“Plant-Based Diets for Improved
Mood and Productivity” A 2014 systematic review and
meta-analysis of dietary patterns and depression concluded that a healthy
diet pattern was significantly associated with the reduced odds of depression. But out of the 21 studies they could
find in the medical literature, they were only able to find one
randomized controlled trial, considered the study design that
provides the highest level of evidence. And it was the study I profiled in
“Improving Mood Through Diet”, in which removing meat,
fish, poultry and eggs improved several mood
scores in just two weeks. We’ve known those eating plant-based
tend to have healthier mood states— less tension, anxiety, depression,
anger, hostility and fatigue, but you couldn’t tell if
it was cause and effect until you put it to the test,
which they finally did. But what could account
for such rapid results? Well, eating vegetarian does give
you a better antioxidant status, which may help with depression. Also, as I’ve previously addressed, how consumption of even a
single carbohydrate-rich meal can improve depression, tension, anger,
confusion, sadness, fatigue, alertness, and calmness scores among patients
with PMS, but what about long term? Overweight men and women were
randomized into a low carb, high fat diet or high carb, low fat diet for a year. By the end of the year, who had less
depression, anxiety, anger and hostility, feelings of dejection,
tension, fatigue, better vigor, less confusion
or mood disturbances? The low carb dieters are
represented by the black circles, and the low fat dieters
are represented in the white. These sustained improvements
in mood in the low fat group compared with the low carb group are consistent with results
from epidemiological studies showing that diets high in carbohydrate
and low in fat and protein are associated with lower
levels of anxiety and depression and have beneficial effects
on psychological well-being. The overall amount of fat in their diet
didn’t change in this study, though. But the type of fat did. Their arachidonic acid
intake fell to zero. Arachidonic acid is an
inflammatory omega-6 fatty acid that can adversely impact mental health
via a cascade of neuroinflammation. It may inflame our brain. High blood levels in the bloodstream
have been associated with a greater likelihood
of suicide risk, for example, and major depressive episodes. How can we stay
away from the stuff? Well, Americans are exposed
to arachidonic acid primarily through
chicken and eggs. But when you remove chicken
and eggs, and other meat, we can eliminate preformed
arachidonic acid from our diet. So while high-quality treatment studies
investigating the impact of diet on depression are scarce, there
is that successful 2-week trial, but even better:
How about 22 weeks? Overweight or diabetic employees
of a major insurance corporation received either weekly group instruction
on a whole food plant-based diet or no diet instruction
for five and a half months. There was no portion size restriction,
no calorie counting, no carb counting. No change in exercise. No meals were provided, but the
company cafeteria did start offering daily options such as lentil soup,
minestrone, bean burritos. No meat, eggs, dairy, oil or junk, yet
they reported greater diet satisfaction compared with the control group
participants who had no diet restrictions. How’d they do though? More participants in the
plant-based intervention group reported improved digestion, increased
energy, better sleep than usual at week 22 compared
with the control group. They also reported a significant
increase in physical functioning, general health, vitality,
and mental health. Here are the results
presented graphically, where the plant-based group beat out
controls on nearly every measure. There was also significant
improvements in work productivity, thought to be due in large part
to their improvements in health. So what this study demonstrated was
that a cholesterol-free diet is acceptable, not only in research settings, but
in a typical corporate environment, improving quality of life
and productivity at little cost. All we need now is a large,
randomized trial for confirmation, but we didn’t have
such a thing, until now. Ten corporate sites across the country
from San Diego to Macon, Georgia. Same kind of set up as before. Can a plant-based nutrition program
in a multi-center, corporate setting improve depression, anxiety,
and productivity? Yes. Significant improvements
in depression, anxiety, fatigue, emotional well being,
and daily functioning. Lifestyle interventions have
an increasingly apparent role in physical and mental health,
and among the most effective of these is the use
of plant-based diets.