An avocado a day keeps the doctor away

This column is written by Stig Bengmark – Professor Emeritus, scientist, lecturer and writer. Read more of Stig Bengmark’s columns here.

Avocado – one of the five miracle fruits

For millennia, the world’s population has used plants to preserve and restore health. Before the advent of modern healthcare, our health was taken care of by the church and monasteries – health was obtained from plants and their ingredients from the large monastery gardens (something that was already being done in ancient times).

It leaves an impression when you read books by the nun Hildegard von Bingen, who was in charge of a couple of monasteries in Germany in the middle of the 12th century. In the books, she describes the influence of different plants on health in detail and gives recipes on how they can be used as food. The book ‘Physica’ (recently published in a new edition in English ISBN 978–089281-661-3) is about health and healing and describes in detail how the healing properties of different plants were perceived, which is not very different from our current perception. Even long after the advent of modern hospitals and synthetic drugs, the range of drugs in pharmacies was still mainly sourced from the plant kingdom.

The phrase ‘an apple a day keeps the doctor away’ shows the way people thought in past times. The longing for sweetness meant, unfortunately, that the scientists of the last century were driven to breed traditional fruits so that they became sweeter. This happened at a time when not enough was known about the harmful effects of sugar on health, for example. Today we might wish that this had never happened, but there is no way back now, as with all the other plants we use for food. Instead, we’re forced to ration our consumption of fruits that we traditionally ate lots of, to a maximum of 15 grams of fruit sugar a day – i.e. a maximum total of three apples, pears or oranges.


Today there is an intensive hunt for cereals that have better nutritional qualities than the over-processed cereals; wheat, rye and barley (oats are still okay). Instead, we’ve started using products such as buckwheat and quinoa and sought out ancient African cereals such as amaranth, sorghum/durra, millet and teff (unfortunately, these are probably also bred, albeit to a much lesser extent). The same goes for fruit – a number of completely new fruits (for us) have ended up on our tables in recent years – hence some that have been named ‘the five miracle fruits’: avocado, coconut, longan (Chinese fruit), mangoes and mangosteen.

This column is dedicated to avocados – I hope to return to the other fruits and cereals some other time. Avocados have been on tables in South America since 7-8000 BC, they reached North America at the beginning of the last century and have been in Europe for only a few decades.

Avocado – a health power station

One of the absolute advantages of avocados is that they contain hardly any sugar at all – a whole avocado of normal size contains less than half a gram of sugar, i.e. about 3 calories corresponding to 1/5 of a lump of sugar. But since avocados are rich in fats, they are still high in calories – a whole avocado contains upwards of 250 calories – corresponding to about 1/8 of the recommended daily requirement of energy for an adult. One of the many advantages of avocados is that they are really ‘loaded’ with several hunger-suppressing and health-promoting plant fibres – an avocado contains no less than 11 grams of fibre, which is not far away from half the recommended daily requirement of fibre for an adult. The content of various fibres is described as being roughly the same as for an unripe green banana – which has so far been considered one of the very best sources of fibre (yellow bananas, on the other hand, are mostly sugar). For centuries, people have been eating green bananas when they want to lose weight and yellow bananas when they want to gain weight. The content of protein is also high in an avocado – 4 grams/avocado – which is much more than in most other fruits.

It’s the fat profile of the avocado that makes it a unique ‘superfood’

What makes avocados so attractive, however, is their unique fatty acids and their high content of useful minerals, vitamins and antioxidants. The nutritious salt, potassium, as well as vitamin K, various B vitamins, vitamin C and vitamin E are all abundant. They’re also rich in antioxidants such as alpha-carotene, beta-carotene, beta-cryptoxanthin, chrysanthemaxanthin, lutein, neochrome, neoxanthin, violaxanthin and zeaxanthin, all of which have been shown to have major health benefits. Lutein, for example, has been shown to counteract cataracts and keep the macula healthy, and is often recommended by doctors. The significant content of fat in the fruit makes it easier for the body to assimilate these valuable substances.

Replaces butter and cream in food

The high fat content has made avocados especially useful in our daily domestic lives. In addition to us being happy to eat them as they are, they can easily be used instead of cream in various dishes. Raw soups and smoothies become really ‘creamy’ with the help of avocados – the same goes for unripe green bananas (which, however, do not contain as much fat and calories by a long way). Avocado worshippers claim that you can often replace the butter in a recipe with an equal or double amount of avocado, and you can actually even bake gingerbread cookies with avocado instead of butter.

Humans need fat in their diets – at least 20-30% – and there are some fats we cannot produce by ourselves, but which need to be added to the diet. Among these are the polyunsaturated fatty acids alpha-linolenic acid (mother of omega-3) and linoleic acid (mother of omega-6). Alpha-linolenic acid is found mainly in rapeseed oil, linseed oil, soybean oil, and walnuts, and linoleic acid is found in various vegetable oils such as corn oil, sunflower oil, and soybean oil. However, in avocados, the levels of these fatty acids are moderate. The avocado’s great merit, rather, is the abundant presence of monounsaturated fatty acids, i.e. the fats that made olive oil famous for its anti-inflammatory properties and total lack of long-chain fatty acids, the same as with trans fats.

Long chain fats such as ‘tallow’ are dangerous for your health

Fats with a longer chain length than 12 carbon atoms cannot be absorbed directly to the liver but have to take the detour via the large lymph duct (ductus thoracicus) and the blood, where they often remain for several hours after a high-fat meal, then exposing the body’s tissues, especially the coronary artery of the heart and brain, to too great a strain;

* Dramatic increase in the inflammatory bacterial toxin, endotoxin, in the blood (same effect as smoking three cigarettes)
* A powerful cascade of neurotransmitters that increase inflammation
* Increased number and activation (combat readiness) of white blood cells
* A significant increase in the degree of inflammation in the body (inflammation increases the more sugar there is in the blood at the same time)

This effect has been named ‘postprandial inflammation’ and is, especially if repeated often, a dominant risk factor for the development of atherosclerosis and its consequences, strokes and heart attacks (Khor A et al Nutr Res. 2014;34:391-400). It’s important to point out that only a small part of what our ancestors ate (> 10%) went directly into the blood via the lymph, today, in western countries, it’s 4-5 times larger (about 40%), and in LCHF followers significantly higher – often 60% of total calorie intake. After all, like people have said in recent years, it’s probably time to be really ‘scared of fat’.

The endotoxin disappears but the inflammation persists

The bacterial toxin, endotoxin, disappears after 1-2 hours, but the high fat content in the blood remains for at least 2-4 hours, and the inflammation even longer.

It’s an absolute bonus if the food is very rich in short fats (SCFA fats) and medium fats (MCT fats), which are immediately delivered and metabolised in the liver via the portal vein. Coconut oil and palm kernel oil are rich in MCT fats, and it has recently been observed that MCT fats can also be found in rocket/arugula.

Avocados reduce coagulation time and prevent clotting

Avocados are not rich in MCT fats but have another very important advantage in the war against atherosclerosis – they prevent the ‘clogging’ of platelets and blood clots, which prevents the development of atherosclerosis. Some other plants that have been shown to have the same unique properties and which are excellent tools for thinning the blood are turmeric and raw ginger – plants that myself and my wife personally grate up and consume quite often, including when we’re going on longer flights where the risk of blood clots is much higher. Quite recently, it’s been observed that using several pieces of avocado also has the same properties.

Unfortunately, a lot of doctors who prescribe blood-thinning drugs, such as Waran and Trombyl, advise their patients not to eat certain fruits and vegetables with similar effects – the list of substances that can delay coagulation is long, but as a rule, doctors’ recommendations only cover some of them. The protective effect you get from Waran and Trombyl is in no way better than the effect you get from a regular intake of avocados and/or raw ginger, for example. I’d prefer that they called for regular use of the above plants instead – they’re not only healthier but also much cheaper.

Avocados lower the degree of inflammation and cholesterol levels

A large part of the population, especially middle-aged and older people, suffer from something called metabolic syndrome, which is known as a precursor to chronic diseases – everything from Alzheimer’s to prostate enlargement – but above all diabetes and cardiovascular disease. The syndrome consists of obesity (often abdominal obesity), high blood pressure, too much fat in the blood, elevated blood sugar, decreased levels of healthy cholesterol, elevated levels of ‘bad’ cholesterol as well as uric acid in the blood – changes that are often all seen in the same person. In clinical trials, consuming at least one avocado a day has been shown to lower levels of fat and bad cholesterol by an impressive 22%, and increase good cholesterol by no less than 11% (Fulgoni VL et al Nutr J. 2013 Jan 2;12:1). In addition, avocados give an early feeling of satiety and contribute significantly to weight loss/reduced BMI.

Avocados have strong inhibitory effects on cancer cells, and they lubricate joints

In studies, avocados have been shown to have strong inhibitory effects on cancer cells without damaging healthy cells (P<0.05), which has raised the hope that avocados can become a tool in so-called palliative cancer care. The strongest effects have been observed on cancer cells in the oesophagus – 2/3 of the effect achieved with the cancer drug, cis-platinum. Effects have also been observed on colorectal cancer (Larijani V et al Acta Med Iran 2014; 52 (3): 201-205).

In addition, avocado ‘lubricates’ joints and protects against osteoarthritis – the most common cause of joint prostheses. In animal trials, significant histological and clinical improvements have been observed after treatment with a mixture of avocado and soybean ingredients (see, inter alia, Boileau C et al Arthritis Res Ther 2009; 11 (2): R41).

The ‘quality’ of the immune system in newborns determines how their later life will be

In 1992, the English paediatrician, David Barker, shocked the world with his observation that the diet you are given during your first year of life and how your mother lived before and during her pregnancy, largely determines how you will fare later in life and what diseases you’ll suffer from at this time (Barker, D.J.P. ‘Maternal Nutrition, Fetal Nutrition, and Disease in Later Life’. Nutrition, 1992;13: 807-813 Curr Opin Nephrol Hypertens 1997; 6:106-110). His observations were later confirmed by others and are now fully accepted.

With this in mind, I’m enormously grateful that my mother lived an extremely healthy life, that I was not given any industrially manufactured breast milk substitutes, nor any dietary supplements of any kind. My mother lovingly mashed various fruits and vegetables and gave them to me and my siblings from an early age. I am convinced that this contributed to me, in old age, being completely healthy and not only able to work all day but to still have energy left over for the evenings. If I were a parent of small children today, I’d do exactly the same as she did – early on, I’d be mashing avocados that contain everything an infant could need, and giving it to my child. This would soon be followed by green banana and various fruits. Families with babies have so many opportunities today!

Avocados – like green bananas – can be frozen

In modern households, especially those who make a lot of raw food, avocados and green bananas are invaluable elements. We always have these fruits stored in the freezer, which helps with our economy. If we have children visiting, for example, we can quickly make ice cream from avocado or banana by blending them in our high-speed blender together with raspberries or strawberries, for example. When the fruits are frozen, they’re not much good for eating as they are or in a salad, but they’re excellent for using in smoothies and raw soups. At the time, it was an excellent addition to our lives, being able to eat frozen green peas, and now we’re waiting for an entrepreneur to embrace the idea of selling frozen green bananas, avocados and turmeric – a health-giving root in a class of its own.

If you can, and you’re interested – get involved! There’s money to be made here, the world could be your marketplace!

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