Diabetes is caused by an insufficient level of a hormone called insulin. This condition can also occur due to a decreased sensitivity to insulin. Insulin helps every cell in your body obtain energy in the form of glucose. Without insulin, glucose accumulates in the blood and cannot get into cells. If hyperglycemia (high blood glucose) is not treated, it can cause organ damage and even death. While the occasional drink with dinner is generally harmless for a diabetic, excessive alcohol consumption can be dangerous.

Before discussing how alcohol affects diabetes, it’s important to describe what diabetes is and how it affects the body.

What Is Diabetes?

Every cell in your body needs energy in order to function properly. The most efficient form of energy comes from a sugar called glucose, which comes from the metabolic breakdown of carbohydrates in your diet. For about four hours after you eat, glucose circulates in your bloodstream (where cells have access to it) before being stored in the liver for future use. In order for cells to be able to take up glucose, they need something that can help them transport the glucose out of the blood. This help comes in the form of a hormone called insulin. When insulin is not present, cells cannot take up glucose.

Consequently, glucose levels build up in your blood (hyperglycemia), causing damage to your cardiovascular system and preventing cells from being able to function normally. Diabetes is characterized by a failure of insulin-assisted transportation of glucose cells. Without medical intervention, it can be fatal.

There are two types of diabetes:

• Type 1 diabetes is a disorder that is characterized by a total loss of insulin-producing cells. Type 1 diabetes is typically diagnosed in childhood, and management requires daily insulin injections and careful monitoring of blood glucose levels. Type 1 diabetes makes up 5% to 10% of diabetes cases, and although the cause is unknown, genetics likely contribute.
• Type 2 diabetes is generally a consequence of lifestyle habits (poor diet and lack of exercise are major contributors) and is characterized by insufficient insulin production or cells that become resistant to insulin. Type 2 diabetes is usually diagnosed in adulthood and makes up 90% to 95% of diabetes cases.

Alcohol and Blood Sugar

Alcohol affects blood sugar levels by causing them to initially spike over a two-hour period and then drop over the next 10 to 12 hours. The empty calories found in alcohol keep the body from fully processing sugars while it is processing alcohol. This causes blood sugar levels to spike.

Once alcohol has been processed by the body, the elevated sugar levels and the effects of alcohol on the pancreas cause insulin levels to increase, lowering blood sugar. At the same time, alcohol prevents the liver from releasing sugar normally and keeping blood sugar at regular levels. This combination causes a drop in blood sugar after alcohol has been metabolized.

Effects of Alcohol on Diabetes

Alcohol can be dangerous to those with diabetes, especially when heavy drinking or binge drinking occurs. Most people with diabetes use medicine to lower their blood sugar levels. The drop in blood sugar that ultimately occurs when drinking heavily can cause dangerously low blood sugar levels that can lead to a coma or even death.

Can Diabetics Drink Alcohol?

The National Institute of Diabetes and Digestive and Kidney Diseases recommends that women with diabetes have no more than one alcoholic drink per day and men have no more than two drinks per day. Alcohol increases the risk of low blood sugar (hypoglycemia). Hypoglycemia and alcohol intoxication have similar symptoms (dizziness, confusion, trembling), and intoxicated diabetics may attribute symptoms of dangerously low blood sugar to alcohol. This can be dangerous or even fatal.

Different types of alcohol will affect blood sugar differently; for example, beer and sugary cocktails are carb-heavy, so they temporarily increase blood glucose. However, all types of alcohol can lead to potentially dangerous drops in blood pressure. In order to prevent alcohol-induced hypoglycemia, it is important that diabetics eat food whenever they drink.

Type 1 Diabetes and Alcohol

Type 1 diabetics are particularly sensitive to alcohol because they are unable to make insulin.

• Effects: Alcohol causes a rapid drop in blood sugar. Because type 1 diabetics cannot produce insulin, they rely on insulin that they’ve administered themselves. Determining the correct insulin dose to account for alcohol consumption is challenging.
• Risks: Unless they carefully monitor their insulin levels, type 1 diabetics risk hypoglycemic unawareness and potentially fatal hypoglycemic shock when they drink alcohol. Going to sleep while drunk is very dangerous for type 1 diabetics.

Type 2 Diabetes and Alcohol

Type 2 diabetes is less sensitive to alcohol-induced hypoglycemia than type 1.

• Effects: Alcohol reduces levels of blood sugar. However, type 2 diabetics produce some insulin, so their cells have less risk of being completely unable to access glucose compared to someone with type 1 diabetes.
• Risks: As with type 1, type 2 diabetics could have hypoglycemic episodes when they drink alcohol. Fatalities are less common than in type 1.

Both types of diabetes are associated with similar risks for other alcohol-related problems, including:

• Peripheral neuropathy (PN): PN, especially in the feet and legs, is one of the most common complications of diabetes and can be very painful. PN has been shown to occur more quickly and be more severe in diabetics who regularly drink alcohol, even in moderate amounts.
• Retinopathy: Retinopathy is often called “diabetic eye disease” because it is so common in people with diabetes. Frequent alcohol consumption has been linked to more rapid development of retinopathy.

Can Pre-Diabetics Drink Alcohol?

Pre-diabetes is a condition in which your blood sugar levels are elevated, but not enough to be considered diabetes. This condition comes before type 2 diabetes and means that you are at a higher risk of developing diabetes.

While there are no absolute restrictions on drinking alcohol if you have pre-diabetes, heavy alcohol use does increase your weight and decrease your sensitivity to insulin. These two factors increase the likelihood that you will ultimately end up with diabetes.

Red Wine and Diabetes

There are some who believe that red wine can help improve diabetes symptoms. This incorrect assumption arises from some studies that indicate that moderate use of wine decreases the risk of developing type 2 diabetes. 

These studies are somewhat controversial, as many argue that other ingredients of wine — not the alcohol — actually cause this benefit. While wine could help reduce the risk of developing diabetes, it is not best to use alcohol if you have diabetes.

Can Alcohol Cause Diabetes?

Although alcohol cannot directly cause type 2 diabetes, it can increase the risk of developing it. This can occur through:

• Reduced sensitivity to insulin: Studies have shown that binge drinking increases insulin resistance and can increase the risk of developing type 2 diabetes. Interestingly, moderate alcohol use in healthy adults actually reduces the risk of type 2 diabetes.
• Obesity: Obesity (BMI ≥ 30) significantly increases the risk of developing type 2 diabetes. Even overweight people who are not obese (BMI of 25–29) are at higher risk.
• Chronic pancreatitis: The pancreas is the organ that produces insulin. Chronic pancreatitis damages insulin-producing cells, which can cause diabetes.

Can Quitting Alcohol Reverse Diabetes?

Type 1 diabetes is permanent, however, type 2 diabetes can be reversed. This may cause people who use alcohol to ask if stopping alcohol use would reverse type 2 diabetes. Type 2 diabetes is related to a variety of lifestyle choices and health factors; alcohol is only one factor. For some people, however, alcohol can be a significant lifestyle factor that affects many facets of their overall health. Stopping alcohol use can improve a person’s weight and sensitivity to insulin.

Quitting alcohol is not guaranteed to reverse diabetes, but it is likely to improve your overall health and help diabetes symptoms. This could just lead to improved diabetes symptoms, but could also lead to the eventual reversal of type 2 diabetes.