Hello,
In my previous blogs I started a series of communications on macronutrients and I promised to finish this series with alcohols. It's a bit of controversial topic for a couple of reasons. First of all, it's a bit unusual to talk about alcohol as of a macronutrient and second, people mostly associate alcohol with either fun or alcohol abuse, not with nutrition. I'm taking a bit of liberty by considering its nutritional value, but that's what my personal blog is for - to take unconventional approaches and think them through. Also, as a side note - we will not focus on alcohol's abuse potential today, that would be a subject for another blog.
What is alcohol?
The word "alcohol" comes from Arabic "al-kuhl", which effectively stands for "eyeliner" - alcohols were used to produce it as well as for many other things. Later, the chemistry and chemical nomenclature have developed greatly and nowadays the term alcohol means a molecule that has an -OH radical in the primary position and there are lots of substances that meet this criterion. Surprisingly, cholesterol is one of them. In medicine and nutrition science, we usually use only some of them and I will talk about the most important ones, at least from the nutritional standpoint, such as ethanol and sugar alcohols.
Ethanol (the Alcohol)
I'll start with ethanol, arguably, the main alcohol that I would call a macronutrient as it's so abundant and energy-dense. This substance is produced by fermentation of sugars by various microorganisms. Alcoholic beverages are produced by industrial fermentation, but I would like to draw your attention to the fact that inside of our gut there are microorganisms that might ferment sugars to alcohol and sometimes they are so active that it leads to something called the "auto-brewery syndrome" i.e. they produce so much alcohol that the person is almost constantly inebriated.
One important thing to mention about ethanol is that it is very energy-dense. Each gram of pure ethanol contains 7 calories, which is almost as high as fat, so when you're having a drink or two you're effectively consuming around 100-200 calories (the amount really varies between countries as standard drinks' sizes vary between 8 and 13.6 grams of ethanol). In addition to that, some beverages contain other macronutrients, mostly carbohydrates, as well as biological active molecules that might impact our metabolism. The purest drink would be vodka and next to it would be spirits in general such as whiskey, gin, cognac etc. Some drinks such as Bailey's Irish Cream or Kahlua are especially high on sugar and can easily disrupt a low-carb diet. Beer, also is high in carbohydrates and a can of beer usually holds around 150 calories. In addition to that, beer contains phytoestrogens - substances of plant origin that act as estrogens in our bodies, which is never a good thing.
The last thing about alcohol is that it affects number of systems in our bodies - it affects our cognition in multiple ways that eventually leads to diminished control over our food intake, but it also affects our livers to an extent of substantially disrupting the metabolism of other substances and it does affect our hormonal regulation in several ways. So, for all these reasons, alcohol consumption should be significantly limited if not stopped completely if you want to follow your diet to a t. I would encourage you to take a look at Canada's low-risk drinking guidelines, which suggest that people do not consume more than 2-3 drinks per day and no more than 10 drinks per week for women or no more than 15 drinks per week for men.
Sugar alcohols
Sugar alcohols are interesting substances - they are both sugars and alcohols at the same time. Good examples would be xylitol (chewing gums), sorbitol (some "sugar-free" products) and erythritol (Stevia). They are "natural sweeteners" as they tend to be way sweeter than table sugar and at the same time they usually carry less calories and don't cause the same changes in insulin levels. And, yes, "they don't increase your blood sugar levels", which is simply because they are not the "sugar" we measure (glucose). Also, in many cases, food manufacturers started separating sugar alcohols from sugars in carbohydrates section and thus tricking us to believe that there is less sugar in the food. Also, some of them can be added to "sugar-free" drinks and foods and it's a very vicious trick in my book as sugar alcohols are very similar to sugars and they still are metabolized effectively as sugars and though they might not cause the same insulin response, they still affect your metabolism as sugars would, so use them sparingly. Ideally, don't use them at all.
Summary
These were two groups of alcohol I wanted to talk about today and I guess now you can see why I call both of them macronutrients - ethanol carries a lot of calories and sugar alcohols are industrial substitutes for sugars and are also used in quantities that are comparable to sugars. And they also are carbohydrates. I would say that these alcohols are very often ignored when analysing nutritional patterns (at least by non-professionals) and even if they are included the evaluation of their metabolic impact is limited to their caloric value, but as you can see there is way more to them than just calories. So, my general recommendation is to limit alcohol consumption for many reasons, or to completely avoid it. If you really want to have some alcohol stick to those beverages that have less other macronutrients. The same recommendation applies to sugar alcohols - try to avoid them and study the nutritional labels well as you might be deceived. Actually, the most preferable way of controlling your sugar alcohol intake is to cook your own meals and to avoid processed foods unless you are 100% sure of what they have in them.
I hope that this clarified the subject a bit and now you know what you're consuming and this information will help you to plan your nutrition and body transformation well. Feel free to ask questions and makes suggestions, I'm very open to them and I would like to know what is interesting for you and what isn't.
Sincerely Yours,
Dr.Sam
Video: Macronutrients Made Simple Part V - Alcohols