You are What You Eat

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Tempeh with quinoa, bulgur, purple cabbage and greens

The idea that gut health is essential for overall health is not new. Almost 2500 years ago, Hippocrates said that ‘all disease begins in the gut’, and he wasn’t far from the truth.

Good diet is one of the pillars of good health; if we eat well we will nourish our bodies with all the micro and macro nutrients, all systems will function well, and our gut will be healthy. Plenty of research studies found links between poor gut health and mental health disorders as well as autoimmune, neurological, endocrine, gastrointestinal and cardiovascular disorders, cancer and obesity. Gut health mainly depends on your gut microbiota, the community of trillions of microorganisms living in the gastrointestinal tract. You get your gut microbiota at birth, but later in life, it’s mainly influenced by what you eat, positively or negatively impacting your health.  

Microbiota-Brain-Gut Axis 

The human body is an intricate web of interconnected systems, and our homeostasis depends on all systems working well - the relationship between the gut and the brain is a testament to this. This intricate communication network, or the gut-brain axis, is vital to our health and well-being. Scientists have observed that different emotional states can affect our digestion since the 19th century. But, it also works the other way around; the gut sends signals to the brain, influencing your mood, emotions, and cognitive functions. Over the past two decades, however, there has been a growing recognition that the microbiota plays a critical role in the gut-brain function. 

The microbiota-gut-brain axis refers to the bidirectional communication system between the gut microbiota, the gut, and the brain. This communication occurs through multiple pathways, including the immune system, the vagus nerve, and the enteric nervous system (often referred to as the ‘second brain’). Essentially, it means that the health and composition of the gut microbiota can influence brain function and vice versa. This axis has implications for a wide range of physiological processes, including digestion, mood regulation, cognition, and even behaviour. 

Gut health for overall health 

The influence of the gut on mental health has gained significant attention in recent years. Research has shown that the gut microbiota plays a crucial role in this connection. The gut microbiome produces neurotransmitters, such as serotonin and dopamine, essential for mood regulation. Any imbalance in the gut microbiome can potentially impact mental health, leading to conditions such as anxiety and depression. It has also been linked to autism.  

Beyond mental health, the brain-gut connection is vital in regulating the immune system. The gut houses a significant portion of the body’s immune cells and is the first line of defence against pathogens entering the body through food. The communication between the gut and the immune system is intricate, with the gut microbiome playing a crucial role in modulating immune responses. Disruptions in the brain-gut-immune axis can lead to various health issues, including autoimmune diseases, allergies, and inflammatory conditions. 

Emerging research suggests a potential link between the brain-gut connection and neurological disorders, including Alzheimer’s disease and Parkinson’s disease. Studies have shown that changes in the gut microbiota composition may contribute to the development and progression of these disorders. The bidirectional communication between the gut and the brain also implicates the gut in influencing neuroinflammation, a common feature in many neurological conditions.

These are just some of the well-researched positive correlations between poor gut health and disease; there are many more.

The good, the bad (and the ugly)

A healthy gut contains a diverse community of microorganisms, including both good and potentially harmful bacteria. It is the balance between these populations that’s crucial. When the balance is disrupted, it can lead to dysbiosis, where harmful bacteria overgrow, causing various health issues. Healthy microbiota contains many good bacteria essential in digestion, nutrient absorption, immune system function, and mental health. They help break down food, produce vitamins like B and K, and maintain the integrity of the intestinal lining. On the other hand, harmful bacteria can cause infections, inflammation, and digestive disorders (gas, constipation, diarrhoea, heartburn, IBS), which can produce toxins and interfere with the balance of other microorganisms. Apart from digestive disorders, symptoms of possible overgrowth of harmful bacteria can include chronic fatigue, sleep issues, mood disorders such as anxiety or depression, skin rashes, sugar cravings, weight gain, allergies, high frequency of infections (common cold, for example) and so on. 

Put in plain language, what you consume feeds either good or bad bacteria. You feed your bad gut bacteria with processed foods (due to additives, preservatives, saturated fat content etc), refined sugar, meat (especially red meat), dairy, foods containing antibiotics (such as most meat), fried foods and alcohol. In addition, foods you are intolerant to (and may not know) can damage your gut health. In addition, unhealthy lifestyles such as lack of exercise, poor sleeping habits, smoking and stress can all cause bad gut microorganisms to flourish. 

Foods for a healthy gut 

Prebiotic and probiotic food promote the growth and activity of beneficial bacteria in the digestive system and a healthy gut. Prebiotics are non-digestible fibres found in many plant-based foods. Common sources of prebiotics include certain fruits, vegetables, whole grains, and legumes. Jerusalem artichokes, garlic, leeks, and onions are the most prebiotic-dense foods, but they can be found in many plant-based foods such as bananas, avocado, asparagus, oats, barley, cacao, mushrooms, beans, etc. Eating a diverse, plant-based diet means you don’t need to worry about prebiotics. 

Probiotics are live microorganisms, typically bacteria or yeasts. They can be found in fermented foods such as tempeh, kimchi, sauerkraut, miso paste, pickled veggies, and sourdough bread, as well as drinks such as kombucha and water-based kefir. You can also take probiotic supplements, of course, but if you consume one of these foods daily, there is no need for supplements. In periods of increased mental, emotional or physical stress, when I don’t sleep so well, or when I travel, I might take probiotic supplements or simply increase the foods and drinks containing them. 

You are what you eat 

Eating well is one of the pillars of good health and well-being. Plenty of research shows that a plant-based diet is superior to other diets concerning healthier gut microbiota that can help us stay healthy or even heal. But for me, ‘you are what you eat’ extends further than a healthy gut. By avoiding foods that can not only harm my body but, perhaps more importantly, the environment and innocent beings, I choose more than just health. You are what you eat not only because your food choices can make you healthier and happier but also because they can make you a more compassionate, kind and aware human being. 

References:

Beam, A., Clinger, E. and Hao, L. (2021) ‘Effect of Diet and Dietary Components on the Composition of the Gut Microbiota’, Nutrients, 13(8), pp. 2795-. Available at: https://doi.org/10.3390/nu1308279 

Gershon, M.D. and Margolis, K.G. (2021) ‘The gut, its microbiome, and the brain: connections and communications’, The Journal of clinical investigation, 131(18). Available at: https://doi.org/10.1172/jci143768.

Gulati, G. and Mulryan, D. (2021) ‘The Psychobiotic Revolution: Mood, Food and the New Science of the Gut-Brain Connection’ Edited by Scott C. Anderson John F. Cryan and Ted Dinan 320 pp. ISBN 9781426218460. National Geographic, Washington, DC, 2017’, Irish journal of psychological medicine, 38(3), pp. 240–240. Available at: https://doi.org/10.1017/ipm.2018.26.

Hou, K. et al. (2022) ‘Microbiota in health and diseases’, Signal transduction and targeted therapy, 7(1), pp. 135–135. Available at: https://doi.org/10.1038/s41392-022-00974-4.

Hyland, N. and Stanton, C. (eds) (2016) The gut-brain axis : dietary, probiotic, and prebiotic interventions on the microbiota. London: Academic Press.

Inchingolo, A.M. et al. (2023) ‘Interconnection between Microbiota-Gut-Brain Axis and Autism Spectrum Disorder Comparing Therapeutic Options: A Scoping Review’, Microorganisms (Basel), 11(6), pp. 1477-. Available at: https://doi.org/10.3390/microorganisms11061477.

Kassam S. et al. (2022) ‘Plant-Based Nutrition in Clinical Practice’ Hammersmith Health Books

Lee, Y. and Kim, Y.-K. (2021) ‘Understanding the Connection Between the Gut–Brain Axis and Stress/Anxiety Disorders’, Current psychiatry reports, 23(5), pp. 22–22. Available at: https://doi.org/10.1007/s11920-021-01235-x.

 Liang, S., Wu, X. and Jin, F. (2018) ‘Gut-Brain Psychology: Rethinking Psychology From the Microbiota-Gut-Brain Axis’, Frontiers in integrative neuroscience, 12, pp. 33–33. Available at: https://doi.org/10.3389/fnint.2018.00033.

Sakkas, H. et al. (2020) ‘Nutritional Status and the Influence of the Vegan Diet on the Gut Microbiota and Human Health’, Medicina (Kaunas, Lithuania), 56(2), pp. 88-. Available at: https://doi.org/10.3390/medicina56020088.

Tomova, A. et al. (2019) ‘The Effects of Vegetarian and Vegan Diets on Gut Microbiota’, Frontiers in nutrition (Lausanne), 6, pp. 47–47. Available at: https://doi.org/10.3389/fnut.2019.00047.

Wekerle, H. (2016) ‘The gut-brain connection: triggering of brain autoimmune disease by commensal gut bacteria’, Rheumatology (Oxford, England), 55(suppl 2), pp. ii68–ii75. Available at: https://doi.org/10.1093/rheumatology/kew353.

Plant-based complete protein sources

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Tempeh with rice and greens

Another prevailing protein myth is that complete protein is only available from animal sources. Apart from being untrue, the belief that we must get all the essential amino acids from one source is entirely unfounded. But let's start at the beginning.

What does a complete protein refer to?

Our bodies use amino acids from food to make protein which is then used for many essential physiological functions, as explained in part one of this blog series. Two main amino acid groups are essential and nonessential. Our bodies can produce nonessential amino acids, but not the nine essential ones that must come from food. A food source which contains all nine essential amino acids are referred to as a complete protein source.

Complete protein plant-based sources

While foods that come from animal sources have all nine essential amino acids, some plant-based foods are also considered complete proteins. These are soy and soy-derived foods such as tofu and tempeh, hemp (seeds, powders), quinoa, chia seeds, buckwheat, amaranth, and spirulina.

Does it matter?

But is it vital that you get all the nine essential amino acids from one food item? The short answer is no. Just as you don't need to get all your vitamins and minerals from one food item, the same goes for the essential amino acids. Your body does not care if it gets what it needs from one food item or three, even one meal or three combined; it cares that it gets the macronutrients and micronutrients it needs from various food sources. In fact, the more variety on your plate and your meals, the more likely you will nourish your body with all it needs.

Bottom line

Even if you don't include tofu, quinoa or hemp seeds in your meal, combining different foods will provide the needed amount of complete protein. Legumes combined with wholegrains will amount to a complete protein, such as beans with rice, hummus with wholegrain pitta, or peanut butter on wholegrain toast. So, nothing complicated; all simple meals and snacks provide complete protein.

Variety is key, but it does not need to be complicated. Just sprinkle seeds on your soup, add a few nuts to your salad, ensure that you include good carbs and fats in your meals and don’t worry about protein!;)

Plant-based protein sources

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When it comes to diet myths, some are more persistent than others, and the one that gets a gold medal for persistence is certainly the protein myth. I can't count the number of times I had a protein discussion with people, hoping I won't have to one day. This is my effort towards that day:). I will break down this subject into three parts, answering three questions - "where do you get your protein from?", "what about B12?" and "what about complete protein sources?

What is protein?

Protein is an essential macronutrient. It is the building block of our muscles, bones, skin and other tissue; we need it for growth, repair and maintenance of muscles and bones. Our connective tissue is made of collagen, one of the main types of protein in the body. Haemoglobin, an important molecule that transfers oxygen in the blood from the lungs into the tissues, is another. Proteins are molecules made out of over 20 amino acids. Nine of these are called "essential" because they cannot be made by our body; they need to be provided through food. We will return to those in the final post of the protein series.

How much protein do you need?

The answer is - it depends. If a couch potato is on one end of the scale and an endurance athlete on another, where are you? If you find yourself somewhere in the middle, meaning you might have a sedentary job, but you exercise at least 30 min a day and have your pedometer set to 10000 steps, and you adhere to it religiously, you'll need 0.8 grams per kilo body weight. In my case, that is about 45 grams which I round up to 50-55 due to daily exercise and because plant-based protein sources can be less digestible, so it is recommended to increase the protein intake by about 10%. If you're a couch potato, it's still advisable to eat 0.8 grams, but you could do with less (less calories in general). But, according to the International Society of Sports Nutrition, If you are an endurance athlete, you might want to increase your intake to 1.4 - 1.6 grams per kilo body weight as energy expenditure, especially during peak training, is huge. Children also require a bit more protein per day as well as pre-natal (+6 grams) and post-natal women (+11 for the first 6 months of lactation, +8 for the next six months). Finally, it is good to know that our body cannot store extra protein, so once the needs are met, the remaining energy is stored as fat. In fact, protein deficiency does not exist in the developed world, regardless of diet choice. However, obesity does alongside of micronutrient and fibre deficiency due to unhealthy, processed food diets.

Where do you get your protein (on a plant-based diet)?

There's protein in everything, not only meat, fish and dairy. You might find it surprising that, for example, two tablespoons of peanut butter on toast contains more protein than an egg (8g vs 6g). Three tablespoons of hemp seeds = 9 grams of protein. 100 grams of lentils contains over 20 grams of protein. 100 grams of tofu contains 10-15 g of protein per 100 grams (firm more than soft), while 100 g of tempeh is around 20 grams (and no, soy is not bad for you, I will write about that some other time). 100 grams of white beans contain 8 grams of protein, and mung beans 7 grams. Beans, peas, lentils, nuts, seeds and grains are all a great source of plant-based protein.

Below is an example of breakfast, lunch and dinner (recipes below). Even with 1300 calories (less than an average person needs if not on a restrictive diet), these three meals will get you 58,4 g of protein. In my case, this already surpasses my daily needs by 10%. (Recipes below nutrition facts)

Not all protein is created equal

Finally, there is one more important thing to consider when talking about all macronutrients, not only proteins. Not every protein source is created equal. Apart from being a good protein source, plant-based sources are cholesterol free (or have an insignificant amount) and packed with other nutrients. In the three meals (which, again, were not the only thing I ate), I got enough dietary fibre, full RDV (Recommended Daily Value) of Calcium, 75% of Iron and 50% of potassium, as well as many other micronutrients (vitamins and other minerals).

To summarise, you can get more than enough protein from a plant-based diet, and not only that - plant-based sources of protein are also packed with other macronutrients and micronutrients. On the other hand, apart from being packed with protein, meat and dairy sources are also packed with cholesterol, saturated fat and sodium - all things that cause a plethora of diseases, from cardiovascular to type II diabetes and cancer. In fact, studies show that eating healthy protein sources can lower the risk of several diseases and premature death.

Please let me know if you have any questions regarding anything in this article; feel free to comment and share.

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