Eggplant and tomatoes come up whenever someone asks whether food can stand in for a nicotine patch. Both are nightshades, and both contain nicotine. This guide sets out the measurements that exist, shows the arithmetic in full, and explains what the numbers can and cannot tell you. It does not recommend food or patches for any purpose.
Which foods contain nicotine
Nicotine is an alkaloid made by tobacco and by several other members of the nightshade family, Solanaceae. That family includes tomatoes, potatoes, eggplant (also called aubergine) and peppers. The amount in each food is small, and the published figures disagree on how small. That depends on which food, which variety and how ripe it was when measured.
The two studies that measured it
Domino, Hornbach and Demana measured nicotine in supermarket vegetables and published the results as a letter in the New England Journal of Medicine in 1993. PubMed confirms the citation (volume 329, page 437). The full text sits behind a paywall, and we could not open it, so this guide does not use its numbers.
Siegmund, Leitner and Pfannhauser measured nicotine in tomatoes, potatoes, eggplant, peppers and some processed products, and published the work in the Journal of Agricultural and Food Chemistry in 1999. We read the abstract. Its headline figure is a range of 2 to 7 micrograms per kilogram for fresh fruit. A microgram per kilogram is the same as a nanogram per gram, so that is 2 to 7 ng/g. The abstract does not name the analytical method, and it gives no separate figure for eggplant.
The abstract also reports that nicotine in tomatoes fell significantly as the fruit ripened. The authors wrote that it "decreased significantly with increasing degree of ripening of the fruits." That finding matters for the numbers below, because a green tomato and a ripe one can differ several-fold.
Where the figures disagree
Not every source agrees with Siegmund. The Domino letter is often quoted with much higher figures, especially for eggplant. We could not open it to check those figures, so we do not repeat them, but the gap is worth knowing about if you meet a larger number elsewhere.
Three things can move a result: the variety tested, the ripeness at harvest and the measurement method. Siegmund's ripening finding shows how much one of them matters. Until the full papers are read side by side, the honest reading is a range, not a single number.
How to read a food nicotine figure
Units decide a lot here. Nanograms per gram are parts per billion. Micrograms per kilogram are the same figure written differently. Some studies report fresh weight, which is the food as eaten, and others report dry weight, which removes the water. Dry weight numbers look much larger, because a tomato is mostly water. A dry-weight figure cannot be compared with a fresh-weight one without converting it.
Before trusting any food figure, check four things: the unit, the weight basis, the ripeness and the number of samples. A figure from one fruit from one shop is a snapshot, not a value for the vegetable.
The unit
Nanograms per gram and micrograms per kilogram are the same figure written differently.
The weight basis
Fresh weight is the food as eaten. Dry weight removes the water and looks much larger.
The ripeness
Siegmund's tomatoes fell in nicotine as they ripened, so a green fruit and a ripe one can differ several-fold.
The sample count
One fruit from one shop is a snapshot, not a value for the vegetable.
The arithmetic, with the working shown
The question is how much fruit would hold the same amount of nicotine as one 7 mg patch. We use Siegmund's range, because it is the one primary measurement we opened. The sum compares total content: the nicotine in the food against the nicotine loaded into the patch.
Step 1. One patch holds 7 mg. That is 7,000 micrograms.
Step 2. At the top of Siegmund's range, 7 micrograms per kilogram, the food needed is 7,000 divided by 7, which is 1,000 kg of fresh fruit.
Step 3. At the bottom of the range, 2 micrograms per kilogram, the food needed is 7,000 divided by 2, which is 3,500 kg.
Result. On Siegmund's range, the nicotine in one patch equals the nicotine in somewhere between 1 and 3.5 tonnes of fresh fruit. We did not run a sum on the higher figures quoted from the Domino letter, because we could not check them against the original.
Siegmund and colleagues also estimated how much nicotine people take in from food: about 1.4 micrograms a day on average, and 2.25 micrograms a day at the 95th percentile, across the countries with consumption data. One 7 mg patch holds 7,000 micrograms. That is the same as about 5,000 days of the average dietary estimate, or roughly 13 to 14 years.
7,000 µg
nicotine in one 7 mg patch
The amount loaded, not the amount absorbed
1 to 3.5 tonnes
fresh fruit with the same nicotine
On Siegmund's 2 to 7 µg per kg range
1.4 µg
average nicotine a day from food
Siegmund's dietary estimate
about 5,000 days
of that average intake
Roughly 13 to 14 years
Siegmund et al., J Agric Food Chem, 1999 (abstract). A unit conversion, not a dose comparison.
Why the food sum is not a patch sum
The sum compares what is in the food with what is in the patch. It does not compare what reaches the bloodstream, and that is the comparison that matters. Eating and wearing a patch are different routes. A patch releases its contents slowly through the skin over its wear period. Food is absorbed through the gut and follows its own pattern.
The 7 mg on the box is the amount loaded into the patch, not a measured amount delivered. This guide has no absorption figure for either route, so the tonnage above is a unit conversion. It is not a dose comparison, and it should not be read as one.
What Dr Ardis has said, and what we could check
Dr Bryan Ardis has made nicotine a recurring theme across his videos. Most of them are hosted on Rumble, and their titles cover nicotine, pharmaceuticals and the GLP-1 drugs. The eggplant comparison has been attributed to him in secondary coverage. We could not check that attribution against his own words. No transcript of a relevant video was obtained, and no quote has been verified word for word.
So the eggplant comparison should be read as a claim that has been reported, not one that has been established. The figures above do not settle it, because the question it raises depends on how much nicotine a person absorbs from food, and that is the figure we do not have.
Dr Ardis has no connection to this store and does not endorse its patches.
Tobacco leaf and nicotine, a short clip
Uploaded by TalkToTheBody
Watch on RumbleA short clip on tobacco and nicotine, posted by another channel. We have not checked it against the figures above.
Why some people prefer a plant source
Some people want to know whether the nicotine in a patch comes from a plant or is made in a lab. This patch's nicotine comes from natural tobacco extract, a plant extract listed by name, with the amount stated as 7 mg per patch. That describes where the ingredient comes from. The label does not claim that the source changes how the product works.
Whether a plant source matters to you is a personal choice. The label gives you the source, the amount and the other ingredients, so you can make that choice from the facts on the box.
What the numbers can and cannot tell you
The food measurements show that nicotine is present in edible nightshades, at amounts that differ between studies and change with ripeness. They do not show how much nicotine a person absorbs from a meal, and they do not show what a patch delivers over its wear period. Both gaps need data this guide does not have.
Nicotine is pharmacologically active whether it comes from a plant, a food or a patch. Keep nicotine products, including patches, away from children and pets. Talk to a doctor first if you are pregnant, breastfeeding or have a medical condition.
These sources are about nicotine in food and in general. None of them is a study of this patch.
Further reading
The linked research covers each ingredient on its own and is not a study of this patch. These statements have not been evaluated by the FDA or the TGA. This product is not intended to diagnose, treat, cure, or prevent any disease.
