Are ultra-processed foods 'shrinking' our brain?

Walking around the supermarket and health store aisles I see more and more 'foods' that are very different from wholefoods. It goes from the usual crisps that have lost any resemblance with potatoes, cereals with bright colours, ready meals with an incredibly long ingredient list, but also 'healthy' snacks that don’t look or taste like the foods they are supposed to be based on.

What do all these foods have in common? They are ultra-processed!

What are ultra-processed foods?

Ultra-processed foods are deconstructed and somehow combined back together with extra ingredients such as emulsifiers, preservatives, artificial colouring and flavouring, corn fructose syrup, etc. Some can look healthy – some examples are protein shakes and snack bars, vegan burgers, gluten-free bread, lentil-based crisps, and cereals with added vitamins and minerals.

The alarming fact is that the UK has the highest consumption of these ultra-processed foods, especially coming from commercial breads (read the label if you have it at home!), ready meals and crisps. Statistics show that women, probably in the quest for 'healthy foods' and 'healthy snacks', are eating more ultra-processed foods than men.

Those deconstructed foods have lost the original food matrix, so they are not recognised by the brain and gut microbiota (the system of bacteria, viruses and fungi in our gut), leading to various health outcomes ranging from weight gain, altered metabolism and immunity, low mood and inflammation, to name just a few.

Gut microbiota, and especially the 'good' gut bacteria, thrive on whole foods and fibre, which is fermented to produce short-chain fatty acids (SCFA) and neurotransmitters. SCFA are involved in metabolism, immunity and further neurotransmitter productions.
For example, some serotonin (our happy hormone) is also produced in the gut by the metabolisation of amino-acid tryptophan by bacteria.

The impact of ultra-processed foods on our brain

The food we eat can influence an area of the brain called the hippocampus. This area is associated with learning and memory in all life, as well as mood regulation. People suffering from severe diagnosed depressive conditions show shrinkage of the hippocampus, which enlarges when they recover.

Recent studies show that neurons in this area are the only ones that can grow and regenerate all life long, even in adulthood. Recent research in Australia, and studies in the UK and Netherlands, show that hippocampus size can be related to people’s diet quality.
People with a lower-quality diet and a higher intake of ultra-processed foods and alcohol have a smaller-sized hippocampus, which is associated with reduced learning and memory capacity as well as lower mood. Data from those studies point to the fact that 60% of abnormal hippocampus shrinkage could be related to a diet poor of whole foods and rich in ultra-processed foods.

But it is not all doom and gloom! Brain cells in the hippocampus respond quickly to a whole foods diet, so the damage could potentially be undone.

How can you do that?

The first step is to read the labels of the foods you buy carefully; if the list of the ingredients is too long and has ingredients you can’t pronounce, it is likely to be an ultra-processed food.

Try to make some easy swaps, for example, having oats instead of breakfast cereals or swapping flavoured yoghurts with plain ones, adding some fruit for flavour.

Eating a wholefood diet can also be cheaper than a processed one; frozen vegetables, eggs, legumes, and grains such as rice are all excellent wholefood sources that won’t break the bank.

Many snacks marketed as 'healthy' are not really needed – a boiled egg is likely to have the same proteins as a protein snack bar, even if less glamourous to bring to work.

Seek the help of a qualified nutritional therapist or nutritionist for suggestions on which are the best swaps to help you enjoy your diet and enrich it with gorgeous whole foods that will leave you thriving!