insulin resistance-milk-diabetes.
Dairy Consumption & Metabolic Syndrome The relationship between dairy consumption and metabolic syndrome, also known as insulin resistance syndrome (IRS) or syndrome X, is complex, with studies suggesting both beneficial and neutral effects [1, 2]. Metabolic syndrome is characterized by obesity, insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia (low HDL-C and high triglycerides), hypertension, and impaired fibrinolytic capacity [2]. Beneficial effects of dairy consumption: • Reduced risk of IRS: Increased dairy consumption is associated with a lower incidence of IRS in overweight individuals [2-5]. A study found that the 10-year incidence of IRS was reduced by more than two-thirds in overweight people who consumed the most dairy (≥5 servings per day) compared to those who consumed the least (<1.5 servings per day) [4-6]. Dietary patterns characterized by increased dairy consumption may protect overweight individuals from developing obesity and IRS, both of which are key risk factors for type 2 diabetes and cardiovascular disease [3, 7, 8]. • Improved insulin sensitivity: Dairy products, especially those high in fat, have been linked to improved insulin sensitivity [9, 10]. Specific components of milk, such as bioactive peptides (e.g. Ile-Pro-Pro and Val-Pro-Pro), whey proteins, amino acids, and medium-chain fatty acids, may contribute to this effect [9, 11, 12]. • Improved glycemic control: Milk contains bioactive molecules that regulate glucose homeostasis and improve insulin signalling [1, 11]. Milk powder supplemented with inulin and resistant dextrin has been shown to improve glycemic control and insulin resistance in elderly patients with type 2 diabetes [13]. Additionally, the consumption of full-fat dairy products may be associated with lower insulin resistance [10]. • Reduced risk of type 2 diabetes: Higher dairy consumption is associated with a reduced risk of type 2 diabetes [14]. A study found a 14% reduction in the risk of type 2 diabetes for those with the highest intake of dairy products [14]. Furthermore, people who were exclusively breastfed (as opposed to bottlefed) had significantly lower rates of type 2 diabetes [15]. • Other health benefits: Dairy consumption has also been linked to reduced risk of hypertension, coagulopathy, coronary artery disease and stroke [16]. The calcium, potassium, and magnesium content in dairy products may contribute to the reduction of these risks [3, 7, 8]. Factors influencing the effects of dairy consumption: • Type of dairy product: The effects of dairy consumption on metabolic health can vary depending on the type of dairy product [1, 13]. High-fat dairy products like yoghurt and milk have been associated with a lower risk of prediabetes and reduced insulin resistance, whereas low-fat dairy products showed inconsistent associations [17]. Full-fat dairy intake is inversely associated with HOMA-IR, whereas low-fat dairy intake is not significantly associated with any IR markers [10]. • Individual metabolic responses: Individual metabolic responses to dairy can vary [1, 13]. • Dietary patterns: Dietary patterns characterised by increased dairy consumption show strong inverse associations with IRS [2]. • Reduced-fat vs. full-fat dairy: Milk with 2% fat is considered reduced-fat, while cheeses and desserts with less than 15% milk fat are considered reduced-fat [16, 18, 19]. • Other components of dairy: Calcium and other minerals in dairy products may play a role in reducing blood pressure and improving weight control [9]. Additionally, lactose, citrate, proteins, and peptides in dairy products may improve calcium bioavailability, thus indirectly improving weight control, blood pressure, and plasma lipids [9]. Furthermore, dairy consumption improves the bioavailability of folate and other secondary plant components [9]. Mixed findings and cautions: • Some studies show that low-fat dairy consumption can improve insulin resistance, as measured by HOMA-IR, as well as reduce waist circumference and body weight [17]. • There is evidence that milk intake has decreased significantly over the past three decades, while the prevalence of obesity and type 2 diabetes has increased [16].
