What is an avocado?

An avocado, also called alligator pear, or butter fruit is a large berry with a single large seed covered by a smooth and oily golden-green flesh, and a dark leathery skin. The skin of an avocado can be green, brown, purplish, or black while the shape can be pear-shaped, egg-shaped, or spherical. The term avocado can refer to both the tree and the fruit. An avocado tree (Persea americana) is an evergreen tropical and Mediterranean tree belonging to the Lauraceae family. The trees are partly self-pollinating, but a new plant is grown through grafting to keep up production, standard, and quality of the fruit. For commercial purposes, the fruits are picked unripe and ripened after harvesting.

The avocado tree can grow between 9-20 meters while the fruit is 7-20 centimeters long and weighs between 100-1000 grams. On the other hand, the seed is around 5-6.4 centimeters long. Avocado has a neutral or slightly earthy flavor, and it is not sweet. But because of its nutritional and health benefits, the avocado has been called a superfood.

Which avocado is the best and heathiest to eat?

There are more than one hundred varieties or types of avocados classified as A-type or B-type cultivars based on the pollination and flowering behavior of the avocado tree flowers. All these varieties are classified into three main groups namely West Indian, Guatemalan, and Mexican. The most common and most popular type (or variety) of avocado is the Hass avocado. The Hass avocado is popular because of its high fat content and rich nutty flavor which makes it very creamy and irresistible for most recipes.

The second most popular type of avocado after the Hass is the Fuerte avocado. Although the Fuerte avocado is less creamy and waterier than the Hass avocado, it is sweeter and fruitier with notes of hazelnut and grassy flavor. Although not as popular as the Hass avocado, the Reed avocado is the best tasting avocado. The Reed avocado is larger, creamier, and denser than the Hass avocado although they taste slightly less oily and less nutty than the Hass avocado. Although avocados might vary in flavor, taste or fat content, the overall nutritional difference between them is very negligeable.

Health benefits and uses of avocado

No matter the popularity, taste, or flavor, both A-type (green) and B-type (dark) avocados provide multiple health benefits. The health benefits of eating avocado include:

  1. Enabling the body to absorb fat-soluble nutrients during a meal. This comprises of alpha-carotene, beta-carotene, and vitamins A, D, E, and K.
  2. It helps improve LDL (bad) cholesterol levels in people who are overweight or obese.
  3. Makes you feel full faster and longer and hence beneficial to consume during weight loss efforts. This is because of its high monounsaturated fat and rich fiber content. This also helps reduce the risk of heart disease, obesity, and diabetes.
  4. Lowers the harmful effect of blood pressure since it contains higher potassium content. For example, a 100 gram of avocado contains 485 milligrams of potassium but only 7 milligrams of sodium.
  5. Supports brain function, healthy memory, and cognitive vision.
  6. Contain no cholesterol and hence lower the risk of cardiovascular diseases.
  7. It contains more than 25 essential nutrients including amino acids, vitamins, and minerals.
  8. Avocado helps to boost the immune system since it is rich in vitamin E and vitamin C.
  9. Avocado is a substitute for fat-based ingredients in recipes, condiments to dip snacks in or spreads on your sandwiches. More than 75 % of avocado’s fat is good fat. It is one of the only fruits rich in monounsaturated fat, making it a good substitute for food high in saturated fat. Saturated fats cause cholesterol to build up in the artery, increasing the risk of heart attack and stroke. Saturated fatty acid also increases liver and belly fat. Fortunately, avocado does not contain any saturated fat and no cholesterol.

How to know if an avocado is ripe and ready to eat

To know if an avocado is ripe and ready to eat, then squeeze it gently. If it yields to firm gentle pressure, then it is ripe and ready-to-eat. The skin of A-type avocados like reed remains green even when ripe while B-type like Hass and Fuerte become very dark, almost black, when ripe.

It is also possible to tell if an avocado is ripe without squeezing it. To achieve this, pull back the small stem or cap at the top of the fruit. If it comes away easily and you find green or yellow underneath, then it is ripe and ready-to-use.

Nutritional facts

Avocado is high in calories and rich in several nutrients including vitamins, amino acids, minerals, antioxidants, phytochemicals, healthy fat, carbohydrates, and proteins. In fact, all the amino acids which are essential for your body to make proteins are present in this fruit.
The table below summarizes vitamins, amino acids, minerals, and other nutrients found in avocado.

Table 1: Vitamins, minerals, amino acids, antioxidants, and phytochemicals present in avocado.
Vitamins Minerals Amino Acids Antioxidants and Phytochemicals
  • Vitamin A
  • Thiamine (Vitamin B1)
  • Riboflavin (Vitamin B2)
  • Niacin (Vitamin B3)
  • Pantothenic Acid (Vitamin B5)
  • Vitamin B6
  • Folate (Vitamin B9)
  • Vitamin C
  • Vitamin E
  • Vitamin K
  • Calcium
  • Iron
  • Magnesium
  • Phosphorus
  • Potassium
  • Sodium
  • Zinc
  • Copper
  • Manganese
  • Selenium
  • Fluoride
  • Tryptophan
  • Threonine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Cystine
  • Phenylalanine
  • Tyrosine
  • Valine
  • Arginine
  • Histidine
  • Alanine
  • Aspartic Acid
  • Glutamic Acid
  • Glycine
  • Proline
  • Serine
  • Choline
  • Betaine
  • Alpha Carotene
  • Beta Carotene
  • Beta Cryptoxanthin
  • Lutein
  • Zeaxanthin

One whole avocado weighing 201 grams including the skin and seed contains 322 calories (1350 kilojoules), 147 grams water, 4.02 grams protein, 29.5 grams fat (68% monounsaturated fat, 17% saturated fat, and 14% polyunsaturated fat), 17.1 grams carbohydrates, 13.5 grams fiber, 1.33 grams sugar (sucrose, glucose, fructose, and galactose), 0.221 grams starch, 14.1 milligrams sodium, 4.8 grams saturated fatty acids, 19.7 grams monounsaturated fatty acids and 3.66 grams polyunsaturated fatty acids. Avocados contain no cholesterol, no trans fatty acids, no vitamin D, and no caffeine.

How much avocado can you eat per day or per week?

Although avocado is rich in many nutrients and provides several benefits, getting nutrients from various sources is key to maintaining a healthy diet. Therefore, it is recommended to eat half to one whole avocado per day and not more than seven avocados per week. However, individuals following a low-FODMAP diet or those with intestinal bacterial overgrowth need only an eighth (1/8) an avocado serving.

A Harvard university study showed that those who consumed two or more servings of avocado per week had a 16 percent lower risk of cardiovascular diseases and a 21 percent lower risk of coronary heart disease. For reference, one serving amounts to half of an avocado in this study. However, according to the California Avocado Commission, the avocado serving size is officially 1/3 of a medium avocado, which equates to 50 grams (1.7 ounces) of avocado. A serving of avocado (50 grams) contains 80 calories (335 kilojoules), 36.6 grams water, 1.0 gram protein, 7.35 grams total fat, 4.26 grams carbohydrate (by difference), 3.35 grams dietary fiber, 0.33 grams sugar, 0.055 grams starch, 3.5 milligrams sodium, and 242 milligrams potassium.

Disadvantages or side effects of avocado

Avocado is a very delicious and nutritious food loaded with antioxidant compounds, phytochemicals, dietary fiber, vitamins, minerals, and healthy fats. But such benefits come only when taken in moderation. However, avocado should be completely avoided when taking anti-inflammatory or anti-coagulant medications, when following a low FODMAP or low calories diet, and when expecting or breastfeeding. Side effects of excess or avocado abuse include stomach discomfort, gastrointestinal irritation, nausea, vomiting, constipation, diarrhea, migraine, headache, allergy, hypersensitivity, liver damage, and asthma.

The disadvantages or side effects of avocado include:

Affects weight loss when on diet

Avocado is very high in calories and rich in fat. Eating too much can affect your weight loss and throw-off your daily calorie intake. Therefore, it should be avoided when trying to lose weight.

Gastrointestinal irritation

When consumed in excess, avocado causes stomach upset or gastrointestinal irritation. Due to its high fiber content, excess avocado also leads to constipation. Individuals whose body does not absorb water properly from consumed avocado may experience diarrhea.

Affects individuals with sensitive stomach or irritable bowel syndrome

Avocados are higher FODMAP food. A FODMAP food is one containing short chain carbohydrates which are not properly digested by the stomach or absorbed well by the small intestine. Such carbohydrates are not good for individuals with sensitive stomachs or irritable bowel syndrome. Those following a FODMAP diet should limit their avocado intake.

Liver damage

Avocado possesses anti-inflammatory and antioxidant effects which protect against chemically induced liver damage. But because of its high level of monounsaturated fats, combining avocado with food high in starch will instead cause accumulation of fat in the liver and accelerate fatty liver diseases. Fatty liver disease is a risk factor for metabolic disorders like type 2 diabetes and hypertension.  Also, the avocado leaves from Mexico cultivars contains estragole which is carcinogenic. Most avocado plants including the leaves, fruit and pit have been reported to be toxic to herbivores by causing cardiotoxicity. Therefore, avocado oil especially those from Mexico should be avoided by individuals suffering from compromised liver.

Affects mother during pregnancy and breastfeeding

Avocado is a nutrient rich diet and perfectly safe to eat during pregnancy and breastfeeding when taken in moderation. However, majority of women (75%) have one or more functional bowel disorder. This can extend until lactation and it is caused by hormonal fluctuation. Because of this, pregnant women tend to be more prone to symptoms such as bloating, constipation, abdominal pain, and other psychological symptoms. Avocado is well known to be a high FODMAP diet and can easily cause symptoms of irritable bowel syndrome and affect individuals with sensitive stomach. Therefore, it is recommended that pregnant and breastfeeding mothers should take no more than a quarter of an avocado per serving. Consuming avocado in large amounts can also cause the baby to have an upset stomach. However, there is not enough evidence to support this claim.

Avocado hypersensitivity and allergy

Allergy sensitive individuals experience immediate hypersensitivity to avocado. Clinical manifestation to avocado hypersensitivity includes systemic anaphylaxis, angioedema/urticaria, vomiting, bronchial asthma, and rhinoconjunctivitis. Patients sensitive to latex and fruits such as chestnut, banana, kiwi, walnut, amongst others experience avocado hypersensitivity. Symptoms due to avocado allergy include itchy mouth, scratchy throat, swelling in and around the mouth and throat, swelling of the lips, sneezing, itchy eyes, stomach discomfort and hives. Individuals sensitive to pollen may also experience skin reactions when they touch an avocado or use avocado oil.

Interaction with medications

Consuming avocado is not recommended when on medication. Avocado can interact with certain anti-inflammatory and anti-coagulant medications and hence diminish their effectiveness. For example, the anticoagulant drug warfarin (coumadin) is used to slow down blood clothing. But avocado decreases the effects of warfarin and increase the risk of blood clotting. The effect of non-steroidal anti-inflammatory drugs such as ibuprofen or naproxen is affected by avocado consumption. Also, avocado influences the effect of cholesterol lowering medications. Patients on such medications should consult with their doctors. Lastly, Avocado contains moderate amounts of tyramine which can increase the risk of high blood pressure when taken with monoamine oxidase inhibitors (MAOIs) such as socarboxazid, phenelzine, and tranylcypromine.

Decrease absorption of HDL (good) cholesterol

Avocado is rich in fat but contains no cholesterol. This helps to lower the levels of LDL (bad) cholesterol but increases the level of HDL (good) cholesterol. However, avocado is rich in beta-sitosterol. This compound can interfere with the absorption of cholesterol. Therefore, when consumed in large amounts, avocado can decrease the overall serum total cholesterol level

Other adverse effects

Other adverse effects that can result from consuming excess avocado include paralysis, drowsiness, dizziness, and flu.