A review article published last month in the journal European Neuropsychopharmacology details the emerging evidence on how our diets affect our moods and mental well-being.
It makes sense, the researchers write, because “the composition, structure, and function of the brain are dependent on the availability of appropriate nutrients.” People with specific mental health conditions — including epilepsy, depression, and anxiety — may need to alter their diets in different ways. Here’s what the research has shown to date:
- Several credible systematic reviews have shown that a diet rich in fresh fruits and vegetables, whole grains and lean proteins can help to improve overall mood and general feelings of happiness; it can also reduce symptoms of depression.
- Specific diet interventions can help improve the symptoms of some mental health disorders. For example, there is credible evidence that the ketogenic diet, which cuts back on carbohydrates and focuses on calories from protein and fat, reduces the frequency of seizures in children with epilepsy.
- Not getting enough of a specific nutrient can affect your mental health. For example, a deficiency in vitamin B12 leads to fatigue, lethargy, depression, poor memory, and is associated with mania and psychosis. When pregnant women don’t get enough folic acid, their children can have developmental problems, and those children are more likely to develop depression as adults. And not getting enough niacin can lead to dementia, diarrhea, and itchy skin.
- There is clear evidence that diet has an effect on cognitive function later in life, the researchers write, even though we still don’t understand how this works in the body. Still, evidence shows that the Mediterranean diet — which focuses on whole foods and lean proteins and cuts out processed foods and sugars — is associated with higher levels of cognitive function later in life. And that diets high in sugar and fat lead to cardiometabolic diseases, which have negative effects on cognition.
A new study in mice led by UCLA biologists strongly suggests that serotonin and drugs that target serotonin, such as anti-depressants, can have a major effect on the gut’s microbiota — the 100 trillion or so bacteria and other microbes that live in the human body’s intestines.
Serotonin — a neurotransmitter, or chemical messenger that sends messages among cells — serves many functions in the human body, including playing a role in emotions and happiness. An estimated 90% of the body’s serotonin is produced in the gut, where it influences gut immunity.
The team — led by senior author Elaine Hsiao and lead author Thomas Fung, a postdoctoral fellow — identified a specific gut bacterium that can detect and transport serotonin into bacterial cells. When mice were given the antidepressant fluoxetine, or Prozac, the biologists found this reduced the transport of serotonin into their cells. This bacterium, about which little is known, is called Turicibacter sanguinis.”
“In rats that show depressive-type behavior in a laboratory test, we found that stress changes their gut microbiome–the population of bacteria in the gut,” said study leader Seema Bhatnagar, PhD, a neuroscientist in Department of Anesthesiology and Critical Care at Children’s Hospital of Philadelphia (CHOP). “Moreover, when we transplanted bacteria from those stress-vulnerable rats into rats that had not been stressed, the recipient animals showed similar behavior.”
Bhatnagar added that stress also increased inflammation in the brains of vulnerable rats and that this inflammation appeared in unstressed rats after they received transplants from vulnerable animals.
The study team published its findings online March 4, 2019, in Molecular Psychiatry.”
“Changing your nutrition can be a great addition to traditional therapy, like CBT and medication, [but it] comes at a much smaller cost and can be a great way to self-care,” says Anika Knüppel, researcher and PhD student at University College London and contributor to the European MooDFOOD program, which focuses on preventing depression through food.
There are two ways nutritional interventions can help mental health: by increasing healthy habits and reducing unhealthy ones. For the best outcome, you have to do both, says Knüppel.
Try It: Mediterranean Diet
- Get your starch fix with whole grains and legumes.
- Fill up on plenty of fruits and veggies.
- Focus on eating fatty fish, like salmon or albacore tuna, in place of red meat.
- Add in healthy fats, like raw nuts and olive oil.
- Enjoy sweets and wine in moderation.
The Mediterranean diet is more about what you’re adding in — fresh fruits and vegetables, protein-rich legumes, and fatty fish and olive oil (high in omega-3s).
One study looked at 166 people who were clinically depressed, some being treated with medication. The researchers found that after 12 weeks of eating a modified Mediterranean diet, the participants’ symptoms were significantly better.
An earlier study from 2011Trusted Source found that when medical students increased their omega-3 fatty acid intake, their anxiety reduced by 20 percent (though with no changes to depression), while in 2016, Spanish researchers found people who followed the Mediterranean lifestyle closest were 50 percent less likely to develop depression than those who didn’t follow the diet as well.
Try It: DASH Diet
- Embrace whole grains, vegetables, and fruit.
- Get protein from chicken, fish, and nuts.
- Switch to low-fat or nonfat dairy.
- Limit sweets, sugary drinks, saturated fats, and alcohol.
Alternatively, the DASH diet is about what you’re taking out, namely sugar.”