Does alcohol raise or lower blood sugar?
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Alcohol can lower blood sugar and cause a low, most of all in people taking insulin or a sulfonylurea who drink without eating. The low can come hours after the last drink. Without those medicines the effect is small. In 67 men drinking 30 g of alcohol a day for 4 weeks, fasting sugar didn’t change. Sweet mixers are the part that pushes it up.
What we’d do
If you don’t take diabetes medicine, judge the drink by what’s in it. In a trial of men at high heart risk, a month of daily wine or gin didn’t change fasting sugar, while a sweet cocktail is a sugary drink with alcohol in it. If you take insulin or a sulfonylurea, eat when you drink, check your sugar before bed, and ask your prescriber how to drink safely.
Why the answer seems to flip
A sweet cocktail can send a sensor up, and people on insulin get told to watch for lows after drinking. Both are true, and they come from two different parts of the same glass, the sugar in the mixer and the alcohol itself.
What alcohol does to your liver
Between meals and overnight, your liver keeps your blood sugar up by releasing glucose. Alcohol gives it another job. The American Diabetes Association says that when you drink without eating, the liver deals with the alcohol first and lets blood sugar slide, and the low can strike hours after your last drink, especially if you’ve exercised.
It’s like a factory that stops making its main product to clean up a spill, so the shelves start to empty.
Who gets lows
The Endocrine Society’s guideline on low blood sugar names insulin, and the pills that make the pancreas release more insulin such as sulfonylureas, as the most common cause of lows. Alcohol adds to that risk, and drinking alcohol is on the CDC’s list of things that raise the chance of a low in people with diabetes. In people without diabetes, the guideline lists drugs among the causes a doctor checks first when a low is confirmed.
What a month of drinking did to fasting sugar
In a 2013 trial, 67 men at high risk of heart disease had three 4-week stretches in random order. They drank red wine with 30 g of alcohol a day, about two standard US drinks, the same red wine with the alcohol taken out, or gin with 30 g of alcohol. Fasting blood sugar stayed the same through all three. Insulin and a measure of insulin resistance improved after both red wines, with or without alcohol, and not after gin, which points at something in the grapes rather than the alcohol.
A US standard drink has about 14 g of alcohol, which is 12 ounces of beer, 5 ounces of wine or 1.5 ounces of spirits (NIAAA).
The mixer
A regular soda mixer brings sugar like any sweet drink. In a pooled study of 17 groups of people, each daily serving of a sugary drink went with 13% more type 2 diabetes, even after adjusting for weight. A gin and soda water and a gin and regular tonic are very different drinks for your blood sugar.
If you ever feel shaky, sweaty or confused after drinking, check your sugar if you can, and eat. The numbers for a low and when to call 911 are on what blood sugar level is dangerous? Alcohol also lowers HRV and raises blood pressure, covered on hrv.guide and bloodpressure.guide.
6 sources
- American Diabetes Association, Alcohol and diabetesdiabetes.org
- Cryer PE and others, Evaluation and management of adult hypoglycemic disorders: an Endocrine Society clinical practice guideline, Journal of Clinical Endocrinology and Metabolism, 2009pubmed.ncbi.nlm.nih.gov
- Chiva-Blanch G and others, Effects of red wine polyphenols and alcohol on glucose metabolism and the lipid profile: a randomized clinical trial, Clinical Nutrition, 2013pubmed.ncbi.nlm.nih.gov
- NIAAA, What is a standard drink?niaaa.nih.gov
- CDC, Low blood sugar (hypoglycemia)cdc.gov
- Imamura F and others, Consumption of sugar sweetened beverages, artificially sweetened beverages, and fruit juice and incidence of type 2 diabetes, BMJ, 2015pmc.ncbi.nlm.nih.gov
