This is the first report to investigate avocado consumption among the US population ≥ 19 years of age, and explore its relationships to diet quality, energy and nutrient intakes, and physiological markers of health. In this report, avocado consumption was associated with significant differences in diet quality and nutrient intakes, higher HDL-C levels, and lower body weight, BMI, waist circumference, and risk of metabolic syndrome. The improved diet quality, nutrient intake, and HDL-C outcomes associated with avocado consumption are consistent with the avocado composition and clinical data [5, 9–16]. Since energy intake was not different between consumers and nonconsumers, the reported lower body weight, BMI and waist circumference for the avocado consumers needs to be further investigated. The effect of diets on weight control may be dependent of a number of factors such as energy density, macronutrient bioavailability, and potentially other factors such as food physical properties [36–38]. Epidemiological evidence and intervention studies generally support the association between the consumption of energy-dense/high-fat diets with being overweight [36, 37]. Insulin resistance, a key pathogenic link underlying the cluster of metabolic abnormalities seen in metabolic syndrome, is adversely effected by saturated fat and improved with MUFA [39–41]. Tree nuts, which are similar to avocado in dry weight composition including dietary fiber and MUFA content, have not been shown to increase body weight or metabolic syndrome risk in numerous clinical and epidemiological studies [42–46].

Epidemiologic studies dating back to the 1970s show the health benefits of MUFAs [45]. The Seven Countries Study found that death rates were positively related to the average percentage of energy from saturated fatty acids (SFAs) and negatively related to the percentage of dietary energy from MUFAs [47]. Prospective studies of US nurses have demonstrated an estimated reduction of 19% in the risk of coronary disease when the intake of MUFAs is increased by 5% (as a percentage of total energy intake) [48]. More recently, Moreno et al. [49] found that a MUFA-rich diet may have favorable effects on cardiovascular risk by preventing the oxidative modifications of LDL-C and reducing macrophage uptake of plasma oxidized LDL. Studies also suggest that MUFAs may have a modest antihypertensive effect and could improve insulin sensitivity [40].

Results of this study indicate avocado consumption is associated with improved nutrient intakes including higher intake of mono- and polyunsaturated fat, dietary fiber and several vitamins and minerals; lower body weight, BMI, and waist circumference; higher HDL-C; and decreased risk of metabolic syndrome. These findings suggest a role for avocados in improving dietary quality and possibly reducing the risk of metabolic syndrome in the United States. Further research is needed to verify this epidemiological data and study the potential association between increased intake of avocados and other dietary components.

Limitations of the study

Energy and food group/nutrient intakes, including HEI-2005 scores, in this study were based on single 24-hour dietary recalls. While dietary recalls were collected via AMPM, the best methodology available, there are still limitations to this dietary collection method [24]. Recalls may be inaccurate and biased due to misreporting or memory lapses. Even though the AMPM method has been validated against weighed food records, energy can be underestimated by 3% for a population of normal weight and up to 11% for overweight and obese persons [18, 24].

The present report comes from cross-sectional epidemiological data and thus cannot provide causal evidence between avocado consumption and improvements in diet quality, nutrient intakes, body weight, BMI, waist circumference, or indices of health. The number of avocado consumers was relatively small and while we used numerous covariates in an attempt to remove effects of other variables, residual confounding may still exist. The associations reported here should be interpreted accordingly.