Food Trends: You Are What You Eat? The Doctrine of Signatures.

Published on 25 Jan
10 min read

An Ancient Knowledge

Could the knowledge from the ancient world be the key to optimal health and well-being for the mind, body and soul?

The real voyage of discovery consists not in seeking new landscapes but in having new eyes.
Marcel Proust

A medicinal practice, known as the Doctrine of Signatures, has roots going back almost 2 million years ago to a Greek called Dioscorides, who is famous for his groundbreaking pharmaceutical work De Materia Medica. Dioscorides was a doctor for the Roman Emperor Nero’s army, and as a result of this, he travelled extensively throughout Asia Minor and collected plants and substances to create his 5-volume masterpiece which is still influential till this day[1]. This system looks at the shape, colour, smell and characteristics of plants which indicate their healing properties on parts of the body. The Doctrine of Signatures has led the way for alternative medicine and has branched off into smaller practices such as herbalism and homeopathy.

Most of our modern day science is based on physicians in Ancient Greece
Most of our modern day science is based on physicians in Ancient Greece

Mystical Middle Ages

The Signatures likewise are taken notice of, they being as it were the Books out of which the Ancients first learned the Vertues of Herbes; Nature or rather the God of nature, having stamped on divers of them legible Characters to discover their uses.
William Coles

Opium was used during surgery during the Renaissance
Opium was used during surgery during the Renaissance

The Doctrine of Signatures was ‘rediscovered’ and reinterpreted during the Renaissance period of the Middle Ages. Doctors and mystics added to the knowledge discovered over 1000 years before and believed that God had left signs in nature for them. A Swiss physician called Paracelsus, although he discarded ancient thought, discovered the mineral zinc and is believed to have invented anaesthetics from opium[2] and much of his research and notions inspired homeopathy.

A German mystic, Jakob Boehme, wrote about the subject[3] in his book The Signature of all Things, written in 1621, Boehme states that all objects in the natural world have meaning and how these meanings interact with each other. This has inspired other philosophers including Hegel and Nietzsche. Boehme believed that God created plants as medicine. Plants were given signs that signified what plant is attributed to which part of the body[4].

Nicholas Culpeper was an English herbalist during the 17th century who took inspiration from the ancients. He believed that this information should be available to all and translated many key works from Latin to English including Galen’s Art of the Physick which irked the physicians and priests at the time[5]. His most famous work is A Complete Herbal links astrology with medicine. Culpeper believed that planet energies could be found within plants could heal maladies as well as being a source of food[5].

Mixing up a magic brew in the apothecary's room
Mixing up a magic brew in the apothecary’s room

The signature of plants is basically how they look. Their outer appearance to the world. The signatures help us to determine which plants are good for which part of our bodies, especially if we are feeling dis-ease. The plants that are used for various parts are similar in colour or shape and used to treat ailments within the body. Despite the Western world stepping away from natural medicines, 80% of the world still use traditional medicines as their primary source of healing[6]. This knowledge of the world around us and the signs in nature is not universally known or accepted.

the mercy of God … maketh … herbes for the use of men, and hath … given them particular Signatures, whereby a man may read … the use of them
William Coles

Just a Pseudoscience?

During the Enlightenment era, scientific systems such as The Doctrine of Signatures became almost obsolete and were branded as archaic, naive and thus forgotten.

Although these ancient remedies aren’t advocated by the medical system, there is sufficient evidence to suggest that the ancients who saw the similarities between food and body are intrinsically linked to our health and well-being. Despite the sceptics in the professional field who critique such a simple explanation of the world, eating a range of whole foods does benefit our mind and body. Some foods, such as tomatoes, walnuts and carrots, have been noted as containing chemicals that help to maintain certain parts of the body. This has been substantiated by a plethora of medical studies, so it can be ascertained that other foods and plants can also have these medicinal properties.

Those against this medical practice suggest that we have no need for ancient thought today due to the advance of technological advancements in medicine, surgery and diagnosing illness. However, this is beside the point. This way of thinking has formed the basis of modern medicine.

Further research into this subject shows that foods which are good for certain parts of the body resound certain characteristics. For instance, take the skeleton which is made up of around 200 bones, foods such as celery and bok choy are recommended to help support the skeletal system. Not only do celery and bok choy look similar to bones, but they also have a similar sodium content. Sodium can be extracted from the bone if levels in the body fluctuate[7]. This can result in the loss of important minerals such as calcium in the bone structure. Furthermore, bok choy is rich in essential vitamins and minerals including vitamin K, phosphorus and calcium which help support bone structure[8].

Bok choy could help promote bone density

The universities do not teach all things, so a doctor must seek out old wives, gypsies, sorcerers, wandering tribes, old robbers, and such outlaws and take lessons from them. A doctor must be a traveler … Knowledge is experience.

The Doctrine of Signatures reminds us to look into our intuitive powers and trust in ourselves. The world is full of signified elements waiting to be discovered.

Common Food Signatures

The Kernal hath the very figure of the Brain, and therefore is very profitable for the Brain
William Coles

The Doctrine of Signatures, although rooted in Ancient Western medicine, is similar to other ancient well-being systems from around the world such as Traditional Chinese Medicine, Native American Traditional Healing and Ayurveda. These holistic systems tell us that a bond between ourselves and the natural world can help us not only to rediscover our roots in the natural world but also help us understand our bodies and how they work.

Remedies can be made traditionally

Nature marks each growth … according to its curative benefit

These are the most common foods associated with The Doctrine of Signatures. Each food is said to represent a body part, not only looking but also contains certain nutrients that help to keep these organs functionally normally.


Carrot slices have a pupil, iris and vein-like lines – just like the eye.

Carrots are associated with the eye. When cut widthways the similarities between the carrot and the eyeball is uncanny. Science now proves that carrots can enhance blood flow as well as the function of the eyes[9].


Safe in the shell: the walnut.

Walnuts are associated with the brain. Not only are walnuts wrinkled and is split into sections just like the brain, but it also comes in a hard shell much like our skulls. Walnuts assist neurotransmitters in the brain, which act as messengers, and are a good source of vitamin E[10].


Promote cardiovascular health by consuming grapes.

Grapes are believed to be good for the cardiovascular system. When hanging in clusters, grapes look like the lungs. Grape clusters resemble the tissue structures inside the lungs called alveoli. The alveoli allow oxygen to pass from the lungs to the bloodstream[11]. Grape seeds also contain a chemical called proanthocyanidin which can protect the heart[12].


Tomatoes are associated with the heart. The tomato is a deep red colour and usually has 4 chambers inside, just like the heart. Suggesting that tomatoes are good for heart health is substantiated by a mountain of research. Tomatoes contain lycopene which is proven to reduce the risk of heart disease[13].


Ginger root is associated with the stomach. Ginger is commonly used to soothe gut problems such as digestion and relieving nausea.


Figs can help fight fertility problems.

Figs are associated with the scrotum. Figs are filled with small seeds and generally hang in twos. Figs are an excellent source of folate. Having a diet rich in folate can increase fertility. Consuming figs can increase the number of sperm, as well as mobility[14].

Citrus Fruits

Citrus fruits are full of feelgood vitamins and minerals

Citrus fruits such as grapefruit, lemon and orange are associated with breasts. These fruits resemble mammary glands, and when cut in half, the fruit is similar to the structure of the breast. The high content of vitamin C in these fruits help defend the body from carcinogens which attempt to mutate the cells within our body[15]. Citrus fruits, too, help improve the function of the lymphatic system which is connected to nerves, glands and organs within in the body[16]. This is important throughout the whole body, but many problems with the breasts can begin with a sluggish lymphatic system.

Sweet potato

A sweet potato looks just like the pancreas

Sweet potatoes are associated with the pancreas. The pancreas is an important organ in the digestive system which regulates sugar levels in the body. Sweet potatoes have a low Glycaemic Index (GI) which means it releases sugar slowly so you’re less likely to ‘crash’ after eating[17].

Kidney Beans

Kidney beans look like kidneys, it is as simple as that. Kidney beans are an excellent source of protein as well as soluble and insoluble fibre[18]. Its impressive list of health benefits helps to maintain healthy kidney function.


Sipping on beetroot juice could keep heart disease at bay.

Beetroot, in particular, its juice, is associated with blood. The deep-coloured vegetable is similar to the heart, so similar in the fact that it bleeds too. Studies have suggested that drinking beetroot juice could reduce blood pressure and the risk of heart disease[19].


Sliced mushrooms look like the ear.

Mushrooms, when cut in half, look like ears. Mushrooms are a rich source of vitamin D. We know this is already good for bone health, but studies advocate that a diet rich in vitamin D could also improve hearing[20].

Avocado/ Pear / Aubergine

The ultimate female fruit? The avocado.

Avocados, pears and aubergine are also associated with the womb. The avocado, in particular, is interesting as it takes 9 months to grow, just like a foetus. Aubergines, because they are rich in folates, can help protect infants inside the womb from birth defects[21].


Onions look like body cells. Onions have been proven to help clear waste materials from the body[22]. Onions have been proven to benefit all parts of the body.

Cucumber / Courgette

Impress by eating courgettes.

Cucumbers and courgettes are at the butt of many jokes for their phallic appearance. However, courgettes have been proven to benefit those suffering from penile problems. Consuming courgettes could help reduce the symptoms of a disease called benign prostatic hypertrophy. Unpleasant symptoms from this disease affect sexual and urinary function[23]. Cucumber is believed to help with erectile dysfunction.


A sweet pair. Peanuts can pack a mighty boost for men.

Peanuts look like the testes. As well as coming in twos, the nuts are protected by a shell. Peanuts are believed to help men’s sexual health and desire. Peanuts contain high levels of arginine[24], an amino acid which boosts libido and can be found in viagra[25].


Keep smiling and tuck into a banana

Bananas, when turned the right way, look like a beaming smile. It’s bright colour also highlights this fruit’s happy disposition. Bright-coloured food is believed to improve mood. Bananas, when digested, contain tryptophan which converts to serotonin, a neurotransmitter, which is responsible for regulating moods[26]. Bananas also contain vitamin B6, which helps the body to produce its own serotonin[26].

Sea Vegetables

Seaweed can help improve dull, lifeless hair.

Long strands of sea vegetables washed up on the shore, such as kelp, look like locks of hair. Sea vegetables, although an acquired taste, are bursting with vitamins and minerals which boost healthy looking, and feeling, hair. Essential minerals such as iodine and phosphorus can help to keep hair strong and beautiful[27].

Feeling Intuitive?

So, maybe the next time you’re feeling under the weather, reach into nature’s larder rather than the pharmacy. There is much more to be discovered by looking at past knowledge to inspire the future. Perhaps getting back to nature, in as many ways as possible, is the best thing we can do for ourselves, others and the environment.

Join the conversation on social media. Follow Foodful on Facebook, Twitter and Instagram.

Disclaimer: Check with your doctor before administering any health-related cures.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.