What is Alcohol?
In a strictly scientific sense, alcohol is a broad category of organic compounds. However, the one found in beer, wine, and spirits is ethanol (C2H6O), and is produced by yeast during the fermentation of sugars.
What is Ethanol and How Does it Act as a Toxin?
Ethanol is an amphiphilic molecule, meaning it is soluble in both water and lipids (fats). This dual solubility allows it to diffuse easily across cell membranes and distribute widely throughout the body — underpinning many of its systemic effects. Here's how:
Membrane Slippage
Cell membranes are composed of lipid layers that typically require specific transport mechanisms for entry. Ethanol bypasses this entirely, diffusing directly through the membrane without the need for a carrier.
Rapid Tissue Diffusion
Once it enters the bloodstream, its water solubility allows it to dissolve in the plasma and be easily transported throughout the body (to any organ). Because it isn't blocked by cell membranes, it diffuses rapidly into tissues with high water content, such as the liver, heart, and brain.
Crossing the Blood-Brain Barrier
Most toxins are stopped by the blood-brain-barrier (BBB) — a specialised security system of tightly packed cells. Ethanol, however, is small and lipid-soluble enough to cross this barrier with ease. Once inside the brain, it immediately begins altering the balance of neurotransmitters, which is why you feel the effects of a drink within minutes.
The Process
- Ingestion: Ethanol enters the stomach/small intestine.
- Absorption: It diffuses across the gut wall into the blood.
- Distribution: The blood carries it to the brain.
- Infiltration: It slips through the blood-brain barrier to slow down your neurons.
What Happens When You Drink Alcohol?
During alcohol consumption, the body recognises this as a disruption, prompting the liver to prioritise its breakdown. At this stage, the liver temporarily deprioritises many of its normal functions — such as fat oxidation, blood glucose regulation, and aspects of nutrient metabolism — to focus on clearing ethanol from the body.
Alcohol and the Metabolism
The reason alcohol is so hard on the system isn't just the ethanol itself, but the 'toxic intermediates' created during digestion and metabolism. Said differently, your body doesn't just "burn off" alcohol; it first converts it into a more toxic chemical, then scrambles to neutralise that second chemical.
It's a two-stage detoxification process, with the middle step being the most dangerous.
| Step | Process | Substance Produced | Toxicity |
|---|---|---|---|
| 1 | Alcohol dehydrogenase (ADH) converts ethanol | Acetaldehyde | High — highly reactive, toxic, and classified as a carcinogen |
| 2 | Aldehyde dehydrogenase (ALDH) converts acetaldehyde | Acetate | Low — further broken down into water and carbon dioxide |
Side Effects of Alcohol Metabolism
During periods of higher alcohol intake, a bottleneck can occur at the first step, leading to a buildup of acetaldehyde. The liver can only process alcohol at a fixed rate, so if intake exceeds this (roughly one standard drink per hour), acetaldehyde begins to accumulate. As it lingers in the bloodstream, this highly reactive compound circulates through the body, contributing to cellular stress and many of the adverse effects associated with drinking.
Because acetaldehyde is toxic, the body prioritises alcohol metabolism above all other fuels. This is where most downstream effects begin.
1 - Alcohol Alters Metabolic Function
As a result, the body temporarily reorders how it produces and uses energy:
- Alcohol oxidation ↑ (prioritised)
- Fat oxidation ↓ (suppressed)
- Carbohydrate oxidation ↓ (reduced)
Thus, the following occurs:
Fat burning is temporarily suppressed → Because alcohol is prioritised as a fuel source, the body reduces its use of fat for energy, limiting the mobilisation and oxidation of stored body fat.
Dietary fat is more likely to be stored → Because fat is not being burned efficiently, fat consumed alongside alcohol is more likely to be stored, particularly in the context of calorie-dense meals.
Carbohydrate handling is altered → Because alcohol disrupts normal glucose regulation and reduces carbohydrate oxidation, blood sugar becomes less stable and excess carbohydrate is more likely to be directed toward storage.
Energy is effectively "backed up" → Because alcohol takes priority as a fuel, fat and carbohydrates have fewer immediate pathways for use, increasing the likelihood of temporary energy surplus and storage.
2 - Alcohol Can Contribute to Fat Gain
Alcohol contributes to fat gain through multiple, compounding pathways:
Caloric load increases → Alcohol provides ~7 kcal per gram with little nutritional value, increasing total energy intake without contributing to satiety or nutrient status.
Food intake increases → Alcohol lowers inhibition and alters appetite signalling, leading to increased overall consumption and a preference for energy-dense, high-fat, high-salt foods.
Fat oxidation is suppressed → Because alcohol is prioritised as a fuel source, the body reduces its use of fat for energy, increasing the likelihood that dietary fat is stored.
Metabolic efficiency is reduced → Alcohol disrupts normal metabolic processes, creating a temporary environment in which incoming energy is more likely to accumulate than to be utilised.
Hormonal environment shifts unfavourably → With regular intake, alcohol can reduce insulin sensitivity and increase cortisol, promoting fat storage and impairing nutrient partitioning.
Fat distribution shifts toward the abdomen → Chronic alcohol consumption is associated with increased visceral fat accumulation, contributing to central fat gain and greater metabolic risk.
3 - Alcohol Affects Protein Metabolism and Muscle Protein Synthesis
Alcohol alters the internal environment required for muscle repair and growth:
- mTOR signalling ↓ (suppressed)
- Amino acid utilisation ↓ (impaired)
- Recovery environment ↓ (sleep ↓, inflammation ↑, oxidative stress ↑)
Muscle protein synthesis is reduced → Alcohol suppresses mTOR signalling — the primary pathway responsible for muscle growth — limiting the body's ability to build and repair muscle tissue.
Amino acid utilisation is impaired → Alcohol interferes with the effective use of dietary protein, reducing the incorporation of amino acids into muscle.
Recovery capacity is diminished → Alcohol disrupts post-exercise recovery processes, slowing tissue repair and adaptation following training.
Hormonal environment shifts unfavourably → Alcohol can reduce anabolic signalling and impair the hormonal conditions required for muscle maintenance and growth.
Training adaptation is reduced → Because repair and protein synthesis are compromised, the body adapts less effectively to training stimuli, slowing progress over time.
Muscle gain is slowed → With repeated disruption to protein metabolism, the net balance shifts away from growth, resulting in slower or diminished muscle development.
4 - Alcohol Can Deplete Nutrient Status
Alcohol disrupts the body's ability to absorb, retain, and utilise nutrients. It does so through several mechanisms.
Nutrient absorption is reduced → Alcohol impairs digestive enzymes, transport mechanisms, and gut lining integrity, limiting the effective breakdown and absorption of key micronutrients — particularly B vitamins (B1, B6, folate), zinc, and magnesium.
Nutrient processing is impaired → Alcohol diverts liver resources toward detoxification, reducing its capacity to store, convert, and distribute nutrients effectively throughout the body.
Nutrient losses are increased → Alcohol suppresses antidiuretic hormone (ADH), increasing urine output and accelerating the excretion of minerals such as magnesium, zinc, and electrolytes.
Nutrient demand is increased → Alcohol metabolism generates oxidative stress, increasing the body's requirement for vitamins and minerals — particularly antioxidants and B vitamins.
5 - Alcohol Affects the Nervous System
Neural activity is suppressed → Alcohol enhances GABA (inhibitory signalling) and suppresses glutamate (excitatory signalling), slowing brain activity and producing sedation and impaired cognitive function.
Sleep architecture is disrupted → Although alcohol may promote initial sleep onset, it reduces REM sleep and increases fragmentation, resulting in poorer overall sleep quality.
Recovery capacity is impaired → Reduced sleep quality limits physical and neurological recovery, impairing tissue repair and adaptation.
Hormonal regulation is disrupted → Sleep disruption alters key hormonal rhythms, affecting cortisol, growth hormone, and other regulators of metabolism and recovery.
Appetite control is impaired → Changes in sleep and neural signalling disrupt hunger and satiety hormones, increasing the likelihood of overeating and poor food choices.
6 - Alcohol (Temporarily) Stops Other Detox Processes
Alcohol is treated as a priority toxin by the body. As a result, it temporarily displaces other detoxification processes in the liver.
Detox efficiency is reduced → Alcohol metabolism shifts the NADH:NAD⁺ ratio, altering the liver's redox state and impairing normal detox reactions that rely on NAD⁺.
Clearance of other compounds is delayed → Hormones, metabolic byproducts, and environmental toxins remain in circulation for longer, as their processing is deprioritised.
Repair processes are deprioritised → With metabolic resources directed toward alcohol clearance, the liver and wider system reduce investment in tissue repair, inflammation resolution, and cellular maintenance.
8 - Alcohol and Inflammation
Alcohol disrupts immune regulation and increases inflammatory signalling throughout the body.
Gut barrier integrity is reduced → Alcohol damages the intestinal lining, increasing permeability ("leaky gut") and allowing bacterial endotoxins (LPS) to enter the bloodstream.
Immune activation is increased → The presence of endotoxins in circulation triggers an immune response, leading to increased levels of pro-inflammatory cytokines such as TNF-α and IL-6.
Oxidative stress is elevated → Alcohol metabolism generates reactive oxygen species, which damage cells and further amplify inflammatory signalling.
Systemic inflammation is increased → The combined effect of immune activation and oxidative stress creates a low-grade inflammatory state throughout the body.
Tissue repair is impaired → Chronic inflammation interferes with normal healing processes, slowing recovery and increasing the risk of ongoing dysfunction.
How Alcohol Affects Blood Chemistry
The effects of alcohol are rapidly reflected in blood chemistry. Because alcohol is prioritised for metabolism and directly impacts the liver, nervous system, and metabolic pathways, it creates immediate and measurable changes in key biomarkers. These shifts reflect a temporary disruption in normal physiological balance — affecting lipid metabolism, blood sugar regulation, liver function, and inflammatory signalling.
Ultimately, alcohol disturbs core biomarkers that form the biochemical foundation of health — governing metabolism, nutrient status, and cellular function:
- Serum glucose ↑
- Serum cholesterol ↑
- Serum triglycerides ↑
- Alkaline phosphatase ↑
- LDH ↑
- Magnesium ↓
- Zinc ↓
- Manganese ↓
- Potassium ↓
We Advocate for Zero Alcohol for Those Participating in Our Health Programs
For individuals experiencing metabolic imbalance, nutrient deficiencies, or impaired physiological function, alcohol introduces an additional burden that the body must continually work to offset. As outlined above, it disrupts multiple core systems.
During periods of repair and recalibration, the objective is to create the most favourable internal environment for the body to function efficiently. Alcohol moves the system in the opposite direction — diverting detoxification pathways, impairing nutrient utilisation, and disrupting recovery at a time when demand is elevated.
In this context, alcohol becomes counterproductive. It introduces unnecessary interference into what is otherwise a controlled, corrective process, reducing both the speed and clarity of progress. For this reason, we recommend that participants in our tailored health programs abstain from alcohol for the duration of the program — to allow the body to function without disruption and maximise the effectiveness of the intervention.
Similarly, we caution against heavy and regular drinking — especially for those who have completed our tailored health programs, as it often contributes to systemic dysfunction that leads them to be unwell in the first place.
