4 Things That Happen When You Quit Alcohol for a Month

Curious about the buzz around Dry January and Sober October? We had people sober up for a month to see what happens. Turns out, even a short break can have surprising effects.

Michelle Darian
By Michelle Darian
Jovan Mijailovic
Edited by Jovan Mijailovic

Updated May 9, 2024.

A man dancing happily with his wife because he managed to quit drinking.

In this article

Inside Impact: Our Sober October study

1. Decreased HDL cholesterol 

2. Improved sleep, mood, energy, and hydration 

3. Enhanced RHR

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You may have seen friends and family members participating in month-long challenges like Dry January and Sober October as a way to reset or reevaluate their relationship with alcohol.

This trend—which began as a public health campaign in the UK—has become popular worldwide. But we know little about what happens internally when we abstain from drinking for 30 days.

Recent research suggests improvements in overall well-being. [1] That's why we've decided to do our own study and investigate the effects of this practice on your biomarkers. So, keep reading to find out.

Key Takeaways

  • Evidence suggests that even short-term sobriety can improve perceived sleep, energy, mood, and athletic performance.
  • Our study found that a month-long alcohol abstention correlated with significantly lower high-density-lipoproteins (HDL) cholesterol levels.
  • We also discovered that it decreased the neutrophil-to-lymphocyte ratio (NLR), which is beneficial for immune function and other health outcomes. 
  • Finally, we saw that those who quit drinking for 31 days had reduced resting heart rate (RHR).

Inside Impact: Our Sober October study

We followed 30 light to moderate consumers of alcohol for 31 days. Participants completed a blood draw before and after abstaining from drinking. They also filled out a questionnaire about how they felt.

Results showed that even this short-term break in consumption can impact health markers. According to our study, four effects stood out for subjects who participated in the challenge.

A table representing details of InsideTracker study.

» Read detailed findings on the effects of our Sober October study

1. Decreased HDL cholesterol 

HDL—also known as the “good cholesterol"—protects us by removing harmful particles in the bloodstream before they damage our blood vessels. That's why we also call it cardioprotective.

The people we investigated had significantly lower overall HDL (-9%). Our findings remained significant in compliant people (-9%), females (-7%), and males (-14%).

While many of us would want to raise our HDL, our results are consistent with previous studies that got the same result. It also coincides with the ones that showed moderate alcohol consumption increased the levels of this biomarker. [2–4] 

» Check out how alcohol affects your health

2. Improved sleep, mood, energy, and hydration 

Just as we hypothesized, more than 50% of participants reported improvements in one or more of the following characteristics, which align with current scientific literature on the negative impacts of alcohol:

  • Sleep quality and duration: Studies show that having alcohol within a few hours of bedtime may impair how long you sleep and how rested you feel after. It can disrupt the REM phase, which is particularly important for learning and memory consolidation. [5]
  • Athletic performance: Research suggests it can also hinder aerobic and anaerobic athleticism. [6] 
  • Post-exercise recovery: Repairing and producing new muscle after working out is essential for recuperation. Excessive inflammation hurts this process, and drinking spikes it. [6] 
  • Stress and mood: Heavy alcohol consumption can interfere with the chemical messengers in the brain that impact our emotional state. [7] 
  • Energy level: Alcoholic beverages may increase fatigue. [6] 
  • Hydration: They're also a diuretic that promotes fluid loss and can lead to dehydration. [8] 
A table representing the results of the InsideTracker study.

» Find out if beer has probiotics

3. Enhanced RHR

22 of our study’s 30 subjects wore fitness devices that integrate with the InsideTracker platform, such as Garmin, Apple Watch, or FitBit. They collected heart rate data.

A preliminary analysis showed statistically significant changes in the seven-day average RHR of participants, which moved from 57.5 bpm to 55.5 bpm—a 3.5% reduction (p=0.003).

This finding is consistent with previous studies showing higher breath alcohol concentrations (BAC) are associated with increased RHR, as assessed using an electrocardiogram (ECG). [9]

4. Reduced NLR 

NLR measures two of the five components of white blood cell counts (WBC). Neutrophils make up the largest share—60–70% of the total. They're the immune system’s first responders, ridding the body of pathogens that shouldn’t be there.

On the other hand, lymphocytes represent around 20–40% of circulating WBCs. They also fight foreign invaders, but they have another function. These tiny cells can remember viruses and bacteria they've previously fought and prevent further illnesses from them. We call the effect adaptive immunity.

The relationship between this pair—NLR—is a way to evaluate the balance of systemic inflammation (neutrophil count) and adaptive immunity (lymphocyte number). Emerging evidence says this correlation links to factors that affect longevity, like all-cause mortality.

In the general population, higher NLR suggests a higher risk of death due to influenza or pneumonia. It also relates to heart, lower respiratory, and kidney disease. [10] 

Our results showed significantly decreased neutrophils (-11%) and increased lymphocyte percentage (+9%) among study participants. 

Drinking alcohol can suppress your immune response. In fact, clinical studies have shown that overconsumption of alcohol is associated with increases in infectious diseases. [11]

» Tap into your ancestral hunger with a 24-hour fast

Taking sobriety one step at a time

By participating in challenges like Sober October and Dry January, you may feel more rested and motivated. You'll also see objective changes in your biomarkers, which we already discussed.

Abiding in or abstaining from alcohol is a personal choice. Some participants told us they resumed drinking after the study, though with modifications. Two of them even said they'd continue with sobriety because it felt good.

Evaulating and iterating on the habits that best suit your physical and mental health is key to maintaining your well-being. InsideTracker's Ultimate Plan offers data-driven recommendations on how to do it. Use it as your roadmap for building healthy routines that address your specific goals.

Disclaimer: InsideTracker doesn't diagnose or treat medical conditions. Consult your physician for any health concerns.


[1] R. O. De Visser and J. Nicholls, “Temporary abstinence during Dry January: predictors of success; impact on well-being and self-efficacy,” Psychology & Health, vol. 35, no. 11, pp. 1293–1305, Mar. 2020, doi: 10.1080/08870446.2020.1743840. Available: https://pubmed.ncbi.nlm.nih.gov/32216557/

[2] W. L. Haskell et al., “The effect of cessation and resumption of moderate alcohol intake on serum High-Density-Lipoprotein subfractions,” New England Journal of Medicine/˜the œNew England Journal of Medicine, vol. 310, no. 13, pp. 805–810, Mar. 1984, doi: 10.1056/nejm198403293101301. Available: https://doi.org/10.1056/nejm198403293101301

[3] J. Romeo, M. González‐Gross, J. Wärnberǵ, L. E. Díaz, and A. Marcos, “Effects of moderate beer consumption on blood lipid profile in healthy Spanish adults,” NMCD. Nutrition Metabolism and Cardiovascular Diseases, vol. 18, no. 5, pp. 365–372, Jun. 2008, doi: 10.1016/j.numecd.2007.03.007. Available: https://pubmed.ncbi.nlm.nih.gov/17976963/

[4] S. Brien, P. E. Ronksley, B. J. Turner, K. J. Mukamal, and W. A. Ghali, “Effect of alcohol consumption on biological markers associated with risk of coronary heart disease: systematic review and meta-analysis of interventional studies,” BMJ. British Medical Journal, vol. 342, no. feb22 1, p. d636, Feb. 2011, doi: 10.1136/bmj.d636. Available: https://www.bmj.com/content/342/bmj.d636

[5] I. M. Greenlund, J. Bigalke, A. Tikkanen, J. J. Durocher, C. A. Smoot, and J. R. Carter, “Evening binge alcohol disrupts cardiovagal tone and baroreflex function during polysomnographic sleep,” Sleep, vol. 44, no. 11, May 2021, doi: 10.1093/sleep/zsab130. Available: https://pubmed.ncbi.nlm.nih.gov/34015116/

[6] L. Vella and D. Cameron‐Smith, “Alcohol, athletic performance and recovery,” Nutrients, vol. 2, no. 8, pp. 781–789, Jul. 2010, doi: 10.3390/nu2080781. Available: https://www.mdpi.com/2072-6643/2/8/781

[7] K. P. Abrahao, A. G. Salinas, and D. M. Lovinger, “Alcohol and the brain: neuronal molecular targets, synapses, and circuits,” Neuron, vol. 96, no. 6, pp. 1223–1238, Dec. 2017, doi: 10.1016/j.neuron.2017.10.032. Available: https://pubmed.ncbi.nlm.nih.gov/29268093/

[8] J. Romeo, M. González‐Gross, J. Wärnberǵ, L. E. Díaz, and A. Marcos, “Effects of moderate beer consumption on blood lipid profile in healthy Spanish adults,” NMCD. Nutrition Metabolism and Cardiovascular Diseases, vol. 18, no. 5, pp. 365–372, Jun. 2008, doi: 10.1016/j.numecd.2007.03.007. Available: https://pubmed.ncbi.nlm.nih.gov/17976963/

[9] S. Brunner, C. Drobesch, R. Herbel, and M. F. Sinner, “Effects of acute alcohol consumption on cardiac excitation, conduction, and repolarization: results from the Munich Beer Related Electrocardiogram Workup Study (MunichBREW),” Clinical Research in Cardiology, vol. 110, no. 6, pp. 916–918, Mar. 2021, doi: 10.1007/s00392-021-01839-6. Available: https://pubmed.ncbi.nlm.nih.gov/33738543/

[10] M. Song, B. I. Graubard, C. S. Rabkin, and E. A. Engels, “Neutrophil-to-lymphocyte ratio and mortality in the United States general population,” Scientific Reports, vol. 11, no. 1, Jan. 2021, doi: 10.1038/s41598-020-79431-7. Available: https://www.nature.com/articles/s41598-020-79431-7

[11] J. Romeo, J. Wärnberǵ, E. Nova, L. E. Díaz, S. Gómez‐Martínez, and A. Marcos, “Moderate alcohol consumption and the immune system: A review,” British Journal of Nutrition, vol. 98, no. S1, pp. S111–S115, Oct. 2007, doi: 10.1017/s0007114507838049. Available: https://pubmed.ncbi.nlm.nih.gov/17922947/