The Mediterranean dietary pattern, which is low in saturated fats and high in unsaturated fats, is widely-recognized as a heart-healthy diet when compared to the standard American dietary pattern, which is high in saturated fats. Red meat is traditionally minimized in the Mediterranean dietary pattern to less than 120 grams (about four ounces) per week - roughly the size of a small burger patty; however, this recommendation is largely based on epidemiological evidence, not interventional trials. Authors of a new report aimed to determine the dose-dependent effects of lean beef consumption as part of a Mediterranean dietary pattern on heart disease risk.

Recent research suggests that lean, unprocessed red meat can be included in a heart-healthy dietary pattern. One randomized clinical trial found that consumption of a Mediterranean dietary pattern supplemented with 500 grams (about 17 ounces) of red meat per day over five weeks reduced total and LDL cholesterol.

Fifty-nine generally healthy participants of varying weight status between the ages of 30 and 65 years completed the trial. Participants consumed a Mediterranean dietary pattern (8 percent saturated fat) supplemented with either 0.5, 2.5, or 5.5 ounces of lean, unprocessed beef per 2,000 calories consumed per day. As a comparison diet, participants also consumed an American dietary pattern (12 percent saturated fat). All participants consumed each diet for four weeks in a randomized order and had their blood drawn at multiple time points for cholesterol testing.

Compared to the American dietary pattern, all three Mediterranean dietary patterns significantly reduced LDL cholesterol (0.5 ounces: −10.3 milligrams per deciliter; 2.5 ounces: −9.1 milligrams per deciliter; 5.5 ounces: −6.9 milligrams per deciliter). The authors also reported reductions in LDL particle number for all three Mediterranean dietary patterns, although this reduction was significant for the diets supplemented with 0.5 ounces or 2.5 ounces of red meat but not 5.5 ounces. All four diets resulted in reductions of HDL cholesterol and HDL particle number compared to baseline.

The researchers concluded that the cholesterol-lowering effects of a Mediterranean dietary pattern were not diminished by the inclusion of up to 2.5 ounces of lean, unprocessed beef. They noted that future research should test a similar diet in patients with worse health status than this generally healthy population.

• Link to full report.