Improving gut health with diverse, nutrient-rich foods may reduce ADHD symptoms and support mental well-being. Photo / 123rf
Improving gut health with diverse, nutrient-rich foods may reduce ADHD symptoms and support mental well-being. Photo / 123rf
Gut health has been found to play a pivotal role in managing ADHD symptoms. Here are the best foods to eat.
In recent years our awareness of the importance of a healthy gut has dramatically expanded and, at the same time, there’s been an explosion in the number of people being diagnosed with ADHD.
Now scientists are beginning to link these two issues for the first time.
At the recent 2024 Gut Symposium, where leading experts in gut health from around the world came together to share research, the room was packed for the session on brain health.
Professor Alejandro Arias Vásquez, the head of the Brain, Bacteria and Behaviour Group at the Radboud University Medical Centre, shared his research.
Keep up with the latest in lifestyle and entertainment
Get the latest lifestyle & entertainment headlines straight to your inbox.
“We showed that people with ADHD have an altered gut microbiota profile – some more abundant bacteria, and some less abundant. It’s too early to draw definite conclusions, but it suggests that gut microbiota has a part to play in ADHD,” he says.
People with ADHD are more likely to suffer from ‘leaky gut’
Research has shown that those with ADHD often have reduced levels of short-chain fatty acids. These short-chains fatty acids are produced by specific bacteria in the gut and are important for health. The short-chain fatty acid, butyrate for example, helps to prevent “leaky gut” and fight inflammation. This may be why those with ADHD often have higher levels of inflammation in their blood, which in turn can lead to neuro or brain inflammation.
At the same time, those with ADHD are also more likely to have gut health issues such as constipation, IBS, diarrhoea and pain.
Vasquez and others hope that treating gut health might also help treat the symptoms of ADHD. Research has already shown that gut microbiota can impact our mental health with an imbalanced gut being linked to anxiety and low mood, which often co-occurs with ADHD.
How the gut talks to the brain
The gut is often referred to as the “second brain” and the two systems are in constant communication, intricately influencing each other through various pathways known as the gut/brain axis, or as Vasquez likes to call it: “a bi-directional super-highway” because there is constant chatter in both directions.
“The gastrointestinal tract is home to billions of bacteria (gut microbiota) that influence the production of the precursors of neurotransmitters; chemical substances that constantly carry messages from the gut to the brain.
“Good bacteria positively affect neurotransmitter production, but inflammation can hamper this production, and this leads to changes in the brain, which influences our mood and cognition,” he explains.
ADHD and the dysfunctional gut
People with ADHD are more likely to suffer from gut complaints, and there are many reasons that our guts might not be functioning properly.
“It might be a poor diet, or because of alcohol or substances, or because you’ve inherited it from your mother. One of the things that seed a gut in the first place is vaginal birth, and if a baby is born by caesarean section it doesn’t get that seeding.
“It could also be stress, pollution, antibiotics, ultra-processed foods, these are all things that can alter the microbiome,” says Dr James Kustow, a consultant psychiatrist and author of the new book, How to Thrive with Adult ADHD.
In addition, those with ADHD are more likely to suffer from disordered eating, struggle with blood sugar control and have much higher rates of binge-eating disorder and obesity.
“When tired, hungry or experiencing a blood sugar dip, or when feeling low in mood, those with ADHD are more likely to slip into self-medicating with food. A central issue is that they find it hard to evaluate when they are full and when to stop eating – the signal just doesn’t come through in the same way. This can result in hard-to-control weight gain,” says Kustow.
The gut is often called the "second brain" due to its strong connection with the brain via the gut-brain axis. Photo / 123rf
How to eat for brain and gut health
People with ADHD have more gut health complaints and are more likely to suffer from disordered eating. They can also restrict foods since certain textures and smells can cause sensory overload, which may mean not eating enough of the healthy foods the gut thrives on.
ADHD disorganisation can also lead to missing meals or overeating. Kustow recommends building a routine to help with these challenges – like batch cooking on the weekends to ensure healthy food is on hand, delivery of fruit and veg boxes, or a cooking rota.
Eating a wide variety of plant foods is vital for gut health, as is sticking to that diet over the long term.
“If you want your diet to modify your bacteria, change it and be consistent. Short-term changes won’t have an impact. Say you fly to Thailand tomorrow and stay there for two weeks, if you eat a Thai diet there will be some changes in your microbiota, but when you come home and resume your normal pattern of eating the microbiota will go back to the way it was before you left,” says Vasquez.
The most extensively researched diet for health and brain health is the Mediterranean diet, which includes unprocessed fibre-rich plant foods, moderate amounts of fish, white meat, dairy and eggs, extra virgin olive oil and occasionally red meat.
Jordan Howarth is a gastrointestinal physiologist with the Functional Gut Clinic. He tried the Mediterranean diet for a month, having a stool test to analyse his gut microbiota at the beginning and the end. After a month on the diet, his tests showed that his gut bacteria were significantly more diverse.
“I had more different types of bacteria in my gut, which is good. There was also an increase in butyrate which is important for gut health,” he says. Eating a fibre-rich diet will boost butyrate, which is linked to a reduction in inflammation and anxiety.
A Mediterranean diet improves gut bacteria diversity and boosts butyrate production, reducing inflammation. Photo / 123rf
Reduce ultra-processed foods
In the UK and the US, half the average person’s diet now consists of ultra-processed foods (UPFs). Yet studies have shown that regular consumers of UPFs have a higher risk of dying early, getting cancer and Type 2 diabetes and that UPFs change our gut microbiota and may have an adverse effect on brain health through the gut/brain axis.
Professor Julia Rucklidge is a clinical psychologist at New Zealand’s University of Canterbury and is a leading researcher on the relationship between nutrition and mental health. “The number one thing anyone can do to improve any sort of symptoms, not just ADHD symptoms, would be to reduce your consumption of ultra-processed foods.
“A study this year showed that the removal of ultra-processed foods was effective at reducing the symptoms of ADHD in kids,” she says. Junk food can also increase ADHD symptoms in children and adolescents.
High consumption of ultra-processed foods worsens ADHD symptoms and alters gut microbiota negatively. Photo / 123rf
Eat blue and purple-coloured foods
Experts advise eating a wide range of vibrant-coloured fruits and vegetables, but blue and purple foods are especially beneficial. “Studies have shown that purple and blue coloured foods are particularly helpful for brain health and mood.
“The colour is the result of the phytochemicals they contain, which have been shown to have a wide range of health benefits. An important group of these chemicals is the polyphenols (which include the flavonoids), which are powerful antioxidants, molecules that are protective and will undoubtedly enhance the overall health profile of those with ADHD,” says Kustow.
Purple and blue fruits contain polyphenols, which benefit brain health and mood. Photo / 123rf
Eat choline and omega-3s
Eggs are a beneficial protein and also a good source of choline. “Choline is an important nutrient for brain health. It is a building block of acetylcholine, an important neurotransmitter (chemical messenger) used by the autonomic nervous system.
“Low levels of choline have been associated with anxiety, and anxiety is a hallmark of ADHD. As well as being present in eggs, it is also present in high levels in organ meats, fish, meat, brassica vegetables, soya and shiitake mushrooms,” says Kustow.
Omega-3s are essential for brain function and some people with ADHD have low levels. Omega-3s are found in oily fish, walnuts, chia seeds, flaxseeds and hemp. If you don’t eat fish regularly, a good quality supplement is a good idea.
Omega-3 fatty acids from fish and nuts are essential for brain function and are often low in those with ADHD. Photo / 123rf
Try a good quality multivitamin and consider probiotics
All experts recommend a food-first approach to nutrition, yet many people with ADHD have higher rates of nutritional deficiencies, and some studies have demonstrated improvements with high levels of multivitamins.
Professor Julia Luckridge was the lead author of a study which found that adults given supplements containing vitamin D, B12, folate, magnesium, ferritin, iron, calcium, zinc and copper saw an improvement in ADHD symptoms. “One of the things we have observed is that they do increase the diversity of the microbiome, which is possibly the reason why people get better,” says Luckridge.
Kustow also recommends magnesium to his clients. “Although dietary approaches should come first, studies have shown that children with ADHD are often very deficient and that magnesium may have a calming effect on anxiety and irritability.
“It may also help reduce stimulant-related side effects [resulting from ADHD medication, such as headaches and sleep issues] and plays an important role in supporting neurotransmitter production,” he says.
There’s little conclusive research yet on the effectiveness of specific probiotic strains for ADHD, although Dr Emma Derbyshire, a nutritionist and adviser to the probiotic company PrecisionBiotics cites early-stage research supporting their “Daily Calm” product.
“Interestingly, the specific Bifidobacterium longum 1714 strain was found to ease the tiredness experienced by the brain during a stressful situation. Future research is needed but these underpinning mechanisms could potentially be useful for individuals with ADHD.” Another small study found some beneficial effects for the probiotic Lactobacillus rhamnosus in treating children and adolescents with ADHD.
“In time, I envisage a range of evidence-based treatments for ADHD targeted at optimising gut health, using modified diets and supplementation, including pre-and probiotics,” says Kustow.
“For now, I encourage my clients to build up their guts by eating high-quality and diverse nutrient-rich foods.”
Comments