Will adding more pork to Mediterranean diet maintain health benefits?
The trial will be led from scientists from the University of South Australia and the University of Western Australia.
They believe adding pork may encourage more Australians to adopt the diet, but need to assess the meat's impact on the diet's demonstrated efficacy for reducing the risk of CVD and cognitive decline.
"An Australian population, which typically consumes a high quantity of meat, may find adhering to the meat restrictions of the diet difficult.
"This paper outlines the protocol of a randomised controlled trial that endeavours to compare a Mediterranean diet with an additional source of meat protein against a low-fat control diet," wrote the researchers.
"Findings of the forthcoming study will be relevant at a policy, clinical and individual level, and will provide insight as to whether consuming pork as a part of a Mediterranean diet can improve health outcomes while simultaneously increasing variety and sustainability for the target population."
The research team now plans to recruit participants aged between 45 and 80 who are at risk of developing CVD.
To meet eligibility criteria, volunteers must have elevated systolic blood pressure and at least two other risk factors for CVD.
A 24-week crossover design trial will then compare a Mediterranean diet intervention with a low-fat diet intervention. Each participant will complete both dietary interventions for eight weeks, and the two intervention phases will be separated by an eight-week washout period.
Two to three servings of lean pork will be added to the traditional Mediterranean diet, while subjects will also be encouraged to consume additional pork in place of the standard recommended intakes of chicken and red meat.
Home-measured systolic blood pressure will be the primary outcome measure, while secondary outcomes will include BMI, body composition, fasting blood lipids, C-reactive protein, fasting plasma glucose, fasting serum insulin, erythrocyte fatty acids, cognitive function, psychological health and well-being, and dementia risk.
"To our knowledge, this research is the first to investigate whether an alternate source of protein can be included in the Mediterranean diet to increase sustainability and feasibility for a non-Mediterranean population," said the researchers.
"Findings will be significant for the prevention of cardiovascular disease and age-related decline, and may inform individuals, clinicians and public health policy."
A traditional Mediterranean diet is characterised by a high intake of extra virgin olive oil, vegetables, fruits, cereals, nuts, pulses and legumes; a moderate intake of fish, poultry, dairy, and red wine; and a low intake of eggs, red and processed meat, and sweet and processed foods.
This makes it rich in bioactive nutrients and phytochemicals such as monounsaturated fatty acids, polyunsaturated fatty acids (including omega-3s), polyphenols and flavonoids, vitamins, minerals, antioxidants and fibre.
Compared with other dietary patterns, the Mediterranean diet has consistently improved indicators of cardiovascular health.
For example, it has been shown to improve blood pressure, insulin sensitivity, lipid profiles and markers of inflammation, while reducing the risk of cardiovascular events by 30%.
However, few studies have investigated whether the diet can be successfully adopted in populations beyond the Mediterranean Sea.
"Notably, the MedLey study examined the effects of a Mediterranean diet over six months and found that an older Australian population was capable of adopting the Mediterranean diet," added the paper, published in Nutrition Journal.
"However, participants indicated that one of the most difficult aspects of following the diet was restricting red meat intake."
The trial is being supported by a grant from the Pork Cooperative Research Council.
Source: Nutrition Journal
"Including pork in the Mediterranean diet for an Australian population: Protocol for a randomised controlled trial assessing cardiovascular risk and cognitive function"
Authors: Wade AT, et al.