems so I’ll leave it here and let that be a discussion for our future wiser selves. Yeah right.

UPDATE:  A recent study has demonstrated how caesarian sections have likely resulted in an increase in women with birth canals too narrow for natural birth. This represents a good emerging example of the issues discussed here. Before caesarian sections, women with narrow birth canals (due to narrow hips) would frequently die in childbirth often along with the child meaning the genes for narrow hips were 'purified' from the gene pool. Now, quite rightly, these women are given a chance not only to survive childbirth but keep their children who may well inherit the narrow hip genes. The modest 10 to 20% increase in the prevalence for narrow birth canals over the last 50 years is likely to rise still further given the medical necessity to save lives and the right and desire for women to have children. If we imagine a hypothetical scenario in which caesarian sections can no longer be performed (such as if antibiotics could not be relied upon) then we could see a widespread return to women dying in childbirth or such women avoiding childbirth completely as the buffering effect is lost!