A claim you hear on longevity podcasts
Strong consensus for. Of 10 studies that test it, 8 agree and 2 partly agree.
The claim checked: For women, one or two drinks a week or less is where to aim Hear it at 32:10
Eight of ten studies agree that breast cancer risk rises even at low amounts. In the Nurses' Health Study, risk was higher at 3 to 6 drinks a week. A pooled review found risk rose at half a drink a day or less and found no safe level. Two are mixed. The biggest pooled analysis, of 53 studies, warned that people tend to under-report how much they drink, so it drew no firm conclusion at low amounts.
Computed from 10 studies that test this point, each judged by two readers, in full. 10 more studies are waiting for a full read and do not count yet.
“alcohol, you know, for for women, you know, the general recommendation is less is better, right? And we do know, you know, one or two uh drinks a week or even less is probably where we want to focus from a from decreasing risk of breast cancer.”
pooled analysis · 2015 · landmark
“In the present study, alcohol drinking was associated with cancer of the oral cavity and pharynx, oesophagus (SCC) and female breast even at low doses.”
Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. Br J Cancer
Who: 572 case-control and cohort studies (1956-2012) of solid cancers; female breast estimates from 118 studies
PMID 25422909
other primary study · 1998 · landmark
“Among women who consume alcohol regularly, reducing alcohol consumption is a potential means to reduce breast cancer risk.”
Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA
Who: Women in 6 prospective cohorts in Canada, the Netherlands, Sweden and the United States (Pooling Project)
PMID 9480365
other primary study · 2011 · landmark
“Increasing alcohol consumption was associated with increased breast cancer risk that was statistically significant at levels as low as 5.0-9.9 gm/day, equivalent to 3-6 drinks/week (RR 1.15 (95% CI 1.06-1.24) 332 cases/100,000 person-years).”
Moderate alcohol consumption during adult life, drinking patterns, and breast cancer risk. JAMA
Who: Female registered nurses aged 34-59 in 1980 in the Nurses' Health Study, predominantly White
PMID 22045766
pooled analysis · 2013 · landmark
“In conclusion, alcohol increases the risk of cancer of the oral cavity and pharynx, SCC of the esophagus and breast even at low doses.”
Light alcohol drinking and cancer: a meta-analysis. Ann Oncol
Who: Case-control and cohort studies of light drinkers vs non-drinkers for six cancer sites; breast estimates from 110 studies of women
PMID 22910838
pooled analysis · 2023 · landmark
“Furthermore, light alcohol consumption was significantly associated with the risk of esophageal cancer (RR, 1.39; 95% CI, 1.10 to 1.75), colorectal cancer (RR, 1.04; 95% CI, 1.02 to 1.07), prostate cancer in male (RR, 1.05; 95% CI, 1.01 to 1.09), and breast cancer in female (RR, 1.05; 95% CI, 1.04 to 1.07).”
Cancer risk based on alcohol consumption levels: a comprehensive systematic review and meta-analysis. Epidemiol Health
Who: Cohort studies of adults on alcohol and 10 cancer types, plus the Pooled Korean Biobank
PMID 37905315
other primary study · 2015
“Among women, even consumption of 5-14.9 g of alcohol per day was associated with increased risk of alcohol related cancers, mainly breast cancer.”
Light to moderate intake of alcohol, drinking patterns, and risk of cancer: results from two prospective US cohort studies. BMJ
Who: Female nurses aged 30-55 at enrolment (Nurses' Health Study) and male health professionals aged 40-75 (Health Professionals Follow-up Study)
PMID 26286216
pooled analysis · 2018
“As for female breast cancer, its incidence was increased at even the level of very light drinking (≤ 0.5 drink/day), which can be interpreted that there is no safe level for alcohol drinking regarding female breast cancer.”
Light Alcohol Drinking and Risk of Cancer: A Meta-Analysis of Cohort Studies. Cancer Res Treat
Who: Cohort studies in general healthy populations; female breast incidence from 27 studies
PMID 28546524
other primary study · 2016
“When we categorized alcohol consumption by 5 g/day increments in an aggregated dataset of all studies, a positive linear trend was observed for alcohol intakes up to 55 g/day, beyond which further increases in risk were not observed but < 1% of women reported alcohol intakes > 55 g/day; Figure 1).”
Alcohol consumption and breast cancer risk by estrogen receptor status: in a pooled analysis of 20 studies. Int J Epidemiol
Who: Women in 20 prospective cohorts (Pooling Project of Prospective Studies of Diet and Cancer)
PMID 26320033
pooled analysis · 2002 · landmark
“Any firm conclusion about the risk of breast cancer at low levels of alcohol intake is, however, prohibited by the likelihood of measurement errors, particularly the tendency for underestimation of the amount drunk, and by the possibility that non-drinkers may differ in some relevant, but unmeasured, ways from those who sometimes drink alcohol.”
Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease. Br J Cancer
Who: Women with invasive breast cancer and controls from 53 case-control and cohort studies with both alcohol and tobacco data (Collaborative Group on Hormonal Factors in Breast Cancer)
PMID 12439712
pooled analysis · 2001
“For all these types of cancer, significant increases in risk existed even at the lowest consumption level studied here (i.e., 25 grams of alcohol, or two standard drinks per day).”
Alcohol consumption and the risk of cancer: a meta-analysis. Alcohol Res Health
Who: Case-control and cohort studies of alcohol and cancer at 19 sites; 49 studies of female breast cancer
PMID 11910703
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