Is it okay to chew on grass? Understanding the risks and safe alternatives

January 7, 2026 •

4 min read

According to research published in the Proceedings of the National Academy of Sciences, our early human ancestors did consume grasses around 3.5 million years ago, but modern human physiology has evolved beyond it. The central question for many today remains: Is it okay to chew on grass?

Quick Summary

Chewing common lawn grass is generally not recommended due to significant health risks, including pesticide exposure, dental wear from silica, and contamination. Humans cannot digest it for nutrition.

Key Points

Indigestible for Humans: Your digestive system lacks the enzyme cellulase, making grass difficult to break down and extract nutrients from.
Significant Health Risks: Chewing grass can expose you to harmful pesticides, herbicides, animal waste, and parasites.
Dental Damage: Grass contains abrasive silica particles that can wear down tooth enamel over time, leading to permanent dental damage.
No Nutritional Value: Unlike grazing animals, humans gain virtually no usable nutrition or calories from chewing grass, making it a poor survival strategy.
Safe Alternatives Exist: For a chewing habit or anxiety relief, safe alternatives like chewing gum, sunflower seeds, or drinking herbal teas are recommended over grass.
Distinguish Between Grasses: Be aware that common lawn grass is different from edible types, such as the cereal grains we consume as food staples.

The Fundamental Problem: Why Humans Don't Digest Grass

Unlike ruminant animals such as cows and sheep, humans lack the specialized digestive system required to break down grass effectively. Your body cannot derive any significant nutritional value from a mouthful of lawn clippings. The two main components of this digestive inefficiency are cellulose and lignin.

Inability to Break Down Cellulose

Grass blades are largely composed of a tough carbohydrate called cellulose. To digest this, animals need the enzyme cellulase. Humans do not naturally produce cellulase, and while some gut bacteria can break down small amounts, it is not enough to extract meaningful energy. The grass effectively passes through your system as indigestible fiber, offering minimal benefits.

The Role of Abrasive Silica

Grass plants, a family known as Poaceae, have evolved natural defenses against being eaten. Many species contain microscopic particles of silica, which is essentially a type of glass. While this doesn't affect grazing animals with continuously growing teeth, chewing on these abrasive particles can wear down human tooth enamel over time, leading to serious and costly dental problems.

Serious Dangers Lurking in Your Lawn

Beyond the issues of digestibility and dental health, there are numerous contamination risks that make chewing on grass a dangerous gamble. Your lawn is not a pristine, untouched natural habitat.

Toxic Pesticides and Herbicides

Many homeowners use a variety of chemicals to keep their lawns lush and free of pests and weeds. Common lawn treatments, such as herbicides and pesticides, are toxic to humans and can lead to a range of health issues if ingested. Even small quantities can cause acute symptoms, while long-term exposure may have more serious consequences.

Exposure to Parasites and Bacteria

Any outdoor patch of grass is a public space for local wildlife and pets. This means it can be contaminated with harmful bacteria from feces or urine, as well as parasites like tapeworms or roundworms. Ingesting these contaminants can lead to severe gastrointestinal distress, sickness, or parasitic infection.

Hidden Dangers of Contamination

Runoff: Pesticides and chemicals can be present in water runoff, contaminating grass in unintended areas.
Soil: Heavy metals and other toxins present in the soil can be absorbed by the grass and remain on the blades.
Airborne Drift: Chemicals from neighboring properties can drift onto your lawn via wind, leading to unexpected exposure.

Comparing Lawn Grass and Edible Grasses

It is important to differentiate between the grass blades on your lawn and other plants within the broader grass family that humans can eat. Here is a comparison:


Feature	Lawn Grass (e.g., Ryegrass, Fescue)	Edible Grasses (e.g., Wheatgrass, Cereals)
Digestibility	Very poor; high cellulose content, low nutritional value.	Edible parts (seeds, shoots) are digestible and provide nutrients.
Nutritional Value	Virtually zero usable nutrition for humans.	High in fiber, vitamins, and minerals, especially when juiced.
Dental Impact	Contains abrasive silica that can wear down teeth.	No abrasive properties in the edible parts. Juicing removes fiber.
Pesticide Risk	High, as most lawns are treated with chemicals.	Generally low for commercially grown, certified edible products.
Contamination Risk	High, from animals, parasites, and soil.	Low risk due to regulated and controlled cultivation.

Psychological Aspect and Alternative Solutions

While the physiological risks are clear, the habit of chewing grass is sometimes linked to psychological factors, such as boredom or anxiety. The act of chewing can be a soothing, repetitive behavior. Thankfully, there are much safer and more beneficial alternatives to turn to instead.

Safer Chewing Alternatives

Herbal Tea: Certain grasses, like lemongrass, are used to make flavorful and safe teas.
Chewing Gum: A clean, safe, and socially acceptable way to satisfy a chewing habit.
Sunflower Seeds: A healthy and engaging snack that can keep your mouth busy.
Wheatgrass Juice: Unlike lawn grass, wheatgrass is grown specifically for human consumption. It is juiced to extract the nutrients while leaving the indigestible fibrous material behind.

Conclusion: A Habit Best Left Behind

Ultimately, the risks of chewing on grass far outweigh any potential (and unproven) benefits. Our human bodies are not equipped to digest it, and the hidden dangers of pesticides, bacteria, and abrasive silica pose significant threats to your health. A seemingly innocent childhood habit can lead to serious digestive problems, parasitic infections, and irreversible dental damage. Instead of turning to the lawn for a chew, opt for one of the many safe and clean alternatives available to satisfy a need to chew or connect with nature safely. Remember, simply touching grass has been shown to offer psychological benefits, without the added risks of ingesting it.

For more information on the dangers of common lawn chemicals, you can consult resources like the Penn State Extension, which provides detailed reports on the potential health effects of pesticides.(https://extension.psu.edu/potential-health-effects-of-pesticides)

Frequently Asked Questions

Humans cannot digest grass because our bodies do not produce the enzyme cellulase, which is necessary to break down the tough cellulose fiber that constitutes a large portion of grass blades.

The risks include ingesting toxic pesticides and herbicides, exposure to bacteria and parasites from animal waste, and long-term damage to tooth enamel from abrasive silica particles.

No. While chewing grass might temporarily give a feeling of fullness, it provides virtually no usable nutritional value or calories for humans, and you would still starve.

No. Wheatgrass is specifically grown and prepared for human consumption, often juiced to remove the tough, indigestible fiber. Lawn grass is not safe to consume in the same way and poses health risks.

While the act of chewing can be soothing, it is not worth the associated health risks. Safer alternatives for anxiety or boredom include chewing gum or other edible, non-toxic plants like lemongrass.

For children, ingesting grass poses similar risks to adults, including exposure to contaminants. For pets like dogs and cats, eating grass is common and can sometimes induce vomiting. While a small amount is usually harmless, large quantities can cause digestive issues.

Humans safely consume many parts of the grass family, including the seeds of cereal grains like wheat, rice, and oats. Some specialized varieties like lemongrass stalks and bamboo shoots are also edible.