January 2019 – Clinical Alimentary

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!

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

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)
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)
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)

January 29, 2019September 27, 2019

Jules_GastroRDLeave a comment

Broccoli

Broccoli is a newer addition to the low fodmap family – although particular attention needs to be made concerning which parts are low fodmap. Growing conditions and plant storage of FODMAPs affects the fodmap content of foods. A good example here is the ability to use the green parts of leeks and spring onions and not the bulb (the storage part of the plant.) The same is true for broccoli, the leaves and a small amount of stalk (less than 50g) are low fodmap – the stems alone above 50g per portion are not suitable. Testing individual components of food gives us more information about its fodmap content, and we are continuing to learn more about the diet with the valuable testing of the fodmap content of foods. It is thanks to the continued work by Kings College Nutrition department that has led to more information. Increased testing increases available foods and this makes the diet more varied, which is nutritionally more sound, but can add to the complexity of the diet making access to up to date information more critical. The best sources of information are dietitians who are fodmap trained, which is why it is recommended not to complete this diet alone.

What are the benefits of broccoli?

Nutritionally broccoli is suggested to be a powerhouse vegetable, although so are most others in their own way! The infographic above indicates that it has some good cancer-preventing properties via the content of sulforaphane – content of this chemical is affected by cooking time, and its benefits are debatable, as much of the evidence comes from studies in mouse models and cells in Petri dishes, one or two small studies in humans have been done, but certainly more information is needed. Broccoli provides dietary fibre content, which is always important for people with IBS. It contains good levels of vitamin A (more in the tops than the stalks), Vitamin C (but this will depend on how long the broccoli is cooked) and vitamin K.

What are the effects on the colonic microbiome? Well, in a small study broccoli consumption altered the variety of Firmicutes (reduced) and Bacteroides (increased) although it is really too early to say if this is beneficial in IBS or for those following the low fodmap diet. Interestingly Firmicutes have been found to be increased in people with IBS and reduction in the numbers of Bacteroides – perhaps this just represents people with IBS reducing consumption of those foods that are suggested widely on social media to increase symptoms, such as cruciferous vegetables. It would be interesting to know if including broccoli amounts recommended in the low fodmap diet improves these bacteria numbers and whether this is clinically significant.

What broccoli is unlikely to do:

Detox your body – your liver, kidneys and lungs are all you need for this.
Reduce ‘inflammation’ we don’t have enough information that broccoli has any effect for this unspecific term.
Reduce pain in fibromyalgia

I suggest cutting off the stem of the broccoli as close to the head as possible and discarding (or using for other members of the family or feeding to rabbits), then trimming the stalks contained within the base of the head – you can then weight the stems and calculate how much to add to the dish per portion.

What other cruciferous Brassicaceae vegetables are good to include in the low fodmap diet? Pak Choy, choy sum, kale, white cabbage and red cabbage – so do include these as well as other low fodmap vegetables – remember variety in the diet is best!

Now for the recipe:

Vegan broccoli and pine nut pasta – Low FODMAP

Ingredients

300g Gluten free pasta

40g Pine nuts

1 head of broccoli

2.5 cm square of Vegusto Prosociano

1 Tablespoon of garlic infused oil

A few basil leaves

Seasoning to taste

Method

Chop the broccoli close to the head and then into small ‘trees’

Cook the pasta in boiling water using the packet directions adding seasoning

Add 1 tablespoon of garlic infused oil to a pan and roast the pine nuts.

Add the basil, cooked pasta and broccoli to the pan with a tablespoon of water the pasta was cooked in.

Combine and serve with a sprinkling of the cheese for each portion

Serves 4

https://www.nhs.uk/news/cancer/broccoli-and-breast-cancer/

https://modalitypartnership.nhs.uk/self-help/livewell/topics/superfoods/is-broccoli-a-superfood ,

https://www.ncbi.nlm.nih.gov/pubmed/30317146

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317767/

January 13, 2019

Jules_GastroRD2 Comments

The Aubergine

Aubergines have to be my favourite vegetable. I love that they marry well with other vegetables such as tomato and potato. They have a velvety texture and a creamy taste and more than earn their title as the vegetarian steak.

Although in some quarters they are suggested to produce intolerance, as along with potato, peppers and tomato, the aubergine is a member of ‘the nightshade family’ or Solanaceae, a deadly associated name for a wonderful group of vegetables (and fruit, if you count the tomato, which is technically a fruit). We have little evidence for the problems of the ‘nightshade family’, concerning the above group of four as a whole, and why would you want to exclude these versatile vegetables from your diet? Some are however known as histamine producing – the aubergine and tomato – but histamine intolerance is a rare occurrence and can be identified by knowledgeable practitioners, plus aubergine is only classed as a moderate inducer. Another possible consideration for reactions to the Solanaceae group is the alkaloid solanine, which is found in green potatoes, so store your potatoes well, covered in the dark to avoid sprouting and this should not be a problem.

I have not had experience of the bitter flavour with aubergine so wouldn’t usually resort to salting them, but the above infographic is useful as once salted they will not absorb as much oil, so it might be worth taking the time to do it. Segnit’s flavour thesaurus matches the aubergine with walnut and tomato and a sprinkling of nutmeg. So, here is my recipe for you – please tell me how you like it!