Higher milk consumption is associated with a lower risk of diabetes mellitus: A case-control study

PLOS ONE RESEARCH ARTICLE Higher milk consumption is associated with a lower risk of diabetes mellitus: A case-control study Pornthep Tanpowpong ID1, Wichai Aekplakorn ID2*, Suwat Chariyalertsak ID3, Pattapong Kessomboon4, Sawitri Assanangkornchai ID5, Surasak Taneepanichskul6, Nareemarn Neelapaichit7 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailandand, 2 Department of Community Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand, 3 Faculty of Public Health, Chiang Mai University, Chiang Mai, Thailand, 4 Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand, 5 Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand, 6 College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand, 7 Ramathibodi School of Nursing, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand * OPEN ACCESS Citation: Tanpowpong P, Aekplakorn W, Chariyalertsak S, Kessomboon P, Assanangkornchai S, Taneepanichskul S, et al. (2023) Higher milk consumption is associated with a lower risk of diabetes mellitus: A case-control study. PLoS ONE 18(8): e0289762. https://doi.org/ 10.1371/journal.pone.0289762 Editor: Elsayed Abdelkreem, Sohag University Faculty of Medicine, EGYPT Received: February 23, 2023 Abstract Background & aims Studies have determined that people with genetically defined lactase non-persistence have lower dairy intake that may lead to an increase risk of various non-communicable diseases. Furthermore, lactase non-persistence itself has been associated with insulin resistance. However, data on lactase non-persistence status and dairy intake in developing countries are sparse. We therefore aimed to define 1) the prevalence of lactase non-persistence among individuals with diabetes and non-diabetes in Thai population and 2) the links between lactase non-persistence, milk consumption, and risk of diabetes mellitus. Accepted: July 25, 2023 Published: August 16, 2023 Copyright: © 2023 Tanpowpong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The authors received no specific funding for this work. Competing interests: The authors have declared that no competing interests exist. Abbreviations: DM, diabetes mellitus; FPG, fasting plasma glucose; LNP, lactase non-persistence; LP, Methods We conducted a case-control study from participants of the National Health Examination Survey. DNA was isolated from the blood for LCT −13910C>T (rs4988235) polymorphism and processed using the Bio-rad c1000 touch thermal cycler and MALDI-TOF Mass Spectrometry MassARRAY Typer v4.0 (Agena Bioscience, San Diego, CA, USA) at the Center for Medical Genomics, Faculty of Medicine Ramathibodi Hospital. Cases were participants with previously diagnosed diabetes mellitus or fasting plasma glucose �126 mg/dL (n = 1,756) vs. the controls (n = 2,380). Results We included 4,136 participants, 62% female, and 98.8% were > 30 years old. Homozygous CC genotype (i.e., lactase non-persistence) was noted in 98.6% and only 1.4% carried heterozygous CT. Most (76%) consumed milk <1 portion/month. Participants with either CC or CT genotype had comparable milk consumption and the risk of diabetes mellitus. Males, older adults, and lower education had a lower chance of consuming milk at least one portion PLOS ONE | https://doi.org/10.1371/journal.pone.0289762 August 16, 2023 1 / 10 PLOS ONE lactase persistence; NCD, non-communicable disease. Lactase gene, milk consumption and diabetes per month. Besides various baseline variables, we found that higher milk consumption was associated with a lower DM risk (P = .01). Conclusion The prevalence of lactase non-persistence in Thai population is very high. A significant difference in milk consumption frequency in relation to the lactase non-persistence status was not found. However, higher milk consumption is associated with a lower risk of diabetes mellitus. Introduction Lactose, found in the mammalian milk such as human milk or cow’s milk, is one of the most commonly consumed disaccharides in humans. The digestive and absorptive capacity of lactose depends on the proper gene expression of lactase-phlorizin hydrolase (LCT), also known as ‘lactase’ enzyme, at the enterocytes in conjunction with an intact small intestinal mucosa [1]. Enattah and colleagues reported that a DNA variant, C/T-13910 from the LCT locus was associated with biochemically verified lactase non-persistence (LNP) in the Finnish families [2], this mutation has then become a major factor responsible for maintaining the persistence of LCT gene expression. Individuals carrying homozygous CC genotype are classified as LNP and the ones who carry CT or TT genotype are considered as lactase persistence (LP) [3]. A recent meta-analysis demonstrated that the global prevalence of lactose maldigestion is 68% with large ethnic differences, with the most prevalent in the South Asian and South East Asian background and the least prevalent in the Scandinavians [4]. When analyzing only the studies involving the genotype, the prevalence became 74%. Unfortunately, the previously cited studies from Thailand defined lactose malabsorption via hydrogen breath test (one study, 39 adults) [5] and lactose tolerance test (one study, 140 children) [6]. To our knowledge, no available data on genetic testing of LNP/LP status have been reported in the Thai population; therefore the prevalence of LNP remains undefined. Studies have determined that people with LNP are more likely to consume lower intake of dairy products as compared to individuals with LP [7, 8]. Countries with higher prevalence of LNP also consume less amount of dairy products as compared to the countries with lower LNP prevalence [9]. Hypothetically, the LNP people may be more likely to suffer from intolerant symptoms after ingesting lactose-containing products. Therefore, these people may regularly avoid drinking cow’s milk or eating dairy products. People who consume lower amount of milk products may be at risk for not only nutritional inadequacy [10, 11], but also various non-communicable diseases (NCDs) [12] including diabetes mellitus (DM), hypertension, metabolic syndrome and even increased risk of death [13]. Furthermore, LNP itself (regardless of milk consumption) has been shown to be at risk for having abdominal obesity [14], insulin resistance [15], and metabolic syndrome [16]. However, LNP has been shown to be a ‘protective’ effect for obesity in the people of some ethnic backgrounds [8, 17]. Furthermore, studies defi (...truncated)