From the Guidelines
Coffee consumption is associated with lower risk of type 2 diabetes in a dose-dependent fashion, with the most benefit seen at 3-4 cups per day. According to the study published in Circulation in 2016 1, both caffeinated and decaffeinated coffee are associated with lower onset of diabetes. However, it's essential to consider individual factors, such as the amount of coffee consumed, added sugars, and creamers, which can impact blood sugar control.
Some key points to consider:
- The effect of coffee on blood sugar control varies depending on individual factors, such as the presence of diabetes, amount of coffee consumed, and additives used.
- Black coffee without sugar or cream is preferable for blood sugar management.
- The beneficial effects of coffee may come from its antioxidants and anti-inflammatory compounds, such as chlorogenic acid.
- Caffeine in coffee can temporarily raise blood sugar levels, especially after meals.
- Monitoring glucose response to coffee and limiting intake to 1-2 cups daily, preferably earlier in the day, may be beneficial for individuals with diabetes or blood sugar concerns.
It's also important to note that the 2022 standards of medical care in diabetes, published in Diabetes Care 1, emphasize the importance of individualized meal plans and carbohydrate intake, but do not specifically address the effects of coffee on blood sugar control. However, the study published in Circulation in 2016 1 provides the most relevant and highest-quality evidence on this topic.
From the Research
Effects of Coffee on Blood Sugar Control
- The relationship between coffee consumption and blood sugar control is complex, with some studies suggesting that coffee may improve glucose metabolism in the long term, while others indicate that it may have negative effects on insulin sensitivity and blood glucose levels 2, 3, 4.
- A 2017 study found that five out of seven trials suggested that caffeine intake increases blood glucose levels and prolongs the period of high blood glucose levels in people with diabetes 2.
- In contrast, a 2021 study proposed that habitual coffee consumption may lower the risk of type 2 diabetes through mechanisms that involve improved fat oxidation, preservation of functional beta cell mass, and enhanced mitochondrial function, rather than acute improvement of metabolic control 5.
- A 2019 systematic review of clinical trials found that short-term consumption of caffeinated coffee may increase the area under the curve for glucose response, while long-term consumption may improve glycaemic metabolism by reducing the glucose curve and increasing the insulin response 3.
- A 2018 study found that coffee drinking was associated with a lower risk of pre-diabetes and type 2 diabetes in a population with low coffee consumption, with higher dietary intake of caffeine accompanying a reduced risk of pre-diabetes 6.
- A 2007 randomized, double-blind, placebo-controlled crossover trial found that daily caffeine intake reduced insulin sensitivity, with the effect persisting for at least a week and evident up to 12 hours after administration 4.