Healthy food for a healthy heart and mind

Published: 18 September 2024

What we eat affects our heart health, but did you know it can also affect our mood and wellbeing? Read on to discover more about the link between food and mental health.

The body and mind are intricately connected. Evidence shows that what we eat can affect how we feel, think and behave. 

If you're struggling with your mood, there might be small steps you can take to improve your mental health, including looking more closely at your diet.

How does food affect our mood?

There are billions of bacteria in our gut that work hard to keep the body healthy, known as the microbiome. These bacteria have several different roles in the body and one of them is maintaining the important connection between our gut and our brain.

The link between the gut and the brain goes both ways as they communicate with each other to say what is going on in the body.

Serotonin is a ‘feel good’ hormone that controls our sleep, appetite and mood. 95% of the serotonin in the body comes from the gut. There is a strong link from the brain to the gut in irritable bowel syndrome (IBS), and both physical and mental trauma results in an increase in IBS.

The microbiome begins in the mouth and tracks all the way through the digestive system. It's influenced by oral hygiene and our diet. As the gut plays such a large role in our mood, and everything we eat passes through the gut, it makes sense that what we eat contributes to our mental health.

Are there foods that can make me feel down?

The bacteria, or 'gut bugs' that make up the microbiome feed and survive off the food we eat. It’s not just one or two foods that make the difference to our health. The impact of food on our gut health and mood comes down to what makes up our whole diet. 

Eating lots of ultra-processed foods high in salt, sugar and/or fat feeds the bad gut bugs and can stop the good gut bugs from growing. This can also be said of some drinks we consume, especially sugar-sweetened drinks  and energy drinks. If too many of the bad gut bugs thrive off your food and drink choices, this can negatively impact your health.

Alcohol can often be used to help us unwind or relax after a long day, or during stressful times,  but alcohol is a depressant to the brain. Drinking alcohol can change your mood or worsen a low mood. Unhealthy food choices and high alcohol intake can displace the healthy foods we should be having, and hence we don’t get the positive nutrients needed for physical and mental health. 

If you're experiencing depression, avoid alcohol to help manage your mood. Our latest advice is that no amount of alcohol is good for the heart. Try swapping to zero percent alcohol, or sparkling water flavoured with lemon and mint. If you or others think you may be drinking too much alcohol, talk to your doctor or call the Alcohol Drug helpline.

How does our mood affect what we eat?

As mentioned above, what we eat can affect how we think, feel and behave. In contrast, how we feel can also affect the food choices we make. We sometimes crave comfort foods when we’re tired, stressed or sad. This is because our bodies crave the temporary ‘feel-good’ response from those foods. 

Mental health conditions can affect what we eat as well. Anxiety or generalised anxiety disorder (GAD), depression, or seasonal affective disorder (SAD), can change the amount of food we eat. Some people eat more and turn to food for comfort. Others lose interest in food and eat less.

Medications for mental health conditions can increase or decrease your appetite, food intake and therefore change your weight. Weight changes, loss or gain, in the absence of good nutrition means the brain is deprived of glucose and other nutrients that help it function and help control mood.   

Talk to your doctor if you’re taking medication and the side effects are worrying you. Don't stop taking your medication without talking to your doctor first.

A healthy diet can help your mental health

A diet rich in fibre and healthy fats includes fruits, vegetables, whole grains, nuts, seeds and healthy oils. These foods help support the bugs that keep the gut healthy. 

In addition, eating a heart-healthy diet like the one mentioned above, or the Mediterranean-style diet, have shown to help people with anxiety and depression. 

Thinking about what you drink also helps. Alcohol is best managed on an individual basis, but no amount is good for your heart and the same applies to your mood. Staying hydrated and choosing water first can help reduce irritable or restless feelings. 

The cost of healthy food can be a barrier to eating well. You can reduce the cost of your food budget by cutting down on sugary drinks, convenience foods, takeaways and alcohol. Then prioritise that money towards a healthy-food budget. 

Reducing food waste can help save money as well. Plan your meals in advance to only buy what you need for the week. Choosing frozen or canned fruit and vegetables helps you save money and prevent food waste.

How is heart disease and mental health connected?

Heart health is linked to mental health in two ways:

1. Your risk of heart disease

If you have a severe mental illness, you're more at risk of heart disease.

2. Changes to your mental health after a heart event

Anyone with a heart condition can experience emotional changes after a heart event or diagnosis. This can be related to feelings of uncertainty around the condition or the fear of the unknown.

A lot of the dietary recommendations for a healthy heart are also recommended to maintain good brain health. Whether it's heart disease or mental illness that comes first, in both situations a change in diet can be a key preventative measure.

What can I do to improve my mood?

Reframing how you think about food can help you make changes for your mental health. Thinking about feeding your gut bugs and what they need to keep you well can help get you started. Here are some tips you can try today:

• Include fruit and vegetables (canned, frozen or fresh) in your meals every day.
• Choose high fibre and less processed food for snacks.
• Reduce your intake of ultra-processed foods and sugar-sweetened beverages like fizzy drinks, flavoured milks and juice.
• Plan your meals and snacks before you go shopping to help save money.
• Use a shopping list to reduce the temptation of buying ultra-processed foods in the supermarket aisles.
• If you find it difficult to enjoy food, try to give some structure to your day by planning out physical activity and meals.
• Physical activity can improve your mood by making more ‘feel good’ hormones. Try to get moving every day.
• If your mind is racing, or you’re feeling worried, take a moment to yourself and try some relaxation techniques.

Support

If you’ve had a heart attack and are feeling anxious, you're not alone. There are other people who are feeling the same as you right now. The Heart Foundation’s Journeys are positive stories of how people from across New Zealand have made adjustments to cope following their heart diagnosis.  

If you need some support, talk to your GP or a counsellor and they can help you navigate any changes to your mood that you are experiencing. 

Need to talk? There are a number of services available in New Zealand that offer help with mental health issues.

Free call or text 1737 any time for support from a trained counsellor

Lifeline – 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP)

Suicide Crisis Helpline – 0508 828 865 (0508 TAUTOKO)

Healthline – 0800 611 116

Samaritans – 0800 726 666

You can contact the NZ Mental Health Foundation at mentalhealth.org.nz and access mental health services such as suicide prevention at mentalhealth.org.nz/help