A total of 139 papers were included in the systematic review, and 106 papers were included in the subsequent meta-analysis. Thyroid cancer (male) and laryngeal cancer were not presented because data from 1 or no study were obtained in this study, and information on sex-specific cancer incidence was insufficient. However, it should be noted that for esophageal cancer, the calculation of a large risk value may have influenced the symmetry of the plot. The analysis included risk estimates that were adjusted for confounding factors, and if adjusted values were unavailable, crude values were used. Studies that evaluated specific types of alcoholic beverages only were excluded to avoid potential confounding. We conducted the study following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines (Figure 1).
- Similarly, for certain cancers, there were only a few cases with certain levels of alcohol consumption (e.g., high levels of alcohol consumption in female breast cancer patients).
- The effects of alcohol consumption on cancer risk have been studied for many decades and an association with alcohol has been observed for multiple cancer sites.
- This analysis found that alcohol consumption of at least 50 grams (i.e., 4 standard drinks) per day significantly increased the risk of developing any type of cancer.
- Researchers have made several attempts to determine whether different types of alcoholic beverages have different effects on cancer risk.
- This effect was noted for several digestive tract cancers, specifically cancers of the esophagus and the nonglandular forestomach5 (Doll et al. 1999).
- The most common histological subtype of liver cancer is hepatocellular carcinoma (HCC) and around 154,700 cases of HCC in 2020 were attributable to alcohol consumption .
Lastly, we specifically aimed to include only cohort studies in our analysis, which provide stronger evidence for causal association. Heavy drinkers might underreport their consumption, or individuals may underestimate their alcohol intake due to memory lapses 48,49. Third, the type of alcoholic beverage (e.g., wine, beer, liquor) was not taken into account, although it is known that different types of alcohol may have varying effects on health outcomes. However, due to the limited number of studies available on thyroid cancer, further research is warranted to confirm these findings. Additionally, alcohol might exert a direct toxic effect on thyroid cells, leading to a reduction in thyroid volume and a decreased risk of thyroid cancer .
Risks start from the first drop
Drinking alcohol increases the risk of squamous cell carcinoma of the oesophagus which is the most common histological subtype of oesophageal cancer globally, and contributed the most cases of cancer in 2020 attributable to alcohol (189,700 cases) 1,9. Here, we discuss evidence from large meta-analyses of observational studies and emerging evidence from Mendelian randomisation studies. In addition to associations from epidemiological studies, multiple mechanistic pathways through which alcohol can cause cancer have been proposed.
“It’s very clear from our HINTS data that people trust physicians more than any other source of health information, and we’ve been trying to get out the message that the doctor’s office is really a place where this messaging should be more prominent,” said Dr. Klein. Alcoholic drinks contain ethanol, which is a known carcinogen, and there are several ways in which it may cause cancer. In the United States alone, about 75,000 cancer cases and 19,000 cancer deaths are estimated to be linked to alcohol each year. “Unfortunately, there have been very few attempts at educating the public about the alcohol–cancer link. “Some are drinking less, and that might be because vaping and edibles are more available,” said Elizabeth Kovacs, a professor of surgery at the University of Colorado Anschutz Medical Campus. Several experts also cautioned that it’s not always easy to tell how much alcohol a drink contains.
Cancer risk based on alcohol consumption levels: a comprehensive systematic review and meta-analysis
In this Q&A, Monti weighed in the advisory and shared his perspective about alcohol and health risks. As the surgeon general’s report noted, 89% of Americans recognize tobacco use as a risk factor for cancer, compared to 45% who recognize alcohol consumption as a risk. We have discussed evidence on mechanistic and epidemiological research in the field, and this information must be used to decrease the burden of cancers, as well as other diseases and injuries, attributable to alcohol. This information is useful to corroborate existing evidence, develop chemoprevention strategies, and could improve cancer therapy, but there is already a wealth of evidence to support the need for further alcohol control and cancer prevention efforts. While studies have provided evidence on alcohol’s carcinogenic potential, further understanding of alcohol’s pathways to cancer development will inform the direction of future research.
Cytochrome P-450 2E1 (CYP2E1) activity produces reactive oxygen species (ROS) leading to lipid peroxidation, metastasis, angiogenesis, and further formation of DNA adducts. Both ethanol and acetaldehyde can disrupt DNA methylation by inhibiting S-adenosyl-L-methionine (SAMe) synthesis and DNA methyltransferase (DNMT) activity, and ethanol can impair one-carbon metabolism. A simplification of the pathways by which alcohol, as ethanol, might drive carcinogenesis. Assuming that analyses are conducted appropriately, due to the random distribution of these genetic variants at birth, MR studies should be less prone to conventional confounding and reverse causality. One method which might overcome some of the limitations in observational studies is Mendelian randomisation (MR), which uses genetic variants to explore the causal relationship between exposure and disease outcome.
Brief Intervention for Hazardous and Harmful Drinking (AUDIT)
The meta-analysis by WCRF did not find an increased risk of pancreatic cancer per 10 g alcohol per day (RR 1.00 (95% CI 0.99–1.01)) but there was a possible threshold effect of increased risk for intakes of around 60 g per day (RR 1.17 (95% CI 1.05–1.29)) . The linear dose-response meta-analysis by WCRF resulted in a non-significant RR of 1.02 (95% CI 1.00–1.04) per 10 g alcohol per day, but the non-linear dose-response analysis found an increase in stomach cancer risk for intakes over 45 g alcohol per day . Alcohol might also increase the risk of precancerous lesions in the colon, with a meta-analysis reporting a 27% increased risk of colorectal adenoma (RR 1.27 (95% CI 1.17–1.37)) per 25 g alcohol per day . The meta-analysis conducted by WCRF found a 7% increased risk of colorectal cancer (RR 1.07 (95% CI 1.05–1.08)) per 10 g alcohol per day .
So it doesn’t really matter if you’re drinking liquor, beer, or wine. A recent study estimated that 17,000 U.S. cancer deaths a year could be prevented if everyone adhered to those guidelines. Most guidelines recommend that women should have no more than one drink a day, and men should drink no more than two per day. It has also been linked to cancer of the larynx and the telehealth for addiction online rehab and counseling programs liver. Bernstein has a research and clinical interest in alcohol use disorder, a medical condition defined as an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences. The World Health Organization classifies alcohol as a Group 1 carcinogen – the highest risk group, which also includes asbestos, radiation, and tobacco.
Division of Cancer Control and Population Sciences Program Areas
“Use of tobacco really peaked around 1964, and then started to fall after the surgeon general’s report on smoking and tobacco came out and led to dramatic increases in public awareness of the cancer harms of tobacco use,” she says. “For example, Flush alcohol tips for melanoma, it is difficult to separate the potential effect of alcohol from sun exposure, and whether there is an interaction between the two exposures.” Alcohol is the third most important preventable cause of cancer, after tobacco smoking and excess weight.
The current warning “has long informed consumers about the potential risks of the consumption of alcohol. For example, a genetic variant common among some people of Asian ancestry predisposes a higher risk of developing cancer with exposure to alcohol. In the context of cancer, many people who drink alcohol also smoke.
Why does drinking alcohol raise cancer risk?
“We need to really make sure that we reinforce the message that all alcohol increases cancer risk,” she said. For example, more participants were aware of the cancer risks from hard liquor and beer than about the risk from wine, with some participants believing wine lowers your cancer risk. The study confirmed that most American adults aren’t aware of the link between alcohol consumption and cancer. Doctors said it’s most important to pay attention to the quantity or concentration of alcohol, as opposed to whether it’s liquor, beer or wine, since the alcohol molecules themselves are responsible for raising a person’s cancer risk.
- WCRF found an inverse association between alcohol consumption and kidney cancer risk (RR 0.92 (95% CI 0.86–0.97) per 10 g per day) .
- Moderating (or decreasing) alcohol intake is also a logical target for multi-behavioral interventions focusing on other health behavioral risk factors such as tobacco cessation.
- The risks were even greater among older adults with existing health problems (like frailty, diabetes, or high blood pressure) or those with lower socioeconomic status, such as lower income or limited access to healthcare.
- The linear dose-response meta-analysis by WCRF resulted in a non-significant RR of 1.02 (95% CI 1.00–1.04) per 10 g alcohol per day, but the non-linear dose-response analysis found an increase in stomach cancer risk for intakes over 45 g alcohol per day .
- It should be noted that articles were counted more than once if they investigated multiple cancer types or reported results from multiple cohort studies.
- Regional health leaders agree on actions to promote health through schools, harness traditional and complementary medicine
Funnel plots of the meta-analysis of studies examining the relationship between all cancer and alcohol consumption levels. Consistent with previous studies 41,42, even low levels of alcohol consumption were linked to an increased incidence of breast cancer. Our study results align with previous meta-analyses 11,19,34, indicating a dose–response relationship between alcohol consumption level and cancer risk. Moderate and heavy drinking further escalated the risk, including for additional cancer types, including stomach, liver, and pancreatic cancers.
Are there other factors that can accentuate the effects of drinking alcohol on cancer? That said, the risk is higher if you’re drinking drinks with a higher alcohol concentration and therefore consuming more alcohol overall. If that alcohol molecule is there, the cancer risk is there. The degree to which alcohol increases your risk of cancer varies by the specific cancer type, as well as by the amount you drink, how often you drink, and how long you’re exposed to alcohol. In terms of cancer risk, does it matter how much or how often you drink?
The impact of alcohol consumption on cancer burden differs by cancer type, and cancers of the oesophagus, liver, and breast represent the most alcohol-attributable cases of cancer globally (Figure 1). The report cites a direct link between alcohol consumption and at least seven types of cancer, including of the breast, colorectal, liver and mouth. For someone who drinks but who doesn’t have alcohol use disorder, it’s about helping them understand the risks of alcohol, including the link to cancer, individualized based on their unique patterns of alcohol consumption and medical history. And 10% incorrectly believed that drinking wine reduces cancer risk. When we hear about health impacts from drinking alcohol, often the conversation focuses on things like deaths or injuries from crashes, risk to a fetus during pregnancy, and liver and heart disease. We’re not telling people not to drink; we’re just promoting informed choice based on the most accurate, updated information about alcohol and cancer risk.”
But heavy drinking carries a much higher risk even for those without other health concerns. For example, any amount of drinking increases the risk of breast cancer and colorectal cancer. But good evidence shows that drinking high amounts of alcohol are clearly linked to health problems. The other big risk is cardiovascular disease, particularly atrial fibrillation, which is an irregular, often rapid heart rate that commonly causes poor blood flow — there are clear links between alcohol consumption and atrial fibrillation. Ultimately, a randomized control study with humans is what we need to conclusively prove a causal link between alcohol consumption and cancer. As the surgeon general’s report notes, there is extensive evidence from biological studies that ethanol, the type of pure alcohol found in all alcohol-containing beverages, causes cancer in at least four distinct ways.
The association between various levels of alcohol consumption and an increased risk of liver cancer remains difficult to interpret even with the pooled data used in this meta-analysis. In a September report, the American Association for Cancer Research found excessive levels of alcohol consumption can increase the risk for six different types of cancer, including breast, colorectal, liver, stomach, esophageal squamous cell carcinoma and certain types of head and neck cancers. The study also found that people who believed drinking alcohol increased the risk of heart disease were more aware of the alcohol–cancer risk than those who were unsure or believed drinking lowered the effect on heart risk. This finding aligns with previous research by Bagnardi et al. , whose meta-analysis demonstrating a 30% increased risk of esophageal cancer, particularly squamous cell carcinoma, among individuals with light alcohol consumption (≤ 12.5 g/day; ≤ 1 drink/day).
The researchers cited the change in public perceptions and tighter regulations for tobacco, which show the importance of public health campaigns and physicians explaining Alcohol Use Disorder risks to their patients. One study, for instance, found a 29% increase in drinking in the US in April 2020. Awareness was highest for liquor, but less than one-third of participants said that liquor increases cancer risk. However, based on more recent, comprehensive studies, public health experts now generally agree that alcohol—including wine—does not have a so-called “cardioprotective” effect. There have been decades of public education campaigns about the health risks of tobacco, warning labels on tobacco products, and smokefree laws.
