Research Roundup: Dairy Protein, Cardiovascular Disease and More
In this edition, we cover new research on the association between dairy protein and both bone health and blood pressure, the link between high- and low-fat dairy foods and heart disease, and the emerging science on whole-milk dairy foods and cardiovascular risk factors and more!
Emerging research indicates higher protein consumption from dairy and other animal foods may be related to stronger bones in postmenopausal women
Researchers in Switzerland studied the relationship between protein consumption from different food sources (e.g., dairy, non-dairy animal or vegetable) and bone strength among more than 700 postmenopausal women with healthy lifestyles. They found higher protein consumption, particularly from animal and dairy sources, was associated with less risk of bone fracture. Dairy foods, which are a good source of both calcium and protein, made up more than one quarter of the total protein eaten by these women.
Eating patterns that include low-fat dairy are associated with better bone health worldwide
A scoping review of 49 eating pattern studies conducted in more than 20 countries found that a healthy eating pattern that emphasized fruits, vegetables, whole grains, poultry, fish, nuts, legumes and low-fat dairy foods, and that minimized the consumption of soft drinks, fried foods, meat and processed foods, sweets and desserts, and refined grains was beneficial for bone health. Overall, the authors concluded that adherence to a healthy eating pattern can improve bone mineral status and decrease osteoporosis and fracture risk.
Are unique characteristics of dairy foods associated with reduced risk of coronary heart disease and stroke?
A meeting report updating the science on saturated fat consumption and risk of coronary heart disease (CHD) and ischemic stroke concluded that consuming saturated fat, when compared to carbohydrates, raises LDL cholesterol, a risk factor for CHD. However, studies are beginning to show that not all foods containing saturated fat have the same effect on CHD risk. For example, consumption of dairy foods has not been associated with increased risk of stroke and some evidence links consumption of dairy foods containing saturated fat with lower risk of ischemic stroke. Similarly, consumption of milk and other dairy foods, both high-fat and low-fat, has been associated with a lower risk of cardiovascular disease (CVD), but further investigation is needed.
Saturated fat content alone may not be enough to predict overall health effects of butter and cheese
Previous studies showed that cheese compared to butter did not increase total and LDL cholesterol, despite having the same amount and type of saturated fat. A multicenter, randomized trial extended these findings by comparing the effect on cardiovascular risk factors among five different diets higher in saturated fat from cheese, saturated fat from butter, monounsaturated fat, polyunsaturated fat or high carbohydrate/low-fat in in people at high risk for heart disease. Both cheese and butter diets had a beneficial effect on HDL (good) cholesterol compared to the higher carbohydrate diet. Interestingly, the diet higher in butter did increase LDL (bad) cholesterol, but it also reduced triglyceride levels similar to a diet higher in polyunsaturated fat. These results add to the body of research highlighting the importance of food vs. single nutrients (e.g., saturated fat) when evaluating heart disease risk factors.
Eating dairy foods, regardless of fat level, is not associated with heart disease or mortality
Supporting earlier findings, an updated meta-analysis of 29 prospective cohort studies involving more than 938,000 participants worldwide found total consumption of dairy (i.e., milk, yogurt and cheese) – regardless of fat level – as well as consumption of milk and yogurt was not associated with coronary heart disease, CVD events or death from any cause. A further analysis of fermented dairy foods found that cheese was marginally associated with reduced risk of cardiovascular disease, but the benefit was driven by a single study.
Two proteins that naturally occur in milk may help blood pressure control in adults
A randomized controlled trial in 38 adults with mildly elevated blood pressure tested the effect of drinking shakes containing 28 grams of whey (a natural milk protein), casein (a natural milk protein) or a carbohydrate control twice a day (each for eight weeks) on blood pressure and factors affecting blood vessel function. Compared to the carbohydrate control, the whey protein drink resulted in greater reduction in blood pressure as well as lower triglyceride levels. Both milk proteins led to better blood vessel function as well as lower levels of total cholesterol in comparison to the control. These results are consistent with previous findings that show milk proteins may have a favorable effect on blood pressure and vascular function in people with elevated blood pressure.