It is safe for most people to drink small amounts of alcohol on a regular basis, and have moderate amounts more occasionally. But how much is safe?
Alcoholism and other substance abuse issues run in some families. People who know about this are advised to avoid alcohol, or keenly monitor their drinking patterns.
Some families have a history of certain diseases which alcohol can exacerbate, so the same caution is due here.
But what about people without high risk factors? For years medical studies have shown small benefits of drinking wine; a few other studies showed small benefits from small amounts of any kind of alcohol. And we all know of folks who had a drink every day, and lived well past 100.
Yet for any person, too much alcohol at once can affect the brain, as shown here:
Some new studies are showing that that for many people, there are increased health risks at lower levels of alcohol consumption that once thought. Other studies show that moderate alcohol drinking provides protection against other medical conditions.
Studies which indicate moderate alcohol consumption may be problematic
Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study
Higher alcohol consumption over the 30 year follow-up was associated with increased odds of hippocampal atrophy in a dose dependent fashion. While those consuming over 30 units a week were at the highest risk compared with abstainers, even those drinking moderately (14-21 units/week) had three times the odds of right sided hippocampal atrophy. There was no protective effect of light drinking (1-<7 units/week) over abstinence. Higher alcohol use was also associated with differences in corpus callosum microstructure and faster decline in lexical fluency. No association was found with cross sectional cognitive performance or longitudinal changes in semantic fluency or word recall…. Alcohol consumption, even at moderate levels, is associated with adverse brain outcomes including hippocampal atrophy. These results support the recent reduction in alcohol guidance in the UK and question the current limits recommended in the US.
When reading such studies, we first ask, what is a “unit” of alcohol?
1 unit of alcohol = 10 millilitres (8 grams) of pure alcohol.
Typical drinks may contain 1–3 units of alcohol.
A ten ounce beer (300 ml) at 3.5% ABV contains about one unit;
A medium glass (175 ml) of 12% ABV wine has two units of alcohol
A small glass (50 ml) of sherry or port (20% ABV) contains about one unit.
Most whisky is 40% ABV. At that concentration:
A typical English pub measure (25 ml) -> 1 unit.
A typical American miniature bottle (“nip”) is 50 ml -> 2 units.
A typical American pour at a bar is 2 ounces -> 60 ml -> 2.4 units
Studies which indicate moderate alcohol consumption may be healthy and helpful
A new study conducted by researchers at the University of Rochester Medical Center found that low levels of alcohol consumption can actually lower inflammation in the brain and help it clear away toxins, including those linked to serious diseases like Alzheimer’s.
Older adults who consume alcohol moderately on a regular basis are more likely to live to the age of 85 without dementia or other cognitive impairments than non-drinkers, according to a University of California San Diego School of Medicine-led study. For White Middle Class, Moderate Drinking Is Linked to Cognitive Health in Old Age. UC San Diego Health
Media reports exaggerate risks due to alcohol
Recently, the American Society of Clinical Oncology (ASCO) warned that even light drinking could increase the risk of cancer. Carroll then discusses the ASCO report. He writes:
Let’s stipulate that there may be a correlation between light or moderate drinking and some cancers. We still don’t know if the relationship is causal, but let’s accept that there’s at least an association. For breast cancer — which is the cancer that seems to be garnering the most headlines — light drinking was associated with a relative risk of 1.04 in the announcement.
Relative risk refers to the percentage change in one’s absolute (overall) risk as a result of some change in behavior. (And 1.04 is a 4 percent change from 1.0, which represents a baseline of no difference in risk between an experimental group and a control group.)
A 40-year-old woman has an absolute risk of 1.45 percent of developing breast cancer in the next 10 years. This announcement would argue that if she’s a light drinker, that risk would become 1.51 percent. This is an absolute risk increase of 0.06 percent. Using what’s known as the Number Needed to Harm, this could be interpreted such that if 1,667 40-year-old women became light drinkers, one additional person might develop breast cancer. The other 1,666 would see no difference.
Dr. Gifford-Jones (AKA Ken Walker) writes, in an essay provocatively titled “Puritanical Lies about Alcohol”:
Professor Keith Scott-Mumby, an internationally known U.K. expert on alternative medicine, echoes what I have written over the years, that people who drink moderately live longer on average than teetotalers or those who drink to excess. In fact, there are over 20 studies that confirm this. In court it’s a criminal offence to withhold truth, so why doesn’t the same principle hold true in medicine?
Scott-Mumby points out that the lack of discussion of the beneficial impact of alcohol has for years been a systematic policy of the U.S. public health establishment. For instance, the National Institutes of Health, which funded a research study on alcohol, forbade a Harvard epidemiologist who participated in the study from publishing the health benefits of drinking!
There is strong evidence that alcohol protects against heart disease. Studies show that it increases the good cholesterol HDL. Possibly more important, it dilates arteries and makes blood platelets less likely to clot, decreasing the risk of a fatal heart attack.
But Scott-Mumby says none of these facts were publicly reported when Larry King, the well-known media personality, underwent a bypass procedure in 1987 after a heart attack. Later, in 2007, he hosted a two hour PBS television Special on Heart Disease featuring five experts who talked about exercise, diet and smoking. But there was no mention that abstinence from alcohol was a risk factor for heart disease.
Scott-Mumby also reports good news for Boomers, that the use of alcohol may protect against dementia. He cites the 2008 Research Society on Alcoholism Review based on the Whitehall Study which analyzed 45 reports since the early 1990s.This showed that there were significantly reduced risks of dementia from moderate drinking. So, why don’t we hear more about this fact, particularly, when Alzheimer’s Disease and other forms of dementia are increasing?
He adds that the U.S. is not a heavy drinking nation, yet its health outcomes are poor, as it has almost double the amount of diabetes, cancer and heart disease compared to the English who drink more.
I’ve often written about the advantages of moderate drinking. But, according to Scott-Mumby’s research, even serious drinkers, the ones who drink six or more drinks daily, still live longer than teetotalers! And he claims that puritans can’t stand this fact.
So what’s the message? Neither Scott-Mumby nor I condone the three martini lunch, nor do we urge anyone to start drinking alcohol. What we are both saying is that neither abstainers nor doctors should distort the truth of the health benefits of alcohol. All too often I have witnessed this at medical conventions. Researchers have detailed the many medical benefits of alcohol. But after confirmation by several speakers, finally one says, “But we must not inform the public about this as it will result in car accidents, marriage difficulties and other societal problems.
Critique 208: A statement on alcohol and cancer that ignores the net health effects of moderate drinking, such as increasing longevity of life — 16 November 2017
LoConte NK, Brewster AM, Kaur JS, Merrill JK, Alberg AJ. Alcohol and Cancer: A Statement of the American Society of Clinical Oncology. J Clin Oncol 2017;35:pre-publication. DOI: https://doi.org/10.1200/JCO.2017. 76.1155