What is the effect of drinking coffee on blood sugar? Find out how different types of coffee affect your body's glucose and insulin levels.

Most of us can’t start our day without a cup of coffee, which actually has some good health benefits. In fact, a systematic review found a link between regular consumption of coffee and a lower risk of type 2 diabetes, thanks to the compounds in coffee that aid in the regulation of insulin secretion and blood glucose levels.

However, how you prepare your coffee can influence its beneficial effects. Do you prefer black coffee? Decaffeinated coffee? With cream or milk? With, or without sugar? This article discusses the effects of different types of coffee on your blood sugar levels.

How healthy is my coffee?

A 2019 study showed that coffee grounds contain phenolic compounds that may prevent insulin resistance, inflammation and mitochondrial dysfunction, which may lead to:

• Alzheimer’s disease
• Parkinson's disease
• Heart disease
• Stroke
• Liver disease
• Kidney disease

Of course, how healthy your coffee is depends on the kind of coffee you’re having, the portion size and what you’re having in it.

Can black coffee cause my blood glucose levels to rise?

Some studies have found that healthy subjects who drank black coffee without sugar were better able to control their blood sugar levels. People who drank four to six cups of coffee per day were shown to have a 33% lower risk of developing type 2 diabetes than those who didn't drink coffee at all.

The only caveat with coffee consumption is that it can reduce insulin sensitivity due to the high caffeine concentration in coffee beans, which can be an issue for those with insulin resistance, like in people with diabetes. Patients with type 2 diabetes struggle to effectively use insulin, resulting in poor blood sugar control.

What about drinking coffee with dairy milk?

When compared to black coffee, coffee with dairy milk contains more calories and more carbohydrates, so will potentially have more of an effect on your blood glucose levels. While dairy milk contains carbs, it also contains fats and protein, which can help to mitigate a blood sugar rise. To see the effect of dairy milk on your blood sugars, wearing a continuous glucose monitor (CGM) can help you to monitor how your unique body reacts.

What are the effects of coffee with plant-based milk?

Adding a healthy plant-based milk to your coffee may help control blood sugar and improve insulin levels. It's important to note, however, that not all plant-based milks can do this; some can actually raise blood sugar rather than lower it.

It really depends on the brand you use and whether there are extra ingredients added to the plant milk. Oat milk, for example, can be higher in fibre but can sometimes contain maltose, a rice-derived sugar with a high glycemic index (GI). To avoid blood sugar spikes, aim for foods and beverages with a lower GI.

For those looking to keep their blood sugars stable and who prefer plant-based milk, consider looking for an option with:

• Minimal or no added sugar or sweeteners
• Protein, such as soy milk
• Minimal additional additives

Monitoring your glucose using a CGM is a great way to see the impact coffee is having on your glucose levels. When wearing a CGM, you can monitor your glucose readings, which can help you guide your lifestyle decisions to suit your body. Vively offers a membership that includes glucose tracking using a CGM, plus an app that supports, educates and guides you to live a healthy lifestyle and improve your metabolic health.