It’s well known that preventing diabetes can lower the risk of early death. Keeping your blood sugar levels in a healthy range is an important part of this.
But a new study suggests that even within the “normal” range, some blood sugar levels may be better than others when it comes to living a longer life.
This discovery comes from a small farming town in Japan’s Tohoku Region. For more than 40 years, a project known as the Ohasama Study has been tracking the health of people in the town of Ohasama, located in Iwate Prefecture. Since 1986, researchers have collected regular health data from the residents, including results from blood sugar tests.
Every four years, the people in this study take a test called the glucose tolerance test. This test checks how the body handles sugar. It measures blood sugar levels before and after the person drinks a sugary drink. Specifically, doctors look at the levels two hours after drinking it. This test is usually used to see if someone has diabetes.
In this new research, a team of scientists looked at the test results from 993 people. They wanted to see which blood sugar levels were linked to higher or lower death rates.
The team was led by Junta Imai and Hideki Katagiri from Tohoku University, with help from researchers at South Miyagi Medical Center, Tohoku Medical and Pharmaceutical University, and Teikyo University.
They found that the blood sugar level measured one hour after drinking the sugary drink was strongly linked to how long people lived. This was true even after they took into account other health risks like age, body weight, and smoking.
The researchers divided the people into two groups based on their one-hour blood sugar level. Those with levels below 162 mg/dL had much better survival rates than those with higher levels.
To be more precise, the scientists focused on 595 people who had normal blood sugar levels and had not developed diabetes. They then searched for a more exact cutoff point that best predicted who lived longer. They found that 170 mg/dL was the key number.
They compared people whose one-hour blood sugar was under 170 mg/dL to those who were above it. After 20 years, almost 80% of the people with lower blood sugar were still alive. In contrast, nearly half of the people with higher blood sugar levels had died. That’s a big difference.
When they looked at causes of death, they found that people with lower blood sugar levels had fewer deaths from heart disease linked to clogged arteries. They also had fewer deaths from cancer. These differences were statistically significant.
This study shows that even if your blood sugar is in the normal range, it’s still better to keep it on the lower side—especially after meals. Managing these sugar spikes might help reduce your risk of heart disease and cancer, and help you live a longer, healthier life.
So, beyond avoiding diabetes, paying attention to how your blood sugar changes right after eating may be a smart move for better long-term health.
If you care about diabetes, please read studies that pomace olive oil could help lower blood cholesterol, and honey could help control blood sugar.
For more information about health, please see recent studies that blueberries strongly benefit people with metabolic syndrome, and results showing eggs in a plant-based diet may benefit people with type 2 diabetes.
The study is published in PNAS Nexus.
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