The Valentine’s treat that boosts mood in more ways than one

This month, you may be thinking about getting someone a box of chocolates for Valentine’s Day. It’s a heartfelt way to bring joy to a loved one’s life…and not only symbolically. 

In fact, over the years, I’ve written about studies showing that dark chocolate improves mood not only on an emotional level, but also on a physiological level. And now, a new study reveals how chocolate does just that.1 

Surprisingly, it has more to do with the GUT than the brain…or the heart. 

South Korean researchers recruited 48 healthy young adults and divided the participants into three groups. For three weeks, one group ate an ounce per day of chocolate with 70 percent cacao content. The second group ate an ounce a day of chocolate with 85 percent cacao. The third group didn’t eat any chocolate at all. 

All of the participants took tests assessing their moods and emotional states throughout the study. And results showed that mood scores significantly improved in the 85 percent cacao group, but not in the 70 percent cacao group or the non-chocolate group.  

And I have to say, this isn’t surprising. Other research I’ve reported on shows the MORE cacao content in chocolate, the BETTER its health benefits.  

But the researchers also discovered something totally intriguing… 

Along with the mood assessments, the researchers analyzed the probiotics (good bacteria) in all of the participants’ gastrointestinal (GI) microbiomes.  

And they found that in the 85 percent cacao group, a probiotic associated with improved mood—Blautia obeum—was elevated. The researchers said other studies show that the GI microbiomes of healthy people are also higher in this specific type of probiotic, compared to people with psychological and cognitive disorders.   

Ultimately, the researchers believe that dark chocolate acts as a prebiotic, feeding and nurturing this mood-boosting probiotic.  

This makes perfect sense to me. As the GI microbiome’s wide-ranging role in human health becomes better understood, we’re learning more about the gut-brain axis—or how a probiotic in your GI tract can have a direct influence on the emotional and psychological centers in your brain.  

We’re also learning how diversity of probiotics is key for good health—which is another reason why taking single strains of probiotic bacteria in pills doesn’t make sense. Instead, you should support all of the good bacteria in your gut through probiotic and prebiotic FOODS (see the sidebar for my suggestions).  

Bottom line: Giving chocolate (as long as it has at least 85 percent cacao content) to help improve emotional states and mood for Valentine’s Day (or any other day) has a basis not only in romance—but also in modern science. So go ahead and indulge! 


1“Consumption of 85% cocoa dark chocolate improves mood in association with gut microbial changes in healthy adults: a randomized controlled trial.” J Nutr Biochem. 2022 Jan;99:108854.