America’s Surgeon General raises alarm about the link between alcohol and cancer

BY PAUL JUNOR

There has been worldwide media coverage regarding the released statement by the U.S. Surgeon General regarding the correlation between alcohol and cancer. The U.S. Surgeon General issued an advisory titled, “Alcohol and Cancer Risk.” It states, “This is a public statement that calls the American people’s attention to an urgent public health issue and provides recommendations for how it should be addressed.” The document was not an extensive review of the literature but was developed through a substantial review of the available evidence. It notes further that it is “Specific to alcohol use and cancer risk. It does not review broader health and societal outcomes associated with alcohol use.”

The advisory referred to journal articles in July 11^th, 2024 Cancer Journal for Clinicians, and the April 2024 American Journal of Preventive Medicine, which describes alcohol use as a leading preventable cause of cancer in the United States, contributing to nearly 100,000 cancer cases and about 20,000 cancer deaths each year. A Continuous Update Project Expert Report in 2018 titled, “Diet, Nutrition, Physical Activity And Cancer: A Global Perspective”: published by the World Cancer Research Fund/American Institute for Cancer Research describes a link between alcohol use and increased risk for at least seven different types of cancers. These include:

• Breast (in women)
• Colorectum
• Esophagus
• Liver
• Mouth (oral cavity)
• Throat(pharynx)
• Voice box(larynx)

Aside from highlighting the scientific evidence for the causal link between alcohol consumption and increased cancer risk there are other reasons for the advisory. These include:

• To better inform the public of this relationship
• Offers key recommendations to reduce alcohol-related cancers.

There were approximately 741,300 cancer cases globally that were linked to alcohol consumption in 2020 according to an article titled, “Global Burden Of Cancer In 2020 Attributable To Alcohol Consumption: A Population-Based Study In The Lancet, Oncology, 22(8),1071-1081”. Drink number ranges were based on 14 g= 1 U.S. standard drink. The breakdown shows:

• 3 % or 209,800 cases result from consuming between 2- 4 drinks per day (31~ 60 g)
• 0 % or 185,100 cases from consuming less than 2 drinks per day (0.1 ~ 30 g)
• 0 % or 192,000 cases from consuming approximately 6 drinks per day (> 90 g)
• 7 % or 153,400 cases from consuming between 4 – 6 drinks per day (61 ~ 90 g)

The advisory notes that less than 50% of Americans were aware that alcohol consumption increases cancer risk. This was based on a survey of a nationally representative sample of U.S. adults ages 18 and older conducted by the American Institute for Cancer Research in 2019. The survey question asked, “Do you believe [risk factor] has a significant effect on whether or not the average person develops cancer?” The five risk factors identified were: radiation (91%), tobacco (89 %), asbestos (81 %), obesity (53 %), and alcohol (45 %).

There were comprehensive assessments of scientific evidence and the application of the Bradford Hill criteria (as described in the May 1965: Volume 58(5): 295 – 300 of the Proceedings of the Royal Society Medicine by AB Hill) titled, “The Environment and Disease: Association or Causation.” Observational studies, which involved analyzing large numbers of people over a long time and extensive review of the effects of the risk factors in animal studies, were the basis to determine the causal link.

A specialized cancer agency of the WHO, the International Agency for Research on Cancer (IARC) identified alcohol as a Group 1 carcinogen including: tobacco, asbestos, and formaldehyde in 2012. The agency notes, “There is enough evidence to conclude that it can cause cancer in humans.”

In addition, the World Cancer Research Foundation/American Institute for Cancer Research (WCRF/AICR) describes the evidence as “Convincing.”

The advisory describes four ways that ethanol, the type of pure alcohol present in all alcohol-containing beverages, causes cancer. They are:

• Alcohol breaks down acetaldehyde which damages DNA in multiple ways, causing an increased risk of cancer
• Alcohol induces oxidative stress, increasing the risk of cancer by damaging DNA, proteins, and cells and increasing inflammation.
• Alcohol alters levels of multiple hormones, including estrogen, which can increase breast cancer risk.
• Alcohol leads to greater absorption of carcinogens.