Bread and Circuses

In which I wade into the subject of beer and bread.

I’m publishing this one with some trepidation but, since this substack is about figuring things out, then I reckon nothing ventured nothing gained.

I’ve been thinking about beer and bread in the context of carbohydrates and type-2 diabetes.

From the beginning of my dance with diabetes, I uncritically accepted the notion that beer has a high carb content and can/should be considered a bad thing from the perspective of managing diabetes. But it occurred to me a few days ago that, although the original content of a beer wort is high in carbohydrates, it should ferment out to alcohol in the brewing process to leave a low-carb end result.

It's similar with bread: there is carbohydrate content in flour of course, but when bread is traditionally made the carbs are converted out through fermentation into alcohol (which cooks off in baking) and the gas that causes the dough to rise.

What both products have in common is that they are based on grain and are products of fermentation through the action of yeast. Also in common, discussion of both beer and bread focuses on the glycaemic index of their raw materials without much (or often any) consideration of the effect of fermentation. This is important because even if you can calculate a relatively high GI for beer, that doesn’t matter if the actual carbohydrate content in the consumed product is low. Glycaemic load is calculated by (carbs x GI/100) and so when available carbs are low the GL must also be low. On this line of thought, bread and beer may have limited impact on the sugariness of one’s blood.

It’s more complex than that, of course. In the case of beer, some carbs are resistant to the common strands of brewer’s yeast and so there will always be some carbs in a glass of beer. I don’t have figures for commercial beers (including pilsners that are usually ‘unadulterated’) but in the case of homebrew beer, where the brewer has control of the contents of the drink, the yeast converts somewhere between 65 and 80% of the carbs to alcohol depending on the recipe and the yeast used. That doesn’t sound great, but the bulk of those carbs that survive are - I believe - dextrins which are slow-release carbs. The rest pass through the system and *may* act as prebiotics without impacting blood sugar.

Just to be clear, I’m not talking about industrially-processed commercial beers or supermarket breads, I’m talking about the ‘real’ products produced from grain, water and yeast (plus hops in beer and optional salt in the case of bread). Nor am I talking about going out for a night on the bevvy or stuffing my face with bread.

I follow a generally low-carb diet and run regularly. Does an occasional bottle of beer with a high-protein evening meal, or a slice or two of homemade bread during the day make much difference? (And yes, before you ask, I really do mean a slice or two.) I rather suspect not. I could check if I had a continuous glucose monitor, but I can’t afford one and, given that my T2D is in remission, I’m unlikely to be prescribed one.

My provisional conclusion is that neither good beer nor good bread should automatically be on the low-carb shit list. By happy chance, that conclusion happens to coincide with my predisposition and so I have to be suspicious of it. I daresay I’m missing something obvious and I am still researching, although I found this paper from 2005 persuasive on its face regarding beer.

CW Bamforth, Beer, Carbohydrates and Diet

This newsletter has a relatively low circulation at present, but as I wrote at the top I raise the subject here because I think received wisdom is always worth questioning; as someone used to say to me, what is well-known is rarely known well. In that spirit, I’m happy for informed comment on the science of this.

I must add that my research to date has led me to simply loads of websites infested with the kind of prissy puritanism that wags a prim finger of disapproval at the very idea that alcohol might be enjoyed in any quantity at any time for any reason. Not all of those sites were American. Also, every site took time out to warn of the dangers of alcohol taken in excess, which isn’t the subject under discussion but seems to be de rigueur. One of the things I’m coming to dislike a lot about this whole field is the dogmatic prohibitionism of so many commenters, especially those with things to sell.