A new study suggests that lycopene may have antidepressant-like effects in mice. But what does this really mean for you?
A new study suggests that lycopene may have antidepressant-like effects in mice. But what does this really mean for you?
Mentioned in this episode:
Lycopene Alleviates Depression-Like Behavior in Chronic Social Defeat Stress-Induced Mice by Promoting Synaptic Plasticity via the BDNF–TrkB Pathway (Wiley - Food Science & Nutrition)
Hello and welcome to the Nutrition Diva podcast, a show where we zoom in on the latest nutrition research and then zoom out to look at how (or whether) it applies to our own food choices. I’m your host, Monica Reinagel, and today I want to tell you about some new research on lycopene and its potential role in improving mood–as well as how that research fits into the larger context of diet and mental health.
Just as a quick review: Lycopene is an antioxidant nutrient that is in the carotenoid family. It’s a very colorful nutrient–it’s what gives tomatoes, watermelon, and pink grapefruit their rosy color. If you’ve heard about lycopene before, it may have been in the context of heart health—some studies have suggested it may help lower the risk of cardiovascular disease.
This latest study, published in the journal Food Science & Nutrition suggests that lycopene could also have antidepressant effects—at least in mice. Researchers found that supplementation with lycopene seemed to lessen certain depressive behaviors in the mice. The treated mice were more interested in interacting with other mice, more likely to explore their environment and pursue tasty foods.
Now, obviously, mice are not people, so we want to interpret these findings with caution. There is a long history of using mice to study the effects of stress and depression. And part of this involves developing research protocols to measure just how stressed or depressed a given mouse might feel. Because obviously, we can’t just ask them. We have to surmise based on their behavior.
For example, researchers will measure how long a mouse will struggle to free itself from an unpleasant or stressful situation. If the mouse gives up more quickly, the researchers interpret that as a sign of despair or hopelessness. So, following an intervention, if the mice show a little more spunk and struggles for longer, researchers take that as a sign that the intervention reduces depression.
Some critics have pointed out that we don’t know what is motivating the mouse’s behavior. And it’s entirely possible that we are projecting our own feelings onto that mouse. For example, a mouse may stop struggling not because they are feeling despair but because they perceive the struggle to be useless and are conserving their energy. That way, if the situation changes they will not have worn themselves out with pointless struggle.
However, this study looked at more than just the behavior of the mice. They also looked at their brain chemistry, and found that the lycopene appeared to boost levels of a specific protein in the brain, one that is often lower in people suffering from depression. The researchers hypothesize that lycopene’s effects on this particular brain pathway could be one of the mechanisms behind the anti-depressant effects that they observed.
So, what do we do with this information? Although we are certainly living through some stressful times, I think it’s a little too soon to rush out to the vitamin store for a bottle of lycopene as a hedge against despair and hopelessness. Let’s let the researchers continue to do their research (assuming their funding hasn’t been canceled.)
And in the meantime, this study offers a potential explanation for why diets higher in fruits and vegetables are linked to better mental health in humans. Because they are!
Let’s look at the bigger picture. Lycopene is a single nutrient. And no single compound (or food) is likely to be a magic bullet for depression. But researchers have found that overall dietary patterns definitely play a role in supporting mental well-being.
One of the most well-studied diets in this arena is the Mediterranean diet, which is rich in fruits, vegetables (so: lycopene? check!) as well as whole grains, legumes, nuts, fish, and healthy fats like olive oil. Several really big studies have found that people who follow a Mediterranean-style diet tend to have lower rates of depression and anxiety compared to those who eat a more processed, Western-style diet.
Now, we are talking about correlations here, which don’t prove that diet directly prevents depression. So let’s look at the potential mechanisms. Given what we know about nutrients and how they act in the body, how could our diet support mental health?
We know that polyphenols (compounds found in various plant foods) reduce inflammation and improve neurotransmitter function. And now we know that lycopene boosts certain brain proteins associated with better mood. Omega-3 fatty acids, found in fatty fish like salmon, as well as flax, chia, and walnuts, keep brain cells healthy and flexible. And diets high in fiber support a healthy gut microbiome, which we know is involved in mood regulation. So, not only can we see an association between certain dietary patterns and mental health, but it’s also plausible that these foods and eating patterns would have these effects.
I think this suggests that, instead of trying to isolate single “depression-fighting” nutrients, the best strategy is to focus on a balanced, nutrient-dense diet. But I want to zoom out even further. Because, although diet may well play a role, it would be both irresponsible and overly simplistic to suggest that depression or other mental health challenges are purely a matter of nutrition.
Mental health is complex, and many factors influence it beyond what’s on our plates. Lifestyle factors like sleep, physical activity, and the activities and substances that we may use to cope all play a role. And zooming out yet again, societal factors like isolation, economic security, access to healthcare are all part of this puzzle as well–and these are not necessarily things that can be solved with more salad!
That’s the 30,000 foot view. As we wrap up here, let’s dive back down to the 30-foot view: The study that prompted today’s episode provides some interesting insights into lycopene’s role in supporting brain health. But it’s also a valuable reminder of the role that a healthy diet plays in supporting our mental health.
And while so much of the research focuses on the Mediterranean diet, which reflects foods available in a very specific part of the world, rest assured that you can build a healthy diet using foods from every culture and corner of the world. The common denominators are lots of fruits and vegetables, legumes, and whole grains, nuts, seeds, and healthy fats–ideally prepared in ways that you truly enjoy.
That's all for this episode. If you have a question you'd like me to answer or a study you’d like me to review, you can email me at nutrition@quickanddirtytips.com You can also leave me a message at 443-961-6206
And If you’d like to find out about having me speak at your next live or virtual event, you can learn more at wellnessworkshere.com
Nutrition Diva is a Quick and Dirty Tips podcast. Our team includes Brannan Goetschius, Nathan Semes, Davina Tomlin, Holly Hutchings, Morgan Christianson.and Nate Hoopes.
Thanks for listening! I'll see you next week.