Yes, green tomatoes have nicotine
It may be surprising, but green tomatoes, along with other vegetables in the Solanaceae (nightshade) family, do contain minute quantities of nicotine. This is not a cause for alarm, as the levels are so infinitesimally low that they have no physiological effect on the human body. This natural alkaloid serves a purpose for the plant itself, primarily as a defense mechanism against insects and pests. Tobacco, which contains high concentrations of nicotine, belongs to the same plant family, which is why the connection exists.
Higher concentration in unripe fruit
One of the most interesting facts about nicotine in tomatoes is that the concentration is actually higher when the fruit is unripe. As the tomato matures and turns red, the amount of nicotine decreases significantly. While unripe green tomatoes contain about 42.8 nanograms (ng) of nicotine per gram, a ripe red tomato contains only about 7 nanograms per gram. This stark difference highlights that the plant's alkaloid production is an evolving process throughout its life cycle.
How green tomato nicotine compares to tobacco
To understand just how negligible the amount of nicotine in a green tomato is, a comparison with tobacco is necessary. The sheer scale of the difference is staggering. A single cigarette contains thousands of times more nicotine than a green tomato, with a typical cigarette containing 10–12 milligrams (mg), or 10,000,000–12,000,000 ng, of nicotine. A person would need to consume an absurd quantity of green tomatoes to ingest the same amount of nicotine from just one cigarette, an amount that would likely cause other severe gastrointestinal distress long before any nicotine-related effect was felt. The way nicotine is absorbed also differs drastically; when eaten, nicotine is metabolized much slower through the digestive system than when inhaled through the lungs.
The nightshade family and other sources
Tomatoes are not alone in the nightshade family in containing trace levels of nicotine. Several other common vegetables also produce this alkaloid naturally. This is a reminder that trace compounds can be found in many natural food sources without posing a threat to health. The family is vast and contains many popular dietary staples.
Comparison of nicotine content in vegetables
| Vegetable | Ripeness | Nicotine Content (ng per gram) | Health Implications |
|---|---|---|---|
| Tomato | Unripe (Green) | ~42.8 | None at normal consumption |
| Tomato | Ripe (Red) | ~7.1 | None at normal consumption |
| Eggplant | Ripe | ~100 | None at normal consumption |
| Potato | Green/Sprouting | ~42 | Levels increase in skin/sprouts |
| Potato | Ripe | ~7.1 | None at normal consumption |
| Bell Peppers | Ripe | ~7.7-9.2 | None at normal consumption |
Conclusion: No cause for concern
While the fact that green tomatoes have nicotine may be a surprising piece of trivia, it is not a matter for concern. The amounts are minuscule and are naturally occurring, a result of the plant's evolutionary development to ward off pests. There is no risk of addiction or negative health effects from consuming tomatoes or other nightshade vegetables. In fact, these foods are packed with essential vitamins, antioxidants, and fiber, making them a healthy part of any diet. Concerns about nightshades are more typically related to compounds like solanine for some sensitive individuals, not the harmless traces of nicotine. Enjoy your fried green tomatoes without a second thought about their trace nicotine content. For more information on the chemistry of food plants, see this publication.
