Posts Tagged science

Green is Good?

You may have heard that exposure to nature can improve your health*. There are also many trends floating around the Internet that claim to leverage the benefits of nature to improve your physical and mental health. While proponents claim to be driven by evidence, is there really evidence that nature can improve your health? And if so, is it really necessary to reorganise your daily life, drive out to the wilderness, and/or buy expensive accoutrements in order to leverage the benefits?

Popular Claims

Among the most prominent trends is earthing or grounding, a practice popularised by a variety of holistic health devotees, from nature-loving vegans and Ayurvedic enthusiasts to paleo and primal dieters and Silicon valley biohackers. The trend is based on the idea that the earth has a negative charge; but that modern life bombards us with positive charges, creating an imbalance and reducing our ability to combat free radicals. The benefits of grounding touted by advocates are vast, from reducing jetlag to balancing hormones and normalising blood pressure.

A large field under a blue almost cloudless sky

At its most basic, grounding advocates suggest we simply spend more time walking outside on soil and grass in bare feet; but many advocates also promote grounding mats, blankets, shoes, sheets, bags, and a variety of other devices to counteract modern life and provide ready (and overnight!) access to the benefits of the earth through an electrical charge. Most of these sites enthusiastically link to studies, but any effects seen in these small studies are miniscule and potentially the results of design flaws, as described in a recent segment of Skeptics with a K.

Forest bathing is an older cousin of grounding, referring to the Japanese practice of using your senses to soak in the forest atmosphere. Increasingly popular outside of Japan, it has a small number of researchers who suggest it is not only a way to combat the psychological stresses of increasingly urban life but also a way to combat cancer, lower blood pressure, and boost immune function. Although one would think this is a fairly solitary endeavour, as with many holistic practices, its Western reinterpretation includes guided group visits and sometimes even hugging and speaking to trees.People walking along a footpath surrounded by trees

Understanding the connections between exposure to nature and human health

For most people, the idea of sleeping on a specially designed electrical mat and wandering around barefoot in forests are beyond what they are willing to do for health. Access to nature can also be challenging for city dwellers, and in most developed countries, more than 75% of the population lives in urban areas. In the UK that number is over 90%. While cities offer many benefits, urbanisation increases the incidence of a host of health problems and associated socio-economic costs. For these reasons, it’s perhaps more helpful to investigate what we actually know about urban green space and human health, to see if there are measurable benefits.

A tarmac road lined with trees

The evidence

A considerable body of research is developing, suggesting positive impacts of being in, and leaving near, green space. The amount of green space seems more important for perceived health than the amount of urbanisation, although certain groups may benefit more.

The benefits

Exposure to green spaces has been shown to relieve stress and promote relaxation, and has positive impacts on affect and reducing sadness, which improve cardiovascular disease outcomes and all-cause mortality. The effect may be amplified by the fact that people prefer green spaces for physical activity, making exercise and active forms of transport more attractive. Some studies have shown decreases in salivary cortisol and reduced blood pressure, with women potentially more negatively affected by lack of green space. Although some reviews have noted this effect is not consistent across studies.

Increasingly studies are looking at the dose of nature that we actually need to experience these benefits.  Most studies suggest that the required dose is likely relatively small (perhaps only 5-10 minutes on a given day). Benefits are evident whether you are merely looking at nature or exercising in it, although the latter, perhaps understandably, offers benefits more quickly. Lower rates of blood pressure and depression have been documented from just 30 minutes in green space per week. The shape of the dose-response curve is still in question.

A footpath beneath lots of trees with sunlight shining through

Countering harm

It is also worth noting that green space can contribute to reducing air pollution, which is a major contributor to poor human health outcomes. This effect is direct, in that vegetation can reduce greenhouse gas emissions and reduce pollutants such as particulates (PM10), carbon monoxide (CO), ozone (O3), and nitrogen and sulphur oxides (NOx and SOx). Green space makes walking and cycling more attractive. This contributes not only to improving air quality via reduced vehicle use, but the increased physical activity has associated health benefits.

Green space can also reduce the urban heat island (UHI) effect, wherein cities are hotter than surrounding areas because of the prevalence of dark surfaces such as asphalt and concrete. UHI also contributes to poor air and water quality. By lessening this effect, green spaces can improve the urban environment, decrease health impacts of heat and even reduce mortality from heat waves.

Caveats within the literature

There is a lot of academic literature focusing on the connections between human health and urban green space**. This literature is both theoretical and empirical, and methods are a mixed bag. For example:

  • Self-reported data from individuals on perceived improvements in health (usually gathered via questionnaires)
  • Correlations between access to green space and population-level data
  • Direct measurements of key indicators (e.g. blood pressure, heart rate, salivary cortisol) either linked to exposure or accessibility of green space.

What constitutes health varies across studies, with the first two categories often adopting a fairly broad definition that includes physical health as well as mental health (especially anxiety and depression) and broader indicators such as happiness, life satisfaction, and social cohesion.

A body of water with a bridge in the background and trees on either side

As with all social and health research in the “real world”, teasing out causal relationships is difficult. Confounding factors are controlled for, to an extent, but there are so many causal factors that complicate the issue. For example, people prefer to exercise in green space, but green space tends to be more scarce and of lower quality in areas with multiple social, economic, and health deprivations. However increasing green space (and improving its quality, addressing personal safety issues, etc.) can also improve these indicators.

Conclusion

Spending more time in green areas, whether forests urban parks, is likely to offer you some health benefits and encourage you to be more active. The great news is that it needn’t take much of your time, and no special mats, shoes, blankets, or spiritual guides are required. Green spaces also address some of the environmental problems in urban areas, providing benefits for both people and nature.

Dr Sarah Clement standing in front of a wall and smilingDr Sarah Clement

Sarah is a faculty member in the Department of Geography and Planning within the School of Environmental Science at the University of Liverpool. Her research focuses on environmental governance, science-based policy, and nature-based solutions. She is particularly interested in how reforming policy and practice can enable better ecological, socio-economic, and democratic outcomes, particularly during periods of rapid environmental and social change.  Sarah has worked in the field of environmental science and policy for 16 years as an environmental consultant, researcher, and environmental policy advisor in Australia, the UK, and the USA. She is also on the board of the Merseyside Skeptics Society. She spends most of her spare time hiking in nature, travelling, lifting heavy things, adoring her cat, and documenting all of these in pictures. She tweets as @DrSarahClement, and posts said pictures on IG @umsfromumbridge.

 

Footnotes:

* The most widely used definition of ‘health’ is from the World Health Organisation: ‘physical, mental and social well-being, not merely the absence of disease or infirmity’. Operationalising and measuring this concept is a major challenge that leads to the variety of measures discussed here.

** Also called “green infrastructure” and “nature based solutions” in the literature and public policy. To complicate matters, “blue infrastructure” (i.e. water) is often, but not always, embedded in these terms.

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Gene edited crops arrive in the UK!

The observant skeptic might have noticed a brief flurry of media activity at the end of May that discussed a field trial of gene edited crops that is being conducted at Rothamsted Research in Hertfordshire (1, 2).

You might think, “So what”? There have been loads of field trials on genetically modified crops over the years, why is this news?

Not so, this trial is different as the devil is in its details. This is a trial of both genetically modified (GM) crops AND a trial of gene edited (GE) crops.

This is the first UK field trial of GE crops so although the difference might seem minor it could be extremely important for the future of scientific research and crop improvement in the UK and throughout Europe.

In general, GM involves the addition of foreign genes to your crop of interest. Classically this has included genes from bacteria that confer herbicide or insect resistance. However more recently has included the production of Golden Rice (3) and purple tomatoes (4) both of which have potential health benefits.

All skeptics will know that the debate surrounding the use of GM has been extremely controversial and currently the growth of these crops is prevented throughout the EU. The regulation of these crops is complex but unfortunately in the court of public opinion the positive case for the use of GM has been mostly lost due to the activity of those organisations that fundamentally oppose this technology.

Gene Editing is similar to breeding…but better.

GE is subtly but importantly different to GM. This technique allows the precise modification of genes that are already in the organism without the long term addition of a foreign gene (5). In turn this could alter some growth attribute of the plant. This allows scientists to use their knowledge of plant biology to predict how this alteration will alter crop growth, test it in the lab before applying for a field trial license if the results look good.

Importantly GE is a modern cousin of mutagenesis, a process that has been the genetic basis of conventional breeding throughout the history of agriculture. Over millennia humans have selected new crop varieties that are more nutritious or better suited to different growth conditions, the results of which is the food we eat every day.

Conventional breeding relies on random mutagenesis that ultimately takes many years to develop new varieties. GE allows scientists to target these specific mutations to improve crop growth and therefore remove the years that breeding can take. Importantly the end-products of GE are essentially identical to the products of conventional breeding so why should they be regulated differently?

A figure depicting the difference between genetic modification and genome editing as described in the text

The newly approved field trial at Rothamsted is really a test-case for the regulation of GE crops. The scientists have produced varieties of the potential oil crop Camelina sativa that will allow them to better understand lipid metabolism. At this time the crops won’t be used for food or feed but critically the UK Government Advisory Committee on Releases to the Environment (ACRE) has determined that this GE crop does not need to be regulated like GM crops, mostly because it contains NO foreign DNA (6).

This indicates that in future ACRE will regulate GE crops differently to GM crops and therefore might offer future opportunities for scientists and breeders to develop potentially useful crop varieties.

Unsurprisingly the EU is in regulatory limbo

This decision comes in the light of continued EU delays in a ruling that will decide the fate for the growth of GE crops across Europe. Recently there have been promising noises coming from the EU but as yet this decision has not appeared (7). The decision by ACRE shows that, like Brazil, Argentina, Sweden and the USA (8), the UK has a progressive and evidence-based position for the use of GE crops and is potentially great news for scientific research.

Skeptics: get the facts!

Over the coming months I predict that we will hear plenty about the debate about GE crops so I urge skeptics to arm themselves with facts about the differences between GM and GE. This will allow us to inform our family, friends and colleagues about the benefits of GE and that it really uses the same technique as conventional breeding but is just much cheaper, quicker and more precise!

Promising times ahead for the UK plant science community.

 

Dr Geraint Parry, PhD

Geraint is the national coordinator for GARNet, which is a network that supports uptake of new technologies and knowledge dissemination amongst UK and international plant scientists. He is the science communication manager of the EU INDEPTH COST Action (https://www.brookes.ac.uk/indepth/) as well as being the secretary for the Multinational Arabidopsis Steering Committee. He tweets for GARNet from @GARNetweets and personally @liverpoolplants

 

 

(1)- https://www.rothamsted.ac.uk/news/where-gm-meets-ge

(2)- https://t.co/G77fhPCc9S

(3)- http://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=16278

(4)- http://www.norfolkplantsciences.com/

(5)- The process of gene editing does involve the addition of a foreign gene but is removed during preparation for field trials.

(6)- https://www.gov.uk/government/publications/acre-advice-application-for-a-trial-of-gm-camelina-18r0801

(7)- https://www.rothamsted.ac.uk/articles/edits-mutations-and-gm

(8)- https://www.theguardian.com/science/2018/apr/07/gene-editing-ruling-crops-plants

 

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 GUTS! Does the GAPS diet cure autism?

The clean eating world is obsessed with guts! Your guts, my guts, your child’s guts…..even your dog’s guts. The recurring theme in clean eating dietary advice and health claims is that an unhealthy gut = disease. If you ‘cleanse’ your gut, either through diet or a course of enemas you will prevent and, more importantly, cure disease. One example of this sort of advice, and the reason I became interested in this particular area of pseudoscience, is the GAPS diet.

I first became aware of the GAPS diet after reading a blog post by ‘The Angry Chef’, where he dismantled some of the nutri-nonsense claims made by Jasmine and Melissa Hemsley (Ayuverdic tongue scrapers, Biodynamic eggs etc. Let’s not even go there today) and mentioned the GAPS diet being behind a lot of their ‘bone broth’ recipes and food philosophy. It piqued my interest so I decided to google it, and to be honest I wish I hadn’t. I went further and further down the ‘gut flora’ rabbit hole and ended up in a pretty scary place full of baseless claims, pseudoscience, anti-vax and bad science.

Text reading "mind the gap" from a train station platform

The GAPS diet

The GAPS diet was invented by Dr Natasha Campbell-McBride after her son was diagnosed with autism at the age of 3. She took matters into her own hands having decided that conventional treatments weren’t helping. GAPS stands for Gut and Psychology Syndrome and follows the premise that a wide variety of health problems (particularly psychological and behavioural) are caused by an imbalance of gut microbes, or ‘gut flora’. Dr McBride claims that an imbalance in your gut will lead you towards disease, she claims that autism and ADD, OCD, schizophrenia, epilepsy, depression, and many other conditions are all digestive disorders, but offers a ‘cure’ in the form of her diet plan.

The diet plan is complicated and long, it is recommended to be followed for years, rather than your typical ‘fad’ diets which are often crash diets lasting days or weeks, but it isn’t any less restrictive. There are 8 steps to the diet, the first one being the most restrictive. Step one consists of room temperature water, probiotics and bone broth (which must be made from scratch, you can’t use any store bought stocks, they contain all those nasty toxins and stuff). A worrying line in the introduction to the diet refers to side effects when introducing new foods. It states that if you experience black, sticky diarrhoea, pain or any other digestive distress stop eating the new food, leave it a week and try again. It is important to note that black diarrhoea can be a sign of gastrointestinal bleeding and a possible medical emergency. It should never be ignored, or left for a week! The introduction to the diet also recommends a ‘sensitivity test’ for new foods. Here you place a small amount of the food onto a patch on your wrist and see if there is any reaction…..seems legit.

After the initial stage you can slowly start to introduce other foods, beginning in stage 2 with eggs, but, they must be raw and they must be organic (yummy salmonella), along with homemade yoghurts and fermented fish. I barely have time to make myself a bowl of cereal in the morning, let alone having constant homemade broth, yoghurts, soups and stews on the go all week! And so the stages go on until stage 7 when you’re on the most permissive GAPS diet where some, unrefined starches are allowed.

a cracked raw egg on a black surface with an egg beater in the background

The GAPS diet is based on that classic nutri-nonsense idea of ‘detoxification’ of the body. The idea that our lifestyles and the food we consume are clogging up our bodies and minds, making us sick and fogging up our thought processes. By ‘flushing us out’, these diets can help our body to heal.

It is widely known that the liver and kidneys already do the ‘detoxifying’ bit. It’s kind of their job, and McBride does acknowledge this, but she thinks we need to give our body a helping hand in the shape of a few gallons of meat water, or by starving ourselves, which she believes helps to redirect our bodies energy to fight off disease….

So that’s the GAPS diet in a nutshell……but not a nutshell…because you can’t eat nuts on GAPS……so, in an avocado skin?…….or a chunk of hollowed out cow’s femur? Anyway! There isn’t much scientific evidence of this kind of restrictive diet being able to cure disease, or complex psychological disorders. In fact, there isn’t any evidence. There are no published studies on the GAPS diet and Dr McBride hasn’t produced any research or published anything backing up her claims. It is a dangerous way to go, advising people who are sick to go on such a restrictive diet, but she does, and there’s more.

McBride also believes and claims the following:

  • Children with autism are born perfectly healthy. Abnormal gut flora develops due to diet, and microbes passed from the mother, and makes them ill.
  • Breastfeeding is essential. If you are physically unable to breast feed your child use donated breast milk or a wet nurse. Bottle fed babies are going to develop abnormal gut flora and develop problems.
  • The contraceptive pill has had a ‘devastating effect on gut flora’, she doesn’t explain why.
  • She recommends smearing live yoghurt around and inside your vagina during your third trimester when pregnant to help ‘prepare the birth canal’ with beneficial bacteria. She also recommends doing the same to the armpits and breasts.
  • Big Pharma!
  • You should avoid vaccinating your child until they are around 4-5 years old, and even then, only if the child has a healthy, balanced gut flora.
  • Black elderberry is one of the most powerful anti-viral remedies known to man.
  • Using volcanic rock dust in organic gardening improves nutrition, and if used on a global scale, it would enable the soil to absorb enough excess atmospheric carbon to stabilize global climate change.

The upper arm of a child with a pink t shirt sleeve and a hand holding a syringe to the arm.

As previously stated, there is no published scientific evidence that any of the claims made by Dr McBride are true. The science is shaky and inaccurate. All the ‘evidence’ I’ve seen of the diet working has been purely anecdotal, from people on various forums singing the diets praises and attributing it to their improved health or the health of their child. Which brings me onto my main issue with this, the issue that made me wish I hadn’t investigated all this in the first place. The diet is directed predominantly at children. Children with complex behavioural and psychological problems, the thought of subjecting a child to this incredibly restrictive diet is worrying to me. You are essentially starving your child (albeit for a short period during stage 1 of the diet plan). Even when you reach stage 7 of the diet plan the diet is still extremely restrictive. A healthy balanced diet needs a bit of everything in moderation. Starving the body of sugar for example (unrefined or otherwise) is not beneficial.

The GAPS diet is an extreme, damaging, and potentially dangerous response to a problem that there is no evidence even exists. As with all clean eating fad diets, it preys on peoples’ fears, and offers a solution that seems too good to be true. Unfortunately, it nearly always is.

 

Karin McClure

Karin has been actively involved in skepticism for 4 years and has been involved with the Merseyside Skeptics for 3 years. She has given talks on the pseudoscience around diets and health at QED
Skepti-camp, Ignite Liverpool and Merseyside Skeptics and has been interested in diet and health for 3 years. Karin is also an artist and has sold her work at events around the country and online, information can be found on her website lunalynes.wordpress.com where she also shares posts about her experiences with mental health, as well as art updates.

 

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Unsexy Kale as a Superfood?

As a scientist I’m not particularly impressed with ‘superfoods’ and the idea that certain products have special properties above and beyond conventional nutritional value. Over recent times the diet industry and media has advocated that amongst others, goji berries, beetroot, blueberries or green tea will provide incredible health benefits. The NHS website has looked into superfoods and states that although many of these foods are a healthy option the scientific evidence for any ‘super’ claims is not strong. A well balanced diet is much more important than eating any particular single item.

One such superfood that piqued my interest is Kale, a particularly unsexy plant that appears to sit apart from the other more trendy (and colourful?) foodstuffs. Therefore I was interested to read a recent meta-analysis of the published data about the potential of Kale as a superfood.

Brassica Breeding

Kale is subspecies of Brassica oleracea that has been bred to have more leafy, errr leaves. This species of Brassica is remarkable as other subspecies include a fellow superfood candidate broccoli, hated Xmas ‘treat’ brussel sprouts, boring cabbage and cauliflower, each of which have been bred for different beneficial traits.

a diagram showing the evolutionary background of cabbage, brussel sprouts, kohlrabi, kale, brocolli and cauliflower which all derive from Brassica oleracea

The supposed ‘super’ characteristics of Brassicas result from a high level of glucosinates and antioxidants. Indeed Beneforte Broccoli has been bred to contain higher levels of glucoraphanin. However even their home website will only stretch to a ‘might’ when considering its benefit on cardiovascular health (3).

Kale has been an important part of the human diet for millennia and although it contains many important phytochemicals (plant chemicals) any ‘extra’ beneficial effects in humans have had very limited testing.

The Science

Many ‘superfoods’ are defined by their high levels of antioxidants. These chemicals act as important scavenger molecules that ‘mop up’ damaging free oxygen molecules (termed free radicals) that are produced are part of regular cellular processes. These radicals can indiscriminately damage DNA, which can lead to the formation of cancer if the damage occurs in certain important genes.

A study from 2008 showed that Kale has a higher amount of antioxidants when compared to other Brassicas, including broccoli. However it is extremely challenging to decipher whether it has anti-cancer properties as performing these type of studies in humans is very tricky! A useful proxy test comes from the study of the plant extracts on the growth of tumour cells in a petri dish. Some of these studies have shown that where extracts from Kale, as well as from sprouts and cabbage, have no effect on the growth of normal human cells they will reduce growth in some cancer cell lines. This indicates that they do indeed alter the growth of cancerous cells. However in these studies Kale is no different to other Brassicas or for that matter, members of the onion/ garlic family.

A photo of green, leafy kale leaves on a white background

On a larger scale, Kale also might have legitimate benefits on gut and heart health by either altering potentially damaging stomach microbes or being able to reduce levels of harmful proteins that circulate in the blood.

Eat Kale but not ONLY Kale

The overall conclusion of this analysis is that the authors agreed that Kale, alongside other Brassicas, does have health benefits. Unfortunately and perhaps unsurprisingly there is no study that sets Kale apart from any other species of Brassica!

Overall it will come as no surprise to those skeptical about superfood claims that any benefits of Kale come from the fact it is a vegetable and not because it has some super-plant-power.

In short, keep a balanced diet and you can’t go too wrong!

 

Dr Geraint Parry, PhD

Geraint is the national coordinator for GARNet, which is a network that supports uptake of new technologies and knowledge dissemination amongst UK and international plant scientists. He is the science communication manager of the EU INDEPTH COST Action (https://www.brookes.ac.uk/indepth/) as well as being the secretary for the Multinational Arabidopsis Steering Committee. He tweets for GARNet from @GARNetweets and personally @liverpoolplants

 

 

 

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A List of Skeptical Things…

People are always asking me what skepticism is. As this is a notoriously difficult question to answer accurately in a few words, I tend to mumble something incoherent and run away. The same goes for questions about what happens at Skeptics in The Pub events. Trying to dispel the notion that we simply get together for a few drinks and slag things off is difficult to do in casual conversation. Especially as Skeptics in The Pub does occasionally fit that description. I would rather never have to answer these sorts of questions at all. The problem is that at the same time, I do want to convey to people outside of our strange little world what it is exactly that we do, and why it interests me. Why do I go to skeptical events at all? What first grabbed  me and pulled me into this world that so many of my friends and family think is some kind of science cult for the culturally depressed? Read the rest of this entry »

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The Mass Libel Reform Blog – Fight for Free Speech!

This week is the first anniversary of the report Free Speech is Not for Sale, which highlighted the oppressive nature of English libel law. In short, the law is extremely hostile to writers, while being unreasonably friendly towards powerful corporations and individuals who want to silence critics.

The English libel law is particularly dangerous for bloggers, who are generally not backed by publishers, and who can end up being sued in London regardless of where the blog was posted. The internet allows bloggers to reach a global audience, but it also allows the High Court in London to have a global reach.

You can read more about the peculiar and grossly unfair nature of English libel law at the website of the Libel Reform Campaign. You will see that the campaign is not calling for the removal of libel law, but for a libel law that is fair and which would allow writers a reasonable opportunity to express their opinion and then defend it.

The good news is that the British Government has made a commitment to draft a bill that will reform libel, but it is essential that bloggers and their readers send a strong signal to politicians so that they follow through on this promise. You can do this by joining me and over 50,000 others who have signed the libel reform petition at
http://www.libelreform.org/sign

Remember, you can sign the petition whatever your nationality and wherever you live. Indeed, signatories from overseas remind British politicians that the English libel law is out of step with the rest of the free world.

If you have already signed the petition, then please encourage friends, family and colleagues to sign up. Moreover, if you have your own blog, you can join hundreds of other bloggers by posting this blog on your own site. There is a real chance that bloggers could help change the most censorious libel law in the democratic world.

We must speak out to defend free speech. Please sign the petition for libel reform at
http://www.libelreform.org/sign

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