THE JOURNAL
Illustration by Mr Bruno Mangyoku
The new book by Dr Kimberley Wilson, Unprocessed: How The Food We Eat Is Fuelling Our Mental Health Crisis, is a lot to, well, digest. Its author is a chartered psychologist with a master’s in nutrition (and a 2013 finalist on The Great British Bake-Off). And here, Wilson contends that diet is “a central yet overlooked and ignored underlying factor” in spiralling mental illness rates and our “increased neurological vulnerability”. Not just for thought, then, food impacts mood and behaviour, your brain’s very structure, even the speed that it ages. But four centuries on from philosopher Mr René Descartes’ dualistic distinction between physical and mental, we still think mind and body separate, therefore we are, as Wilson writes, “eating our way to Alzheimer’s”.
“Everyone should be worried about dementia,” Wilson says, more cheerily than the subject matter might suggest. Dementia is an umbrella term for conditions such as Alzheimer’s (the most common) that cause progressive neurodegeneration – nerve cell damage or demise – and loss of brain function. It is the leading cause of death in the UK. And, as Wilson outlines, a third of the modifiable risk factors for dementia pertain to nutrition, including body fat, diabetes, low fibre, high sugar and consumption of alcohol. (Alcohol is a neurotoxin, so if you drink, try to do so with meals and within recommended limits.) Accelerated brain ageing is likely driven in part by “chronically low” intake of omega-3 fats; our brains are 60 per cent fat by dry weight.
Adults in the UK get 55 per cent of their calories from ultra-processed foods: typically, energy dense, but nutrient depleted, high in unhealthy fats, free sugars and refined starches but low in protein, fibre and micronutrients, with five ingredients but often many more, long-lasting, attractive, hyperpalatable, convenient and cheap. (The percentage is even higher in the US.) For British children, the proportion is as high as 80 per cent. In Italy, where life expectancy is longer, but UPFs only constitute 14 per cent of adults’ calories (the lowest in Europe), dementia is eighth in the death-cause rankings.
“People who eat leafy greens have younger brains”
The leading cause of death for UK men under 50 is themselves. Omega-3s have been shown to reduce suicidal ideation, Wilson says, and damp down inflammation: immune system activity that, if excessive or prolonged, can be deleterious, and is associated with depression in about 30 per cent of cases. While nutrition is not a panacea, the Royal Australian and New Zealand College of Psychiatrists’ updated 2020 guidelines for depression management stipulates the institution of a healthy diet as “essential”.
One of the main omega-3s, and a brain cell “building block”, DHA can’t be manufactured in sufficient quantities by our bodies. We get it predominantly by eating oily fish (tinned will do) and other seafood that dine on DHA-synthesising microalgae. Abundant DHA likely helped our fisher-gatherer ancestors build bigger brains; lack of it may be precipitating the global decline in IQ.
People who eat leafy greens (the darker, the better) also have younger brains, Wilson says. And fibrous beans and pulses feed our gut microbiome: the bacteria, yeast, fungi and other microorganisms (yum) resident therein, which in turn produce neuroprotective compounds. While we won’t all make our own baked beans at the age of 12 (“I was just a very nerdy kid”), the more we can cook from scratch, she says, “simply the more nutrition you’ll get into your diet”.
“You can eat how you like. I just want you to be informed and to know what you’re doing”
For breakfast, Wilson typically eats beans, eggs or mushrooms on wholemeal toast, or a (homemade) blend of oats, wheat, barley, rice and spelt that forms a base for muesli, porridge or overnight oats. In summer, she soaks her multigrains in kefir (also homemade) and tops with berries.
Lunch is salad (bought from Aldi) with protein leftover from dinner – beans, chicken, fish – or boiled eggs and bread on the side. To snack, fruit or something “fibre-y”, like roasted fava beans (a favourite in the Mediterranean) mixed with raw nuts.
Dinner might be chicken broth with pulses, fish tacos or pasta with roasted veggies. Whether salad or the occasional slice of cake (again, homemade), she emphasises deliciousness as well as nutritiousness. “There is also value in pleasure,” she says.
Diet tribes and influencers cater to our craving for simple answers to complex questions, says Wilson, but there’s no one “best” breakfast, or way to eat. Vegetarian and vegan diets can be healthier in some regards, but can also lead to deficiencies of nutrients essential for our brains. These include omega-3s DHA and EHA, vitamin B12 (deficiency of which can mimic dementia and is a precursor for Alzheimer’s), choline (brain cell “mortar”, which is hard to get enough of without eggs or supplements) and iodine (which we can get from seaweed, but that’s hardly a store cupboard staple).
“The risk of taking supplements as ‘insurance’ is that you ‘lean back’ instead of striving to eat more fruit and vegetables, oily fish and beans”
“You can eat how you like,” Wilson says. “I just want you to be informed and to know what you’re doing.”
While supplements are good at preventing outright deficiency diseases such as scurvy or rickets, they don’t come close to whole foods and their countless beneficial, synergistic compounds that can’t necessarily be extracted and put into a pill. The risk of taking supplements as “insurance” is that you “lean back” instead of striving to eat more fruit and vegetables, oily fish and beans.
Almost 11,000 people, including more than 300 children, were hospitalised in England last year with malnutrition, up fourfold from 2007-8. “Victorian” diseases including scurvy and rickets are coming back as the cost-of-living crisis bites. Unprocessed lays bare how food also fuels social inequality in an intergenerational cycle – poor nutrition is “both cause and consequence of poverty”.
If you find that hard to stomach, Wilson suggests donating to your local food bank. (Maybe throw in some multivitamins.) And support the campaign for universal free school meals to save four million children from food insecurity. “Any right-thinking adult knows that it’s just unfair,” she says.