The connection between nutrition and stress

15 September 2020 - 6-8 minute read

Stress and diet go hand in hand, especially during these unprecedented times. Our nutrition experts consider the inextricable scientific link between the two, and suggest some delicious recipes to help you eat healthier - and feel healthier too.

With all the added worries and concerns that COVID-19 has brought to our everyday lives, taking good care of our mental health has never been more important. Some NZ scientists have already predicted a rise in post-traumatic stress disorder (PTSD) as an aftermath of the virus1. Stress and diet have a complex interplay with each other and it’s evident that someone eating a healthy, balanced diet is going to have far less impact on their health under stressful situations than someone eating a poor diet. As is the case with other health concerns, the right kind of food choices can have a healing impact on our bodies in these challenging and difficult times as well.

What is stress?

Biologically speaking, stress is the response of the body to any demand for change2. It might be your body reacting to climbing a hill – your heart rate increases – or resolving conflict between children – your brain becomes hyper alert. Whatever the cause, stress is a natural part of everyday life and the way we react to these stressors can critically affect the way our bodies function3. Severe and prolonged stress exposure - something that many people now experience in their daily lives - can impair various bodily systems, and can even affect the way our organs work.

A “stressor” can be anything and can vary in intensity. People have different abilities of coping with an event in their life, whether it be physical or emotional. Chronic psychological stress has profound effects on human health and wellbeing, and it is generally accepted that psychological stress is a burgeoning public health problem in modern day life4. The good news is that as with many health issues, food can be the superhero, and can make a massive difference to the way your body functions.

What exactly happens in the body under stressful conditions?

Stress is usually subdivided into 2 categories:

  1. Acute stress - short-lived situations related to our “fight or flight” response. These everyday small stressors, such as coping with children, deadlines at work, financial or relationship difficulties can also add up and become;
  2. Chronic stress – stress that has built up over time due to constantly being in conflicting, demanding or high-pressure situations.

Acute stress may not disrupt the body’s mechanisms too much, apart from slightly elevating the heart rate, and increasing the breathing. Generally, these changes in the body will go back to normal as soon as the stressful situation is alleviated. In contrast, chronic stress from constant high-pressure situations can wreak havoc on the body’s systems.

Under stressful situations, your body produces several hormones, namely cortisol, adrenaline and noradrenaline. These hormones affect most areas of the body, interfering with sleep and also leading to or exacerbating several metabolic and psychological disorders, including anxiety, depression and psychosis. Researchers have investigated the relationships between stress and many different medical problems such as cardiovascular diseases and even diabetes5.

Interestingly, stress also affects your gut and the digestive system, big time.

Have you ever felt butterflies in your stomach? Or ever felt nauseous because of nervousness? Expressions like, “gut-feeling”, or “trust your gut” are much more than just metaphors. Your gut truly is your “second-brain”, responsible for maintaining the body’s microbiota (the millions of good bacteria in the body) which in turn helps your immunity. Two major neurotransmitters in the body - Serotonin and Dopamine - are both mood-enhancers, and are produced in the gut.

Hence, stress and your immunity and mood are intricately linked to each other.

Nutrition, diet and stress - what’s the link?

2,500 years ago, Hippocrates recognized the link between wellbeing and food, stating, “Let food be thy medicine”. Ironically, all these years on it seems the wisdom of that phrase has been forgotten. Not many people look beyond the simple food they eat for answers, instead turning to easier and more accessible pharmacological remedies.

Food holds enormous healing powers and can be used not just for preventative health but also for relieving symptoms, such as various types of inflammation and pain. In fact, the ‘imbalance’ in the body’s natural ‘balance’ (or homeostasis) caused by stress can be greatly improved by the kind of foods consumed. Yes! Food can help your body deal with stress.

There is plentiful scientific data that proves a direct correlation between stress and appetite. Chronic exposure to stress leads to greater production of certain types of neurotransmitters (the body’s chemical messengers) which can increase appetite. Perhaps you’ve even felt the results of this process. For example, have you sometimes felt insatiably hungry when you’re under stress? The “stress hormone”, cortisol, can also blur your taste sensitivity, which explains why overeating is a common phenomenon while under high-pressure situations6.

In 2001, a study which induced stress to observe the changes in food intake, observed binge eating and unrestrained eating. This included an increased intake of highly palatable, energy-dense foods (that’s right, we’re talking big bags of crunchy, salty chips!) and a decreased intake of high-fibre, low fat foods (that’d be your veggies)7. So, not only do people under stress tend to eat more in general, they also tend to eat more calorie-dense, “hyper-palatable foods”, (i.e. foods designed to be addictive) while shirking on the vegetables and fruit.

Stress can also make some people skip or forget to eat their meals. Hence causing an “anorectic” effect which leads to a decreased sensation of hunger, and in turn less consumption of nutritious food8.

Both situations show that for those living under constant stress, the result is often nutritional insufficiency. The physiological basis of stress-eating and individual differences in stress-related food intake are unknown, but are related to the interplay between various stress-hormones in the body9.

Food for mood – which are the important nutrients?

Your brain consumes 20% of your daily energy and other nutrients, so it’s pretty evident how a poor diet can alter how well it functions. You may even notice a ‘brain fog’ if you are not taking care of yourself.

A healthy diet can have a positive effect on brain health by supplying key nutrients and increasing the blood flow for optimum functioning of the brain. Indeed, there are certain “functional foods” whose inclusion in the diet has shown significant improvements in stress-reduction and perceived stress.

Carbohydrates

The first is complex carbohydrates. Carbohydrates work by increasing the absorption of tryptophan (amino acid) in the body and increasing the production of serotonin: a calming/mood enhancing neurotransmitter synthesized from dietary tryptophan. The relationship is quite directly proportional8.

Interestingly, even simple carbohydrates can increase the uptake of tryptophan in the body, but the serotonin produced has a short life and declines as rapidly as it was increased; which is the same case with energy produced by simple carbs, like white bread, cake, muffins or lollies.

In addition, these carbs (whole, non-processed food sources) also ensure ample amounts of fibre and other essential nutrients in your diet. Adequate fibre means good gut health - and as your gut is your “second brain”, be sure to include a portion of complex carbs in your main meals.

Sources of complex carbs include:

  • Whole grains - wholewheat breads, buckwheat, quinoa, oats, barley, etc.
  • Lentils and legumes - chickpeas, brown lentils, red & yellow lentils, soy beans, etc.
  • Fruits and vegetables - carrots, peas, broccoli, beans, onions, etc.

Check out this recipe for a good source of energy-giving complex carbs - https://feelfreshnutrition.com/blog/2019/7/31/quinoa-feta-and-mint-salad-with-easy-honey-mustard-dressing?rq=quinoa

Protein

Another important nutrient necessary in adequate amounts is protein. Why? Because a consistent supply of protein provides the body with a certain type of amino acid called Tyrosine. It is tyrosine that is further broken down to produce another neurotransmitter called Dopamine. Dopamine plays an important role in cognitive function, motivation and feelings of pleasure.

By eating foods rich in tyrosine, the brain will be able to synthesize dopamine.

Sources of tyrosine include:

  • Fish - salmon, mackerel and sardines
  • New Zealand grass fed cattle
  • Chicken
  • Turkey
  • Eggs - eggs also contain choline, which is necessary for neurotransmission
  • Low-fat milk and milk products

Check out this recipe for an excellent protein source - https://feelfreshnutrition.com/blog/2019/6/27/pesto-crusted-salmon?rq=salmon

Antioxidants

The effects of dietary antioxidants on memory and disease prevention is widely documented and scientifically backed. These antioxidant nutrients include Vitamin A, C, E, selenium and magnesium.

Studies have shown that a decline in memory with age correlates with lower levels of antioxidants10. Several studies have also reported delayed progression of Alzheimer’s and dementia with Vitamin E supplementation11,12. Moreover, consuming foods rich in Vitamin C supports immune strength, plus reduces the levels of cortisol and other stress hormones13.

Both selenium and magnesium help in cell repair and prevent degeneration. A bio-active compound called Resveratrol also exerts excellent antioxidant capacity8.

Sources of foods rich in antioxidants:

  • Citrus fruits
  • Carrots
  • Dark chocolate
  • Kale
  • Acai
  • Spinach
  • Berries - raspberries, goji, blueberries, etc.

Check out this antioxidant-rich recipe- https://feelfreshnutrition.com/blog/2019/6/26/mini-egg-and-vegetable-muffins

Omega 3

The brain needs Omega 3 fatty acids for production of healthy nerve cells. It has been reported that Omega 3 fatty acids are associated with lower risks of depression and other psychotic illnesses14.

Two major types of Omega 3’s - DHA (ducosahexanoic acid) and EPA (eicosapentanoic acid) - play a strong role in turning on the gene that produces serotonin, another feel-good hormone. They can therefore act as natural antidepressants.

Sources of Omega 3:

  • Fish - salmon, herring, sardines, tuna, trout
  • Certain oils - canola, rice bran, walnut oil, soybean oil, etc.
  • Nuts and seeds - flax seeds, sunflower seeds, walnuts
  • Hemp
  • Chia seeds
  • Seaweed and algae like spirulina
  • If you feel you don’t get enough of the foods above, you can also supplement with fish oil

Check out this recipe for yummy seeded crackers - https://feelfreshnutrition.com/blog/2019/7/4/easy-seed-crackers

Vitamin B

Vitamin B-complex plays a huge role in the maintenance of our body’s nervous system. One of the B vitamins is folic acid, believed to relieve stress, anxiety, panic and even depression. Amongst this group of vitamins, perhaps the most important one is Vitamin B5; also called the anti-stress vitamin, it has the ability to support the adrenal glands and promote resilience.

Sources of Vitamin B:

  • Dark green, leafy vegetables like spinach and kale
  • Brussel sprouts and cabbage
  • Whole grain cereals
  • Peanuts
  • Asparagus
  • Fish and poultry

Check out this recipe, loaded with vitamin B - https://feelfreshnutrition.com/blog/2019/6/8/peanut-satay-stir-fry?rq=brussel%20sprouts

L-Theanine

L-theanine is gradually gaining importance; not only can it act as a potent antioxidant but it can also have tranquilizing effects on the brain. It increases the alpha waves in the brain which in turn relaxes and reduces stress - all without causing drowsiness.

Sources of L-Theanine:

  • Tea remains the richest sources of L-theanine, especially black and green tea

Bringing theory to practice – Top Tips

  1. Eat a variety of different coloured fruits and vegetables in order to include various antioxidants
  2. Include herbs and spices in your diet. Herbs like thyme, cilantro, garlic and ginger not only enhance the taste and flavour of foods, but are also loaded with bioactive compounds which are health-protective in various ways
  3. Consume free range meat and poultry to avoid the risk of contamination with antibiotics and synthetics
  4. Make Omega 3s a part of your daily life
  5. Ensure adequate fibre in your diet

The nutritionists at Feel Fresh Nutrition are happy to create customized meal plans personalised for you and your family, complete with pictures, recipes, and nutritional information. Visit their website to see their reduced online pricing. www.feelfreshnutrition.com


References:

  1. https://www.nzdoctor.co.nz/article/undoctored/future-now-implications-covid-19-new-zealand
  2. WebMD. Stress Management Health Center - Stress Management-Effects of Stress. http://www.webmd.com/balance/stress-management/stress-management-effects-of-stress
  3. Selye, H. (1980). The Stress concept today. Dutash IL, Schlesinger LB. Handbook of Stress and Anxiety. Jossey-Bass Inc, London, pp127-143.
  4. Laugero KD. et al. (2011) Relationship between perceived stress and dietary and activity patterns in older adults participating in the Boston Puerto Rican Health Study, Appetite. 56(1): 194–204.doi: 10.1016/j.appet.2010.11.001
  5. Ohman L, Nyberg L, Bergdahl J, Nilsson LG (2007) Longitudinal analysis of the relation between moderate and long-term stress and health. Stress and Health. Journal of the International Society for the Investigation of Stress 23: 131-138.
  6. Bray, G: Autonomic and Endocrine factors in the regulation of food intake. Brain Research Bulletin 14, 505-510,1985. DOI:10.1016/0361-9230(85)90098-x
  7. Epel, E. et al. (2001) Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behaviour. Psychoneuroendocrinology. 26(1):37-49. DOI: 10.1016/S0306-4530(00)00035-4
  8. Dallman, MF. et al. (2003) Chronic stress and obesity: a new view of "comfort food". Proc Natl Acad Sci U S A. 100(20):11696-701. doi: 10.1073/pnas.1934666100
  9. Singh, K. (2016) Nutrient and Stress Management. J Nutr Food Sci, 6: 528. doi:10.4172/2155-9600.1000528
  10. Harvard T.H. Chan. Antioxidants. https://www.hsph.harvard.edu/nutritionsource/antioxidants/
  11. Sano, M. et al. (1997) A Controlled Trial of Selegiline, Alpha-Tocopherol, or Both as Treatment for Alzheimer's Disease. https://www.nejm.org/doi/full/10.1056/NEJM199704243361704.
  12. Cervantes, B. et al, (2017). Vitamin E and Alzheimer’s disease - Is it time for Personalized medicine? Antioxidants; 6(3): 45. Published online 2017 Jun 24. doi: 10.3390/antiox6030045
  13. Kandhalu, P. (2013) Effects of cortisol on physical and psychological aspects of the body and effective ways by which one can reduce stress. https://bsj.berkeley.edu/wp-content/uploads/2013/11/04-FeaturesEffects-of-Cortisol_Preethi-KandhaluKim.pdf
  14. Montgomery, P et al. (2013) Low blood long chain omega-3 fatty acids in UK children are associated with poor cognitive performance and behavior: a cross-sectional analysis from the DOLAB study. PLoS One; 8(6):e666976
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Eating Well
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Covid-19