Uploaded June 2025 | Updated September 2026, 2 weeks ago
Headline in the New York Post: “Pigment in tomatoes and watermelon could help cure depression-but there’s a catch.” There sure is, and it’s a pretty big one. The article in question was spawned by a study in the journal “Food Science & Nutrition” by scientists at the Chongqing Medical University in China. Tomatoes or watermelon were not involved, neither were people. The study was all about male mice that were stressed by being placed in a cage with other mice that had been bred to be aggressive. Half the stressed mice had lycopene, the pigment found in tomatoes and watermelon, piped into their stomach every day, and half were similarly treated with placebo. The researchers then looked at changes in the mice’s behaviour such as extent of struggling when hung upside down by the tail as well as their preference for drinking sugar sweetened water. They also looked for changes in “synaptic plasticity” in the hippocampus of the lycopene treated and untreated mice.
Synapses are the junctions where nerve cells (neurons) communicate with each other or with other cells, like muscle cells. The communication is via chemicals called neurotransmitters that are released by one nerve cell, cross the tiny gap called the synaptic cleft that separates cells, and then fit into proteins termed “receptors” on the receiving cell. “Synaptic plasticity” refers to changes that occur at the synapse, either strengthening or weakening the synaptic connections. The hippocampus is a brain structure that controls many body functions including emotions and behaviour and its performance is dependent on the connections between the nerve cells it harbours, that is, its synaptic plasticity.
At the end of the experiment, the mice were “sacrificed” and their brains examined under the microscope. The hippocampus was also analyzed for a number of synaptic proteins. They found that stress had induced pathological changes in the hippocampus, but less so in the lycopene treated mice. Also, the proteins present in the hippocampus of the treated mice were associated with less synaptic dysfunction, and such dysfunction is believed to be associated with depression. “Believed to be” is not exactly hard science.
As far as behaviour goes, stressed mice are less keen to drink sweetened water and struggle less when hung upside down. Both of these are said to be signs of depression. The stressed but lycopene treated mice struggled for a longer time and were more eager to drink the sweetened water and this was interpreted as being less depressed. Somewhat of a stretch to relate this to human behaviour.
And then there is the big “catch.” The dose of lycopene used in the mouse experiment was the equivalent of 150 mg of lycopene daily for an adult human. That amount would be found in 21 tomatoes or 14 cups of watermelon. No studies have ever used that much lycopene in people, so it is not possible to say whether it is safe. Another headline reporting on the Chinese study wondered “Can eating tomatoes, watermelons cure depression?” My answer would be “nope.”
Headline in the New York Post: “Pigment in tomatoes and watermelon could help cure depression-but there’s a catch.” There sure is, and it’s a pretty big one. The article in question was spawned by a study in the journal “Food Science & Nutrition” by scientists at the Chongqing Medical University in China. Tomatoes or watermelon were not involved, neither were people. The study was all about male mice that were stressed by being placed in a cage with other mice that had been bred to be aggressive. Half the stressed mice had lycopene, the pigment found in tomatoes and watermelon, piped into their stomach every day, and half were similarly treated with placebo. The researchers then looked at changes in the mice’s behaviour such as extent of struggling when hung upside down by the tail as well as their preference for drinking sugar sweetened water. They also looked for changes in “synaptic plasticity” in the hippocampus of the lycopene treated and untreated mice.
Synapses are the junctions where nerve cells (neurons) communicate with each other or with other cells, like muscle cells. The communication is via chemicals called neurotransmitters that are released by one nerve cell, cross the tiny gap called the synaptic cleft that separates cells, and then fit into proteins termed “receptors” on the receiving cell. “Synaptic plasticity” refers to changes that occur at the synapse, either strengthening or weakening the synaptic connections. The hippocampus is a brain structure that controls many body functions including emotions and behaviour and its performance is dependent on the connections between the nerve cells it harbours, that is, its synaptic plasticity.
At the end of the experiment, the mice were “sacrificed” and their brains examined under the microscope. The hippocampus was also analyzed for a number of synaptic proteins. They found that stress had induced pathological changes in the hippocampus, but less so in the lycopene treated mice. Also, the proteins present in the hippocampus of the treated mice were associated with less synaptic dysfunction, and such dysfunction is believed to be associated with depression. “Believed to be” is not exactly hard science.
As far as behaviour goes, stressed mice are less keen to drink sweetened water and struggle less when hung upside down. Both of these are said to be signs of depression. The stressed but lycopene treated mice struggled for a longer time and were more eager to drink the sweetened water and this was interpreted as being less depressed. Somewhat of a stretch to relate this to human behaviour.
And then there is the big “catch.” The dose of lycopene used in the mouse experiment was the equivalent of 150 mg of lycopene daily for an adult human. That amount would be found in 21 tomatoes or 14 cups of watermelon. No studies have ever used that much lycopene in people, so it is not possible to say whether it is safe. Another headline reporting on the Chinese study wondered “Can eating tomatoes, watermelons cure depression?” My answer would be “nope.”
