HealthInfo Canterbury
Alcohol & diabetes
If you take insulin or certain diabetes tablets, alcohol can cause low blood glucose (sugar) levels eight to 10 hours after you've stopped drinking.
The effects of drinking alcohol when you have diabetes
Your liver does all kinds of things for your body. Most importantly in relation to alcohol, it's a blood filter. It removes toxins like alcohol from your blood.
But your liver only does one thing at a time. When your body is dealing with alcohol, the effect of insulin can be delayed. It takes hours for your liver to clear an alcohol binge. For all that time, the insulin stays in your system.
When you've been drinking, your body responds more sluggishly to the treatment of low blood glucose. Alcohol also stops your liver from making glucose if your glucose level is low.
As well as this, alcohol reduces your awareness of having low blood glucose levels and prevents glucagon from working properly.
So, be aware that you may not be aware.
Keeping safe when drinking alcohol
- Have someone with you who knows you have diabetes.
- Wear your medical alert or equivalent. Hypos (low blood glucose levels) can look like being drunk and you may not get the help you need.
- Know what you're drinking.
- Eat carbohydrates while you're drinking.
- Carry food and insulin with you in case you end up staying the night at someone else's place.
- Keep taking your long-acting insulin.
- Check your blood glucose levels before, during and after drinking.
- Before you go to bed, check your blood glucose levels and eat carbohydrates.
- Catch a bus, walk or take a taxi instead of driving.
It's OK to say NO!
Standard drinks
A standard drink is smaller than many people expect. In New Zealand, it's a drink that contains 10 grams of pure alcohol. Drinks poured at home or in a bar tend to be more than one standard drink.
A 1,125ml bottle of spirits contains about 34 standard drinks.
Low-risk drinking
Low-risk drinking is considered to be no more than:
- two standard drinks a day for women and no more than 10 standard drinks a week
- three standard drinks a day for men and no more than 15 standard drinks a week
- at least two alcohol-free days a week.
This is shown in the following graphic from Te Hiringa Hauora Health Promotion Agency.
You can usually have two to three standard drinks before it starts to affect your diabetes.
It takes about one hour for your body to process and clear one standard drink.
Pre-mixed drinks and standard mixers will make you go high initially but they won’t stop you going low.
Getting help for alcohol problems
If you think you have an alcohol problem, contact one of the following services for help:
- Alcohol drug helpline on 0800-787-797 or txt 8681.
- Māori alcohol drug helpline on 0800-787-798 or txt 8681.
- Pasifika alcohol drug helpline on 0800-787-799 or txt 8681.
Written by Christchurch Diabetes Centre. Adapted by HealthInfo clinical advisers. Last reviewed November 2022.
SourcesReview key: HIDIA-21832
