Why Wholegrains?

On a forum a poster wrote the following question.

Can someone please tell me the secret ingredient that's found in in wheat that I can't get from far healthier sources elsewhere? It must be a secret, no one has been able to answer that question up till now. Are we really advocating that refined carbs are better than fibrous, organic vegetables?


Of course it was a loaded question, I don't think anyone advocates refined carbs not yet wheat as the sole grain. What is frequently suggested is to eat whole grains. My answer was quite long, probably too long and took a long time to write (twice because Windows decided to switch off to install upgrades in the middle of it) so as I had intended to blog today I'm using my answer with a bit added as a blog .

I don't think I've ever read it suggested to substitute refined grains for vegetables. What is suggested is that there are health benefits from minimally processed whole grains*(see Slavin below for definition, history of processing , summary of possible benefits and mechanisms) This is far too difficult to summarise so you'll have to read the paper.

Wheat is of course only one type of grain, there are many others. Some I've never heard of , let alone used. I've included the latin names to help me, because the French names are bound to be different!
Amaranth* (Amaranthus spp.),Barley (Hordum vulgare) ,Buckwheat *(Fagopyrum esculentum) Bulgur (Triticum ssp.)(derived from wheat), Corn* (Zea mays mays), Farro / Emmer (Triticum turgidum dicoccum); Grano (Triticum turgidum durum) (Durum wheat 'berries') ;Kamut® Grain (triticum turgidum turanicum) an 'ancient' variety of wheat ;Montina* (Indian rice grass) ;Millet* (Panicum miliaceum) ;Oats (Avena sativa) ;Quinoa* (Chenopodium quinoa)not botanically a true grain but normally counted as one. ;Rice* (Oryza sativa) ;Rye (Secale cereale) ;Sorghum / Milo *(Sorghum spp.) ;Spelt (Triticum aestivum spelta) ;Teff* (Eragrostis tef)(principle source of nutrition for 2/3 of Ethipians!) ;Triticale (x triticosecale rimpaui) modern hybrid of durum wheat and rye ;Wheat (Triticum aestivum; Triticum turgidum) ;Wild Rice *(Zizania spp.)
With all those to choose from, wheat is definitely not the only source of wholegrain. Anyone with coeliac or a gluten intolerance might like to know that according to the wholegrain council those marked with an asterick are gluten free.

It is possible that the suggested health benefits are entirely due to their fibre content. If so then it is of course possible to eat enough vegetables to do this.
I decided to work out just how much:First problem, how much fibre is recommended? The UK suggestion is 18g; however the BNF feels that this is too low suggesting 30g. The WHO recommends an RDA of between 20g and 40g. I have rather arbitrarily used 25g; this is higher than the UK suggestion but the median rec. for women from WHO, though still lower than that suggested for men .
Using a British online source (and different sources will produce different figures) I chose a selection of common vegetables, mostly green but added red peppers and aubergine to widen the variety. After selecting 800gm worth I had reached the British target amount but widened my source to include nuts as these are another nongrain source of fibre. Fifty grams of nuts and still there was still less than 25g of fibre, so I turned to fruit choosing avocado , low in carb but high in fibre. I also counted the carbs; this selection has a carb content of 33 so just over Bernstein’s limit.
Spinach 100 g fibre 2.4g carb 3.75
Broccoli 100g fibre 2.6 g carb 2.1
Cauliflower 100g fibre 1.6 carb 2.7g
Aubergine 100g fibre 2.3 carb 2.8g
Red pepper 100g fibre1.6 carb 6.4g
Savoy cabbage 100g fibre 2.8 carb 3.5g
Courgette 100g fibre 1.2 carb 2.2g
Mixed salad 100g fibre 3g carb 3.4g
Almonds 50g fibre 4.2 carb 4.25g
Avocado 100g fibre 3.4 carb 1.9g

But how many people eat this amount ? The five fruit and veg a day, advice assumes a total of 400grams a day but is set alongside advice to eat starchy carbs, preferably whole grains. You have to eat an awful lot of 'fibrous organic vegetables'.
Even with a mixed diet including grains, legumes , fruit and vegetables many of us probably fall short but it is certainly much easier.
I realised I was a bit low and have tried to include more high fibre legumes recently.

It maybe that not all fibre is beneficial for all purposes. Possibly different types of fibre are useful in specific areas. Beta glucans seem to be beneficial in cardiovascular health, major sources are barley and oatmeal. Residual starch may be beneficial for lipid control and glucose stability, and probably is important for colonic health, this is chiefly found in whole or partly-milled grains and seeds, pulses, and cooked and cooled (retrograded) potatoes. (and some processed breakfast cereals)This becomes difficult to test and to separate out and often results in fairly artificial types of experiments but there have been many. of varying quality. (and the literature search would take a long time!) some of these are summarised by Oldways and the Wholegrain council in the link below.
One recent study did attempt to separate the effects of fibre from wholegrain to that of fibre from other sources in the incidence of colonic cancer. (Schatzkin et al)In this prospective cohort study, total dietary fiber intake was not associated with colorectal cancer risk, whereas whole grain consumption was associated with a modest reduced risk.According to the researchers ”These findings suggest that whole-grain components other than fiber — e.g. vitamins, minerals, phenols, and phytoestrogens affect colorectal carcinogenesis.”

As suggested above .There may be health benefits in whole grains caused by something other than the fibre. It maybe a combination of phytonutrients or vitamins, or minerals etc acting synergistically , ie the whole package (and of course different whole grains will vary, it’s not just wheat!) The Slavin paper discusses this.

Slavin J Nutrition Research Reviews,Vol17:99-110, May 2007Whole Grains and HealthReprinted @http://www.wholegrainscouncil.org/files/SlavinArticle0504.pdfSchatzkin et al., Am J Clin Nutr., 85: 1353-1360, 2007Dietary fiber and whole grain consumption in relation to colorectal cancer in the NIH-AARP Diet and Health Study[urlhttp://www.wholegrainscouncil.org/files/WGResearchSummary_WGCJan09.pdf]Recent research into wholegrains and health from Oldways and the Wholegrain Council (up to you to decide on validity,and check out its origins and funding)http://www.ajcn.org/cgi/content/abstract/85/5/1353[/url]