Embracing a vegetarian diet could make you happier and less stressed.
The reason comes down to fatty acids: Diets that include meat and fish are higher in arachidonic acid (AA), an animal source of omega-6 fatty acids. The average omega-6 to omega-3 fatty acid profile of modern grain-fed meat is 5 times higher than grass-fed meat, like our ancestors ate. And previous research has shown high levels of AA can cause mood-disturbing brain changes.
High-fish diets also mean higher levels of long-chain, or omega-3 fatty acids, like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Both EPA and DHA combat the negative effects of AA. High dietary levels of omega-3 fatty acids are linked to better brain health, better mood and a host of other health benefits. Most health experts recommend an omega-6/omega-3 ratio of about 4:1.
In theory, then, frequent fish eaters should have be protected against the damaging effects of AA because of their higher intake of omega-3 acids. But an recent study found omnivores reported significantly worse moods than vegetarians, despite higher intakes of EPA and DHA.
In this follow-up study, 39 meat-eating participants were assigned to one of three diets. A control group ate meat, fish or poultry daily; a second group ate fish 3-4 times weekly but no meat; and a third group ate strictly vegetarian. After two weeks, mood scores were unchanged for the fish- and meat-eating groups, but vegetarians reported significantly better moods and less stress.
“Restricting meat, fish, and poultry improved … short-term mood state in modern omnivores,” the researchers concluded.