Positive psychological well-being seems to be associated with reduced risk of physical illness, and prospective studies that follow individuals over time have found that people starting out happier may indeed end up healthier and less likely to get sick. As it appears that mental health plays a part in physical health, it’s crucial that the food we eat supports our mind and our body. Common foods from leafy green vegetables to a basic garden-variety tomato may positively affect our brain chemistry. In fact, even simply smelling the common spice saffron may improve your emotional state.

Studies on the emotional health and mood states of those eating plant-based diets suggest that eating less meat may not only be good for us physically, but good for us emotionally, too. Researchers employed two psychological tests, the Profile of Mood States (POMS) and the Depression and Anxiety Stress Scale (DASS). POMS measures levels of depression, anger, hostility, fatigue, and confusion, while DASS gauges other negative mood states as well, including hopelessness, lack of interest, anhedonia (lack of pleasure), agitation, irritability, and impatience with other people. Subjects eating plant-based diets appeared to experience significantly fewer negative emotions than omnivores.

Many plant foods, including apples, berries, and onions, contain phytonutrients that appear to naturally inhibit the monoamine oxidase (MAO) enzyme, as do such spices as cloves, oregano, cinnamon, and nutmeg. MAO controls an important class of neurotransmitters called monoamines, which includes serotonin and dopamine. People who are depressed appear to have elevated levels of the MAO enzyme in their brains, and it has been theorized that depression may be caused by abnormally low levels of monoamine neurotransmitters. This may help explain why those eating plant-rich diets appear to have lower rates of depression. Even on a day-to-day basis, studies have shown that the more fruits and vegetables we eat, the happier, calmer, and more energetic we may feel that day and the next.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.

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