Fat lot of good
I read Jon White’s story on the dietary role of fat with a mixture of despair and amusement (2 August, p 32).
In the 1980s, I spent 10 years of my career at the European Commission in charge of food, refocusing legislation on safety and consumer information 鈥� such as nutrition labelling 鈥� only later to see the obesity epidemic inflate both waistlines and healthcare expenditure. Hence the despair.
Even with simplified presentations such as traffic light labelling 鈥� with green indicating that a food contains healthy levels of a nutrient, red the opposite 鈥� we should not have expected a public indoctrinated with simplistic concepts, such as the idea that “natural” must be “good”, to eat more sensibly.
It is hard enough to scientifically tease out the effect of specific nutrients on health from the complexities of food epidemiology and the variability of human beings, but it is much harder still to use what we know to persuade consumers to improve their health.
Perhaps the doctrine of Paracelsus that underlies all food toxicology, “only the dose makes the poison”, should be applied to nutrition. But how to persuade the consumer to take the right dose? Until we have figured it out, is more nutrition research really worthwhile?
Alcester, Warwickshire, UK
Fat lot of good
Research into the effects of dietary fat on disease has suffered from 40 years of distortion and misinterpretation. The establishment of an early consensus on very flimsy evidence, driven by very forceful personalities, has proved disastrous.
Take one example, the Multiple Risk Factor Intervention Trial (MRFIT), which involved over 12,000 middle-aged American men with high cholesterol. Half received treatment for hypertension, intensive counselling to quit smoking, and advice on changing their diet to lower cholesterol. The other half were told to address their health problems however they desired.
After seven years, the trial reported that mortality rates between the two groups were not significantly different.
The MRFIT results should have acted as a wake-up call, but because they did not fit with the by-then-established dogma, they were explained away by various means and quietly forgotten.
The history of research in this area is littered with poor science, muddled thinking and confusion, which is still with us today.
Waterlooville, Hampshire, UK
Too charming to die
Tim Vernimmen raises some important questions about how we should allocate conservation resources and which species we should save (19 July, p 38).
The broad thrust of his article is that we could focus on the ecosystems or species with the greatest phylogenetic diversity 鈥� put simply, those that are most genetically and behaviourally distinct. I agree this is very important, but other factors should not be ignored.
Keystone species such as the sea otter may not qualify in terms of phylogenetic distinction but their significant ecological influence must make them important targets for conservation action.
Likewise, charismatic megafauna such as tigers may get a low score for phylogenetic diversity, but their conservation will benefit a host of other species sharing their habitat, while they act as effective poster species for fundraising efforts.
Finally, it is important that conservationists take full account of the likelihood of success in deciding which species to adopt. If a creature has slipped far down the slope towards extinction, trying to save it would not be justified.
Newcastle upon Tyne, UK
Keep it above ground
Andy Extance draws attention to an important alternative to conventional geological storage of carbon dioxide, namely in-situ mineral carbonation (19 July, p 30). The idea is that reacting the dissolved gas with alkaline minerals deep within the Earth’s crust allows the carbon to be more safely and permanently stored.
Another alternative is ex-situ mineral carbonation. In this case, alkaline minerals such as olivine and serpentine are mined and milled, then mixed with CO2 in reactors above ground.
The processing costs are inherently higher, but a major benefit is the production of valuable by-products that can be supplied to the construction industry to pay for the process.
Leuven, Belgium
Alzheimer's drug
Andy Coghlan’s informative and timely article reported that the anti-arthritis drug etanercept showed promise in halting Alzheimer’s disease when injected into the bloodstream (19 July, p 10). But he failed to mention years of clinical, off-label use of the same drug for Alzheimer’s, administered by injecting it into the spine.
A decade ago, reports of a reversal in Alzheimer’s symptoms began appearing online, and journals have published case reports of this too. Some of the clinical outcomes have been exciting (Journal of Neuroinflammation, ).
Etanercept is a huge molecule and does not cross the blood-brain barrier. It would appear that injecting etanercept directly into the base of the brain might be necessary for delivering the maximum therapeutic effect in cases of Alzheimer’s.
Cupertino, California, US
It's good to talk
In making comparisons to computer language, perhaps both Thomas Webster (21 June, p 31) and Ian Lewis (12 July, p 27), underestimate the complexity of learning a foreign language, and thereby its positive effects in arresting mental decline.
Both types of language have vocabulary and grammar, but a spoken language also has auditory input and verbal output. These are more or less irrelevant in computer languages. Learning to identify “words” in a string of spoken sounds is a high-level skill that takes an adult years to develop. And reproducing those sounds in an understandable manner is a kinaesthetic activity involving numerous muscles, which also takes time and practice.
It would be beneficial to ask whether it is the mental stimulation and problem-solving associated with learning a language that slows mental decline, or if it is one or more of the features that spoken languages alone have.
A final possibility would be the benefits of human interaction: to learn a language one has to associate with a teacher and, usually, other learners.
Keighley, West Yorkshire, UK
Reckless fracking
Earthquakes and contamination of drinking water may well be the “most feared potential consequences of fracking”, (2 August, p 6), but a greater fear should be that of being trodden on by the elephant in the room.
Fracking simply means a continuation of blinkered business as usual, namely, the use of finite and non-renewable fossil fuels that will produce ever more atmospheric carbon dioxide.
Is anyone, anywhere, going to tell our children and grandchildren that because we must have a few sorry pence off the cost of our petrol, or a few extra percentage points added to GDP 鈥� a dangerously fatuous measure if ever there was one 鈥� there will be nothing left for them when dealing with the increasingly unstable climate we left behind?
Meols, Merseyside, UK
Let Detroit dribble
You report on concerns that shutting off the water supply to non-paying Detroit homes will inevitably result in a public health disaster (16 July, p 6).
In 2011, Auckland Council in New Zealand decided to limit the water supply for non-payers to 1 litre per minute, a fraction of the 15 litres per minute typical of a domestic water supply.
While this reduced rate is adequate for toilet flushing and handwashing, even specially designed low-flow shower heads require about 3 litres per minute to operate.
Perhaps throttling pipes to that rate of supply, allowing a meagre shower, would be both pragmatic and punitive.
Canberra, ACT, Australia
Free vote, free will
Your recent Last Word page details how different voting systems produce different results without revealing the “best” result 鈥� that is, the fairest and most democratic one (26 July).
There are deeper consequences, since the 100,000 billion “voters” that are our brain’s neurons and dendrites will likewise produce inconsistent results, and to make decisions in the face of inconsistency is what underpins free will. Self-awareness eventually emerges from free will, and consciousness follows.
An even deeper consequence is that computers could replicate this mechanism.
Edinburgh, UK
Wave ahoy
Mariners will beat a path to the door of anybody who can provide warning of imminent danger from freak ocean conditions (26 July, p 42).
However, the key to survival will surely be how much time is left to take evasive action. How far away is the monster wave and how long can it remain a monster?
An alarm that isn’t given in time for a ship to move out of the way is of little use, especially to merchant vessels which, unlike naval cheetahs that respond instantly to 20 degrees of wheel, take an age to turn and cannot rapidly reach their full speed.
Nonetheless, I think ship owners worldwide will be taking considerable interest in any project that can shed light on rogue waves.
Bridge, Kent, UK
Flush of success
I read with interest Adrian Barnett’s review of The Wastewater Gardener (2 August, p 46). Near where I live there is a wastewater pumping station which, in severe weather run-off conditions, will sometimes flood an adjacent field.
Months later, there will be an abundant crop of tasty, succulent tomatoes. The grey sludge has proved to be a perfect fertiliser for the crop.
I knew an old chap who worked at a sewage plant. He used to take the odd bag of sludge home to put on his vegetable and flower plot. Perhaps there is a lesson here?
Bletchley, Buckinghamshire, UK
Uncertainty principle
Ken Pettett writes to complain about the uncertain language used by climate scientists (19 July, p 32). Specifically, he compares this way of speaking to the strong language of business leaders and politicians, whose careers he says have never been ruined by a long-term prediction failing.
Science doesn’t work this way. Science is about assigning probabilities to outcomes through experimentation. Sometimes those probabilities will get very close to 1, but a scientist should rarely talk in terms of certainties.
London, UK
Bee content
Where are all these statistics on the decline of the bee coming from, and where are all the observations being made (2 August, p 7)?
I am a gardener and we farm 770 acres in the Cotswold hills. Much as we would like to be, we are by no means pesticide-free, yet we have never seen as many bees and other pollinating insects as in the last few years.
Why all the doom and gloom? We are in a very good position to observe, and we are seeing more insects than ever.
Leafield, Oxfordshire, UK
For the record
鈥� We exercised too much artistic licence in our article on William Latham and Stephen Todd. Their evolving images of organic life were designed in the 1980s, a decade later than we claimed (2 August, p 47).