Is the food you eat connected to how you feel?
There is no single agreed definition of well-being, but there is some general agreement. We know it includes the presence of positive emotions and moods (like contentment and happiness), the absence of negative emotions (like depression and anxiety),and satisfaction with life. Well-being is thought to be impacted by physical, economic, social and psychological factors as well as engagement in meaning employment, education, leisure pursuits, hobbies etc.
Research evidence showing that our diets are linked to mental well-being is not yet definitive but population studies suggest that diets high in vegetables, fruit, whole grains, nuts, seeds and fish with limited amounts of processed foods are associated with lower risk of depression. Studies also suggest that diets high in processed foods, high in fat and sugar are associated with poorer mental health, such as anxiety and depression. It is too early to be absolutely definitive, but it looks very promising and is an area of intense interest and importance given the high prevalence of mental well-being distress amongst populations.
Humans need a steady supply of nutrients, both macro (proteins, fats and carbohydrates) and micro (vitamins, minerals and trace elements), to maintain good health. We consume more than 50 nutrients in the foods we typically eat, all of which are essential for normal body functioning, growth and repair of cells, tissue and organs and overall health and well-being.
These nutrients have different roles and functions in the body and come with different recommended amounts, depending on both different life stages, from infancy, to childhood, adolescence, adulthood and onto older years, and specific circumstances such as pregnancy or breastfeeding. The food pyramid provides a simple way to understand the amount and type of foods we should consume each day, to promote good health and well-being. Alcohol is not essential for health, can have serious adverse effects on mood and is not recommended for children under 18 years.
A recent Lancet report cited diet as the dominant driver of health, with one in five deaths around the world attributed to diets high in salt, low in whole grains, fibre, fruit, vegetables, nuts, seeds and Omega-3s from seafood. In the short-term, hunger mediated by biological processes involving our brain, blood sugar levels, stomach, intestine and certain hormones, in tandem with our daily routines and food availability, influence our dietary intakes. Skipping meals, particularly breakfast, or having long intervals between meals can lead to low blood sugars, irritability, reduced concentration, reduced work/educational performance and increased anxiety levels.
However, longer term dietary intakes may also be important in well-being. It is thought that a number of biological processes play a role in the association between our long-term dietary intakes and mental well-being. These include inflammation, oxidative stress and brain plasticity and the gut, specifically the gut microbiome (trillions of microbes - bacteria, viruses and fungi) is thought to play a key role in influencing these processes.
Often referred to as the "gut-brain axis'', the relationship between the gut and the brain involves a matrix of tissues and organs which includes the brain, the endocrine system, the gut, the immunological system and the gut microbiome all communicating with each other in a very complex manner. The gut and the brain are physically and chemically connected to each other by millions of nerves and chemicals. Neurotransmitters such as serotonin (the happy hormone) and other chemicals which are produced in the gut are known to have effects on mood.
It is thought that altering the types of bacteria in your gut may mprove your brain health by reducing inflammation, oxidative stress, brain plasticity and consequently improve wel-lbeing. Diet plays a key role in the composition of the gut microbiome and dietary factors thought to enhance it include:
· Omega-3 fats: fats found in oily fish.
· High-fiber foods: in whole grains, nuts, seeds, fruits and vegetables
· Polyphenol-rich foods: found in cocoa, green tea, olive oil and coffee.
· Tryptophan-rich foods: an amino acid that is converted into the neurotransmitter serotonin (often referred to as the happy hormone), found in turkey, eggs and cheese.
· The Mediterranean diet which is rich in fruit, vegetables and olive oil
· Antioxidants found in colourful fruits and vegetables.
Article by Mary Rose Sweeney appeared in RTÉ Brainstorm on Monday 15th November 2021