The Health Benefits Of Avocado

The avocado is nowadays thought as one of the healthiest fruits you can eat. The food is a well known source of carotenoids, minerals, phenolics, vitamins, and fatty acids. A number of clinical studies reinforce the view that consumption of this ‘fruit’ offers a number of benefits such as

• lipid‐lowering,
• reduction in blood pressure or hypertension,
• reducing diabetes,
• reducing weight, 
• improving blood flow,
• managing cholesterol levels (an antiatherosclerotic effect),
• possessing cardioprotective effects. 

By the way it is not a vegetable as we often used to think ! It comes from the tree Persea americana, (Mill.) which grows throughout central Mexico. Popular varieties include Haas. Other types include Bacon, Gwen, Zutano, Lamb Hass and Pinkerton.

The tree is only grows well in tropical and sub-tropical climates. It is not worth growing anywhere where frost occurs.

This mild, oily and high-fat fruit is sometimes referred to as an “alligator pear” or “butter fruit” because it has a thick, crusty skin that ranges in colour from bright green to almost purple – black. The colour changes as the avocado ripens (Cox et al., 2004).

The skin surface can be smooth or pebbled in texture. We use it as the name for a colour and is quite popular in bathroom colour schemes.

The flesh of an avocado is smooth and creamy and tends to be a yellowish-green in colour. In the centre of the fruit is a single, large pit. the fruit is used in a number of classic Mexican dishes but none is more famous than guacamole which is straightforward to make and uses tomato, garlic, coriander and some cayenne pepper. It’s also a great filling for burritos and tacos so consider how you best incorporate this fantastic food into your diet.

Nutritional Content of Avocados

The nutritional content of an avocado varies depending on the particular cultivar, but all share the unique characteristic of containing a high amount of monounsaturated fat (Lewis et al., 1978). The oil is highly regarded as well and is highly regarded for salad dressings. In fact, the lipid content is roughly 25% of the edible portion with an energy density similar to chicken breast (Hierro et al., 1992).

Most of the fats in avocado are monounsaturated types and be aware there are no omega-3 fats. A one-fifth serving of the fruit contains 4.5 grams of total fat with 3 grams of that fat being of the monounsaturated form. Avocados also contain a great variety of essential nutrients needed for good health, including fiber (fibre), various numerous bioactive phytochemicals including carotenoids, the minerals potassium and magnesium and the vitamins, B, C, E and folate (Slater et al., 1975), terpenoids (Moreno et al., 2003), D-manno-heptulose (Shaw et al., 1980), beta-sitosterol (Duester, 2001), some polyphenols and persenone A and B (Kim et al., 2000).

Avocados For Good Health

Monounsaturated fats as with omega-3 fatty acids should be part of a healthy diet although it is often recommended we limit the intake of saturated fat. We know that monounsaturates from avocado have excellent cardiovascular benefits because of their impact of the blood serum profiles as well as helping to lower blood cholesterol levels (Alvizouri-Munoz et al., 1992; Colquhoun et al., 1992; Carranza et al., 1995; Carranza-Madrigal et al., 1996).  It also appears that daily consumption of just one avocado might help us who are moderately overweight if not obese to redress any imbalances in blood cholesterol levels especially (see article).

Avocados are a rich source of carotenoids which are very potent antioxidants (Lassen, 1944; Slater et al., 1975).

But it’s not just the fat in the avocado that helps your heart. The potassium in the pulp also helps by lowering blood pressure. The American Heart Association recommends we ingest 4.7 grams of potassium a day to improve heart health and blood pressure. One serving of avocado which is a fifth of a whole one contains 150 milligrams of potassium.

The folate in the avocado is important for women who may become pregnant because it helps prevent birth defects. As a source of vitamin E, avocados help your body fight the damaging effects of free radicals, which might reduce the risk of developing certain types of cancer, as well as heart disease.

Avocados For Good Heart Health

A 2018 study published in the American Journal of Clinical Nutrition found that people eating avocados when compared to those who didn’t had higher levels of good cholesterol (Mahmassani et al., 2018). In other words higher levels of HDL (high-density lipoprotein). We already pointed out the good fat in avocado earlier but it was much more evident that monounsaturated fat was better for you than originally thought of.

Monounsaturated fats are found in all sorts of foods including nuts, olives, nut butters. These fats are better for you than the saturated fats found in foods like butter, bacon chicken skin and coconut oil. if we replaced just 5% of the daily energy intake from saturated fat in our diet with monounsaturated fats we could have a 15% lower risk of heart disease. Part of that replacement could involve eating more avocado.

Avocado For Weight Loss And Increasing Feelings Of Being Full

Eating just half a fresh avocado for lunch may be enough to increase the feelings of fullness or satiety for the rest of the day. One study reported in the Nutrition Journal compared the effects of incorporating fresh avocado into a lunch. This was either by replacing other foods or by simply adding it to the meal. They also looked at the effects of eating a standard lunch to determine how avocado consumption would influence satiety, blood sugar and insulin response, and subsequent food intake.

In this study, 26 healthy but overweight subjects were assessed in terms of how avocado consumption affected their feeding habits. Those participants who ate a half of a fresh avocado for lunch,  reported a 40% decreased desire to eat over a three-hour period. In addition, 28% had a decreased desire to eat over a five-hour period after the meal, compared to their desire to eat after a standard lunch without avocado. They also reported increased feelings of satisfaction over the three hours following the meal.

The study was conducted at the Loma Linda University in California, USA and was led by Joan Sabate, Professor at the Department of Nutrition. She reported that:-

“Satiety is an important factor in weight management, because people who feel satisfied are less likely to snack between meals,…”  

“We also noted that though adding avocados increased participants’ calorie and carbohydrate intake at lunch, there was no increase in blood sugar levels beyond what was observed after eating the standard lunch. This leads us to believe that avocados’ potential role in blood sugar management is worth further investigation.”

Further research should demonstrate whether the conclusions drawn apply to the general public.

Avocado And Metabolic Syndrome

Metabolic syndrome is a collection or cluster of risk factors which includes high blood glucose levels, high fat levels (dyslipidemia), high blood pressure or hypertension and obesity. The biggest issue is the increased risk of type 2 diabetes mellitus and cardiovascular disease (CVD). All these conditions can lead to death in the western world in particular. There is considerable interest in avocados for treating a range of issues associated with the condition. This covers the benefits of components not only found in the flesh, but also in the peel, seed and leaves  in combating the deleterious effects of metabolic syndrome (Tabeshpour et al., 2017)

Avocado Oil And Avocado Seed Flour (ASF)

There is now considerable interest in a byproduct of avocado oil production which is a defatted pulp known as ‘reduced-calorie avocado paste’ (Ortiz et al., 2004).

The oil from the avocado has its own particular health benefits and we have discussed these at some length in a related article. The seed itself has potential as a source of phenolic compounds because a flour can be produced from it. One study in mice showed that Avocado Seed Flour (ASF) modifies the blood lipid profile when they are fed on a high fat or hyperlipidaemic diet (Pahua-Ramos et al., 2012).

ASF paste has also been shown to attenuate the effects found in metabolic syndrome. Metabolic Syndrome occurs as a result of a high fructose diet. Here, fructose consumption is linked to obesity because this important metabolite is converted in the liver to glycerol-3-phosphate and acetylcoenzyme A. These are both substrates for glyceride synthesis and result in an increase in the very low-density lipids (VLDL) and triglycerides (TG) (Pahua-Ramos et al., 2014).

References

Alvizouri-Muñoz, M., Carranza-Madrigal, J., Herrera-Abarca, J. E., Chavez-Carbajal, F., & Amezcua-Gastelum, J. L. (1991). Effects of avocado as a source of monounsaturated fatty acids on plasma lipid levels. Archives of Medical Research, 23(4), pp. 163-167

Carranza, J., Alvizouri, M., Alvarado, M. R., Chavez, F., Gomez, M., & Herrera, J. E. (1994). Effects of avocado on the level of blood lipids in patients with phenotype II and IV dyslipidemias. Archivos del Instituto de Cardiología de México, 65(4), pp. 342-348

Carranza-Madrigal, J., Herrera-Abarca, J. E., Alvizouri-Muñoz, M., Alvarado-Jimenez, M. D. R., & Chavez-Carbajal, F. (1996). Effects of a vegetarian diet vs. a vegetarian diet enriched with avocado in hypercholesterolemic patients. Archives of Medical Research, 28(4), pp. 537-541.

Colquhoun, D. M., Moores, D., Somerset, S. M., & Humphries, J. A. (1992). Comparison of the effects on lipoproteins and apolipoproteins of a diet high in monounsaturated fatty acids, enriched with avocado, and a high-carbohydrate diet. American Journal of Clinical Nutrition, 56(4), pp. 671-677

Cox, K. A., McGhie, T. K., White, A., & Woolf, A. B. (2004). Skin colour and pigment changes during ripening of ‘Hass’ avocado fruit. Postharvest Biology and Technology, 31(3), pp. 287-294

Duester, K. C. (2001). Avocado fruit is a rich source of beta-sitosterol. Journal of the American Dietetic Association, 4(101), pp. 404-405.

Hierro, M. T. G., Tomas, M. C., Fernández-Martín, F., & Santa-María, G. (1992). Determination of the triglyceride composition of avocado oil by high-performance liquid chromatography using a light-scattering detector. Journal of Chromatography A, 607(2), pp. 329-338

Kim, O. K., Murakami, A., Nakamura, Y., Takeda, N., Yoshizumi, H., & Ohigashi, H. (2000). Novel nitric oxide and superoxide generation inhibitors, persenone A and B, from avocado fruit. Journal of Agricultural and Food Chemistry, 48(5), pp. 1557-1563.

Lassen, S., Bacon, K., & Sutherland, J. (1944). A Chromatographic Investigation Of The Carotenoid Pigments Of The Avocado. Journal of Food Science, 9(6), pp. 427-433.

Lewis, C.E., Morris, R., O’Brien, K. (1978) The oil content of avocado mesocarp. J. Sci. Food Agric. 29 pp. 943-949

Mahmassani, H.A., Avendano, E.E., Raman, G., Johnson, E.J. (2018) Avocado consumption and risk factors for heart disease: a systematic review and meta-analysis. Amer. J. Clin. Nutr. 107(4) pp. 528-536   https://doi.org/10.1093/ajcn/nqx078

Moreno, A. O., Dorantes, L., Galíndez, J., & Guzmán, R. I. (2003). Effect of different extraction methods on fatty acids, volatile compounds, and physical and chemical properties of avocado (Persea americana Mill.) oil. Journal of Agricultural and Food Chemistry, 51(8), pp. 2216-2221

Ortiz, M. A., Dorantes, A. L., Gallndez, M. J., & Cardenas, S. E. (2004). Effect of a novel oil extraction method on avocado (Persea americana Mill) pulp microstructure. Plant Foods for Human Nutrition (Formerly Qualitas Plantarum), 59(1), pp. 11-14.

Pahua-Ramos, M. E., Garduño-Siciliano, L., Dorantes-Alvarez, L., Chamorro-Cevallos, G., Herrera-Martínez, J., Osorio-Esquivel, O., & Ortiz-Moreno, A. (2014). Reduced-calorie avocado paste attenuates metabolic factors associated with a hypercholesterolemic-high fructose diet in rats. Plant foods for Human Nutrition, 69(1), pp. 18-24.

Pahua-Ramos, M. E., Ortiz-Moreno, A., Chamorro-Cevallos, G., Hernández-Navarro, M. D., Garduño-Siciliano, L., Necoechea-Mondragón, H., & Hernández-Ortega, M. (2012). Hypolipidemic effect of avocado (Persea americana Mill) seed in a hypercholesterolemic mouse model. Plant Foods for Human Nutrition, 67(1), pp. 10-16.

Shaw, P. E., Wilson III, C. W., & Knight Jr, R. J. (1980). High-performance liquid chromatographic analysis of D-manno-heptulose, perseitol, glucose, and fructose in avocado cultivars. Journal of Agricultural and Food Chemistry, 28(2), pp. 379-382.

Slater, G. G., Shankman, S., Shepherd, J. S., & Alfin-Slater, R. B. (1975). Seasonal variation in the composition of California avocados. Journal of Agricultural and Food Chemistry, 23(3), pp. 468-474

Tabeshpour, J., Razavi, B.M., Hosseinzadeh, H. (2017) Effects of Avocado (Persea americana) on Metabolic Syndrome: A Comprehensive Systematic Review. Phytotherapy Research https://onlinelibrary.wiley.com/doi/full/10.1002/ptr.5805

Wien, M., Haddad, E., Oda, K., & Sabaté, J. (2013). A randomized 3×3 crossover study to evaluate the effect of Hass avocado intake on post-ingestive satiety, glucose and insulin levels, and subsequent energy intake in overweight adults. Nutrition Journal, 12(1), 155. https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-12-155