According to the World Health Organization, depression is now the leading cause of ill health and disability worldwide,1,2 affecting an estimated 322 million people globally, including more than 16 million Americans, 6 million of which are seniors.3
Statistics also reveal we're not being particularly effective when it
comes to prevention and treatment. Worldwide, rates of depression
increased by 18 percent between 2005 and 2015.4
If you or someone you love is struggling with depression or some other
mental health problem, remember that your diet is a foundational aspect
that must not be overlooked. As noted in a 2015 study5 published in the medical journal Lancet: "Although the determinants of mental health are complex, the
emerging and compelling evidence for nutrition as a crucial factor in
the high prevalence and incidence of mental disorders, suggests that
diet is as important to psychiatry as it is to cardiology, endocrinology
and gastroenterology." Recent research6,7,8
looking at the effects of the antihypertensive DASH diet on mental
health concluded this kind of dietary pattern, which is low in sugar and
high in fresh fruits and vegetables, can help reduce the risk of
depression in seniors. Overall, people who followed the DASH diet were
11 percent less likely to develop depression over the following six
years, whereas those following a standard Western diet, high in red meat
and low in fruits and vegetables, had the highest rates of depression. It's worth noting that while many conventional experts recommend the
DASH diet, it is not necessarily ideal for optimal health, as it also
promotes whole grains and low-fat foods, including low-fat dairy.
Healthy fats, including saturated animal and plant fats and animal-based
omega-3, are quite crucial for optimal brain health. I believe the
reason the DASH diet produces many beneficial results is because it is
low in sugar and high in unprocessed foods — not because it's low in
fat. Other studies have shown that unprocessed foods, especially fermented foods, help optimize your gut microbiome, thereby supporting optimal mental health,9,10 whereas sugar, wheat (gluten) and processed foods have been linked to a greater risk for depression, anxiety
and even suicide. The primary information highway between your gut and
your brain is your vagus nerve, which connects the two organs.11
Your gut also communicates to your brain via the endocrine system in the
stress pathway (the hypothalamus, pituitary and adrenal axis), and by
producing mood-boosting neurotransmitters like serotonin, dopamine and
gamma-aminobutyric acid or GABA. These communication links help explain
why your gut health has such a significant impact on your mental health.
A number of food ingredients can cause or aggravate depression, but
one of the most significant is sugar, particularly refined sugar and
processed fructose.12
For example, in one study, men consuming more than 67 grams of sugar
per day were 23 percent more likely to develop anxiety or depression
over the course of five years compared to those whose sugar consumption
was less than 40 grams per day (which is still far higher than the 25
grams per day recommended for optimal health).13
This held true even after accounting for other contributing factors, such as socioeconomic status, exercise, alcohol use, smoking, other eating habits, body weight and general physical health. Lead author Anika Knüppel,14
a research student in the department of epidemiology and public health
at University College London, commented on the findings, saying:15
"Sweet food has been found to induce positive feelings in the
short-term. People experiencing low mood may eat sugary foods in the
hope of alleviating negative feelings. Our study suggests a high intake
of sugary foods is more likely to have the opposite effect on mental
health in the long-term."
Research16
published in 2002, which correlated per capita consumption of sugar
with prevalence of major depression in six countries, also found "a
highly significant correlation between sugar consumption and the annual
rate of depression." A Spanish study17 published in 2011 linked depression specifically to consumption of baked goods. Those
who ate the most baked goods had a 38 percent higher risk of depression
than those who ate the least. This makes sense when you consider baked
goods contain both processed grains and added sugars.
The Compelling Link Between Food and Mood
The Strong Link Between Sugar and Depression