Alcohol’s seemingly central role in a vast array of settings makes it common topic of discussion in nutrition. In my practice, I often get asked questions pertaining to alcohol consumption phrased in a way to coax the desired answer by the patient or client. For example, “What if I only had x amount, just on weekends?” or “IF I did drink, what would be the best choice of alcohol? I hear vodka is better than so and so…” While I won’t deny that there are some benefits to moderate consumption of alcohol, much of these (relatively small) benefits are seen in younger adults (Hvidtfeldt, 2010), who doubtfully practice this. As age progresses, metabolic processes become much more sensitive to toxins (Barnes, 2010) and with this, the disappearance of the potential benefits from alcohol when intake becomes too high – this is a relative amount specific to the individual, depending a numerous variables. Thus, alcohol doesn’t carry nearly the value placed upon it by popular belief – to think otherwise is more so a justification for a personal decision than an objective argument. Those that tout the benefits of red wine, for example, cherry-pick the data, conveniently forgetting (or never truly knowing) about what alcohol really is.
What Is Alcohol Anyways?
Most view alcohol as a classification of some beverages – which is fine in most instances, but when dealing with its effects on metabolism, a more concrete definition needs to be established. Alcohol refers to a class of organic (containing carbon) compounds that contains hydroxyl (and oxygen bound to a hydrogen, OH) groups. Why is this important? Alcohols have a profound effect on livings things, largely due to their ability to dissolve lipids. Many of our cells for example contain a lipid bilayer, which acts as a barrier, keeping the cell’s contents safely guarded. Because alcohols have the ability to dissolve this barrier, they are able to penetrate rapidly into the cells, destroying its contents – which, by the same token, make them useful to kill microbial cells and thus, a useful skin disinfectant.
The Alcohol In Beverages
I used the term moderation earlier on and it is important to know that it carries a specific definition. First, a drink constitutes any alcoholic beverage that contains ½ an ounce of pure ethanol. Moderation is defined as up to one drink (again, ½ an ounce of pure ethanol) per day for women and two drinks (1 ounce of pure ethanol) per day for men. To give this definition a bit more perspective the amounts listed below all contain roughly ½ an ounce of pure ethanol:
- 5 ounces of wine
- 12 ounces of beer
- 1 ½ ounces of 80 proof liquor
As you can see, true moderate drinking equates to very low consumption.
How Alcohol Influences the GI Tract
Much of what I emphasized in my diet plans is the importance of gut health – it is an all too-often forgotten about subject that carries significant weight in determining the efficacy for any given plan. Moreover, it ties in intricately with the functions of the liver (discussed shortly). Understanding alcohol’s influence on these two bodily systems should not be overlooked.
Alcohol differs significantly from food in terms of absorption. Depending on the macronutrient content, food requires differing times for complete breakdown and assimilation. Alcohol however, requires no digestion, and is absorbed within minutes. Earlier, when I discussed the definition of moderation, a question may have popped into your mind: why is the upper limit for men double that of women? Alcohol is broken down by an enzyme in the stomach called alcohol dehydrogenase, which women produce much less of. And so, women absorb more intact alcohol than men (yes, even if they weigh the same) who drink the same amount. Once alcohol makes it way into the small intestine, it gets metabolic “priority” (as it is a toxin) once absorbed – the body will attempt to break it down before any other nutrients – potentially leading to malabsorption of them.
Alcohol’s Detrimental Effect on the Liver – An Athlete’s Bane
The capillaries in the digestive tract merge into veins that carry blood directly to the liver first and foremost. This is an important point as alcohol’s rapid absorption is consequently routed straight to the liver. The liver produces alcohol dehydrogenase as well, so it does provide a bit of a “defense”, so it speak, before alcohol has a chance to move on and cause unchecked destruction. As a practical tip, drink slowly (about 1 drink per hour) – this allows the liver’s production of alcohol dehydrogenase to keep up with the intake of alcohol. Doing so mitigates the potential for circulating alcohol to cause serious detriment to other body organs.
While alcohol negatively impacts every organ in the body, the liver is most severely impacted. As mentioned earlier, alcohol takes “metabolic priority” – that is, the liver will focus its efforts on breaking down the toxin, putting the rest of its responsibilities on hold. Below are just some of the adverse effects alcohol has on liver metabolism:
Fat Accumulation
The liver packages excess fatty acids into triglycerides and ships them out to other cells. When alcohol is present, this process falters, greatly reducing the liver’s ability to metabolize fats. Moreover, the synthesis of fatty acids becomes greatly accelerated in the presence of alcohol, even after just one night of heavy drinking. Alcohol dehydrogenase breaks down alcohol in a two-step process: 1) alcohol is first oxidized into acetaldehyde. 2) Acetaldehyde dehydrogenase converts this acetaldehyde to acetate, which is then converted to either carbon dioxide or something called acetyl CoA (a big player in energy metabolism).These conversions produce hydrogens (H+) and electrons as byproducts, which being acidic in nature, are readily picked up by the coenzyme vitamin B3, niacin. Niacin is needed elsewhere however, so this extra burden causes an inadequacy in other metabolic processes. Without adequate levels of all coenzymes, energy pathways cannot function, causing serious consequences (which will be discussed shortly). The accumulation of acetyl CoA, coupled with inadequate coenzyme levels causes acetyl CoA to take a pathway towards fatty acid synthesis, in the liver. Not only is this damaging to anyone with a physique goal of some sort, but the liver cannot function properly when overburdened with fat.
An Acidic Environment
The aforementioned build up of H+ shifts the body’s pH balance to that of an acidic state. To add to this, alcohol’s interference with energy metabolism begins to favor the production of lactate, furthering this acidic state. This acidic burden placed onto the body ultimately leads to a highly inflammatory state, attributed to inefficient excretion of another acid called uric acid. Usually this equates to painful and stiff joints.
Diminished Protein Synthesis
Amino acid and protein metabolism is impacted as a result of excess alcohol consumption. While those reading this probably associate protein most readily with muscle growth, bear in mind that proteins serve a multitude of functions. For example, protein synthesis crucial to immune health is significantly slowed down as a result of high alcohol consumption. Usually, bodily cells utilize the amino acids and proteins from food consumed, but when alcohol is present the liver deaminates (breaks the amino acids down for energy) these amino acids, and uses their carbon fragments to create either ketone bodies or fat. For those thinking that higher protein intake may mitigate this process, you are wrong – a person will still suffer protein depletion until alcohol consumption has stopped and circulating alcohol has been fully broken down.
Closing Thoughts
This post is not entirely meant to demonize social drinking – but engaging in such an act regularly, needs to be understood if one wishes to make progress towards their physique goals. Justifying regular or excessive drinking (remember, excess in this context is a relatively small amount) without the understanding of the detriment caused unto the body’s delicate metabolic balance is no more than the excuse for one’s personal agenda. While alcohol consumption is inherently bad, this post is not to be interpreted as advocating its complete avoidance. Drinking from time to time, during periods where fat loss or muscle growth is not a primary concern is likely to be fine – it’s the continual and habitual intake that will lead to the deleterious effects mentioned.
References
Barnes, A. J., Moore, A. A., Xu, H., Ang, A., Tallen, L., Mirkin, M., & Ettner, S. L. (2010). Prevalence and Correlates of At-Risk Drinking Among Older Adults: The Project SHARE Study. Journal of General Internal Medicine, 25(8), 840–846. http://doi.org/10.1007/s11606-010-1341-x
Hvidtfeldt, U. A., Tolstrup, J. S., Jakobsen, M. U., Heitmann, B. L., Grønbæk, M., O’Reilly, E., … Ascherio, A. (2010). Alcohol Intake and Risk of Coronary Heart Disease in Younger, Middle-aged and Older Adults. Circulation, 121(14), 1589–1597. http://doi.org/10.1161/CIRCULATIONAHA.109.887513
Whitney, E. N. (2018). Understanding Nutrition. S.l.: Cengage Learning.
Thoughts?