Research Roundup: Protein and Healthy Aging, Yogurt and Inflammation and More

In this edition, we cover new research on yogurt and improved markers of chronic inflammation in women, how protein was associated with physical function in older adults, and an evaluation of the link of whole and fat-free milk to cardiovascular risk factors in healthy adults.

Eating a higher protein diet was associated with maintenance of physical function in older adults
A 12-year prospective study among middle-aged and older adults found that higher protein consumption (at least 1.2 grams per kilogram of body weight per day) was associated with the ability to perform tasks requiring strength and endurance – such as heavy housework, walking half a mile, going up and down stairs, stooping, kneeling or crouching and lifting heavy objects. The lowest rates of physical decline over time were linked to eating more protein and either being more physically active, having more muscle mass or having a lower body mass index. Though results were not specifically related to dairy protein, dairy foods like milk, cheese and yogurt can be good sources of high-quality protein. Eating foods containing high-quality protein can help maintain lean body mass.

Having yogurt before a high-fat, high-carbohydrate meal reduced post-meal inflammation markers in healthy women
A recent randomized controlled trial reported that eating 8 ounces of low-fat yogurt vs. soy pudding immediately before a high-fat, high-carbohydrate meal improved the acute, post-meal response of inflammatory markers and improved markers of intestinal barrier function (i.e., keeping good in and bad out) in premenopausal women. This sub-study was part of a larger clinical trial to evaluate the impact of daily yogurt consumption on inflammation biomarkers over nine weeks. See the blog post on this study for more details.

Eating school meals is modestly associated with eating more nutritious foods among children
A cross-sectional observational study of a diverse national sample of more than 5,000 U.S. school children aged 4 to 15 years old compared the dietary intakes of students who ate school breakfast or school lunch every day with those who ate school meals less often or not at all. Students who ate school breakfast every day reported eating modestly higher amounts of nutritious foods, including fruits and vegetables, whole grains and dairy foods as well as higher amounts of dietary fiber and calcium. Students who ate school lunch daily also ate more dairy foods and calcium. There were no links between eating school meals and eating energy-dense, nutrient-poor foods or added sugars.

New study indicates drinking whole milk may not be linked to cardiometabolic risk factors in healthy adults
A randomized, controlled, three-week crossover study in 17 healthy adults in Denmark compared the effect of drinking whole milk and fat-free milk on blood lipid levels. There were no differences in total or LDL-cholesterol, triglycerides and insulin/glucose concentrations when subjects drank about 2 cups of whole milk per day as part of their regular diet compared to fat-free milk. In addition, drinking whole milk increased HDL-cholesterol, which may be protective against cardiovascular disease in some individuals. A previous randomized trial found that the Dietary Approaches to Stop Hypertension (DASH) eating plan can be modified to include whole milk, yogurt and cheese without sacrificing the benefit of this diet for lowering blood pressure.

Eating yogurt daily may be linked with lower insulin resistance in youth with a family history of obesity
Canadian researchers examined the relationship between eating yogurt and metabolic health in 198 youth (aged 8 to 26) with and without a family history of obesity. In youth with a family history of obesity, one model found eating one or more servings of yogurt daily was associated with lower fasting insulin, lower insulin concentration over a three-hour period, and lower insulin resistance, but was not linked with weight, body composition or any other metabolic variables. This observational study is the first to consider how family predisposition to obesity might affect the relationship between yogurt, body weight and metabolic health.

New study: Whey protein before breakfast may help moderate blood glucose in T2D
High blood glucose that does not come down within a normal amount of time after a meal among individuals with Type 2 diabetes (T2D) is a risk factor for heart disease and complications of T2D. A randomized trial in 11 men with T2D found that drinking a beverage containing intact whey protein (15 grams) immediately before eating breakfast improved post-meal blood glucose. Consuming 15 g of intact whey protein before breakfast and lunch also stimulated insulin release and increased feelings of fullness. This is emerging research and future research is needed to determine if consuming intact whey protein at mealtime is effective in the long term for blood sugar control.

Survey identifies factors that may influence dairy and calcium consumption in college students
Researchers at Ohio State University surveyed over 1,700 undergraduate students to assess their attitudes and habits related to dairy food and calcium consumption. Many students (60% of females and 45.4% of males ages 19 and older) fell short of calcium recommendations (1,000 milligrams per day) for their age group. On average, students liked milk and considered it healthy. These factors were associated with higher calcium intakes:

  • associate milk with certain eating occasions (i.e., breakfast)
  • availability of calcium-rich foods in the dorm/apartment
  • view milk as healthy
  • family members drink milk
  • taking calcium supplements (on average students did not take supplements).

Having parental rules regarding milk and a negative view of milk in dining halls were associated with lower calcium intakes. These findings may be used to help design programs to improve dairy and calcium intake among college students.