What To Eat If You Have A Chronic Illness

Table of Contents

When you received a diagnosis you may have been told to “eat a balanced diet” or to “eat everything in moderation”. As we each look within our families, circle of friends and in our neighbourhoods, it is clear to see that the mainstream mantras of balance and moderation have not been enough to stop the rise of chronic illness. Now that you (or a loved one) is living with a lifelong health challenge, the time has come to embrace a new mantra – optimal.

It is my hope that by the end of this article, you will have a clearer understanding of:

  • Why what goes into your one precious body matters so much more when you are living with a chronic illness.
  • How to put together a dietary template that best supports your wellbeing in the context of your unique circumstances.

The Importance Of Nutrients

Our bodies are made up of building blocks called cells – each with a specific and important function. The purpose of each function is to keep us alive and healthy and the functions performed by each cell are fueled by nutrients. This means that once nutrient levels plunge too low (and remain unreplenished), our cells will begin to malfunction and die – resulting in less than optimal health.

Once your health is less than optimal, your body will require more nutrients to help you:

  • Have the best quality of life possible
  • Slow the progression of your illness

Nutrients fall under two broad categories:

  • Macronutrients: nutrients consumed in the largest quantity and making up the bulk of our calorie intake. These are proteins, carbohydrates and fats.
  • Micronutrients: vitamins, minerals and other compounds needed (in smaller amounts than macronutrients) for normal function. About forty have been identified as being crucial for health and a longer lifespan.

Why We Should Care What Our Ancestors Ate

I know that it may seem difficult to relate to the – seemingly – savage humans who lived roughly two million years ago. We have remained biologically the same (for the most part) as our ancestors and, therefore, still have the same dietary requirements for optimal health.

For 66,000 generations, humans lived as hunter-gatherers. This means that they only ate what they could hunt, catch or forage in the wild. It also meant that they could only eat what was in season. The diseases that we now consider a normal part of life (or ageing) were rare or nonexistent and people were generally lean and fit. It is true that many did not survive the challenges of exposure to the elements, accidents, warfare and the absence of modern medical care. Those who did, however, maintained their good health and vitality well into old age.

There is, of course, no use in discussing what an optimal diet might look like without taking other aspects of life and health into account.

All the technological advancements in the world do not change the fact that we (like our ancestors) feel at our best and reap the benefits of an optimal diet when we:

  • Manage stress and prioritise play and fun
  • Sleep as deeply (and for as long) as possible
  • Move our bodies consistently throughout the day
  • Share our meals in a relaxed setting with people we love

Eating an optimal diet within this context can give you the best quality of life possible – even whilst living with a chronic illness.

The Evolution Of The Standard Western Diet

Two major events in history shaped the food choices that we make today and the health crisis that emerged over the years as a result:

  • The Agricultural Revolution: As time went on, humans decided to form settlements, domesticate animals and grow a selection of plants. The latter were foods that had previously not been consumed by our ancestors (like grains and legumes) and they were higher in calories yet lower in nutrients than wild plants. They were convenient to store and, when agriculture took off on a large scale, they were also found to be easy to transport. Grains and legumes became staples, causing carbohydrate intake to rise significantly. Because there is only so much room in one stomach at any given mealtime, this led to a correspondingly sharp decline in animal protein intake. Studies of the remains of people who lived and ate in this way, revealed evidence of diseases relating to vitamin deficiencies, tooth decay, a reduction in bone density and shrinkage in height when compared with their hunter-gatherer ancestors.
  • The Industrial Revolution: The boom in agriculture led to the manufacture of machinery and processes which turned grains into flour, extracted oil from vegetables at high temperatures and produced refined white sugar. Yet more machinery and processes turned these ingredients into hyper-palatable foods that also happened to be low in nutrients. This (combined with the power of convincing advertising designed to appeal to our desire for convenience) plays a major role in the food choices we tend to make. It has been about six thousand generations since the onset of the Industrial Revolution. With it came the trappings of modern life – mass production, urbanisation and the creation of desk jobs.

While modern life has its perks, it is also responsible for:

  • Increased stress and less emphasis on play and fun
  • Poor quality – and duration – of sleep
  • A rise in the popularity of moving a lot less of our bodies in relatively short blocks of time whilst remaining sedentary the rest of the day
  • Eating at our desks or grabbing something readymade from the supermarket to have on the go

Foods To Include And Why 

Organic is, of course, ideal. This is because herbicides and pesticides (and the foods from animals that ingest plants sprayed with them) are thought to contribute to Parkinson’s symptoms[1] and also initiate and promote the cancer process. That said, buy the best quality you can afford as it is better to eat the foods listed below than to go without.

  • Animal protein: Meat, offal/organ meats, wild game, poultry, fish, seafood [2],[3] and eggs are absolutely vital for the production of neurotransmitters required for neurological health (including dopamine). They are also crucial for the building and maintenance of muscle mass. While I appreciate and respect the fact that not everyone wishes to eat animal protein for various reasons (religious or otherwise), it is important to know the impact that this will have on health. In such situations, it is vital that you work with a nutritionist to help you optimise your diet as best you can.
  • An extremely diverse and rainbow-coloured range of non-starchy vegetables, tubers and starchy plants [3] like sweet potatoes. Studies show that antioxidants found in brightly coloured vegetables (and fruits) are protective against cardiovascular disease, cancer and dementia[4].
  • Fruits[4]: Choose whole, fresh fruits (instead of dried) and favour berries over tropical fruits, apples, pears and grapes.
  • Nuts and seeds: These are a great source of healthy fats. Soak and dry them at low temperatures before eating.*
  • Fermented foods (and drinks): Sauerkraut, kimchi, beet kvass, kombucha and water kefir provide food for beneficial bacteria in the gut[5]. There is a direct link between the gut and the brain which means that the health of the gut is dependent on the health of the brain and vice versa. Fermented foods are also rich in vitamins and antioxidants.
  • Healthy fats: Ghee, tallow, lard, avocado oil and coconut oil are great for cooking while avocados and olives are satisfying snacks. They also contain fat-soluble vitamins (A, D, E, K1 and K2).
  • Herbs and spices: Despite having some of the highest concentrations of beneficial phytochemicals of any plant food, herbs and spices are typically underrated and often used as an afterthought. Experiment with as many different kinds as possible to get the broadest range of nutrients possible. They are, of course, also bursting with flavour and can elevate a mundane dish into something you can really look forward to eating.

*This is necessary for the removal of substances called anti-nutrients that are contained in certain plants and used as a means to protect their nutrient stores. Anti-nutrients inhibit the absorption of nutrients from the foods in which they are housed and also impair digestion. The indigestion and suboptimal health that humans experience as a result is nature’s way of discouraging us from relying too heavily on such plants for food in future.

Additionally, the foods below can be eaten in small to moderate amounts but only after they have been found to be well-tolerated following a 30- to 90-day elimination and a subsequent reintroduction period. The following are worth bearing in mind:

  • Buckwheat: Despite its name, buckwheat is not at all related to wheat and is a seed rather than a grain. It is best eaten no more than three times a week and with the more nutritious foods listed above. This is because it is not particularly nutrient-rich and also contains anti-nutrients – though in much lower levels than grains. It, therefore, requires soaking, fermenting and sprouting before cooking to make it more digestible and to make what little nutrients it does contain more likely to be absorbed.
  • Beans and pulses (e.g. chickpeas): These also contain anti-nutrients and require soaking, fermenting and sprouting (before cooking) to make them more digestible. Contrary to popular belief, they mainly contain carbohydrates and are not a like-for-like equivalent of animal proteins. The protein found in legumes is mainly bound to fibre and is, therefore, indigestible to humans. Even if plant proteins were readily digestible and easily absorbed, they cannot make significant amounts of dopamine (and other neurotransmitters required for neurological health) nor can they build and maintain muscle mass. Beans and pulses can be included in your diet (once you have met the criteria above) as sources of carbohydrate.
  • Dairy: More recently, there has been a sharp increase in dairy consumption. This is partly due to the rise in dairy farming and also due to the further evolution of certain populations with regards to the ability to digest lactose into adulthood (lactase persistence)[6][7]. If you discover (via the elimination process above) that you do not have this tendency and find dairy difficult – or impossible – to tolerate, you would be better off avoiding it and getting its nutrients elsewhere. Dairy is a great source of retinol, vitamin K2 and calcium, if tolerated.

Foods To Avoid And Why

Everything (except alcohol) on the following list is commonly found in processed, readymade foods – which you are better off avoiding, anyway.

  • Cereal grains: Thanks to slick and relentless marketing, foods like those made from wheat (bread) and oats (porridge) are believed to be healthy ways to start the day. To add to the confusion, artisan and slow food movements are passionate advocates for sourdough bread and other baked-from-scratch goods as part of a healthy diet. Despite the logical notion that making it yourself makes it better for you, these foods (and grains in general) are still lacking in the substances that have a positive impact on health and contain substances (like phytic acid, as mentioned previously) that actively prevent the absorption of what little nutrients they contain. Additionally, studies show that gluten sensitivity remains underrecognized as a major contributing factor to psychiatric and neurologic disorders – including the same motor symptoms seen in Parkinson’s disease[8][9].
  • Industrial seed oils: Often described as vegetable oils, these fragile fats degrade remarkably easily sitting on a shelf and even more so when heated. They include rapeseed oil, sesame oil, sunflower oil, etc. and are often thought of as healthy. Heating destroys any vitamins and antioxidants in these oils and creates substances called trans fats. It is important to mention that naturally occurring trans fats (present in the fats listed in the Foods To Eat section above) are shelf- and heat-stable and beneficial for health. Trans fats from industrial seed oils have been shown to increase the risk of obesity, heart disease and cancer while animal-derived trans fats are known to decrease the risk of these conditions[10][11].
  • Refined sugar and artificial sweeteners: We all know that refined sugar is neither necessary nor beneficial for health. It is high in calories, devoid of nutrients and extremely easy to overeat. It also feeds non-beneficial bacteria in the gut, leading to suboptimal gut health which – in turn – affects brain health via the gut-brain axis. In long-term studies, consumption of artificial sweeteners showed an increased incidence of cardiovascular events, metabolic syndrome and type 2 diabetes[12]. As this was an observational study (with participants themselves reporting on how much artificial sweeteners they consumed), the jury is still out on the safety of artificial sweeteners. Erring on the side of caution by avoiding them is best.
  • Processed and unfermented soy: This is a recent addition to the human diet produced using techniques that denature the proteins within, making them harder to digest[13]. As it is difficult to know their effect on long-term health, processed soy (in the form of flour, milk, protein powder, isolate, etc.) are best avoided.
  • Alcohol: This is known to interact with certain dopaminergic and central nervous system medications. Drinking alcohol if you have been prescribed Levodopa is known to increase the risk of low blood pressure, for example[14].

The Bottom Line

Change takes time, consistent effort and requires a helping hand to make the transition from one deeply entrenched way of eating to another as painless as possible. Attempting to improve your diet is a complex process and can be overwhelming – especially with all the internet noise disguised as information.

If in doubt, remember:

  • It’s true that you are what you eat. You are also what your – beneficial and non-beneficial – bacteria eat, what you do or do not absorb and what you do or do not detoxify.
  • There is no one-size-fits-all. The same food that enables a person to thrive may enable another to merely survive. A registered nutritionist can order relevant tests to assess your baseline nutrient (and overall gut health) status and help you create a personalised diet that works for you.

I support people living with Parkinson’s and cancer at my clinics in Oxfordshire and Warwickshire as well as online. Book a complimentary 20-minute Introductory Session today to see how I can be of help.


  1. Nandipati, S. and Litvan, I. (2016). Environmental Exposures and Parkinson’s Disease. International Journal of Environmental Research and Public Health, [online] 13(9), p.881. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5036714/
  2. Ferraro, J.V., Plummer, T.W., Pobiner, B.L., Oliver, J.S., Bishop, L.C., Braun, D.R., Ditchfield, P.W., Seaman, J.W., Binetti, K.M., Seaman, J.W., Hertel, F. and Potts, R. (2013). Earliest Archaeological Evidence of Persistent Hominin Carnivory. PLoS ONE, [online] 8(4), p.e62174. Available at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0062174
  3. Hardy, K., Brand-Miller, J., Brown, K.D., Thomas, M.G. and Copeland, L. (2015). The Importance of Dietary Carbohydrate in Human Evolution. The Quarterly Review of Biology, [online] 90(3), pp.251–268. Available at: https://core.ac.uk/reader/191983512?utm_source=linkout
  4. Joseph, J., Cole, G., Head, E. and Ingram, D. (2009). Nutrition, Brain Aging, and Neurodegeneration. Journal of Neuroscience, [online] 29(41), pp.12795–12801. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6665319/
  5. Tillisch, K., Labus, J., Kilpatrick, L., Jiang, Z., Stains, J., Ebrat, B., Guyonnet, D., Legrain–Raspaud, S., Trotin, B., Naliboff, B. and Mayer, E.A. (2013). Consumption of Fermented Milk Product With Probiotic Modulates Brain Activity. Gastroenterology, [online] 144(7), pp.1394-1401.e4. Available at: https://pubmed.ncbi.nlm.nih.gov/23474283/
  6. Krüttli, A., Bouwman, A., Akgül, G., Della Casa, P., Rühli, F. and Warinner, C. (2014). Ancient DNA Analysis Reveals High Frequency of European Lactase Persistence Allele (T-13910) in Medieval Central Europe. PLoS ONE, [online] 9(1), p.e86251. Available at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0086251
  7. Ranciaro, A., Campbell, Michael C., Hirbo, Jibril B., Ko, W.-Y., Froment, A., Anagnostou, P., Kotze, Maritha J., Ibrahim, M., Nyambo, T., Omar, Sabah A. and Tishkoff, Sarah A. (2014). Genetic Origins of Lactase Persistence and the Spread of Pastoralism in Africa. The American Journal of Human Genetics, [online] 94(4), pp.496–510. Available at: https://www.cell.com/ajhg/fulltext/S0002-9297(14)00067-6#secsectitle0010
  8. Jackson, J.R., Eaton, W.W., Cascella, N.G., Fasano, A. and Kelly, D.L. (2011). Neurologic and Psychiatric Manifestations of Celiac Disease and Gluten Sensitivity. Psychiatric Quarterly, [online] 83(1), pp.91–102. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3641836/
  9. Vinagre-Aragón, A., Zis, P., Grunewald, R. and Hadjivassiliou, M. (2018). Movement Disorders Related to Gluten Sensitivity: A Systematic Review. Nutrients, [online] 10(8), p.1034. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115931/
  10. Bowman, G.L., Silbert, L.C., Howieson, D., Dodge, H.H., Traber, M.G., Frei, B., Kaye, J.A., Shannon, J. and Quinn, J.F. (2011). Nutrient biomarker patterns, cognitive function, and MRI measures of brain aging. Neurology, [online] 78(4), pp.241–249. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3280054/
  11. Gebauer, S.K., Chardigny, J.-M., Jakobsen, M.U., Lamarche, B., Lock, A.L., Proctor, S.D. and Baer, D.J. (2011). Effects of Ruminant trans Fatty Acids on Cardiovascular Disease and Cancer: A Comprehensive Review of Epidemiological, Clinical, and Mechanistic Studies. Advances in Nutrition, [online] 2(4), pp.332–354. Available at: https://academic.oup.com/advances/article/2/4/332/4591508?login=true
  12. Azad, M.B., Abou-Setta, A.M., Chauhan, B.F., Rabbani, R., Lys, J., Copstein, L., Mann, A., Jeyaraman, M.M., Reid, A.E., Fiander, M., MacKay, D.S., McGavock, J., Wicklow, B. and Zarychanski, R. (2017). Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. Canadian Medical Association Journal, [online] 189(28), pp.E929–E939. Available at: https://www.cmaj.ca/content/189/28/E929
  13. Fao.org. (2021). Technology of production of edible flours and protein products from soybeans. [online] Available at: http://www.fao.org/3/t0532e/t0532e00.htm
  14. NICE – The National Institute for Health and Care Excellence (2021). BNF: British National Formulary – NICE. [online] Nice.org.uk. Available at: https://bnf.nice.org.uk/interaction/levodopa.html

Chi Feasey

I’m a registered nutritionist, Kresser Institute Trained Practitioner and your ally in your mission to have the best quality of life possible. I help people like you tap into the physical and emotional resources you already have – but may have lost sight of – so that you can live as fully as possible despite having a chronic illness.


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