Karen J. Murphy, PhD, APD, on Whether Adding Dairy to The Mediterranean Diet Could Help Lower CVD Risk

Although the Mediterranean diet – named the Diet of the Year for 2019 in the United States – is known for a wealth of health benefits, researchers say the traditional version of the diet “may not meet Western recommendations for calcium and dairy intake.”¹

In hopes of helping Mediterranean diet followers meet daily dairy recommendations, Australian researchers recently studied the cardiovascular effects of the MedDairy diet – a traditional Mediterranean diet supplemented with dairy foods – compared with a low fat diet.

The findings were encouraging. Study data suggested that adding more dairy foods to the traditional Mediterranean diet was associated with significant improvements in cardiovascular markers over 8 weeks compared with a low-fat diet.

Consultant360 discussed the study’s clinical takeaways with lead author Karen J. Murphy, PhD, APD, of the University of Southern Australia.

Karen J. Murphy, PhD, APD, is a senior lecturer in Nutrition and Food Sciences at the University of South Australia’s School of Pharmacy and Medical Sciences.

Consultant360: Could you discuss the importance of supplementing the Mediterranean diet with dairy foods? How does it compare with the traditional Mediterranean diet?

Karen J. Murphy: Previous research has estimated the calcium content of the Mediterranean diet to be around 700 mg to 820 mg per day from dairy and non-dairy sources. The Mediterranean diet foundation suggests 2 servings of mainly low-fat dairy foods per day.

However, Australia’s recommendation for calcium intake is 840 mg to 1300 mg per day and, for dairy foods, is between 2.5 to 4 servings daily, depending on sex and age (compared with US recommendations of approximately 3 servings of low-fat or fat-free dairy per day ²).

It is reported that nearly 5 million Australians have poor bone health, of whom 22% have osteoporosis and 78% have osteopenia. We know that calcium and dairy foods are important for good bone health, but we are unsure of the longer-term effects of a Mediterranean diet in Australian and other populations, particularly on bone health. So, before we recommend the pattern over the long term, we need to ensure that it suits these populations, but also can be adhered to and result in the same cardiovascular benefits that have been reported for the pattern previously in Australia and globally.

Interestingly however, according our latest health survey in Australia, most people are only consuming 670 mg to 780 mg of calcium per day and around half of the recommended dairy intake, so in reality, we are actually probably consuming less calcium and dairy than what is recommended in the traditional Mediterranean diet. Following a Mediterranean diet with additional dairy may actually help boost calcium intakes and also achieve heart health benefits of the magnitude indicated in the present study.

C360: What were the main differences between the MedDairy intervention and low-fat intervention in your study?

KJM: Participants in the MedDairy group were asked to follow the guidelines of a Mediterranean diet, as outlined on page 3 of our article, in conjunction with guidelines for meal preparation. Guidelines included dressing salad and vegetables with extra virgin olive oil, cooking with sofrito (a tomato based sauce) at least twice a week, limiting consumption of red meat to less than 1 serving per week, and drastically reducing or eliminating discretionary foods like takeout, sugar-sweetened beverages, and baked goods.

Participants in the low-fat diet group were asked to remain on their habitual diet, but to choose low-fat versions of foods that they regularly consumed and to cook with methods that required minimal use of fat.

C360: How can clinicians identify patients who would be well-suited to the MedDairy diet?

KJM: There is no reason why anyone should be excluded from following a MedDairy diet, unless of course a patient medical issues or dietary intolerances such as lactose intolerance or allergies. This study showed that men and women who were “at-risk” of cardiovascular disease (meaning they already exhibited some risk factors such as obesity, untreated hypertension, glucose intolerance, family history, etc.) could follow the MedDairy diet for at least 8 weeks and experience subsequent improvements in their cardiovascular health, including improved blood pressure and heart rate, lower triglycerides, improved high-density lipoprotein (HDL) cholesterol, and a lower ratio of total cholesterol to HDL cholesterol. This was significantly different from the low-fat diet group.

C360: What can clinicians recommend to their patients to help them successfully adopt the diet?

KJM: Some basic advice would be to adopt a predominantly plant-based diet; consume lower amounts of red meat and replace with white meat, oily fish, and legumes; reduce the intake of discretionary foods; and be mindful of food choices and portion sizes. Many patients would benefit from consuming vegetables with main meals, having fruit daily, enjoying a small handful of nuts on most days, having a glass of red wine with meals and with friends, and/or enjoying whole grain cereals. Extra virgin olive oil should be used as a main culinary fat. Patients can choose a mixture of low-fat and regular-fat dairy foods and have around 2 to 3 servings of dairy foods per day, including milk, yogurt and cheese.

Clinicians should also encourage patients to pay attention to their hunger cues and “tie the bag off at 80% full.” This may help prevent overeating and help them watch their portion sizes. Lastly, we can take advice from the Mediterraneans and stress less and move our bodies more. It’s a lifestyle pattern, after all.

—Christina Vogt

Reference:

1. Wade AT, Davis CR, Dyer KA, Hodgson JM, Woodman RJ, Murphy KJ. A Mediterranean diet supplemented with dairy foods improves markers of cardiovascular risk: results from the MedDairy randomized controlled trial. Am J Clin Nutr. 2018;108(6):1166-1182. https://doi.org/10.1093/ajcn/nqy207.

2. Dairy. United States Department of Agriculture. Page last updated December 14, 2018. https://www.choosemyplate.gov/dairy. Accessed on February 5, 2019.