Dr Justus Apffelstaedt: Marriage and metabolism – why wine doesn’t divide equally

Many readers of this column will be familiar with following scene unfolding at the dinner table: A particularly delectable bottle of wine has been opened and negotiations have to be entered into how to distribute the contents fairly. Here, my beloved wife insists that her fair share of the bottle is half; after all, we are married in community of property and that property also includes a good number of bottles and cases of wine.

Furthermore, men and women are equal before the law and any discrimination according to gender and a lot of other things is unfair and plainly unlawful. Ever the medical nerd that I am, my reply was: “Not so. Because while it is so, that before the law, men and women are equal, biologically and specifically medically, they are quite unequal. Therefore, I should have a bigger share of that bottle.” And proceeded to give her the following explanation:

To start off with, men are generally taller and heavier than women, meaning that what in pharmacology is called the “distribution volume” is larger in men. This means in practice, that the same amount of wine ingested will reach higher concentrations in women than in men.

Additionally, body composition is different in men: Men have a higher water content per kg of body weight whereas women have a higher fat content (no need to get worked up ladies, I merely quote scientific fact). Since wine distributes easily in water and much less easily in fat, this leads to proportionally higher concentrations in the blood of women.

After ingestion, a crucial role is played by the stomach: Gastric emptying is slower in women than in men meaning more of the potentially toxic component of wine, alcohol, is absorbed into the bloodstream in women and faster so, too. On top of that, men have a much higher activity of gastric enzymes detoxifying alcohol and a faster liver metabolism of alcohol. This means, that women reach toxic blood alcohol levels much faster than men. Since blood from the stomach drains to the liver, women have a higher risk of liver damage at the same levels of wine consumption then men.

After the stomach, the picture becomes much fuzzier. Wine is composed of a multitude of biochemically active compounds beyond alcohol and the scientific details of gender specific metabolism of these are at best scant and poorly understood. What we do know, however, is that moderate wine consumption has a multitude of positive effects that are not gender specific. Chief among these is activation of the body’s own oxidative stress defense mechanisms. Long-term oxidative stress is a major cause of atherosclerosis, which in itself leads to heart attacks and strokes, and is involved in the causation of cancer as well as many other age related chronic diseases in humans.

Another important effect is an anti-inflammatory effect of polyphenolic compounds which are abundant in red wine. Again, inflammation plays an important role in atherosclerosis and cancer; both anti-inflammatory and anti-oxidative effects are linked at multiple points in human physiology – remember resveratrol and other polyphenols? As expected, in epidemiological research on large populations and their dietary habits a reduction chiefly of cardiovascular deaths was found mainly in those who consume wine moderately.

A major deficiency of these studies, however, is that still there is little comparison between men and women and that does not really help me in my dinner table argument. Should I perhaps mention, that in an admirably long-termed study over 34 years in Sweden, wine-consuming women were much less likely than consumers of other alcoholic beverages or teetotalers to be diagnosed with dementia and so weaken my position? So, I argued, that at the bottom of the second glass, most of the benefits of moderate wine consumption have evaporated for females and from a third glass detrimental health effects become progressively apparent.

In conclusion, there are good physiologic reasons to for the difference in recommendations for wine consumption by health authorities by females versus males. These rest more in the acute than the chronic health effects. So, you may ask how our argument was decided. Let me just say, that I salute same-sex relationships for not having such dinner-table arguments to fight. Cheers to that!

• Dr. Justus Apffelstaedt is a specialist in breast and thyroid health, leading Apffelstaedt & Associates in Cape Town and Windhoek. A surgeon with a specific interest in surgical oncology and researcher, he was Associate Professor of Surgery at Stellenbosch University (1994–2017) and Head of Surgical Oncology, managing 1,000-plus cancer cases annually. He has more than 50 publications, shaped South Africa’s breast cancer screening policy, and co-founded Breast Surgery International. A sought-after speaker, he has given over 100 international lectures. He also holds an MBA and a Diploma in Wine. Through Apffelstaedt & Associates, he continues to advance specialized, patient-centered care in Southern Africa.