Does eating dairy influence mental health?

The Gut and Mental Well Being

Can dairy foods help us to manage our anxiety levels. Perhaps dairy can influence the decisions we make, or cope with stress. We have known for a long time that individuals who eat a great diet, and exercise regularly,  tend to manage stress and anxiety much better than others. Certain foods are associated with cognitive performance e.g. oily fish, nuts and seeds, because of the omega 3 oils they contain. But what about other foods e.g. dairy? And how might they influence how we feel?   Is this influence related to the connection between the gut and the brain?

The Bi-Directional Nature of the Gut-Brain Axis

The gut and the brain communicate with each other all the time. The relationship is bi-directional i.e. the brain talks to the gut and the gut talks to the brain. The chatter is constant.  Much research focuses on how the brain influences feelings of fulness or satiety.  But what communication mechanisms exist to relay to the brain that I have eaten?  What might happen in terms of neurotransmitter production – chemical messengers – which  tell me to stop eating. We now know that these neurotransmitters are produced not only in the brain and nervous system, but also in the gut. These neurotransmitters tell the brain how I am feeling eg butterflies in my tummy because I am nervous.

The Helpful Bacteria

Bacteria, viruses and fungi live in the gut and help to make up what we refer to as the gut microbiome. We think the bacteria living in the gut mights affect the production of neurotransmitters signalling to the brain.  In this way the health of the microbiome in our gut can affect activity in the brain and influence our decision making, as well as our ability to manage anxiety.

Current research suggests two types of bacteria are considered particularly beneficial to the gut and the brain – Bifidobacteria  and Lactobacillus. High levels of stress reduce the concentration of lactobacillus in the gut.

The Gut-Microbiome and Anxiety

Dr Kathrin Cohen Kadosh describes  fine-tuning of the gut-brain axis occurs during the second decade of life. The second decade is a time of enormous change, we start secondary school,   we go through puberty and adolescence, and we are especially vulnerable to peer pressure.  Socially, we search for our tribe. This decade is also where 2/3rds of mental health problems are considered to start – problems which we often carry with us through life.

The Dairy Study

Dr Cohen-Kadosh described a comprehensive study which looked to psychological profiling, nutritional markers, stool sampling, and brain imaging, for assessment. The study then delivered a  targeted dietary intervention . The idea was to look for changes in neurotransmitter production.  The study population was divided into two groups – those classed as of low anxiety traits and those with high anxiety traits.  The dietary intervention was  the provision of a dairy derived prebiotic: a galacto-oligosaccharide. Prebiotics are those foods which contain nourishment for the good bacteria in the gut. Most prebiotics are plant based with just the one dairy derived  galacto-oligosaccharide identified.

Following the dietary intervention,  those individuals who presented with high anxiety traits displayed less anxiety than before the intervention. They also improved in  positive decision making scores. Those individuals who were already of low anxiety traits did not show any difference in outcomes.

What is a serving of dairy?

See below for suggested servings – aim for ≥3 servings per day to meet your needs, with live yogurt being considered especially beneficial to gut health. Dairy derived galactic-oligosaccharides will be found in yogurt and cow’s milk.

• 120-150ml yogurt – plain low fat or Greek preferred versus fruit flavoured which may contain added sugar or sweeteners

• 200ml cows’ milk

Dairy foods in the right amounts can be part of a healthy diet. Ideally you are eating a certain amount of dairy each day for a variety of health reasons, including nourishing your gut microbiome.  We don’t know that dairy replacements will have the same influence, but they might.

If you feel you would like to work with me on your gut nutrition, please get in touch.