Yavelle Journal · Diet & Lifestyle · 6 min read
Deuterium is a naturally occurring heavy isotope of hydrogen, usually measured in parts per million (ppm). Ordinary water sits at roughly 150 ppm. Foods differ in how much deuterium is bound into their organic molecules, and the general pattern described in this literature is that fats sit at the low end and sugars and grains at the high end.
The Measured Values
Reported deuterium content of common fats, oils and fat-bearing foods, ordered from lowest to highest.
| Fat or oil | Deuterium (ppm) |
|---|---|
| Duck liver fat | 110 |
| Ghee | 116 |
| Lard | 116 |
| Pork rind | 117 |
| Olive oil, extra virgin | 128 |
| Avocado oil, cold pressed | 129 |
| Coconut pulp oil cream, organic | 129 |
| Peanut butter, 50% plant butter | 131 |
| Cocoa butter, 100% solid fat | 132 |
| Vegetable oil spread | 136 |
| Coconut, shredded unsweetened | 142 |
Source: Lech & Boros, Deutenomics of Food (see references). Each figure is a single sample. Fats and oils not listed here were not in the dataset, and we do not publish a figure for them.
The animal fats occupy the bottom of the list, with duck liver fat lowest at 110 ppm and ghee and lard together at 116 ppm. The liquid plant oils cluster in the high 120s. The spread from top to bottom is 32 ppm, which is a wider range than most food categories show, so within fats the choice of fat does move the number.
Why Dairy Fats Are Not in the Table
We have deliberately left butter out, and it is worth explaining why rather than leaving a gap.
Every figure above is a single test of a single sample. For most of these products that is a reasonable guide, because a pressed olive oil or a rendered lard is a fairly consistent thing. Dairy is not. The deuterium content of butter moves with the herd, the season, the region, the pasture and the water the cows drank, and the source dataset notes that its own butter sample came from cows in the Netherlands grazing unfractionated perennial ryegrass near sea level. A one-off test of one block of butter from one producer in one country tells you about that block of butter. It does not characterise butter.
Publishing a single number against the word "butter" would imply a consistency the measurement cannot support, in either direction. So we have not.
Where These Numbers Come From
It is worth being precise about the source, because we have not always been. These figures come from Deutenomics of Food, a dataset published by James C. Lech and László G. Boros. It names the people who prepared the samples, the scientist who performed the measurements and the department and university where they were performed, which is more than most figures circulating online can offer. It is also not peer reviewed. It is a compilation published by its own authors, it reports single samples rather than replicates, and it gives no measurement uncertainty for the entries above. Both of those things are true at once, and we would rather print the source and its limits than either hide the numbers or dress them up.
Fats and Oils, by Type
Not every fat in a kitchen appears in the dataset. Grouped by type, here are the ones that come up most often in low deuterium cooking, measured or not.
| Type | Examples |
|---|---|
| Animal fats | Duck and duck liver fat, beef fat and tallow, pig fat and lard, ghee, butter |
| Tropical and saturated plant fats | Coconut cream and coconut oil, palm kernel oil, cocoa butter |
| Liquid plant oils | Olive oil, avocado oil, sunflower seed oil |
| Nut and seed pastes | Unsweetened peanut butter and other nut butters |
Treat this as a list of what is commonly used, not as a ranking. Butter, beef tallow, palm kernel oil and sunflower oil are examples of fats for which we do not publish a measured figure, either because they are not in the dataset or, in the case of butter, because a single test cannot stand for the category.
What the Published Literature Does Report
One finding in the peer-reviewed literature is specific enough to quote, and it concerns how an animal is raised. A 2024 scoping review in Metabolomics reports lower deuterium content in grass-fed animals, below 130 ppm, and higher content in grain-fed animals, above 140 ppm (Korchinsky et al., 2024).
That comes from a small research literature, much of it framed by its own authors as hypothesis. It describes composition and chemistry. It does not establish a health outcome.
Where This Overlaps With Ketogenic Eating
A ketogenic diet is built mainly around fat. Because fats are the food group described as lowest in deuterium, a diet built mainly around fat is also, compositionally, lower in deuterium. That is an observation about what the food is made of, and nothing more should be read into it.
Source Matters: Origin, Season and Batch
As with all foods, the deuterium content of a fat depends on its origin and on upstream factors like how an animal was raised, what it drank, and when in the year the product was made. It is the reason the same product will not test the same from one producer to the next, or from one season to the next with the same producer. Our article on grass-fed versus grain-fed meat goes into this in more detail.
Fats for Cooking
Separately from deuterium, the saturated fats, ghee, lard, tallow, butter and coconut oil, are stable at heat and hold up well to frying and roasting. That is a straightforward property of the fat and a good reason to keep them in the kitchen.
How to Read These Figures
A few things are worth keeping in mind, and we would rather set them out than leave them implied.
Every figure here is one test of one sample. Deuterium values vary with origin, feed, season, processing and batch, so a figure describes the jar that was tested rather than every jar on the shelf. Retesting the same product from a different producer, or the same producer in a different season, would not be expected to give the same number. Do not read a 1 or 2 ppm difference between two rows as meaningful, and do not treat any of these as a fixed property of the food.
The dataset is a research compilation published by its authors rather than a peer-reviewed paper. It names the scientist who performed the measurements and the institution where they were performed, but it does not report replicate counts or measurement uncertainty for these entries. Treat the numbers as indicative rather than exact.
And deuterium is only one measure. There are many other reasons to choose or avoid a given fat, from smoke point to cost to taste to how it behaves in a pan, and none of them are settled by an isotope figure.
The Bottom Line
Fats are the food group this literature places lowest on the deuterium scale, and the measured figures are consistent with that: duck liver fat at 110 ppm is the lowest single entry in this part of the dataset, with the animal fats below the plant oils. Every figure is a single sample from a compilation published by its authors and not peer reviewed, so they are indicative rather than exact, and products that vary a great deal by herd, season and region are better left without a number than given a false one. Everything on this page is a description of composition, not a claim about what eating it will do.
Where to Go Next
For the wider picture, our low deuterium food list covers which whole foods are described as high and low in deuterium, and our article on grass-fed versus grain-fed meat explains why an animal's diet shapes the deuterium in its fat.
References
- Lech, J. C., & Boros, L. G. Deutenomics of Food: Food Deutenomics Data, Universal Nanomotor User Guide. Samples prepared by S. Dorfsman and P. Davelaar; measurements performed by J. C. Lech, Department of Physics and Astronomy, Physics of Living Systems, Vrije Universiteit Amsterdam, The Netherlands. Published by the authors at laszlogboros.com. Not peer reviewed.
- Korchinsky, N., Davis, A. M., & Boros, L. G. (2024). Nutritional deuterium depletion and health: a scoping review. Metabolomics, 20(6), 117. https://doi.org/10.1007/s11306-024-02173-4
- Répás, Győri, Buzás-Bereczki, & Boros. (2025). The biological effects of deuterium present in food. Discover Food, 5, 57. https://doi.org/10.1007/s44187-025-00327-4
This article is for general information. Reported deuterium values are single-sample measurements, vary by source, season and testing method, and should be treated as approximate.
Yavelle 25ppm Deuterium-Depleted Water is a packaged food. It is not a therapeutic good and is not intended to diagnose, treat, cure or prevent any disease. Information on this page is general and is not medical advice. If you have a health condition or are undergoing treatment, speak with a qualified health practitioner.