We know that food affects the body -- but could it just as powerfully impact the mind?

While the role of diet and nutrition in our physical health is undeniable, the influence of dietary factors on mental health has been less considered. That may be starting to change.

For the first time, a report by a task force advising on new dietary guidelines, commissioned by the departments of Health and Human Services and Agriculture, included a point considering the possible role of diet in mental health outcomes. The USDA and HHS report notes, for example, that the American Psychiatric Association classifies omega-3 fatty acids (which are most commonly found in oily fish) as a complementary treatment for depression. However, the advisory panel concluded, for now, that the research was too limited to make policy suggestions.

Some psychiatrists, too, have recently launched a rallying cry for a more integrative approach to mental health care -- one that takes diet and other lifestyle factors into account in diagnosing, treating and preventing mental illness. In a paper recently published in The Lancet Psychiatry, an international group of scientists (all members of the International Society for Nutritional Psychiatry Research) argue that diet is "as important to psychiatry as it is to cardiology, endocrinology and gastroenterology."

With over 450 million people globally suffering from some form of mental disorder and a pharmacological approach having achieved only limited success in treating debilitating mental health conditions, the field of psychiatry may be reaching a sort of tipping point.

"We're now facing this huge epidemic of mental health disorders," one of the paper's authors Dr. Drew Ramsey, an integrative psychiatrist at Columbia University and author of Fifty Shades of Kale, told The Huffington Post. "Depression is the leading cause of disability in the world and soon it will be the leading cause of disability in America. So, as somebody who treats depression, it's of great interest when we see a data signal that suggests that we can treat depression by focusing on nutrition and what we eat."

Ramsey and colleagues' paper cites a number of studies attesting to the vital role of certain nutrients in brain health, including omega-3s, Vitamin D, B vitamins, zinc, iron and magnesium. The modern diet, while dense in calories, tends to be lacking in these important nutrients, which may be contributing to the rise in mental health conditions. Many studies have linked depression with low levels of key B vitamins, for instance, while low maternal Vitamin D levels have been found to play a role in the child's risk of developing schizophrenia.

The research has been mounting in recent years, and has expanded from a focus on individual nutrients to dietary patterns more broadly. In 2011, a large study found the modern Western diet (which is high in processed, high-calorie and low-nutrient foods) to be linked with increased depression and anxiety, as compared to a traditional Norweigan diet. 2014 review of studies, too, linked unhealthy dietary patterns with poor mental health and children and adolescents.

"For a long time in psychiatry, we've known that individual vitamins can have a big impact on mental health -- vitamin B12, iron, magnesium -- but really in the past 10 years, studies have begun to look more at dietary patterns, and that's been quite revealing," said Ramsey.

Growing evidence of the brain-gut connection also lends support the hypothesis that when it comes to mental health, food matters. The idea that there might be a significant link between gut health and brain health -- and that gut bacteria imbalances in a number of neurological conditions, including anxiety, depression, autism, ADHD and schizophrenia -- has gained steam in the scientific community. A 2014 neuroscience symposium even called the investigation of gut microbes a "paradigm shift" in brain science.

"The idea that brain health depends on gut health... that's certainly the next wave of this," Ramsey noted.

However, up to this point, the traditional line of treatment for mental heath problems has been pharmaceutical interventions or treatments like talk therapy, or some combination of the two. Diet and exercise are rarely taken into consideration, except by "alternative" practitioners. Bringing diet into the equation would represent a major shift in the field of mental health care, opening up new modes of treatment and low-cost, low side-effect interventions for individuals suffering from a range of mental health concerns.

"Food should be the first line of defense because it's a foundational treatment," said Ramsey. "We really need to move away from thinking of things like diet and exercise as 'complementary' or 'alternative.' That's really bad thinking that's gotten psychiatry into trouble."

Of course, it's important to remember that the causes of mental health problems are complex, and can span psychological, biological, emotional, environmental and dietary factors. But improving one's diet with brain-healthy nutrients can only support mental and neurological health.

"A well-nourished brain is going to be more resilient," says Ramsey. "Being a modern human is stressful. There are a lot of demands for our attention and we're exposed to a lot more trauma ... Through diet, over time you make the brain more resilient."