London’s Gatwick airport intends to make flying a little less miserable. Last month, the airport announced that its terminal restaurants were working with a nutritionist to design meals chock-full of serotonin, a mood-influencing neurotransmitter believed to be important to feelings of well-being (the most common antidepressants, SSRIs, are designed to increase serotonin levels). 

These meals, indicated by a smiley face on menus, include ingredients like salmon, chickpeas, bananas, and oats, according to The Telegraph“Happiness is a complex thing," airport nutritionist Jo Travers told the British newspaper, "but there are certain foods that will help the ‘happy’ chemicals in your brain to keep flowing.”

But don’t expect to find a newfound joy in flying after grabbing a banana and a salmon salad. The chemical cocktail of happiness is a little more complicated than that, and eating serotonin isn’t going to lift your mood. 

While eating healthy at the airport might help you feel a little better than hitting up McDonald's (just as it would on a normal day), a lot of serotonin in your stomach doesn’t translate into serotonin in your brain. “Although it is true that bananas contain serotonin, it does not cross the blood–brain barrier,” Simon Young, a professor emeritus of psychiatry at McGill University, wrote in a 2007 study on the neurotransmitter. 

The same may be the case for other chemicals rumored to have anti-depressant qualities, like tryptophan (the chemical in turkey and other foods like cheese, soybeans, and egg whites). The amino acid is key to producing serotonin in the brain, but Young argues that “although purified tryptophan increases brain serotonin, foods containing tryptophan [like turkey] do not.”

However, α-lactalbumin, a whey protein in milk with a high tryptophan content, has been shown to improve people’s ability to cope with stress. The best way to get that protein is through breast milk, where it’s the dominant protein. Unfortunately, regular cow’s milk has it in much lower concentrations.

And some studies have found that in adolescents, better nutrition can translate into better behavior. In a study of violent young adult prisoners ages 18 to 21, kids who received food supplements with all their daily requirements of vitamins, minerals, and essential fatty acids committed 26 percent fewer offenses than kids who received a placebo. 

The links between nutrition and chemical happiness are complex, and eating a nutrition-rich food like salmon isn’t quite the same as taking an anti-depressant. That doesn’t mean you shouldn’t opt for a healthy salad instead of a burger and fries at the airport. Just don’t expect to be skipping down the terminal to your plane afterward.