New research in the Journal of the American Heart Association suggests that inclusion of one avocado per day as part of a moderate-fat diet may help to improve specific blood lipid markers compared to an energy-matched moderate-fat diet without avocado or a low-fat diet with avocado.
The randomized, crossover, controlled feeding trial enrolled 45 healthy, overweight men and women ages 21–70 years of age with body mass index (BMI) 25–35kg/m2), low density lipoprotein cholesterol (LDL‐C) in the 25th to 90th percentile, and normal blood pressure (≤140/90mmHg) or well controlled with blood pressure‐lowering medication. All participants were nonsmokers, free of cardiovascular disease, diabetes, liver, or renal disease, and not taking lipid‐lowering medications or supplements. Subjects were instructed to follow a typical American diet high in saturated fat for two weeks as a baseline and then followed three different calorie-controlled diets for five weeks each, with a two-week compliance break between diet periods. The diets were matched only for calories and macronutrients.
The calorie-controlled diets were as follows:
- Low-fat diet (6–7% of energy from saturated fat from the typical American diet replacing complex carbohydrates, mostly from grains)
- Moderate-fat diet (6–7% of energy from saturated fat from the typical American diet replacing monounsaturated fat mainly from high oleic acid oils such as sunflower oil and canola oil and some low-fat dairy products)
- Avocado diet (similar to the moderate fat diet, but 6–7% of energy from the saturated fat replacing monounsaturated fat mainly from one fresh avocado daily)
While all three diets decreased LDL-C and total cholesterol (TC) compared to baseline, the avocado diet led to a significantly greater reduction in LDL-C and TC compared to the other two diets. HDL-C decreased less on the moderate-fat diet and avocado diet compared to the low-fat diet. The avocado diet was the only one that significantly decreased LDL particle number, small dense LDL cholesterol, and the ratio of LDL/HDL from baseline.
Although additional research is needed to further assess the generalization of these findings to all populations, the authors posit that the effects of the avocado diet may be due to the unique combination of vitamins, minerals, fiber, phytosterols, and other dietary bioactives in avocados.
For more information visit AHAJournals.org.