How bad can foot eczema be?

shoe-1029734_640I remember hearing a woman interviewed on the radio a few years ago. She was claiming income support (welfare) and lamented that she was unable to attend job interviews because she was allergic to shoes. This was at a time when the press were vilifying any unemployed people who appeared ‘undeserving’ of welfare payments. In the prevailing mood, it was difficult to accept the foot condition as a valid excuse.

At the time, even though I had already succumbed to severe hand eczema, foot eczema was just an abstract idea, something for my imagination. I felt thankful it was only on my hands, bad as that was. But I did develop eczema on my feet, and it was only a matter of months after that radio interview. And it turned out, I had become allergic to my shoes.

IMAG0847-adjusted-small
Foot eczema

It was bad. The itching was intense. Tense blisters appeared, making it impossible to put shoes on. I had to sleep with my feet hanging over the edge of the mattress, as I couldn’t stand even the weight of my feet on the bed.  I was thankful that I was able to work at home for several days, as it was impossible for me to leave the house.

Eventually, I had some patch testing. It revealed that I was allergic to two rubber accelerator chemicals (vulcanisers), which commonly occur in the rubber found in the soles of shoes. I still remember studying the vulcanisation (creating a polymer) of rubber in A level chemistry.  These substances can also be found in the adhesives used in joining leather.  As shoes become worn in and are exposed to moisture, the chemicals leach out and come in contact with the skin. Step number one – know your enemy!

Translating chemical names into which shoes you can wear is something else entirely. Shoes don’t come labelled conveniently with things such as ‘contains thiuram chemicals’ or ‘contains carbamates’. The dermatology advice was to ‘wear all-leather shoes with no inner sole (like moccasins), plastic shoes or wooden clogs. If you have difficulty acquiring shoes without rubber insoles, remove the insoles before wearing and replace with those cut from piano felt, cork, or plastic.’ Try going into a shoe shop and asking what their insoles are made of! Try removing the insoles from women’s shoes.  As I suspected that simply sweating was also a likely factor in my eczema, I was keen to avoid plastic shoes too. The advice was also to discard old socks, as they can harbour the harmful chemicals.

I bought some wooden clogs online, and discarded all my socks. Hobbling around with my sore, bare feet (not yet able to go sock shopping) in wooden clogs, I began my campaign to find wearable shoes.

SatraFootwearI contacted Satra Technology, a company based in Kettering, UK, known as a ‘leading technical authority for footwear and leather’. They advised me on alternatives to leather or plastic soles. Interestingly, thermoplastic rubber (TR) and crepe are not vulcanised, so they were safe. Also, I could look out for polyvinyl chloride (PVC), polyurethane (PU) and ethylene vinyl acetate (EVA) soles. Try going into a shoe shop and asking what their soles are made of.

Some shoe retailers were more helpful than others. I was very relieved to find that my recently acquired Trespass walking boots could get the thumbs up – the only rubber component was the outer sole – the midsole and insoles were fine. I discovered that many shoe manufacturers source the leathers and various components from all over the world. It was almost impossible for them to vouch for the exact materials used, especially the glues. Even craft shoemakers relied on glues/cements to keep their leathers in line.

The only assurance I could obtain on leather adhesives was with Gore Tex.  Clarks informed me that glues were not used in joining the uppers and linings of Gore Tex shoes. I was also very thankful when I found Easy Wellies, who made it extremely easy to search their stock for PVC boots and garden shoes.

I eventually had to give up on asking about the cements in leather shoes. My life was slipping away week by week, with one manufacturer after the other unable to give assurances on this. I was becoming tired of existing in PVC wellies and wooden clogs (and my hefty walking boots).  Step number 2 – avoiding the enemy – was proving very hard.

These days, my first stop for shoes is Hotter. Many, but not all, of their styles use polyurethane for soling. Yes! Quite a few of their styles contain elastic (made with rubber?), so I avoid those. Their customer services department is very helpful and will bend over backwards to research the various materials in their shoes. I buy their leather shoes on the understanding that one day I might have a reaction to the leather cement, although apparently they use it sparingly. I just try not to sweat.

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Is ageing inevitable?

I started writing this article when ageing was again in the news, this time in connection with shift workers. We have mounting evidence that working night shifts can accelerate ageing and decrease longevity. But what is ageing exactly? And can we protect ourselves against it?

Edward_S._Curtis_Collection_People_086

Although we can see and experience getting old as a process of ‘slowing down’, becoming forgetful, and the accumulation of skin wrinkles and grey hair, it takes study at the cellular level to appreciate what is actually happening. Studying the internal workings of cells reveals unimaginable complexity and the inevitability of the ageing process. We will be hard pushed to come up with any elixir for longevity.

‘Longevity’ simply means a long life. The longest life on record is that of a French woman Jeanne-Louise Calment (1875-1997) who lived to nearly 123 years old. The biological world describes longevity as a phenotype – a set of observable characteristics of an individual resulting from the interaction of their genes with the environment. You might ask, then, how is the interaction between genes and environment affecting our longevity and causing us to age?

Our genes are strung together on chromosomes inside each of our body’s cells. Humans have 46 chromosomes in each cell. During growth and renewal, certain cells divide to produce new cells. A lifetime average is 10 million cell divisions every second. The genetic code perpetuates by processes of chromosome replication, followed by orderly separation of the duplicates in the creation of a new cell. We tend to think that each cell division faithfully reproduces and passes on the genetic blueprint, but this is far from true.

Aneuploidy

Take aneuploidy, for example. Chromosome separation sometimes goes wrong during cell division. The result of this is that some new cells may have more than or less than 46 chromosomes. Cells can usually limp along in these cases, but they have lost their vitality – in other words, they show signs of ageing.

Mutations

Mutations are probably the genetic errors with which we are most familiar. Simply put, they are random changes occurring in the genetic code within a chromosome affecting a single gene or a larger piece of the chromosome.

Telomere shortening

Telomeres
Image of chromosome, with telomeres indicated pink

Another mechanism involved in cellular ageing is telomere shortening. Telomeres are specialised pieces of DNA that cap the ends of all chromosomes. Without a telomere, the integrity of a chromosome is severely threatened. This may result in the chromosome ends forming loops by joining together, and serious difficulty in replicating at all. Critically, each time a cell divides, the chromosomes naturally lose a fragment of telomere – they progressively shorten until they eventually reach the end of the line.

Epigenetics

Epigenetics is a fascinating topic involving the study of gene expression. Certain structures within a cell are able to ‘switch’ genes on and off. Epigenetic mechanisms are what makes different body tissues do their specialised jobs – all our body cells contain the same genes, but only some are turned on.  In a chromosome, proteins known as histones form packaging material that helps to condense over 2 metres of DNA to fit into the nucleus of each of our cells. Subtle changes in these histones can interfere with their control of gene expression.

The effects of all this interference with the expression of the genetic code in our cells accumulate over time. The structure and function of the molecules that maintain the cell deteriorate with ageing, leading to a decline in the function of the cell. As the number of declining cells increases, so our bodies age more. This fits Edward Masoro’s classic definition of ageing as deterioration with advancing age, which increases vulnerability to biological challenges and hinders an individual’s ability to survive. This interpretation of ageing is also known as senescence.

Returning to the night-shift workers, the point is made that sleep is essential for enabling our body systems to replenish themselves. Upsetting normal wake-sleep patterns seems to trigger harmful processes – perhaps we do not handle sugar, stress, or appetite quite so well, for example. Toxins might not be cleared up quite as efficiently as normal.

Whether or not we work shifts, our bodies are continually mopping up harmful chemicals and dealing with the effects of bombardment by solar and other background radiation. Harmful chemicals can be external pollutants or by-products of metabolism. The more we can do to maintain our bodies in a healthy state, the better equipped we are to fend off these threats.  In the long run, though, it seems we have little defence against advancing senescence.

I gleaned much of this information through studying a free MOOC in Futurelearn: ‘Why do we age? The molecular mechanisms of ageing’  A very steep learning curve, but well worth the effort!

Do anti-ageing diets really work?

Three years ago this month, Dr Michael Mosley demonstrated ‘the power of intermittent fasting’ on the BBC programme Horizon.  He based his argument for this regime on evidence that had been mounting for some time that calorie restriction can prolong life.

However, many scientists challenge these assumptions, partly because of a lack of consistency between the various studies on monkeys, mice, rats, and even fruit flies. A review published in 2014 recognised that calorie restriction diets might be inadvertently correcting pre-existing imbalances in nutritional intake in the laboratory animals.

A team of researcher in Sydney took a different approach. They already knew that individuals who were deficient in certain growth factors did not suffer from cancer or diabetes, both of which are associated with the ageing process. They also knew that production of these cellular growth factors required particular amino acids. As amino acids are the building blocks of protein, it made sense to explore the effects of differing amounts of protein in the human diet. They analysed the proportion of protein in people’s diets, drawing on an existing national USA dataset. They also had access to health and mortality information about the people in their sample.

The Sydney team discovered something quite remarkable. Among the age group 50-65, high animal (not plant) protein intake was associated with shorter lives. This high protein group were almost four times more likely to die from cancer, when compared with the low protein group.

For those aged 66 plus, however, the tables turned. For this older group, longevity was associated with high protein intake. Those with a high protein intake were far less likely to develop cancer than those on low protein diets.

These are early days yet, and it is likely to be some time before any clear dietary recommendations can emerge. Much of the current advice for slowing the ageing process is based on having a good intake of antioxidants, dietary fibre and omega-3 fatty acids.

Antioxidants are purported to help moderate DNA damage – genetic mutations and chromosome damage – which can build over time and gradually disable more and more cells. Dietary fibre helps to moderate things such as the sugar and fats in our blood, as well as helping to maintain a healthy bowel. Omega-3 fatty acids are ‘good’ fats, for which many unproved claims are made, and even the case for promoting heart health is debated.

Does improving health through diet increase longevity? Having healthy heart and bowels may not protect us from the inevitable march of cumulative DNA and chromosome damage. Even the link between free radicals and antioxidants may not lengthen life.

It seems we have a long way to go before we can stop ageing in its tracks, but I suspect that many of us would opt for a moderately long and healthy life rather than simply a very long life.

Potato wars

Many a time I’ve picked up a potato when preparing a meal and asked myself is it too green? How green does a potato have to be before you discard it? A quick internet search soon reveals conflicting advice. The Food Safety Authority of Ireland gives a reassuring message that most of the toxins in a green potato are near the skin, so peeling will remove most of the harmful substances. However , if they still taste bitter once cooked, it would be best to discard them. Medline Plus the US National Institutes of Health’s Web site produced by the National Library of Medicine, the world’s largest medical library, takes a more cautious approach, advising never to eat potatoes that are spoiled or green below the skin, and to always throw away the sprouts.

Photo of potatoes, some green
Beware the green potato!

So, what is all the fuss about? The harmful substances we are concerned about in green potatoes are known collectively as glycoalkaloids (GAs). Although we mostly hear about the glycoalkaloid solanine it is accompanied by chaconine, which is more toxic. They are present throughout the plant and protect it from insect pests and fungal infections as well as deterring herbivores. This is definitely good news for the plants! The trick that potato growers need to pull off is to preserve these protective properties in the green shoots while keeping the GAs in the actual potato tubers (the bits we eat) as low as possible.

photo of a whole potato plant
Whole potato plant

One well-kept secret is that all potato tubers contain GAs, even the white ones. If you weigh 50kg, you would need to eat 100mg or more of GAs before you are at risk of developing symptoms of abdominal pain, vomiting, and diarrhoea. 100mg of GAs is typically present in only one kilo of non-green potatoes, although that is a lot for a small person to eat in a day. Peeling potatoes can remove half of the GAs, depending on how thick the peel is, for instance. The average potato consumer should be safe, although there are individual variations in susceptibility.

That is not the whole story. Some varieties of potatoes have much higher levels of GA than others. Behind the scenes of the supermarket shelves, scientists and farmers have been waging a quiet war against certain varieties of potato that have been found with dangerous levels of GA.  Sweden has outlawed one potato variety, which has over three times the recommended maximum levels of GA. GAs also fluctuate in all potato varieties according to growing and storage conditions. Any damage to the tuber causes a local rise in GAs.

A green potato is a signal of a GA ‘hotspot’, a protective response by the plant to exposure of the tuber above the soil. The green pigment itself, chlorophyll, is harmless. Removing the green parts of the tuber does indeed greatly reduce the amount of GAs left in the potato. Some GAs are also lost in cooking, but mainly though leaching into the cooking water as they need very high temperatures before they are destroyed. Unfortunately, the ‘lazy cook’s’ method of microwaving whole potatoes for a quick meal is a sure way of carefully preserving all the GAs present.

Am I still going to eat potatoes? Yes. Am I going to throw away any green potatoes? I might be more likely to in future.

Information sources:

  • Machado, R. M. D., Toledo, M. C. F. and Garcia, L. C. (2007) ‘Effect of light and temperature on the formation of glycoalkaloids in potato tubers’, Food Control, vol 18, no. 5, pp. 503-508.
  • Mensinga, T. T., Sips, A. J. A. M., Rompelberg, C. J. M., van Twillert, K., Meulenbelt, J., van den Top, H. J. and van Egmond, H. P. (2005) ‘Potato glycoalkaloids and adverse effects in humans: an ascending dose study’, Regulatory Toxicology & Pharmacology: RTP, vol 41, no. 1, pp. 66-72.
  • Valcarcel, J., Reilly, K., Gaffney, M. and O’Brien, N. (2014) ‘Effect of Genotype and Environment on the Glycoalkaloid Content of Rare, Heritage, and Commercial Potato Varieties’, Journal of Food Science, vol 79, no. 5, pp. T1039-T1048.

Image credits: Chase Studio / Photo Researchers and JANE SHEMILT / SCIENCE PHOTO LIBRARY, both of Universal Images Group

In praise of Brassica oleracea

 

Cauliflower
Cauliflower

There can be few edible plant species that are quite as impressive as Brassica oleracea. It is difficult to appreciate that Brussels sprouts, cabbage, kale, cauliflower, brocolli and kohl rabi all belong to this single species. I sometimes liken it to the domestic dog, in all its glorious breeds and varieties, originating from the wolf, Canis lupus.

Brussels sprouts
Brussels sprouts

Brassica oleracea vegetables are a good source of Vitamin C, although the levels of this vitamin are heavily dependent on growing and storage conditions as well as the preparation method. Brocolli and sprouts retain their Vitamin C much better than kale during storage, an indication that growing your own kale and picking and eating on the same day are well worth it. Vitamin C is commonly accepted to possess therapeutic properties protecting against cardiovascular disease, cancer, supporting the production of collagen (e.g. in skin and bones), and promoting iron absorption.

Cabbage
Cabbage

In addition to Vitamin C, Brassica oleracea is also a good source of Vitamin E and carotenoids (the most well-known carotenoid is beta-carotene, the chemical that gives carrots their characteristic orange colour and gives us Vitamin A). All these vitamins act as antioxidants in the body, mopping up toxic compounds known as free radicals, and protecting against malignancy.

While the evidence in support of vitamin supplements is weak, the health-promoting effects of eating vegetables such as brassicas are gaining ground. Moreover, scientists are beginning to suggest that the unique chemical make-up of brassicas can boost health in ways other vegetables cannot achieve. Brassicas happen to be very well endowed with phytochemicals, which are substances derived from plants, that support human health. Phytochemicals include vitamins and a range of other substances that have active biological effects on our bodies.

Kohlrabi
Kohlrabi

One of the key health-promoting components of Brassica oleracea are glucosinolates, which are phytochemicals unique to brassica vegetables.  As with Vitamin C, glucosinolates can be lost or damaged during cooking by mechanisms such as breakdown by plant cell enzymes, heat degradation, and leaching into the cooking water. A recent investigation of cooking methods found that steaming, microwaving at high power and stir-frying helped to reduce the amount of these valuable compounds lost in cooking, in comparison to boiling or fermentation.

Stir-frying brocolli
Stir-frying brocolli
Purple sprouting brocolli Credit : Nigel Cattlin / Photo Researchers / Universal Images Group
Purple sprouting brocolli

Glucosinolates have a role in promoting the health of the liver and in protecting against cancer. Plant breeders and food scientists are beginning to work together to find ways of improving glucosinolate content, durability and better ways of processing our vegetables to further enhance their health-promoting potential.

If you are keen to grow your own, it’s a good idea to check your soil acidity first. You can obtain very inexpensive kits online or from your local garden centre. Brassica oleracea is susceptable to a fungal disease known as club root in acid soils. So, if your pH turns out to be less than 7, you should consider adding lime to the soil. The best time to do this is when you dig the soil over in the winter. Growing your own is highly rewarding, and the plants can look quite magnificent.

Kale growing Credit : Food and Drink Photos / Universal Images Group
Kale

Photo credits Universal Images Group: Brocollli and Kohlrabi – Nigel Cattlin;  Brussel sprouts – Michael P. Gadomski; Cabbage and cauliflower – Dorling Kindersley; Kale – Food and Drink Photos; brocolli stir-fry David Munns / Science Photo Library

Related articles

Forget the antioxidant pills https://theconversation.com/forget-the-antioxidant-pills-just-stick-with-veggies-45409

Brilliant brassica http://blog.tgac.ac.uk/brilliant-brassica/

Living with hand eczema

Have you ever experienced extreme itching and burning on your fingers and hands? If your skin erupts in clusters of tiny blisters filled with clear fluid, it’s possible you have a type of eczema called pompholyx. This is something I have personally been dealing with and trying to make sense of for the last two and a half years, and it seems a fitting subject for my first blog entry on the topic of health and science.

http://upload.wikimedia.org/wikipedia/commons/0/00/Finger_Pompholyx_1.tif
Finger Pompholyx 1

About 10 percent of people experience hand eczema, and it has a considerable impact on quality of life. It can be caused by contact with irritant chemicals or allergic reactions to non-irritant substances, and it is often claimed that emotional stress or a history of childhood eczema are key factors. Heat, cold, and sweating are also common triggers. Its impact on quality of life can be due to the centrality of our hands for every aspect of daily living and the extreme inconvenience of available measures to minimise exposure to hazards and to protect sore and itchy skin on fingers and hands. Itching is the number one source of distress, and itching on hands can be particularly harrowing.

The physiology of itching is still poorly understood. It is likely that certain chemical (e.g. insect bite) or physical (e.g. wool fibres) stimuli activate itch receptors that cause the brain to interpret the sensation as an itch. One of my personal theories is that the pressure of tense pinpoint pompholyx blisters onto the itch receptors also aggravates the itch. The inevitable scratching makes the skin sore and over-sensitive. Use of steroid creams and ointments leaves skin very dry and even more sensitive. Once the blistering has exhausted itself, the skin often starts to peel off. In my case, this occurred in the areas where the blisters had previously appeared.

Flakyhand
Peeling fingers and palm

At the peeling stage, loss of the tough epidermal layer that normally protects hands from wear and tear leaves the skin particularly fragile and vulnerable. When this first happened to me, I became acutely aware of how I used to take the skin on my palms for granted. Without this layer, I was unable to handle paper without causing my fingertips to bleed from the friction, and all sensations (heat, cold, touch) were magnified and distorted.

The epidermis also forms a barrier against micro-organisms. The bacterium Staphylococcus aureus commonly colonises the skin of people with eczema. This bacterial colonisation aggravates eczema. I have had some protracted episodes of skin flaking and erosion as a result. As you can infer from the close-up of my thumb, this state makes normal life impossible. Even the cotton gloves I have come to rely on would get caught up in the rough (and surprisingly sharp) edges of peeling skin.

Photo of infected and flaky thumb
Infected and flaky thumb

It is important to seek medical advice in case of infection. Extreme cases result in skin breakdown to the extent that the skin becomes ‘raw’ and tissue fluid weeps out. Cotton gloves are frequently recommended for protecting hands when carrying out any tasks that involve coming into contact with irritants. As many of these situations involve getting hands wet, thin vinyl (or PVC) gloves over the top of cotton gloves can provide a waterproof layer. These PVC gloves are not very strong when doing heavy cleaning or gardening jobs, and it is possible to get hold of thick PVC gloves if you have allergies to rubber or latex. I often wear these over the top of cotton + thin PVC gloves, as it makes it easier to slide the thicker gloves on.

Finding a soothing emollient cream or ointment and applying frequently is also important. It can be easy to just soldier on and hope the problem will go away, but if it doesn’t, make sure you get medical help. Probably one of the most useful things to consider with persistent hand eczema is to get some patch testing done. Patch testing involves applying a range of known contact allergens to the skin on the back for 48 hours, and then observing for signs of inflammation. In the UK, you will need a referral to a specialist clinic by your GP.

Here are a few online sources of useful information: http://www.patient.co.uk/doctor/Eczema-on-Hands-and-Feet.htm http://www.patient.co.uk/doctor/pompholyx-pro http://www.eczema.org/

Severe hand eczema: Major new clinical trial compares treatments “head to head”. http://www.bbc.co.uk/programmes/p03tqv2c