UHPLC-MS Tracks Tomato Alkaloids in Human Blood

Tomatoes contain natural compounds called steroidal alkaloids, which may be behind some of the health benefits of eating plenty of tomatoes. However, little is known about what happens to these compounds after we eat them. This led researchers to study how the body absorbs, processes, and clears these compounds, and how much of them reaches the bloodstream after a single tomato-based meal. For this study, eleven healthy adults, six men and five women, avoided tomatoes for two weeks and then drank about 505 grams (roughly two cups) of tomato juice. The researchers took blood samples at 11 points over the next 12 hours and measured the tomato compounds in them using ultra-high-performance liquid chromatography–mass spectrometry (UHPLC–MS) to separate the components of a sample and then identify and measure them precisely. The team published their findings in the American Journal of Clinical Nutrition.¹

What Is Known About the Health Benefits of Tomatoes, and What Remains Unclear?

Large studies that track people’s diets and health, along with reviews that pool the results of many such studies, show that people who eat more tomatoes are less likely to develop or die from major long-term diseases such as heart disease and cancer.^2-5Backing up these findings, carefully controlled studies in which people were asked to eat tomatoes also suggest they are good for health. Eating raw tomatoes or tomato products such as juice or sauce has been shown to improve signs of heart health, lowering overall cholesterol and raising “good” high-density lipoprotein (HDL) cholesterol compared with people who did not eat them.^6-8

“Even though increased tomato consumption has been found to be beneficial for health,” write the authors of the paper,¹ “the specific components and the mechanisms that drive bioactivity have yet to be fully elucidated.”

How Did the Researchers Track the Tomato Compounds in the Blood?

To work out how the body handled the tomato compounds, the researchers used standard calculations to find the total amount that reached the blood over 12 hours, the highest level reached, and how long it took to get there. They also estimated what share of the compounds in the juice ended up circulating in the blood, either unchanged or in a broken-down form. Because pure reference samples were not available for some of the broken-down compounds, the team made their own by mixing the tomato compounds with liver enzymes, which helped them identify what they were seeing with more confidence.¹

What Did the Researchers Find About How the Body Absorbs and Processes Tomato Compounds?

On average, about 10% of the tomato compounds from the juice made it into the bloodstream, though this varied widely from person to person, from about 2% to 18%. More than 99% of what was found in the blood had already been chemically changed by the body. Blood levels peaked at an average of about 407 nanomoles per liter, ranging from about 104 to 1,146, and it took about 9 hours on average to reach that peak, anywhere from 6 to 12 hours. Levels were still higher than at the start after 12 hours, which means the study likely underestimated how much the body absorbed. Making reference samples with liver enzymes, including of two broken-down forms of a tomato compound called tomatidine, gave the researchers greater confidence that they had identified the compounds correctly.¹

“This study,” write the authors of the paper,¹ “reports the first pharmacokinetic data for tomato steroidal alkaloids, demonstrating moderate absorption and extensive metabolism after tomato juice consumption. These data provide context for future studies investigating the potential role that these compounds may play in human health.”

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References

1. Do, D.; Sholola, M. J.; Cooperstone, J. L. Absorption and Metabolism of Steroidal Alkaloids from Tomato Juice in Healthy Adults: a Pharmacokinetic Study. Am J Clin Nutr. 2026, 101597. DOI: 10.1016/j.ajcnut.2026.101597
2. Cheng H. M.; Koutsidis, G.; Lodge, J. K. et al. Tomato and Lycopene Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-analysis. Atherosclerosis 2017, 257, 100-108. DOI: 10.1016/j.atherosclerosis.2017.01.009
3. Jacques P. F.; Lyass A.; Massaro J. M. et al. Relation of Lycopene Intake and Consumption of Tomato Products to Incident Cardiovascular Disease. Br J Nutr.2013, 110, 545. DOI:10.1017/S0007114512005417
4. Mazidi, M.; Katsiki, N.; George E. S. et al. Tomato and Lycopene Consumption is Inversely Associated with Total and Cause-specific Mortality: A Population-based Cohort Study, on Behalf of the International Lipid Expert Panel (ILEP). Br J Nutr 2020,124, 1303-1310, 10.1017/S0007114519002150
5. Mazidi, M.; Ferns, G. A.; Banach, M. A High Consumption of Tomato and Lycopene is Associated with a Lower Risk of Cancer Mortality: Results from a Multi-ethnic Cohort. Public Health Nutr. 2020, 23 (9), 1569-1575. DOI: 10.1017/S1368980019003227
6. Cuevas-Ramos, D.; Almeda-Valdés, P.; Chávez-Manzanera, E. et al. Effect of Tomato Consumption on High-density Lipoprotein Cholesterol Level: A Randomized, Single-blinded, Controlled Clinical Trial. Diabetes Metab Syndr Obes. 2013, 6, 263-273. DOI: 10.2147/DMSO.S48858
7. Silaste, M.L.; Alfthan, G.; Aro, A. et al. Tomato Juice Decreases LDL Cholesterol Levels and Increases LDL Resistance to Oxidation. Br J Nutr2007, 98, 1251-1258. DOI: 10.1017/S0007114507787445
8. Valderas-Martinez, P.; Chiva-Blanch, G.; Casas, R. et al. Tomato Sauce Enriched with Olive Oil Exerts Greater Effects on Cardiovascular Disease Risk Factors than Raw Tomato and Tomato Sauce: A Randomized Trial. Nutrients 2016, 8 (3), 170. DOI: 10.3390/nu8030170