The power of no-wheat flour

There is an increasing array of flours that can be used as substitutes for wheat flours for people who require gluten- or grain-free diets, and a popular one that often pops up is almond flour. This may not be suitable for those with food sensitivities, and is clearly not good for anyone who is allergic to almonds.

Two other alternatives are breadfruit flour and plantain flour which are relatively new to the NewZealand market. You’ll find them in health food stores and at major supermarkets.

Breadfruit flour

Breadfruit flour is a gluten-free flour becoming increasingly popular as a substitute for wheat flour. Breadfruit originates from the Pacific (it is traditionally called ulu) and is a staple food in many cultures. It is much like taro, in that when cooked it has a very starchy texture and bland flavour.

Like most flours, its calories come from the starch component, not being a particularly rich source of either protein or fat. Though the raw fruit contains good amounts of vitamin C, this nutrient is destabilised through heat, so it is unlikely to still be present when ground down to a flour.

Like most carbohydrate foods, when they are ground down the effects on overall blood sugar levels will change — the raw breadfruit may elicit a lower glycaemic response, but the flour will likely be higher (though there is little research on breadfruit flour to show this is indeed the case).

My gut feeling here is that the benefits of using this flour come more from its ability to be used in place of wheat flour as a 1-to-1 substitute, rather than from any specific health promotingproperties.

Plantain flour

Plantain — green banana — flour is another gluten-free flour emerging on the health scene that can also beused as a 1-to-1 substitute for wheat flour. The plantain fruit looks like a very large unripe banana — it originates from tropical Southeast Asia and is also indigenous to Northern Australia.

Otherwise known as cooking bananas, plantains are predominantly carbohydrate and though the fruit contains vitamins and minerals, most are denatured by heat in processing the flour, with potassium remaining the only nutrient of note.

The main benefit of this flour, however, is its resistant starch content. Resistant starch is not digested by us and passes through the digestive tract to be food for our gut bacteria, producing beneficial short-chain fatty acids (SCFA) like acetic acid, butyric acid and propionic acid.

It has garnered attention over the past few years due to its favourable effect on blood sugar parameters and, though it is less clear in human trials, research in rodent models using plantain flour in place of other flours found improvement in blood sugar control and insulin sensitivity to the same extent as metformin, a blood sugar-lowering medication.

This does mean it may be a better type of flour for people who need to manage their blood sugar, however resistant starch is highly fermentable. Studies in humans looking at where the starch is digested have found that, without another source of fermentable carbohydrate, it can be digested in the upper digestive tract and not make its way down to the lower digestive tract where it would be more beneficial.

The digestion of it high in the digestive tract could lead to increased growth of bacteria in an area where we don’t want it, resulting in bloating, abdominal cramps and the production of inflammatory substances called lipopolysaccharides (LPS).

In addition, this prevents the bacteria in our lower gut getting the fuel it needs to produce the SCFA we need to support the health of cells in our small and large intestine, and consequently they could die off. Over time this will reduce the diversity of our gut bacteria, associated with a lower risk of chronic disease.

These flours may be a good choice for someone with blood sugar management problems but who wants to bake — no food is “bad” in the context of an appropriate diet. If you notice an unfavourable impact on your digestive system after eating the flour, either lower the amount you use or choose another flour. Neither of these flours are particularly budget-friendly, however they may provide a good alternative for occasional baking if you can’t tolerate nut flours.

Take a look at our gluten-free baking collection for cakes, cookies and more