Spinach, a superfood – fable, fact or just wartime propaganda?

If I had a pound every time a patient says spinach is high in iron in the clinic, I reckon I would be relatively wealthy. Also, if I knew what I was about to find out about this story whilst researching it, I would have looked into this much earlier. Thanks to Andy Brunning at compoundchem.com for the story background and links, a story of the importance of evidence and good referencing.

Although spinach is a green vegetable, which is particularly versatile and useful to include in a healthy balanced diet, the above infographic from Compound Chem shows the availability of iron from spinach is poor, unfortunately. So, what does it contain that is great for nutrition? Spinach is a good source of manganese, folate, vitamin A, vitamin K and fibre, which is excellent, as the fibre at least is an essential part of the diet if you are following a low fodmap diet. It is the content of polyphenols in spinach that bind with the iron rendering it insoluble, not the fact that it is a non-heam source, which is usually able to be absorbed, if a source of vitamin C is consumed at the same time.

The type of polyphenol compounds found in spinach varies but the example below accounts for the majority of polyphenol compound at 37.37 mg/100g FW. What no-one seems to have considered here is what effect microbial interaction in the bowel has on these polyphenols. Whether microbial digestion of these polyphenols affects their structure and whether this process helps the availability of iron to digestion. Interesting, Huh? Needs investigating – Yes!

http://phenol-explorer.eu

Many people assuming that spinach is high in iron is probably due in part to social history. Popeye, a cartoon character developed in 1931, ate spinach to give himself ‘strength’ – “I’m strong to the finish cause I eats mi spinach”. But an original report of the iron content of spinach was stated to have contained a decimal point error, that gave the iron content as 10 times more than the actual amount. This is what I was told, as a student from 2003-2007, although others report that this was an error of reporting the iron content of dried spinach as fresh spinach. But whatever the cause, the erroneous reporting of the content of iron from spinach being higher exists to this day and has consequences. This is a particularly pervasive nutritional myth that has been investigated and reviewed by Sutton and published in the Internet Journal of Criminology, see the link below, it is a fasinating read of failings to attribute data with references and looking for clues from original sources.

Spinach does have the same iron content as some meat, but the important point to note is the availability of the iron from both foods. Spinach is a poor source, and as I have stated before in this blog, micronutrients need to be absorbed for them to be useful to us, it is no good just looking at the bare numbers. Also, Sutton states it was, in fact, the vitamin A content that Popeye was eating spinach for. This may be true, as spinach is a good source of vitamin A, from carotenoids. But also reminds me of another UK wartime ‘fable’ of eating plenty of carrots to improve eyesight. Improved eyesight only occurs if someone has a severe vitamin A deficit and night blindness, no improvement is gained with those who have adequate vitamin A stores. I wonder if spinach was the USA wartime equivalent of the UK carrot propaganda? How ironic that would be!

Why are these stories essential to debunk? Wikipedia states that during the first world war spinach was given to soldiers who had suffered haemorrhage, presumably to ‘replace’ iron. It was delivered in red wine – presumably to ‘help’ absorption, by chemical conversion to increase the solubility, by the acidity of the red wine. Red wine also contains iron – but also contains polyphenols, which will also inhibit the absorption of iron – likely a double error occurred in this case, then. Another point to make here is that diet alone currently cannot be used to treat anaemia. Usually, iron sulphate supplements are the chosen option, containing 65mg per dose, (which can, by the way, have devastating effects on digestive symptoms for those with IBS. Sodium federate is perhaps a better choice and if you have low iron/anaemia and IBS ensure your doctor has investigated the cause.) Although less of a ‘tonic’ than it was supposed to be, a ration of wine during World War 1 was probably welcomed by the soldiers.

What does this have to do with IBS you might ask? Well actually, rather a lot, particularly for those people who are vegans. The Low FODMAP diet is low in iron as many foods such as pulses and dried fruit – good sources of iron for vegans are limited on the diet. This shows the importance of proper knowledge and the impact of following such a diet has on nutrition and health. The importance of seeing a registered dietitian cannot be underestimated. Other sources are watercress, kale and include allowed portions of pulses with a source of vitamin C – although to what degree the overall polyphenol content of the vegan diet might affect absorption is not established and unlikely to be so. Digestion is complicated, this is a fact.

Spinach does have some really great other nutritional benefits, but it is no more a superfood concerning vitamin A content than the cheaply available carrot, (spinach has marginally more vitamin A content) or a good source of iron. It is, however, a source of vitamin K that can prevent blood clotting problems. The recipe below can be made for those who respond to a low fodmap diet and others who are just interested in tasty recipes!

Cream of spinach soup

  • 100g Broccoli tops
  • 35g carrots
  • 70g celeriac
  • 200g spinach (fresh or frozen)
  • 1/4 teaspoon nutmeg
  • 1/4 teaspoon cumin
  • 1/4 teaspoon cinnamon
  • 2 tablespoons of lactose-free mascarpone cheese
  • 600ml water

Method

  • Chop the vegetables finely
  • Add them to a pan with 600ml water and spices
  • Cook till soft
  • Blend with a hand blender
  • Add the mascarpone cheese just prior to serving
  • Serves 4

https://www5.in.tum.de/~huckle/Sutton_Spinach_Iron_and_Popeye_March_2010.pdf

  1. Neveu V, Perez-Jiménez J, Vos F, Crespy V, du Chaffaut L, Mennen L, Knox C, Eisner R, Cruz J, Wishart D, Scalbert A. (2010) Phenol-Explorer: an online comprehensive database on polyphenol contents in foods. Database, doi: 10.1093/database/bap024. Full text (free access)
  2. Rothwell JA, Urpi-Sarda M, Boto-Ordoñez M, Knox C, Llorach R, Eisner R, Cruz J, Neveu V, Wishart D, Manach C, Andres-Lacueva C, Scalbert A. (2012) Phenol-Explorer 2.0: a major update of the Phenol-Explorer database integrating data on polyphenol metabolism and pharmacokinetics in humans and experimental animals. Database, doi: 10.1093/database/bas031. Full text (free access)
  3. Rothwell JA, Pérez-Jiménez J, Neveu V, Medina-Ramon A, M’Hiri N, Garcia Lobato P, Manach C, Knox K, Eisner R, Wishart D, Scalbert A. (2013) Phenol-Explorer 3.0: a major update of the Phenol-Explorer database to incorporate data on the effects of food processing on polyphenol content. Database, 10.1093/database/bat070. Full text (free access)


Is ginger useful for treating IBS?

Chemistry-of-Ginger-1024x724
http://www.compoundchem.com/2014/11/27/ginger/

The next ingredient to be reviewed is ginger. Ginger has many studies into its use to treat vomiting in pregnancy and to treat nausea during treatments such as chemotherapy or reducing sickness after surgery. Ginger has a long history of being used as a natural treatment for nausea, so one might expect that it could be used to reduce some of the symptoms of IBS. It is one of the most common herbal treatments used by patients to attempt to ameliorate symptoms of IBS (1). The action of ginger on the digestive tract is suggested to be an increase in prokinetic action of the tract (increasing movement or contractions without disrupting the rhythm) and it has also been suggested to be useful in pain reduction. The active ingredients in ginger can be seen in the diagram above and a placebo-controlled RCT parallel study in IBS (2) used the pharmaceutical grade ginger containing 2.29 mg/g of gingerols and 6-shogaols.  Raw and cooked ginger contain different chemical compounds and may have different modes of action on the digestive tract.

tea-599227_1920

The study had a good choice of placebo (brown sugar) tolerated by most patients with IBS. Study numbers were small – a larger trial with at least 100 patients per group would give a chance of better results. Larger doses appeared to give poorer results from this study, but the numbers in each group were small. We are aware that IBS is a very heterogeneic condition (wide variation in symptoms between people) and studying those people reporting more upper GI symptoms of IBS such as nausea and reflux plus constipation might improve results if the mode of action is to increase stomach emptying and increase digestive tract motility. The study, unfortunately, did not show that ginger was effective compared with placebo so we have therefore no evidence that ginger is an effective treatment for IBS.

ginger-1432262_1920

Does it cause harm?

Side effects in the study chosen were greater in the placebo group, the relevance for this is unknown – IBS is a challenging condition to treat with relapsing-remitting symptoms – no significance can be seen in regard to side effects as no statistics were applied to check whether this was significant in the study reviewed. Ginger is thought to be a safe treatment – ginger is also suitable to be used for the Low fodmap diet.  So a great tasting low fodmap ingredient – but don’t expect it will stop your IBS symptoms.

Just the ticket for a recipe then!

 

This is a very easy recipe to prepare and these biscuits can be stored in an airtight tin. They may go soft if not stored correctly.

Ingredients

325g Gluten Free self-raising Mix (I used Doves Farm)

1 tsp. xanthan gum

a beaten egg

75g muscovado sugar

75g golden syrup

75g butter

2 tsp. ground ginger

Method

Melt the butter, sugar and golden syrup in a pan then cool till the mix is only just warm

Beat the egg

Add the dry ingredients to a bowl and ensure the xanthan gum is mixed into the flour.

Add the wet ingredients to the dry and mix well till the mixture forms a dough.

Work this well.

Roll out the pastry dough into a thin sheet on grease-proof paper or a Teflon sheet and cut out the biscuits.

Add the biscuits to a greased baking tray and cook till golden brown in a moderate temperature oven – gas mark 4 or 180 degrees C

Makes around 30 biscuits (depending on what size cutter is used.)

1.Van Tilburg MA, Palsson OS, Levy RL, et al. (2008) Complementary and alternative medicine use and cost in functional bowel disorders: a six month prospective study in a large HMO. BMC Complement Altern Med. 2008; 8:46.

2. VAN TILBURG MA, PALSSON O S, RINGEL Y and WHITEHEAD WE (2014) Is ginger effective for the treatment of Irritable Bowel Syndrome? A double blind randomized controlled pilot trial Complement Ther Med. 22(1): 17–20. doi:10.1016/j.ctim.2013.12.015

 

Turmeric – medical jack-of-all trades, or just a great curry ingredient?

Chemistry-of-Turmeric
http://www.compoundchem.com/

Turmeric is a wonderful ingredient to add to a curry – it has also been exalted as a wonder food with lots of great benefits for health. Some of the more pervasive anecdotes with regards to turmerics ‘heath benefits’ are antioxidant, anti-inflammatory and anti-cancer effects and benefits for digestive health and IBS.

I have always had a bit of a problem with the anti-oxidant hypothesis in health, as an ex-polymer chemist, I was very experienced in protecting polymer products such as paints and adhesives from the effects of oxidation and environmental free radical degradation. This was not always easy to achieve – even the in simplest of formulations.

These free radical reactions do occur in our bodies – at a base level we are a very complex mix of chemical reactions and our bodies contain polymers. Turmeric is a polyphenol, and polyphenols do show anti-oxidant properties. With anti-oxidant protection, as a chemical reaction, one factor needs to be fulfilled – the anti-oxidant has to be situated at the site where the free radical reactions occur to be able to mop them up. Therefore any research involving turmeric in Petri dishes to observe it’s anti-oxidant (and anti-inflammatory or anti-cancer effects), or by feeding animals unsustainably large amounts may be very interesting, but far from proving it to be an effective anti-oxidant in our body. There is a problem with turmeric – it is very poorly absorbed in the digestive tract, it has poor solubility – therefore it would be difficult to transport it to the site of reaction. If the anti-oxidant cannot physically be transported to the site of free radical reaction, then it is clearly not possible for it to react! Until this problem is solved it is perhaps an entirely useless medical treatment, and of course, it needs to be studied in humans as a treatment, with randomized controlled trials and ultimately a systematic review. These problems can possibly be solved – by utilizing chemistry.

But…but…turmeric is ‘natural’, is the response, so therefore it is surely better for us than all those ‘chemicals’ in medicines? If you are going to use the anti-oxidant theory for the promotion of ‘alternative’ natural care, then you are buying into chemistry by using this as your argument. Spoiler alert – curcumin, the active compound in turmeric, is a chemical – see the infographic above. If it was effective it would be called a medicine, which may be possible in the future with lot’s more health research – but certainly, we are a very long way from this now. One research paper proposed turmeric as a jack-of-all-trades, in other words ‘useful’ for numerous health areas, which concomitantly also means master of none, an insightful figure of speech here, perhaps.

For digestive complaints, turmeric has a long history of use in Ayurvedic medicine as a compound which can be useful for indigestion, but with little strong evidence for effective use in either IBS or indigestion – just tantalizing pre-clinical trials and uncontrolled studies.

Past history has taught us that medicines are often derived from naturally occurring pharmacological plants, so research of turmeric should certainly continue – but we really shouldn’t be tempted to jump the gun with promoting turmerics alleged health effects, this is disingenuous.

So does turmeric have any benefits at all? Of course! Turmeric is low fodmap as a spice and can be used to flavour low fodmap recipes for people who have irritable bowel syndrome and imparts these foods with a very vibrant colour. If you are wanting a January ‘health kick’ from turmeric, or use it to ‘cure’ your IBS, then think again, but enjoying a great, warming, vibrant low fodmap meal made from turmeric, either low fodmap curry, or the low fodmap soup recipe below, in the depth of winter, is surely a sublime use of this wonderful spice?

Carrot, ginger and turmeric soup

Ingredients

500g carrots

1 tablespoon of oil

1 teaspoon of Moroccan spice (Fodify)

1 teaspoon of ginger

2 teaspoons of turmeric

1500mls water

seasoning to taste

Method

Peel and chop the carrots

Fry the spices in oil to release the flavour

Add the water and carrots to the spices

Cook till the carrots are soft, then blend with a hand blender

Season

Serves 3-4

https://www.nhs.uk/news/cancer/curry-spice-kills-cancer-cells/

https://www.nhs.uk/news/food-and-diet/spice-for-mice/

https://www.nhs.uk/news/food-and-diet/could-curry-spice-boost-brain-cell-repair/

https://link.springer.com/article/10.1007%2Fs11894-016-0494-0

Chestnut, carrot & celeriac soup – low fodmap Christmas recipes

Having guests around for Christmas lunch and wondering what to serve for a starter? This recipe is a tasty soup, suitable for vegan low fodmappers and has Christmas flavours with mixed spice. I have been using my copy of the flavour thesaurus by Niki Segnit, a gift for my birthday, and this marries chestnuts with carrot, celery (celeriac is a low fodmap food with a similar flavour to celery – a good substitution) carrot and rosemary and yes, this really works. It is a slightly sweet, winter roots flavour with a light addition of spices. Your guests will never know you have a low fodmap starter for them that is really easy to make and really tasty!

OLYMPUS DIGITAL CAMERA

Ingredients

200g celeriac

500g carrots

200g cooked chestnuts

1/4 teaspoon of mixed spice

10 g rosemary

Drizzle of hazelnut oil

Some chilli flakes (if tolerated)

Seasoning

OLYMPUS DIGITAL CAMERA

Method

Chop the vegetables

Add all ingredients to a pan

Add water to just cover the vegetables

Season to taste

Puree

Serve, drizzle with hazelnut oil and chilli flakes!

serves 6

 

 

 

 

 

 

 

 

 

 

Tomato, pepper and spaghetti squash soup

This is a lovely flavoured soup and has a very vibrant colour. A great winter soup to warm you up on cold days!

Ingredients

800g of plum tomatoes

1 large spaghetti squash

400g tin of roasted red pepper

1 teaspoon of ginger

1 teaspoon of cinnamon

500ml water

2 teaspoons of oil

season to taste and sprinkle with poppy seeds

Method

This couldn’t be easier, fry the tomatoes and spices in oil then add the squash, water and red pepper. Cook for 15 minutes and blend using a hand blender. Serve sprinkled with poppy seeds.

Serves 6-8

Celeriac Soup – low fodmap

I have half a celeriac left so as promised I have made a soup. This was very easy to do and is based on home made chicken stock and has a topping based on bacon, pecan and sunflower seeds. If you want a vegetarian version just omit the bacon and chicken stock and use vegetable stock instead. I really like soup, it is filling and yet low calorie and this soup has a very refreshing flavour due to the added tarragon.

Ingredients

Half a celeriac

1 courgette

2 carrots

A small cup of home made chicken stock

2 teaspoons of chopped fresh tarragon (use one if dried)

1 pint of water

Seasoning to taste

For the topping

1 rasher of bacon

1 tablespoon of sunflower seeds

1 tablespoon of chopped pecan nuts.

1 teaspoon of vegetable oil

Method

Chop vegetables and add stock, water and tarragon and bring to a boil then simmer for 20 minutes till the vegetables are soft.

Blend

Chop the bacon after remove fat and rind. Fry the bacon in a teaspoon of oil, add the pecans and sunflower seeds and toast.

Sprinkle on the top of the soup and serve

Serves 2-3

celeriacsoup1