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Research Roundup: Dairy Proteins, Mediterranean Diet, Health Care Costs and More

In this edition, we cover new research on whey protein and its effect on muscle protein synthesis, the effect of healthy eating patterns on health care costs, the relationship between dairy foods and diabetes risk and more.

Whey protein may offset muscle loss in periods of physical inactivity among older adults
A study in older adults (mean age of 69 years in men and 68 in women) found protein supplementation (1.6 g/kg/day protein) may offset muscle loss in periods of physical inactivity, which can occur during hospitalization. Study participants received a supplement of either collagen peptides or whey protein and were in a simulated state of inactivity. While both groups experienced loss of leg lean mass during the period of energy (calorie) restriction and step reduction, only those in the whey protein group had increased leg lean mass and increased rates of muscle protein synthesis during recovery from inactivity and energy (calorie) restriction.

Following healthy eating patterns has potential to reduce health-care costs
A recent modeling study found that closely following two healthy eating patterns recommended by the 2015-2020 Dietary Guidelines for Americans (DGA) is projected to save billions in health-care costs. If people improved how they eat to be 20 percent more compliant to either the Healthy U.S.-style or Mediterranean-style eating patterns, there is potential for an estimated annual cost savings of $31.5 billion and $16.7 billion, respectively.

Protein specific to dairy may help decrease risk of cardiovascular disease
Participants in a new study were separated into groups who drank glucose (75 g) alone, glucose and fat-free milk (473 ml), glucose and whey protein (16.5 g) or glucose and casein (16.5 g). Postprandial hyperglycemia (i.e., high blood sugar after eating) can impair vascular endothelial (blood vessel) function in an oxidative-stress-dependent manner and as such, adults with prediabetes were tested to assess the postprandial effects of glucose, milk and dairy proteins on vascular endothelial function. As shown in the group that had glucose alone, high blood sugar after eating can often impair the function of blood vessels. The researchers suggested that dairy milk, mediated by its whey and casein proteins, attenuates postprandial hyperglycemia-mediated impairments in vascular endothelial function by limiting oxidative stress. These findings lend support to emerging studies that suggest dairy is linked to reduced risk of cardiovascular disease.

Incorporating three to four servings of dairy in the Mediterranean diet may help reduce risk of chronic diseases
While the Mediterranean diet traditionally includes about two servings of dairy each day, a new study found that incorporating three to four servings each day for 8 weeks were beneficially associated with cardiovascular disease risk factors. The control diet instructed participants to follow their habitual Mediterranean diet while reducing their total fat intake by choosing low-fat foods and using low-fat cooking methods for 8 weeks. Compared to the low-fat control diet, the Mediterranean diet with 3-4 servings of dairy foods resulted in reduced morning systolic and diastolic blood pressure, elevated HDL cholesterol and lowered triglycerides. These additional servings of dairy foods would also provide much-needed calcium, helping to support bone health and other nutrient needs that the Mediterranean diet alone often lacks.

Dairy fatty acids associated with decreased risk of type 2 diabetes
A large meta-analysis of 16 cohort studies found that certain fatty acids found in dairy foods were associated with a lower risk of type 2 diabetes. This study also found that naturally occurring ruminant trans fat was associated with lower risk of type 2 diabetes; however, they were not able to distinguish the biomarkers from exactly which foods they came from (milk, cheese or yogurt). Additionally, the authors stated while these biomarkers are known to reflect dairy fat consumption, their levels could also be influenced by other factors. Based on these results, more research is needed to determine the health effects of dairy fat in interventional studies.

Dairy foods may improve bone health in Hispanic adults with sufficient vitamin D levels
A recent cross-sectional study examined the effect that dairy consumption had on bone mineral density in adults from the Boston Puerto Rican Osteoporosis Study. When evaluating the total sample population (N=904), higher intakes of dairy foods and milk were associated with higher femoral neck bone mineral density. When considering vitamin D status, the study found that for participants with sufficient vitamin D levels, total dairy, fluid dairy, and milk consumption were significantly related to higher both femoral neck and lumbar spine bone mineral density. However, for participants who were vitamin D insufficient, eating dairy had no effect on bone mineral density.

Skipping breakfast associated with increased risk of type 2 diabetes in adults
A recent systematic review and meta-analysis of cohort studies was done to identify if there was a link between skipping breakfast and increased risk of type 2 diabetes in adults. Six studies were reviewed with a total of 96,175 adult participants. This study found that the risk for type 2 diabetes increased with each day that breakfast was skipped. The findings plateaued at four to five days per week of skipped breakfasts each week, which was associated with a 55 percent increased risk of type 2 diabetes. This study provides evidence linking breakfast skipping to increased risk of type 2 diabetes, further emphasizing the importance of daily breakfast within recommended dietary patterns.