In the Netherlands a standard drink is 10 grams of pure alcohol. That is the unit behind every guideline and every research finding about drinking. The problem: the glass in your hand is rarely one of them.
Dutch participants poured themselves an average of 129.4 ml of white wine at home, where the standard glass is 100 ml (PMID 30909986). For spirits it was 47.0 ml against a standard of 35 ml.
What exactly is a standard drink?
A standard drink holds roughly 10 grams of ethanol, whatever is in the glass. That is the whole point: a beer, a glass of wine and a shot should contain roughly the same amount of alcohol when poured in a bar. The Dutch Voedingscentrum and the Gezondheidsraad both work with this unit.
Internationally the unit is not fixed. Across 37 countries the standard drink ranged from 8 to 20 grams (PMID 27073140). The Netherlands sits at 10 grams, the most common value, but a British or American study is counting in different numbers.
How many millilitres is one glass?
That depends on the alcohol percentage. The stronger the drink, the smaller the standard glass. The arithmetic is simple: millilitres times alcohol percentage times 0.789 (the density of ethanol), divided by 100.
| Drink | Standard measure | Alcohol percentage | Grams of alcohol | Standard drinks |
|---|---|---|---|---|
| Lager | 250 ml | 5% | about 10 g | 1.0 |
| Craft or strong beer | 330 ml | 8% | about 21 g | 2.1 |
| Wine | 100 ml | 12% | about 9.5 g | 1.0 |
| Wine, poured at home | 129 ml (measured) | 12% | about 12 g | 1.3 |
| Spirits | 35 ml | 35% | about 9.7 g | 1.0 |
| Spirits, poured at home | 47 ml (measured) | 35% | about 13 g | 1.3 |
| Fortified wine (port, sherry) | 50 ml | 18% | about 7 g | 0.7 |
| Fortified wine, at home | 94 ml (measured) | 18% | about 13 g | 1.3 |
The measured values come from a study of 201 Dutch adults who poured their own portions at home (PMID 30909986). The authors' conclusion was blunt: at-home consumption in the Netherlands is underestimated.
Why do you pour bigger at home?
Because there is no measure on the glass, and because glasses have grown. Anyone pouring for themselves aims at the glass, not at the millilitres. In an English study, a self-defined "usual glass" held an average of 1.90 units of wine and 1.93 units of spirits, almost double what people believed (PMID 23278164).
People who poured larger also underestimated the alcohol content more sharply. The error compounds itself.
Is what you report about yourself accurate?
Usually not, and not by a little. Population surveys typically underestimate alcohol consumption by 40 to 50 percent (PMID 25486405). Compare surveys against actual sales figures and those surveys account for only 22 to 32 percent of what was sold (PMID 20626370).
Say you put your intake at 10 glasses a week. On those underestimation figures, 15 to 20 is the more plausible number. Not because you are lying, but because 129 ml of wine is one glass in your head.
What does the Gezondheidsraad advise?
The Dutch dietary guidelines from the Gezondheidsraad are short: do not drink alcohol, or in any case no more than one glass a day. The Voedingscentrum carries the same advice. That is not a safety line below which nothing happens. It is the amount at which the risk stays small.
From how many glasses does a blood test see it?
Here I have to be careful, because the honest version is less tidy than the version you will read elsewhere. CDT responds to sustained heavy use, on the order of 60 grams of alcohol a day, roughly six standard drinks, kept up over weeks.
Even then the marker is not a lie detector. In a controlled study, 10 volunteers drank 60 grams a day for three weeks. Mean CDT rose significantly. Yet only 2 of the 10 crossed the manufacturer's cut-off (PMID 8048718).
In a large WHO sample of 1,387 people, CDT did outperform the liver values. The ROC area for heavy drinking was 0.83 in men and 0.82 in women. For gamma-GT it was 0.69 (PMID 18411243). Of the routine markers CDT is the strongest. And a normal result still does not prove abstinence.
If you want to see your own value, a CDT test for alcohol will quantify it, and the CDT marker page explains what the number means. How CDT compares with EtG and with a liver value is covered in detecting alcohol and in gamma-GT too high.
If this was about one heavy night rather than a pattern, binge drinking is the piece you want.
Every blood test result at Zuivertest includes a professional assessment by a BIG-registered doctor. Discuss your results with your GP before making treatment decisions.
Sources
- de Beukelaar M.F.A. et al., "How full is your glass? Portion sizes of wine, fortified wine and straight spirits at home in the Netherlands", Public Health Nutrition, 2019 (PMID 30909986)
- Kalinowski A. and Humphreys K., "Governmental standard drink definitions and low-risk alcohol consumption guidelines in 37 countries", Addiction, 2016 (PMID 27073140)
- Boniface S. et al., "Actual and perceived units of alcohol in a self-defined usual glass of alcoholic drinks in England", Alcoholism: Clinical and Experimental Research, 2013 (PMID 23278164)
- Livingston M. and Callinan S., "Underreporting in alcohol surveys: whose drinking is underestimated?", Journal of Studies on Alcohol and Drugs, 2015 (PMID 25486405)
- Nelson D.E. et al., "US state alcohol sales compared to survey data, 1993-2006", Addiction, 2010 (PMID 20626370)
- Salmela K.S. et al., "Carbohydrate-deficient transferrin during 3 weeks' heavy alcohol consumption", Alcoholism: Clinical and Experimental Research, 1994 (PMID 8048718)
- Bergström J.P. and Helander A., "Clinical characteristics of carbohydrate-deficient transferrin measured by HPLC", Alcohol and Alcoholism, 2008 (PMID 18411243)
- Gezondheidsraad, Dutch dietary guidelines (gezondheidsraad.nl)
- Voedingscentrum, information on alcohol and the standard drink (voedingscentrum.nl)
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