New Research Results Show How Alcohol Use Really Affects Overall Health and Fitness

Latest Research Overview: How Alcohol Use Really Affects Overall Health and Fitness

This science digest synthetizes research results from recent landmark studies answering questions such as:

• How harmful is alcohol in small and low doses of intake?
• How do wine, beer, and liquor affect physical fitness, muscle building and calorie consumption?

One thing is clear: alcohol, i.e. ethanol, is a cell poison from a biochemical point of view.

The ethanol in beer, wine, and liquor causes enormous damage to the human body. It fuels inflammatory processes, damages the liver in particular, and leads to cardiovascular diseases, nerve damage and cancer. The more alcohol a person consumes, the more serious the consequences.

The World Health Organization sums up:

In early 2023, the World Health Organization (WHO) issued a statement based on a review of world-class science:

The risks and harms associated with drinking alcohol have been systematically evaluated over the years and are well documented. The World Health Organization has now published a statement in The Lancet Public Health: when it comes to alcohol consumption, there is no safe amount that does not affect health.

WHO Statement “No level of alcohol consumption is safe for our health”, January 2023

WHO is very clear: It is the alcohol that causes harm, not the beverage. Ethanol (alcohol) causes cancer through biological mechanisms as the compound breaks down in the body, which means that any beverage containing alcohol, regardless of its price and quality, poses a risk of developing cancer.

We cannot talk about a so-called safe level of alcohol use – the risk to the [alcohol consumer’s] health starts from the first drop of any alcoholic beverage,” explained Dr Carina Ferreira-Borges, acting Unit Lead for Noncommunicable Disease Management and Regional Advisor for Alcohol and Illicit Drugs in the WHO Regional Office for Europe.

Dr Carina Ferreira-Borges, acting Unit Lead for Noncommunicable Disease Management and Regional Advisor for Alcohol and Illicit Drugs, WHO Europe

Despite this, the question of beneficial effects of alcohol has been a contentious issue in research for years.

Overcoming bias to properly communicate alcohol’s health risks

Scientists have now shown that the claim that people who regularly consume small amounts of alcohol live longer than alcohol abstainers is based on methodological flaws and measurement errors. Previous studies often did not take into account that many people who were alcohol abstainers were once alcohol dependent and therefore still suffer from long-term damage – the sick quitter effect.

And biases pervade the field of alcohol epidemiology and still confuse communication about alcohol’s health risks.

In a study published in January 2024, researchers identified 107 longitudinal studies by systematic review with 724 estimates of the link between alcohol use and all-cause mortality for 4,838,825 participants with 425,564 recorded deaths.

The researchers concluded that participant selection biases had warped the findings of dozens of alcohol mortality studies over the years, creating “the false appearance of health benefits from moderate [alcohol consumption].”

Studies with life-time selection biases may create misleading positive health associations. These biases pervade the field of alcohol epidemiology and can confuse communications about health risks.

In March 2024, a study showed why alcohol deaths have been underestimated during the past 30 years.

Over 70% of systematic reviews and meta-analyses published to March 2022 of all-cause mortality risk linked with alcohol use did not exclude former alcohol users from the reference group and may therefore be biased by the ‘sick-quitter effect’.

The sick-quitter effect

The ‘sick quitter effect’ is when people with compromised health due to previous alcohol use behaviours appear in health data as non-alcohol users, when in fact they are ex-alcohol users with health problems due to alcohol use. When a study compares to this group of people, it can falsely make the harms of alcohol consumption appear smaller or non-existent, or even make it seem like consuming small quantities of alcohol protects against harms. 

Dr Sarich, lead author of the study, said that of the 30% of reviews that were not affected by the ‘sick-quitter’ issue, only one was considered a high-quality review, and found that the risk of death increases with increasing alcohol intake, with no evidence of any protective effects for low-level alcohol use. All of the remaining reviews may have understated the health harms of alcohol. 

And the positive substances in wine are probably present in too small quantities to provide any real benefit.

Better understanding alcohol’s real harm

In 2019, a much-noticed study was published in the renowned medical journal “The Lancet” that reinforces the improving understanding of alcohol’s real harm: every drop of alcohol consumed increases the health risk. Data from more than 500,000 Chinese people were evaluated; many of them cannot break down alcohol due to a genetic predisposition, and their alcohol consumption was very low, in some cases even zero. The researchers found that the alcohol use risk can be analyzed well in these people, as their lifestyles were otherwise no different.

The result of this study: Even one alcoholic drink a day increases the risk of stroke.

Alcohol consumption increases blood pressure and the risk of stroke,” the scientists wrote.

Conventional and genetic evidence on alcohol and vascular disease aetiology: a prospective study of 500 000 men and women in China, Millwood, Iona Y et al. The Lancet, Volume 393, Issue 10183, 1831 – 1842

And most recently, a review study showed that alcohol has no life-prolonging effect. The study was published in the journal “JAMA” at the end of March 2023. The researchers analyzed 107 studies with a total of more than 4.8 million people. Women who drink alcohol in particular die younger than those who abstain.

Underestimated cancer risk factor

It is also becoming increasingly clear that alcohol is a previously underestimated cause of cancer.

Around 4% of new cancer cases worldwide in 2020 were due to alcohol consumption, with many of those cancer cases being due small and low-dose alcohol intake. In the case of breast cancer in particular, any alcohol consumption seems to contribute to the risk. For example, WHO Europe reported in 2021 that breast cancer is the most frequently diagnosed cancer type in the WHO European Region, with 1579 women diagnosed every day. Alcohol consumption is one of the major modifiable risk factors for the disease, causing 7 of every 100 new breast cancer cases in the Region. 

The large research project Global Burden of Disease is classifying illnesses and deaths worldwide. Regarding the role of alcohol, the scientists write about the data from 1990 to 2016:

Alcohol inhibits muscle growth

It is well known that chronic alcohol use and addiction damage muscles. People with an alcohol use disorder or addiction suffer from muscle weakness because ethanol appears to suppress certain signaling pathways in muscle cells and the synthesis of proteins, for example via the so-called mTOR kinase.

A study of eight athletic men examined how alcohol consumption after a workout affected muscle growth. They trained on machines and completed high-intensity interval training, then consumed six vodka-orange juice mixtures, some with protein added, or a pure protein drink.

Biopsies taken from their muscles showed that the signaling pathways in the cells were disrupted and muscle growth was reduced by more than a third, or by a quarter when ethanol was combined with proteins.

Metabolism is disrupted

Ethanol disrupts the metabolism of humans. It is produced by fermentation processes from sugar and provides around seven kilocalories per gram. However, these are not used like energy from other foods, for example they are not stored by the body.

Alcohol also has a high thermal effect, which means that the body has to use a lot of energy to metabolize it. And alcohol inhibits other important processes such as fat burning. To put it simply, the body is busy breaking down the alcohol.

Therefore, if people want to lose weight, they should avoid alcohol. In addition, alcoholic drinks often contain a lot of calories in addition to the ethanol.

In addition, despite the calories it contains, alcohol does not fill people with nutrition, but actually stimulates people’s appetite. Researchers have decoded the underlying mechanism in the laboratory using the brains of mice. Certain nerve cells that are involved in regulating the feeling of hunger, the so-called AgRP neurons, are activated by alcohol. They usually fire especially when there is a severe lack of food.

Alcohol also stimulates the appetite indirectly through its diuretic effect: the body loses important electrolytes in the urine. This deficiency is often easily compensated the next day with an extra-large portion of breakfast.

The more alcohol a person consumes, the greater is the risk of obesity.

REM sleep is suppressed

Another important factor through which alcohol harms the human body is the disruption of sleep – and thus of important regenerative processes.

Alcohol has a depressant effect via the GABA receptor in the brain. And alcohol suppresses the important REM sleep.

Overall, anyone who wants to improve their physical fitness should drink less alcohol or avoid it entirely.

Studies cited

The Lancet: “Conventional and genetic evidence on alcohol and vascular disease aetiology: a prospective study of 500 000 men and women in China”

JAMA Network Open: “Association Between Daily Alcohol Intake and Risk of All-Cause MortalityA Systematic Review and Meta-analyses”

The Lancet Public Health: “Health and cancer risks associated with low levels of alcohol consumption”

Journal of Studies on Alcohol and Drugs: “Why Do Only Some Cohort Studies Find Health Benefits From Low-Volume Alcohol Use? A Systematic Review and Meta-Analysis of Study Characteristics That May Bias Mortality Risk Estimates”

Addiction: “The association between alcohol consumption and all-cause mortality: An umbrella review of systematic reviews using lifetime abstainers or low-volume drinkers as a reference group”

National Cancer Institute: “Alcohol Tied to 750,000 Cancer Cases Worldwide in 2020”

WHO Europe: “Alcohol is one of the biggest risk factors for breast cancer. Simply reducing alcohol consumption can greatly reduce the risks, says WHO/Europe”

The Lancet: “Alcohol use and burden for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016”

Journal of Applied Physiology: “Alcohol impairs skeletal muscle protein synthesis and mTOR signaling in a time-dependent manner following electrically stimulated muscle contraction”

PLOS One: “Alcohol Ingestion Impairs Maximal Post-Exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training”

Source Website: Frankfurter Allgemeine Zeitung [translated from German]