The role of nutrition in the development of mood disorders has recently become a central focus of clinical research. In recent years, public awareness of the intimate relationship between the brain and mental wellbeing has increasingly grown. The high metabolic and nutrient demands of the brain — which consumes 20% of a person’s daily caloric intake — suggest a connection between dietary choices and cognitive function, sparking a multitude of studies seeking to determine the specific connections of nutrients and mood disorders.
While medical experts have long known of the correlation between psychological and physical health, mental illness was not considered a major risk factor for cardiovascular disease—until a recent series of research confirmed that depression may serve as one of the most significant causes of heart problems.
Approximately 350 million people suffer from depression globally, according to data from the World Health Organization. According to new research, the risk of fatal heart disease in men due to depression is almost the same as the risk from elevated cholesterol levels, obesity, and smoking. The findings further pointed to a greater need for heart health screenings among patients with depression, in addition to mental health checks for patients with cardiovascular disease.
The causality is twofold, as patients with pre-existing heart disease conditions are more likely to become depressed due to their poor health and otherwise healthy people diagnosed with depression are likewise significantly more apt to develop heart disease, compared to the general population. Viewed across the population, depression accounts for roughly 15% of cardiovascular deaths—comparable to the other known risk factors.
A professor of medicine at Harvard Medical School, Ahmed Tawakol, has conducted extensive research surrounding the connection between stress and heart health, stating that only over the past few decades “has mounting evidence suggested that stress and depression may be more than simple markers of heart disease; they might be important causes.”
While it remains unclear exactly how depression impacts heart health, it is likely that stress hormones play a critical role. Yet leading a healthy lifestyle—including diet, physical activity, managing stress, being smoke-free—is known to be effective in preventing and treating both depression and heart conditions.
At A4M/MMI, we believe that all of the body’s systems are interrelated, and function through a consistent mind-body connection. Indeed, recent research indicates that the intimate ties between mental health and physical disease represent a dual diagnosis rooted in concrete, tangible evidence.
While doctors once believed that the link between mental and physical health problems was purely behavioral, scientists are now learning that “seemingly unrelated psychological and physical issues” may have close connections and correlations. There is a physiological change that additionally occurs: a new study that focuses on the physical and mental health of people afflicted with psoriasis, a dermatological autoimmune disease that results in red, flaky scales and patches on the skin’s surface, demonstrates that depression is common among these people, due to social stigma and discomfort.
Still, researchers also found that patients with psoriasis and a diagnosis of depression were 37% more likely to develop psoriatic arthritis—a complication that involves joint inflammation—than those without depression. Authors articulate that depression can spur behaviors that act as triggers for the condition, or exacerbate pre-existing causes. For those with a genetic predisposition to the disease, factors such as poor nutrition and physical inactivity can negatively impact the severity of the symptoms. Yet the association still held when authors controlled for many of these behaviors, which suggests that the root cause of the depression has a direct influence on the development of psoriatic arthritis.
Research over the last several decades has demonstrated that inflammation in the body—one of the primary triggers of psoriatic arthritis—can also drive the development of depression. The processes are now known to be similar to those that drive some physical illnesses, as well. Moreover, elevated levels of the stress hormone cortisol may link psychological and physical conditions, as high levels of cortisol areas associated with depression and can likewise contribute to an inflammatory state—and conditions like diabetes and heart disease.
Previous studies have confirmed the link between depression and an increased risk of conditions like stroke and diabetes, while a study last year found that depressed mood was as strong a predictor of heart disease as other well-known risk factors, like high cholesterol and obesity. Other mental-health diagnoses, including bipolar disorder and schizophrenia, have synonymously been associated with increased risks of physical health problems.
The silver lining, however, is that treating depression and other comorbid mental health conditions may help improve overall physical symptoms, or reduce the risk of future problems—particularly if doing so can ultimately lower cortisol levels, and other markers of inflammation. Correspondingly, treating physical illnesses and controlling symptoms can help improve general mental health.