“Wouldn’t it be okay if I drank a little bit of alcohol?”
This is an idea that anyone who is worried about their health but finds it difficult to completely quit drinking has probably tried it at least once. In particular, many people believe that small amounts of alcohol will not pose a major health problem as long as you avoid excessive drinking.
However, if your blood sugar level is higher than normal, the story may be different.
Recently, a study showed that people with impaired fasting blood sugar levels, which correspond to diabetes or pre-diabetes, have a higher risk of colon cancer even if they drink relatively small amounts of alcohol.
Colon cancer is one of the common cancers in Korea. According to the national cancer registration statistics released this year by the Central Cancer Registry Headquarters, the number of new cases of colon cancer in 2023 was 32,610, accounting for 11.3% of all cancers, ranking third.
According to the latest issue of the international academic journal 'Journal of the National Cancer Institute (JNCI)', a joint research team from Samsung Seoul Hospital and Soongsil University analyzed the effects of blood sugar status and drinking on the risk of colorectal cancer among 4,475,492 adults who underwent national health examinations in 2012.
The median follow-up was 9.3 years, and 51,592 people were diagnosed with colorectal cancer during this period.
First of all, there was a difference in the risk of colon cancer just by looking at the blood sugar level. Blood sugar was classified as normal if fasting blood sugar was less than 100 mg/dL, and impaired fasting blood sugar if it was 100 to 125 mg/dL. Diabetes was defined as a fasting blood sugar level of 126 mg/dL or higher or a prescription for treatment with a diabetes diagnosis code at least once a year.
Compared to people with normal blood sugar levels, the risk of colon cancer was 11% higher in people with impaired fasting blood sugar levels and 26% higher in patients with diabetes.
When alcohol was added, the difference widened further.
The research team classified drinking less than 30g per day for men and less than 20g for women as substandard drinking. Converting this to general alcohol, 20g of alcohol is equivalent to 2 to 3 glasses of soju, and 30g is equivalent to about 3 to 4 glasses of soju.
As a result of the analysis, among moderate drinkers, the risk of colorectal cancer among those with impaired fasting blood sugar was 23% higher than that of people with normal blood sugar but who did not drink, and for patients with diabetes, this risk rose to 48%.
This shows that alcohol can act as a factor that increases the risk of colon cancer in people with high blood sugar levels.
The difference became larger in cases of heavy drinking. Compared to normal blood sugar and non-drinkers, the risk of colorectal cancer was 17% higher in the normal blood sugar heavy drinking group, 41% higher in the fasting blood sugar disorder heavy drinking group, and 77% higher in the diabetic heavy drinking group.
In particular, this study observed a 'synergistic effect' in which when people with impaired fasting blood sugar levels or diabetes drink alcohol, the risk of colorectal cancer is greater than simply combining the effects of the two risk factors.
The research team suggested the overlap between oxidative stress and inflammation as one of the possible explanations.
Drinking alcohol can accumulate acetaldehyde, a carcinogen produced during the alcohol breakdown process, and increase mucosal inflammation and oxidative stress. High blood sugar can also increase oxidative stress through the production of advanced glycation end products and activation of the inflammatory signaling system. It is possible that these two processes overlap, creating an environment in which colon cells are vulnerable to turning into cancer.
They also estimated that the mutation in the gene (ALDH2), which prevents acetaldehyde from being broken down well, is a relatively common trait among East Asians, including Koreans, and may be one of the reasons why it increases the risk of colorectal cancer even when drinking relatively little alcohol.
The research team said, "A correlation with an increased risk of colorectal cancer was confirmed even at moderate or lower levels of drinking, and this correlation was especially noticeable in people with impaired fasting blood sugar levels or diabetes," and added, "For people with abnormalities in blood sugar metabolism, minimizing alcohol intake may help lower the risk of colorectal cancer."
