Research Roundup: Type 2 diabetes, sustainable diets and more
In this edition, we cover new research on how dairy and other foods containing protein can have different associations with the risk of Type 2 diabetes (T2D). We also look at the role dairy foods play in sustainable diets and chronic disease risk.
Food sources of protein have different associations with risk of T2D
A systematic review and meta-analysis of observational studies found not all proteins are the same when it comes to risk of T2D. Even animal proteins, like meat and dairy, are not associated with the same T2D risk. Though total and animal protein consumption were risk factors for T2D in all subjects, this was mainly due to eating red and processed meat. On the other hand, total dairy products, whole milk and yogurt were associated with a reduced risk of T2D in all subjects. Soy and plant proteins were also associated with a reduced risk of T2D in women.
Adding whey protein to meals may improve blood sugar levels
According to proceedings from a conference in the United Kingdom, eating whey protein at or near meal times may help control blood sugar levels after eating. The amino acids (building blocks of protein) in whey protein may act directly to increase insulin secretion or indirectly to reduce blood sugar. Future research may help identify the most effective way to use whey protein in meal plans
Dairy foods can be part of a sustainable diet
According to the Food and Agriculture Organization, a sustainable food pattern needs to be nutritionally adequate, economically affordable, socially acceptable and conserve natural resources; however, it is a challenge to meet all these criteria at the same time. This special article published in Nutrition Review describes how each sustainability domain is measured and how dairy foods stack up. Using these metrics, dairy foods are nutrient-rich, affordable, acceptable and appealing. Though it takes more resources to produce meat, milk and dairy foods than grains and sweets, these foods are also higher in nutrients compared to calories. The author says, “The environmental impact of dairy farming needs to be weighed against the high nutrient density of milk, yogurt and cheese as compared with some plant-based alternatives.”
Eating about one serving of cheese per day was found to be associated with lower risk of CVD
Results of a large meta-analysis suggest that a serving (i.e., about 40 g) of cheese a day could be part of a healthy eating plan. The analysis compared different amounts of cheese to the risk of CVD. Eating about 40 g of cheese a day was associated with the greatest reduction in overall CVD risk, which includes coronary heart disease and stroke. This amount is slightly less than one USDA MyPlate serving (i.e., 1.5 ounces) of hard cheese, such as cheddar. Total CVD risk began to rise as cheese consumption increased above 40 gram/day, though risk of stroke and coronary heart disease continued to decline or remain the same, respectively, with higher daily cheese consumption. The authors say the protective effect of cheese may be due to its content of vitamins, minerals, protein or other components. A recent systematic review found that high quality evidence indicates that cheese consumption is not associated with CVD risk and that moderate quality evidence indicates that cheese consumption is associated with reduced risk of stroke.
Yogurt’s characteristics help support heart and metabolic health
Eating yogurt has been associated with healthy lifestyles and a reduced risk of diet-related disease, especially T2D, according to a recent review. The researchers analyzed the evidence and identified calcium, protein, and bioactive peptides as the factors possibly responsible for yogurt’s beneficial effects. Beyond individual nutrients, the physical structure (food matrix) of yogurt may also be important because it protects the live cultures and influences how nutrients interact. The article lists questions for future research, since there is still much to be learned.
Dairy is among foods associated with lower blood pressure
A systematic review and meta-analysis summarized the evidence from 12 groups of foods and found that 200 g dairy foods, 30 g whole grains, 100 g fruits and 28 g nuts were associated with lower risk for high blood pressure. These findings were consistent with current dietary guidance for blood pressure management.
Researchers found certain foods, including dairy, are associated with lower risk of colorectal cancer
A systematic review and meta-analysis found higher consumption of whole grains, vegetables, fruit and dairy foods and lower consumption of red and processed meat, was associated with a lower risk of colorectal cancer (CRC). Eating up to ~400 grams (for reference, a cup of milk is ~244 g, 6 oz yogurt is ~170 g, and an ounce of cheese is ~28 g) of dairy foods per day was associated with a 17 percent decreased risk of CRC. Higher consumption levels appeared to show additional decreases in risk. The paper discussed how various nutrients and components of dairy foods, including calcium and vitamin D, may protect the colon.
Dairy is among groups of foods associated with reduced stroke risk
A new paper provides the first overview of results from previous systematic reviews and meta-analyses to identify foods with an association to a decreased risk of stroke. A higher consumption of dairy foods, nuts, fruits, vegetables, fish and tea, and moderate consumption of coffee and chocolate, was associated with decreased risk of stroke. According to the authors, minerals found in dairy foods (e.g., calcium, potassium and magnesium), vitamins in dairy foods (e.g., riboflavin and B12) and dairy proteins (i.e., casein and whey) may be protective factors.