It is well known that the quality of the food we eat is closely linked to our physical health. Cardiovascular disease, diabetes, obesity and even some form of cancer are influenced by what we eat.
Research also tells us that there is a strong link between mental and physical health. People who suffer from heart disease, diabetes or obesity, are more at risk of developing depression as they condition brings limitations and discomfort in their lives. Likewise, people who suffer from depression or other conditions such as schizophrenia or bipolar disorder, may end up spending more time indoors and being inactive, hence becoming more at risk of developing physical diseases, such as cardiovascular disease, heart disease, diabetes and obesity.
But there’s more, recent studies have revealed that what we eat has also a direct influence on our mental health. Research shows that mental disorders are not exclusively limited to the brain. The immune system and gut microbiota, for example, can affect the health of our brain and our overall well-being proving that the connection between what we eat and our mental health is rather strong.
From the data we have today it’s quite apparent that the quality of our diet is linked to our risk for depression and dementia and this starts early on. What our mothers ate when pregnant, what we as children ate in the first few year of life and later on in life, can greatly influence our mental health and emotional regulation.
Studies found that the relation between the risk of depression and how depressed teenagers can become is linked to their diets, independently of things like family conflict and socio-economic status. In fact, just half of all mental disorders start before the age of 14, so this is why it’s very important we implement healthy food choices not just for ourselves but also for our children.
Of course, there are many other factors that contribute to mental disorders such as genetics, early life trauma, life stress, poverty and disadvantage. However, these are perhaps the ones that are more difficult to control and alter, whereas we can control our diet as well as how much exercise we do.
Defining mental health and mental disorders
First of all, to make sure we are all on the same page, let’s define mental health.
According to the World Health Organization (WHO), mental health is “a state of well-being in which every individual realizes his or her own potential, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community.”
Ok, so what is a classified as a mental disorder?
The World Health Organization (WHO) define mental disorders as “comprising a broad range of problems, with different symptoms. However, they are generally characterized by some combination of abnormal thoughts, emotions, behaviour and relationships with others. Examples are schizophrenia, depression, intellectual disabilities and disorders due to drug abuse. Most of these disorders can be successfully treated.”
It is estimated that we all experience some form of mental illness at some point in life. The intensity of it can vary hugely, from a short period of stress to persistent forms of depression and anxiety. Some less acute forms of mental illness can sometimes be overcome with self-help but other forms require adequate attention and support. Sadly, often what prevents many from getting the right help is the stigma that is associated with mental illness.
“The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge”
Stephen Hawking
To demystify and help remove this stigma, I think it’s important to take a closer look to truly understand how rather common mental illness can be. Perhaps the most common mental health and brain disorder is depression. According to the World Health Organization (WHO), depression affects approximately 300 million people worldwide and is currently one of the leading causes of disability. Recurring symptoms include low mood, mood swings, loss of interest, irritability, feeling tired, changes in appetite and sleep and bodily complaints or fatigue without defined physical problems.
But there are many other brain disorders which include anxiety, substance-related or addictive disorders, bipolar affective disorder, schizophrenia, other psychoses, and neurodevelopmental and neurodegenerative disorders, such as autism and dementia.
There are many causes that can lead to mental illness and here are some of them:
- Genetic factors: the complexity of genetics is huge and it is still been studied today.
- Psychological factors: our personal resilience, self-esteem, optimism and self-confidence can act as moderators of mental states and this means they can help decrease the risk of developing mental illness and support trauma-related recovery.
- Environmental factors: these include factors such as parental mental health but it can also include exposure to neurotoxic substances such as mercury, lead or pesticides as well as drugs and alcohol abuse which are known to be detrimental to the human brain.
- Social factors: status, economic situation, education and access to care and support can hugely affect mental health. This means that areas of social disadvantage with low levels of education and unemployment, poverty and hostile household are the ones most at risk.
There is a lot of evidence showing that lifestyle factors have an impact in the development and progression of many negative states on the mental health. These factors include: alcohol and substance use, poor sleep, physical activity and… diet!
Although mental disorders are of a very complex nature, in this article we will concentrate on the how mental health can be improved though the quality of our diet.
How the quality of our diet influences our mental health
Evidence shows that many mental and brain states are linked to immune system and inflammation.
The gut regulates the immune system via a bi-directional communication between gut and brain. Most of the signals go to the brain but about 10% go to the gut. For example, when we are stressed, stress affects out gut and as the gut is under stress it affects our mental health.
Our immune system is also designed to get into action when there’s an injury or infection in order to fight and repair the body. However, modern Western-style diets (which are high in processed meats and foods with added sugar, salt and fat) have a pro-inflammatory impact on the body. They create inflammation which is essentially a low-grade chronic activation of the immune system. What happens then? Studies have shown that the molecules that are released are consistently linked to an increased risk for many diseases including cardiovascular disease, diabetes, cancers, common mental disorders, dementia and Alzheimer’s disease.
But when we look into it deeper, it gets even more interconnected. The microorganisms living in the gut are collectively known as the gut microbiota. In recent years, the gut microbiota has been considered as an important biological key in impacting human health and disease. Then there’s the gut microbiome which includes all of the microorganisms in the gut microbiota and their genetic make-up. The latest research links the gut microbiome to metabolism, immune functions and autoimmune diseases, as well as…hear hear… mental and brain health. Some studies have been able to show that, in Alzheimer’s disease, the gut microbiota is different. And the same factors that impact the gut microbiome impact someone’s risk of developing a neurodegenerative disease such as Alzheimer’s disease. From the data available we can see that the gut microbiota composition is affected by age, health state or medication use and that it is linked to different mental states, such as stress, depression, anxiety, and serious mental disorders, such as schizophrenia and bipolar disorder. We also know that the microbiota is dictated not only by what we eat but also by things like exercise, sleeping patterns, smoking and hygiene practices. Once again, this should be a viewed as a reminder of the importance of eating healthily alongside doing regular exercise.
Perhaps even more fascinatingly, 10/15 years ago, neuroscientists found that diet has a very direct effect on hippocampal volume and in its functionality. And what is the hippocampus responsible for? It’s a region of the brain that is associated primarily with memory and key to learning. In other words, the plasticity of the hippocampus and our ability to retain memory and continue to learn is also affected by the quality of our diet.
Interestingly, the Mediterranean and Nordic diets, which are high in plant-based food and fish, are consistently associated with a decrease in pro-inflammatory response which, in turns, suggest they may decrease the risks of mental illness and support cognitive functions. Also, diets that are high in fibre from whole grains, vegetables, fruit, legumes, seeds and nuts have also been shown to support immune functioning. The other common components of the Mediterranean diet are use of olive oil, moderate consumption of dairy, low consumption of red and processed meat and increased consumption of fish. What’s interesting about this is that many of these components are thoughts to prevent or improve inflammation and improve depressive symptoms.
Eating behaviours
In 2017, the Global Burden of Disease (GBD) carried out a truly insightful project and published a paper that analysed 15 selected dietary risk factors in adults aged 25 years or older across 195 countries from 1990 to 2017. The massive amount of data collected showed that, world-wide, we don’t consume enough whole grain, fruit, vegetables, legumes, nuts and seeds. It also found that we overconsume processed meat, sugar-sweetened beverages, and sodium (salt). How is this relevant? Well, rather shockingly, the study showed that in 2017 alone there have been 11 million diet-related deaths. The two main leading causes? High consumption of sodium, which caused 3 million deaths, low intake of whole grains which caused 3 million deaths, and low intake of fruit, which caused 2 million deaths.
You can see why, in a world where poor diet and poor mental health are the leading causes of mortality and diseases worldwide, there is growing interest around this subject.
So, what influences what we eat or don’t eat? Eating behaviours are not just driven by huger (I is hungry = I shall devour whatever I can find) and biological needs which are dependent on how active we are, but by a variety of many other reasons. These can be personal beliefs, knowledge and education but also dictated by social views such as culture, ethnicity and religion. But they can also be environmental, such as seasonal availability and finally economic, so dependent on cost and personal income.
One thing is clear though: in the western world, where food is not scarce nor does it need to be hunted but rather readily available, our eating attitudes are a complex combination of many of the reasons above listed and often move in periodical trend and mood waves.
Micro, Macro, Diets…pffffff…. Choose a whole diet!
Food is comprised of macro and micro nutrients. The reason I am often so dismissive about explaining in depth the difference between macro and micro nutrients and which vitamin is present in which food is because we should not think of isolated nutrients at all! Food should instead always be considered in its complexity because the various nutrients in foods interact with each other and they behave very differently when isolated. Focusing on a whole-diet approach and a whole-diet quality is a far better way to look at nutrition!
Diets are another big marketing nonsense! Every year there’s a new trend around food regimes, from the Atkins to the Paleo diet, from the lemon detox to the cabbage soup and the baby food diet just to mention a few. Poor information is simply damaging our health!
Fad diets promise dramatic weight loss (sometimes even skin tone improvements), but they are also often unrealistic and unsustainable as they are aimed at short-term pros vs long-term cons and based on very limited or no scientific evidence at all which can be potentially dangerous for some. A famous example is the Cigarette Diet, which advertised tobacco smoking to manage weight in the 1920s. If you think this is silly, don’t think for even an instant that today is a different story: you only need to look at the cabbage soup diet! Many highly restrictive diets that involve exclusion of food groups are often lacking evidence on long-term health impact and cannot be recommended as safe and sustainable.
The solution to a healthy and nutritional diet is simple: eat a varied diet rich in fresh fruits and vegetables. This is why the “whole diet” approach is highly recommended with no more focusing on a single nutrient.
Yes, okay…some nutrients have been known to be particularly good in aiding specific conditions or needs, for example, omega-3 fatty acid or folate, have been known to have an impact on mood. But, it’s important to understand that nutrients need to interact with other nutrients to be fully absorbed and become beneficial to our body and this is why nutrients that are isolated, for example when they are taken as pills or added fortified foods, sometimes can be poorly absorbed by our body. Not only this but, specific nutrients can even be harmful when consumed in excess.
Want a simple straight forward tip about food?
- Eat plenty plant-based foods such as vegetables, fruit, wholegrains, nuts and seeds.
- Moderate/limit/avoid intake of proteins such as meat, seafood and dairy as well as, and especially, highly processed foods.
Dietary Guidelines
The first publication of the Dietary Guidelines for Americans was released in 1980. This did not go unnoticed by the rest of the world and as the various Departments of Health around the globe, some clever people, noticed the alarming food habits, they too slowly started to publish their dietary guidelines. The United Kingdom, for example, published its first set of dietary guidelines in 1994, and they have been regularly updated since then.
Food-based dietary guidelines are country-specific guidelines that take into account socio and environmental aspects and are intended as helpful evidence-based recommendations on foods to promote overall health and prevent chronic diseases. What they all resonate is the recommendation to consume a wide variety of unprocessed fruit, vegetables, legumes, nuts and whole grains while limiting sugar, fat and salt consumption. No miracle nutrient!
The World Health Organization (WHO) also outlines universal dietary recommendations that are based on fundamental principles of a healthy diet for adults. Want to hear it again? Consume a large variety of unprocessed fruit, vegetables, legumes, nuts and whole grains while limiting sugar, fat and salt consumption. And again, no miracle nutrient!
Reports indicate that following dietary guidelines and recommendations is associated with better physical and mental health across different countries and cultures. Examples are a decrease of Alzheimer’s in Korean elderly and a decrease of depressive symptoms and the weight status in Australians.
Nutrition Science
A personalised nutritional plan by a nutrition and dietetic professional is possibly the best way the get the most out of nutrition. This is because dietary recommendations tailored to the individual can take into account specific health needs but also preferences and socio-economic environment. Generally speaking, we can safely stick to dietary guidelines and eat plenty fresh fruits and vegetables, but when it comes to particular conditions there is definitely plenty benefits from getting the help of a professional.
Evidence also shows that dietary interventions developed and implemented by dietetic professionals do bring improvements in mental health.
Here’s a big word: Nutraceuticals
Nutraceutical is another term for functional food. A nutraceutical product is essentially a food or fortified food product with functional capacity to prevent or treat disorders. Examples of nutraceuticals are natural foods, including antioxidants, dietary supplements, fortified cereal and dairy products, minerals and herbals to give some examples.
Current research shows that some nutraceutical and dietary supplements could help manage mental health. These nutraceuticals include:
- Omega-3 fatty acids (found in foods such as fatty fish and other seafood, nuts and seeds, oils and animal foods).
- S-adenosylmethionin (SAMe), a chemical compound that is naturally occurring in the body.
- Vitamin D.
- St. John’s wort (a flowering plant used for a treatment of a mild depression. This is useful in mild depression but cannot be taken with other anti-depressant medications or some supplements due to interactions.)
Now, the thing to remember about nutraceuticals is that they are not tested and regulated to the same level as pharmaceutical drugs. Got that? Not regulated and this is also why, although nutraceuticals may provide a beneficial addition in the treatment of some mental health disorders, they should not be viewed as substitutes in place of a good quality diet.
The SMILES trial
The SMILES (Supporting the Modification of Lifestyle in Lowered Emotional States) trial was the first study in the world to demonstrate that making dietary changes can be effective in improving mental health in individuals with depression. To make sure participants at the time of recruitment fit the “clinically diagnosed depressed profile”, they were selected according to the Diagnostic and Statistical Manual of Mental Disorders. All participants were classified as having moderate to severe major depressive disorder and poor dietary intake.
The study commenced in 2012 and recruitment was completed in 2015.
67 participants were chosen for the trial and randomly allocated into two different groups:
- Dietary support group These 33 participants received personalised dietary recommendations based on the modified Mediterranean diet – the ModiMedDiet – during regular consultations with a trained dietitian.
- Social support group These 34 participants received social support that included regular meetings with trained personnel to discuss topics of interest, such as sport or music as well as playing games together.
After 12 weeks of intervention, the dietary support group showed significant improvements in mental health compared to the social support group with a 32% rate of participants achieving full remission, meaning they were no longer considered depressed!
The main focus of this trial was purely on mental health and what the study showed was that higher intakes of fruit, vegetables, whole grains and fish along with a lower intake of highly processed and sugary foods were consistently associated with better mental health.
ModiMedDiet: the modified Mediterranean diet
The SMILES trial used the ModiMed diet, based on the traditional Mediterranean diet.
The traditional Mediterranean diet is one of the most researched dietary styles. This is because it consistently demonstrates numerous health benefits including an association with a reduced risk of inflammation and depression.
What’s I personally find very interesting is that the ModiMedDiet, essentially a modified Mediterranean diet, is focused on aiding a positive change and improving diet quality by including an abundance of accessible, appealing and nutritious recommendations and meal ideas. In other words: easy, delicious and in abundance. The dietary recommendations also included several tips to help decision making around food such as:
- Select fruits, vegetables and nuts as a snack. Include 30g (1.5 tablespoons) of unsalted nuts daily.
- Include vegetables with every meal. Eat leafy greens and tomatoes every day.
- Reserve sweets for special occasions only.
- Choose water as the best drink.
ModiMedDiet also suggested meal ideas using simple food combinations from three main food groups. For example: eggs (protein) on wholegrain toast (cereal and starchy vegetables) with capsicum, spinach and mushrooms (vegetables).
The idea behind the ModiMedDiet model is to promote healthy relationship with food, with a focus on the inclusion of a wide variety of nutritious, easy and tasty meals and snacks that would improve diet quality and facilitate long-term behaviour change. It did not have weight-change focus and participants were expected to eat according to their appetite.
The cost of a healthy diet
It’s a common misconception that healthy diets are more expensive. This perceived high cost is one of the most common barriers to healthy eating.
Interestingly, a detailed cost analysis of 20 participants before and after the SMILES trial, showed that the healthy diet actually cost less than the low-quality diet.
There are several factors in its favour. Firstly, meat is more expensive than vegetables and ready meals are more expensive than buying raw ingredients. Less meat and ready meals = cheaper shopping bill. Favouring fresh fruits and vegetables encourages preparing meals at home, which are also cheaper than eating out or ordering takeaways.
However, to fully succeed, motivation and a willingness to change behaviours needs to be fully welcomed and embraced in order to maintain it in the long term. One more fascinating fact that seems to be a real winner when looking at changing our eating habits, is that maintain a positive mindset is key.
Think positive!
“When people are in a positive frame of mind are more likely to collaborate & problem-solve (instead of fight & resist).“
Chris Voss – ‘Never split the difference‘
Our thoughts influence the way we experience life and this is why optimism and positive-thinking are key factors to successful outcome when it comes to dietary changes. A positive mindset gives us the ability to adjust, focus, solve problems, and contributing to better mental health and physical well-being. Interestingly, previous research has shown that, when talking about long-term dietary habits, pessimism decreases an individual’s potential for improving.
“The hardest part about change is not making the same choices you made the day before.“
Dr. Joe Dispenza
When making changes, it’s important to have realistic expectations to avoid setting ourselves up for failure. Especially when talking about changing habits, it can be extremely challenging as familiar habits are difficult to get rid of. This is particularly hard for people who suffer from depression, stress or anxiety. In these cases, an empathetic and supportive environment is very important.
Changing eating habits requires creating dietary strategies, setting goals based on individual needs and abilities, and exercising a continuous willingness to carry on. It may also help to seek social support and interaction which can help reducing and managing stress and negativity.
Top tips around food
To ensure long-term sustainable changes it’s paramount to implement simple, achievable changes. Here’s some tips:
- Forget about macro, micro, diets, what vitamin is in what vegetable etc. Just set yourself to eat plenty fresh fruit and vegetables.
- Limit the intake of meat, dairy and processed foods.
- Snack can be real monkeyshines!!! Make sure you have healthy snacks that require minimal preparation and cooking. For example, bite size celery and carrots, pre-cut and pre-washed salad and delicious mini tortillas to wrap vegetables with.
- Ensure you always have some extra non-perishable items, such as caned or dried beans and legumes or small bag of rice. They can be real lifesavers.
- Favour home cooking over eating out. Google recipes and have fun with your ingredients. I am not a fan of following recipes but I often google images of two to three of the ingredients I have available in the house. You’ll be amazed how much inspiration you can get just by looking at some pictures!
- Do not shop when you are hungry and stick to the shopping list you made. Avoid temptation islands/shelves and buy what’s in season to keep the cost down and your palate amused.
- When eating out or ordering takeaways, favour healthier options. For example, consider sushi or falafels and salad wraps over a mixed meat kebab.
- Do treat yourself sometimes. Perhaps a Friday or Saturday night takeaway? And when you do, enjoy it!
- Be positive and celebrate improvements.
- It’s ok to have set backs, but don’t give up just because you slipped and you are now ready to paint it all black.
