Folklore deemed the avocado an aphrodisiac because of its likeness to the male family jewels. The tortilla chip should be forever grateful to this orb of green velvety pulp, after all it’s really about the guacamole. But until now, the heart has been left out of this love fest. A new study on avocados is shifting the understanding of the role of monounsaturated fatty acids (MUFA) on cardiovascular disease risk. This study shows one avocado per day as part of a moderate‐fat, cholesterol‐lowering diet has additional LDL‐C, LDL‐P, and non‐HDL‐C lowering effects, especially for small, dense LDL. Published in Journal of the American Heart Association, 2015, by Li Wang, PhD; Peter L. Bordi, PhD, et al.
Researchers evaluated the effect avocados had on traditional and novel cardiovascular risk factors by replacing saturated fatty acids from an average American diet with unsaturated fatty acids from avocados. Forty-five healthy, overweight or obese patients between the ages of 21 and 70 were put on three different cholesterol-lowering diets. Participants consumed an average American diet (consisting of 34 percent of calories from fat, 51 percent carbohydrates, and 16 percent protein) for two weeks prior to starting one of the following cholesterol lowering diets:
- Lower fat diet without avocado (24 percent of calories as fat (11 percent from MUFAs);
- Moderate-fat diet without avocado (34 percent of calories as fat (17 percent of calories from MUFAs);
- Moderate-fat diet with one avocado per day, (34 percent of calories as fat (17 percent of calories from MUFAs).
1. Compared to the baseline average American diet, low-density lipoprotein (LDL) was 13.5 mg/dL lower after consuming the avocado moderate diet, as compared to 8.3 mg/dL lower in the moderate fat diet and 7.4 in the low fat diet.
2. Non‐high‐density lipoprotein (HDL) cholesterol on the avocado diet (−13.5 mg/dL, −14.6 mg/dL) was greater than the moderate fat (−8.3 mg/dL, −8.7 mg/dL) and low fat (−7.4 mg/dL, −4.8 mg/dL) diets.
3. The ratio of LDL/HLD decreased by 6.6% with the avocado diet.
4. The moderate fat and avocado diet HDL-C was 47.2mg/dL and 46.92mg/dL, as compared to 44.82mg/dL in the low fat diet.
5. The avocado diet elicited a 9.3% reduction in non-HDL-C versus the moderate fat diet (-5.1%, P= 0.01).
6. The low fat diet significantly increased triglycerides and VLDL-C by 17.6% and 10.9%, respectively, while the other diets did not.
7. The low fat diet increased the triglyceride and cholesterol ratio (TG/HDL-C) by 27.3% from baseline, while the moderate fat and avocado diets did not.
8. The avocado diet resulted in a significantly greater reduction in the number of LDL particles ( -80.1 nmol/L, P= 0.001), as compared to the moderate fat diet (-38 nmol/L, P= 0.07).
9. The avocado diet decreased the small dense LDL particle number −4.1 mg/dL, P=0.04 from baseline.
10. The avocado diet reduced the ratio of apoB/apoA1 (an apolipoprotein and predictor of subclinical cardiovascular events) to .67mg/L, as compared to the low fat diet .72mg/L.
OTHER HEART HEALTHY NUTRIENTS
The Hass variety (used in this study), which is mainly consumed in the United States, is relatively high in MUFA and other fat-soluble vitamins. One Hass avocado (136 g, without skin and the seed) contains 13 g of oleic acid, which is similar to the amount of oleic acid in 1.5 oz (42 g) almonds or 2 tablespoons (23 g) of olive oil. The researchers noted that the moderate fat diet did not have the same benefit as the avocado diet, which clearly indicates that other nutrients and bioactives beyond fatty acids contribute to the health benefits. The heart health benefits probably come from more than just the healthy fats. It may be the combined benefits of the MUFAs with other nutrients present in avocados, such as beta-sitosterol (plant sterols), pantothenic acid, vitamin K, vitamin B6, potassium, vitamin E as well as fiber.
One Hass avocado (136 g) provides 114 mg of beta-sitosterols plant sterols (one cup mashed 175mg). Current understanding of plant sterols is a reduced risk of heart disease when consuming foods with at least 0.65 grams plant sterols per serving, eaten twice a day with total intake of 1.3 grams. Another contributing factor may be that avocados also contain a unique seven carbon (C7) keto sugar – mannoheptulose and its polyol form perseitol (about 4 g per fruit) – which may suppress insulin secretion and promote calorie restriction.
These measurements are all considered to be cardio-metabolic risk factors in ways that are independent of the heart-healthy fatty acid effects, said Penny M. Kris-Etherton, Ph.D., R.D., senior study author and chair of the American Heart Association’s Nutrition Committee and Distinguished Professor of Nutrition at Pennsylvania State University in University Park, Pennsylvania. “This was a controlled feeding study, but that is not the real-world – so it is a proof-of-concept investigation. We need to focus on getting people to eat a heart-healthy diet that includes avocados and other nutrient-rich food sources of better fats,” Kris-Etherton said.
This research offers a relatively easy and effective way to replace saturated fatty acids with healthier MUFAs. Avocados are culturally relevant to Hispanic and Latino, Mediterranean and Middle Eastern cultures and are familiar foods to most Americans. The key is to introduce the avocado as more than a partner to corn chips. Their uses are vast, as a component in breakfast dishes, salads, sandwiches, entrees, as well as soups, smoothies and even to replace saturated fat in baked goods. For more ideas link to http://www.avocadocentral.com.