Calcium supplement reduced lycopene absorption from tomato paste in people
What it found
Adding 500 mg of calcium to a meal cut the amount of lycopene absorbed into the blood by 83 % in ten healthy adults.
Lab digestion tests showed calcium lowered the electrical charge on tiny fat particles that carry lycopene.
What they found
Studies in people
Lycopene absorption in people
When the calcium supplement was added to the test meal, lycopene reaching the blood dropped by 83 %. Nine out of the ten adults absorbed less lycopene with the extra calcium.
Timing of lycopene rise
Without added calcium, blood lycopene started to go up 2 hours after the meal. With the calcium supplement, it did not rise until 5 hours had passed.
Animal and lab studies
Micelle charge in lab tests
In lab digestion tests, adding calcium did not change how much lycopene moved into tiny fat particles or their size. However, it lowered the electrical charge on those particles by 39 %.
What the authors conclude
- They conclude that a normal dietary amount of calcium can strongly reduce how much lycopene the body absorbs from tomato paste.
- They suggest this happens because calcium lowers the electrical charge on the tiny fat particles that carry lycopene to gut cells.
- The authors call for more research on whether calcium affects the absorption of other similar nutrients.
How it was done
Lycopene levels in the body have been linked to lower prostate cancer and heart disease risk. Earlier lab work suggested calcium might block lycopene from being taken up, so the authors wanted to check if this happens in people.
Ten healthy adults ate a meal with tomato paste providing 19 mg of lycopene, once alone and once with a 500 mg calcium supplement. Blood was checked over 7 hours after each meal, with at least 3 weeks between them. The team also ran lab digestion tests using added calcium doses between 10 and 80 mg per meal.
What it can’t tell you
- Only ten people took part, so scientists do not yet know if the same drop would happen in a larger group.
- The study measured what happened over 7 hours after one meal, not what happens over weeks or months of eating calcium with tomatoes.
Who paid
- Authors work at
- Aix-Marseille University, France; Université d'Avignon et des Pays du Vaucluse, France; Université d'Auvergne, France
The paper
- Title
- Dietary calcium impairs tomato lycopene bioavailability in healthy humans
- Type
- Randomised controlled trial
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Borel P, Desmarchelier C, Dumont U, et al (2016). Dietary calcium impairs tomato lycopene bioavailability in healthy humans. The British journal of nutrition. doi:10.1017/S0007114516004335Free full textPubMed 28069089DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error