The researchers conducted the study to find out the association between calcium-rich food consumption and incidence of T2DM among Korean adults.
Previous studies have suggested that the level of calcium intake may help prevent T2DM, as calcium is essential for insulin secretion and is involved in the mechanism of insulin action through the regulation of intracellular calcium levels.
In this study, researchers further found that the source of calcium plays a crucial role in the development of T2DM.
For example, consuming calcium-rich foods, such as milk and anchovies, may not lower the risk of developing T2DM.
Yogurt, on the other hand, was associated with a decreased risk of developing T2DM.
Data from a 10-year (2002 to 2012) follow-up on 8,574 Koreans aged 40 to 69 was used for the study.
These participants live in the Ansung and Ansan areas of the Gyeonggi Province, and the data comprises of their diet, lifestyle, environment factors, and diseases.
T2DM-related data was collected via biennial questionnaires, health examinations, and clinical tests.
The researchers found that “a higher intake of yogurt was associated with a decreased risk of incident T2DM.”
For instance, the number of participants which developed T2DM without consuming yogurt at all was 323. This figure decreases steadily as the weekly consumption of yogurt increases.
The number of T2DM cases dropped to 295 and 241 when the weekly consumption of yogurt was 1.3 and 5 respectively.
The other major calcium sources popular with the Koreans, such as milk, cheese, anchovies, lettuce, perilla leaves, sea mustard, laver, and beans, however, did not exert a significant impact on reducing the risk of T2DM.
For instance, the number of T2DM cases stayed between 271 and 288 when the participants consumed two and eight servings of milk respectively.
A similar observation was also seen in participants consuming anchovies.
The number of T2DM cases was 310 for participants who consumed 0.2 servings of anchovies per week. However, there was no significant changes observed when the weekly consumption of anchovies increased to 1.8 and 4.6, with282 and 288 cases of T2DM were reported.
The researchers concluded that “this study’s results show that among the intakes of several different calcium-rich foods, those of yogurt alone reduces T2DM risk.”
Previous studies have already suggested that the level of calcium intake affects the incidence rate of T2DM.
For example in Japan, higher intake of total dairy products was also associated with a lowered T2DM risk among Japanese women, but not among Japanese men.
The power of calcium in reducing T2DM was also seen in Australian men.
The researchers acknowledged a number of shortcomings of the research.
They pointed out that the results could have been affected by other residual factors that they could not measure or were unaware of.
In addition, it is also difficult to generalise the study’s results for other populations, since the participants were limited to the residents of the Ansung and Ansan area in South Korea.
As such, they pointed out that further large-scale randomised controlled trials should be conducted, considering the composition of sugar, fat, and probiotics in yogurt at the same time.
Effects of Consuming Calcium-rich foods on the incidence of Type 2 Diabets Mellitus
Authors: Jeon J, et al.