Can you eat tree wood?

Table of Contents

Quick Answer

No, humans cannot safely eat most types of tree wood. While wood contains some nutrients, it is mostly made up of indigestible cellulose along with potentially toxic compounds. Eating wood can lead to intestinal blockages, damage to the digestive system, and poisoning. However, there are a few edible tree products that can be consumed in moderation, such as sap and nuts.

Can Humans Digest Wood?

Tree wood is primarily made up of cellulose, lignin, and other polysaccharides that cannot be digested by the human gastrointestinal system. Humans lack the enzymes needed to break down the tough fibers and extract nutrients from them.

While termites and some other invertebrates can digest wood thanks to special microorganisms in their gut, human digestion ends in the large intestine and enzymes in our stomach and small intestine cannot break down the dense, fibrous cellulose molecules.

If a human swallows a small piece of wood, it may pass through the digestive system intact without causing harm. But larger pieces can become stuck in the esophagus, stomach or intestines, leading to choking or intestinal blockages requiring emergency endoscopic or surgical removal.

Repeatedly eating wood can also cause microscopic tears and abrasions in the digestive tract over time. Splinters may penetrate the intestinal wall and allow bacteria to enter the bloodstream, potentially causing an infection.

Toxic Components in Wood

Aside from the indigestible cellulose, some types of tree wood also contain toxic compounds that can cause poisoning symptoms if consumed by humans.

For example, yew trees contain taxines, toxic alkaloids that can cause dizziness, difficulty breathing, paralysis and death, even from small doses. The seeds inside cherries, apricots and peaches contain cyanogenic glycosides which break down into hydrogen cyanide. When metabolized, the cyanide inhibits cellular respiration and oxygen utilization in the body.

Tannins, which are found in oak trees and some others, have an astringent taste and can cause stomach pain, nausea, diarrhea and kidney damage when ingested. Heavy metals like arsenic may also be absorbed from the soil by certain tree species.

Nutritional Content of Wood

While wood itself has very little nutritional value for humans, trees do contain some vitamins, minerals, carbohydrates and phytochemicals that could theoretically be extracted and consumed.

For example, sap from maple or birch trees can be boiled down into syrups that contain vitamins, minerals, antioxidants and nutrients. Fruits, seeds and nuts from trees are also edible for humans and provide beneficial nutrition.

But the wood itself, including the trunk, bark, branches and roots, is made up of indigestible cellulose along with potentially toxic compounds. Just because a material comes from a tree does not mean it is safe or nutritious for human consumption. The specific plant part must be evaluated.

Dangers of Eating Wood

Some potential dangers and side effects of eating wood include:

Choking hazard from swallowing large fragments that block the esophagus
Gastrointestinal obstruction or blockage in the stomach, intestines or rectum
Internal bleeding or perforation of the stomach, intestines or rectum

Infection from foreign body penetration through intestinal wall
Inflammation and irritation of the mouth, throat and GI tract
Vomiting and diarrhea

Severe dehydration from fluid loss
Malnutrition as wood fibers take up space in the digestive tract
Toxicity from poisonous compounds absorbed into bloodstream

Liver or kidney damage
Death in cases of ingesting highly poisonous wood types

If a piece of wood becomes lodged in the esophagus or digestive tract, it must be removed via endoscopy or surgery. Seek emergency medical treatment for symptoms like difficulty swallowing, intense abdominal pain, vomiting, diarrhea or obstruction.

Is it Ever Safe to Eat Wood?

It is very rare for eating wood to be safe for humans. However, a few specific tree products and extracts can be consumed in small quantities as food or medicine:

Maple syrup – Made from boiled down maple tree sap containing nutrients and antioxidants. Safe in moderation.
Cinnamon – The inner bark of cinnamon trees contains the spice cinnamaldehyde. It has health benefits but high doses may be toxic.

Willow bark tea – Contains salicin which the body metabolizes into salicylic acid, similar to aspirin. Relieves pain and fever but can irritate stomach.
Fruit seeds – Seeds from cherries, apricots, peaches, pears and apples are edible when peeled and roasted but contain cyanide if eaten raw.
Banana tree stems – The tender inner core and shoots can be cooked and eaten like vegetables in some tropical regions.

Gum arabic – Edible sap harvested from acacia trees used as an emulsifier and thickening agent in some foods.

So while humans cannot safely eat most wood, a few specific tree products can offer nutrition and health benefits when carefully prepared and consumed in moderation. But the bark, trunk, branches and roots of trees should not be eaten.

Historical Cases of People Eating Wood

There are some historic reports of humans actually consuming wood, often with deadly consequences:

Nicholas Baudin recorded in the 1800s that aboriginal Australians would eat wood shavings as part of their diet.
The Donner Party resorted to making meals from old timber and leaves during their 19th century trek through the Sierra Nevada.
Some women in Victorian times ate chalk and wood splinters, inflicting self-harm to adhere to social norms of frailty.

Cases of pica, an eating disorder involving consuming non-food items, include incidents of people eating wood chips and tree bark.
Cellulose derived from wood pulp is processed into a powdered filler or extender in some low-quality foods.

However, all of these cases resulted in chronic health problems and provided little to no nutrition. While humans can technically ingest wood, it should never make up a substantial portion of the diet due to its lack of digestibility and nutrients.

Alternatives to Eating Wood

Instead of eating wood from trees, humans should focus on getting fiber, vitamins and minerals from these natural, healthy, digestible sources:

Fruits, vegetables, whole grains – Contain fiber without irritating cellulose.
Beans, lentils, nuts, seeds – Excellent sources of plant protein and nutrients.

Herbs and spices – For flavor and phytochemicals without toxicity.
Plant-based beverages – Such as maple syrup in moderation, coconut water, herbal tea.
Edible mushrooms – Like shiitake, provide nutrients without indigestible fibers.

Sprouted grains – More easily digested and higher in vitamin content.
Supplements – Can provide micronutrients without consuming any actual wood.

A balanced, whole food diet can give you all the benefits of plants without the dangers of eating wood. Focus on the edible parts of trees like fruits, seeds and sap instead of the indigestible wood.

Can Animals Eat Wood?

Some animals are specially adapted to extract nutrients from wood:

Termites – Digest wood using cellulose-digesting protozoa in their gut.
Beavers – Benefit from wood as a food source due to intestinal microorganisms.

Porcupines – Feed on bark, roots and branches of trees to obtain minerals.
Woodpeckers – Occasionally ingest bark and tree sap while drilling cavities for nests.
Sloths – Slow metabolism and gut flora allows them to subsist mostly on toxic leaves.

Carpenter ants – Harvest fungus gardens growing in tunnel galleries chewed into wood.

However, while wood can sustain forest-dwelling animals, pets and livestock cannot properly digest it either. Dogs, cats, rodents and farm animals should never be fed tree branches or bark as it could cause intestinal injuries.

Can Wood Be Modified to Become Edible?

Researchers have been working to find ways to convert wood into a digestible food source for humans. Possible methods include:

Chemical processing – Using acids, salts, and solvents like ionic liquids to dissolve and isolate components of wood.
Enzymatic hydrolysis – Breaking down cellulose with cellulase enzymes into fermentable sugars.
High-pressure processing – Subjecting wood to extreme pressure allows some nutrients to be extracted.

Genetic engineering of microbes – Using synthetic biology to design microorganisms that can digest cellulose.
Bioconversion to edible mushrooms – Some fungi can grow directly on wood, digesting lignocellulose.

While research continues, currently no wood products on the market have been modified to be safely and nutritionally edible for humans without extensive processing. For now, wood remains non-food and indigestible.

Conclusion

Humans cannot safely eat most forms of tree wood. While wood does come from trees, it contains mostly indigestible cellulose along with potentially toxic compounds. Eating sizable quantities of wood can therefore cause intestinal obstructions, toxicity, malnutrition and even death.

Very specific tree products like sap and some fruit seeds and nuts can be edible in moderation. But the trunk, roots, bark and branches are all still made of the same indigestible lignocellulose that makes up wood. Research continues into processing methods that could make wood digestible and nutritious someday. But for now, it’s best to avoid eating tree wood.