Clutching at Straws
Some will claim that we need some of this fodder in our diet, though, if for no other reason than to provide fibre required for efficient bowel function. This is another common claim we hear from those who argue for the essential nature of grains in the diet. Again, what does the science show?
The main sort of fibre contained in foods such as wholemeal bread and high-bran breakfast cereals is technically termed ‘insoluble’ fibre (also colloquially referred to as ‘roughage’). Insoluble fibre is said to be important to give the bowel ‘something to grab onto’ and ensure waste moves nicely along our large bowel to be expelled with ease. But is insoluble fibre really essential for bowel regularity and health? There is, in fact, some evidence that suggests it can do more harm than good.
In one study, more than sixty adults with persistent constipation for which no medical cause could be found were asked to take a quite unconventional dietary approach: instead of being asked to eat more fibre, they were asked to eat none at all.7 Study participants were instructed to eliminate breakfast cereals, wholemeal bread and brown rice (as well as fruit and vegetables) from their diets for two weeks. They were asked to continue eating as little fibre as possible if this helped their symptoms.
Six months after the start of the study, the majority of patients had persisted with the ‘no-fibre’ diet and had seen their bowel frequency increase from an average of once every few days to once every day. In contrast, in the minority of individuals who remained on a higher fibre diet, bowel function had not improved at all.
In other words, the results showed that the more fibre there was in the diet, the more constipated individuals tended to be. Here’s how the study authors attempted to explain their findings:
The role of dietary fiber in constipation is analogous to cars in traffic congestion. The only way to alleviate slow traffic would be to decrease the number of cars and to evacuate the remaining cars quickly. Should we add more cars, the congestion would only be worsened. Similarly, in patients with idiopathic constipation [constipation of no known cause] and a colon packed with feces, reduction in dietary fiber would reduce fecal bulk and volume and make evacuation of the smaller and thinner feces easier. Adding dietary fiber would only add to the bulk and volume and thus make evacuation even more difficult.
It’s difficult to argue with the logic here, nor the results achieved in this study. And the results mirror my own experience in practice, where I find stripping out grains from the diet (and leaving fruits and vegetables in) usually improves constipation and other symptoms such as bloating and abdominal discomfort. Scientific research supports this approach in management of ‘irritable bowel syndrome’.8
‘Roughage’ does not seem to be essential for regular bowel function, but some claim it helps prevent colon cancer. The truth is, though, the best evidence does not support this idea at all.9–11 In fact, in a review of the evidence relating to fibre and bowel health, the authors concluded that: ‘there does not seem to be much use for fiber in colorectal diseases.’12
The evidence shows that we simply do not need grains for energy, ‘vital nutrients’ or fibre. But, in addition to their non-essential nature, there are reasons for positively avoiding them. We know, for example, just how disruptive they can be to blood sugar and insulin levels, and how they can impair the nutritional value of food because of the phytates they contain. But grains pose others additional hazards, too, specifically through a mechanism known as ‘food sensitivity’.
Sensitive Issues
It’s well-recognized that specific foods can sometimes trigger unwanted reactions in the body. In their most extreme form, these can take the form of allergic reactions known as ‘anaphylactic shock’ that can be life-threatening. However, other types of reactions to food can occur too that, although not as obvious, can nonetheless have debilitating effects on wellness and health. While any foodstuff may do this, grains are a common cause of problems in practice.
Grains contain proteins known as ‘lectins’ that are difficult to break down in the gut and can trigger problems with food sensitivity. This situation is made worse by the fact that grains also contain what are known as ‘protease inhibitors’ that impair proper breakdown of proteins, including lectins. The end result is that lectins can remain relatively intact and can then be absorbed into and even through the gut wall, subsequently to be recognized as something ‘foreign’.
This can cause the body to react in ways that may manifest themselves in the form of digestive strife (including pain and bloating), or problems beyond the gut such as headaches, asthma and eczema.
Of the grains, the one that I find particularly troublesome in this respect is wheat (found in, among other foodstuffs, most forms of bread, breakfast cereals, biscuits, cakes, pastries, pasta and pizza). Wheat is particularly rich in gluten – a protein that can trigger adverse reactions in the body. Some individuals have extreme sensitivity to gluten in the form of what is known as ‘coeliac disease’. However, there is good evidence that it is possible to be sensitive to gluten even if tests for coeliac disease have proven negative.13,14
In my experience, sensitivity to wheat and/or gluten is quite common, and frequently manifests itself as fatigue. This, in addition to a tendency to disrupt blood sugar levels, is another reason why eating something bread-based at lunch might lead to someone feeling tired or possibly ‘knocked out’ in the afternoon. If you ever find yourself wondering why you are struggling to get any real work done at this time, it might have something to do with that sandwich or foot-long baguette you ate at lunch. I once got chatting to a nutritionist at an obesity conference I was speaking at, and the subject strayed into the problems that can ensue for working people who eat something bread-based for lunch. ‘Death on the high street’ she called it.
To summarize, grains:
1 Are generally disruptive to blood sugar levels in a way that predisposes to fatigue, mood problems, waking in the night, hunger and sweet cravings
2 Tend to induce surges of sugar and insulin that predispose to issues such as weight gain, type 2 diabetes and heart disease in the long term
3 Are generally un-nutritious
4 Don’t seem to have an important role in maintaining bowel health and regularity
5 Contain phytates that impair the absorption of key nutrients
6 Can be rich in lectins and gluten that may provoke a range of symptoms including digestive discomfort, bloating and fatigue
With all this in mind, does it really make sense for these foods to form the cornerstone of our diets, as governments and health professionals usually advise?
Does all this bad news mean we should eat no grain at all? Not necessarily. Some individuals do seem to tolerate grain products reasonably well, in my experience. But, overwhelmingly, I find that when individuals eat less of these foods (or none at all), they are almost always rewarded with benefits in terms of changes such as weight loss, improved disease markers (see below) and, crucially, a sense of heightened vitality.
Beans and Lentils
Beans and lentils (collectively referred to as ‘pulses’ or ‘legumes’) represent potential alternatives to grain at certain meals. Like grains, though, they are relatively rich in lectins and enzyme inhibitors that impair the digestion of food.15
On the plus side, there is evidence that these substances can be reasonably well deactivated through thorough soaking and cooking prior to eating.