What Causes Food Intolerances?
Nobody really knows for sure what causes food intolerances. Research is beginning to help us uncover some of the likely ...
Doing a ‘detox’ has become quite the thing. Loved by many, loathed by more, and labelled a potentially dangerous fad by an increasing number of experts, it’s hard to know what to believe.
Read on to find out what detoxing is, if it works and whether or not it’s for you.
What does detoxing even mean?
Is your gut struggling?
Your body is designed to detoxify
What are the symptoms of an unhealthy gut?
How do I cleanse my gut?
Crucifers: your detox heroes
What do you eat on a gut cleanse?
Gut cleansing: What it isn’t
How to detox your gut naturally
A quick word on fasting and elimination diets…
How does diet impact the gut?
The best foods for your gut
What are the worst foods for your gut?
Humans have detoxed in one way or another for thousands of years. We just didn’t always call it that.
Native Americans had sweat lodges, Hippocrates recommended enemas after overindulging, bloodletting was an orthodox medical procedure until 200 years ago and people have fasted since the dawn of time.
The rise of the wellness industry in the 21st century has seen detoxing and gut cleansing go mainstream once more. But detoxing doesn’t have a real medical definition, so anyone can claim that their product, method or diet will detoxify you. The same goes for gut cleansing.
Both terms are a bit misleading. This is because our body is constantly detoxifying on its own. The main function of your liver is to filter and remove toxins from your body. There are many mind-bogglingly complex ways it does this, using enzymes, oxygen and amino acids—among many other things—to send toxins on their way out of the body through bile or urine.
If you want to cleanse or detoxify your gut, the good news is you’re already doing it. It’s just a question of how well you’re doing it.
Your intestines have a barrier from beginning to end called your gut epithelium. Under normal circumstances, it does a great job of detoxifying.
Made up of a layer of cells, connected to each other by tight junctions, this wall prevents proteins and other substances escaping from your gut into your bloodstream. When this happens, it’s known as intestinal permeability, or leaky gut (Source: NCBI)
Leaky gut isn’t the same as dysbiosis—which is an imbalance of the microbes in your gut—but they’re definitely partners in crime. At the moment, we don’t know if one happens before the other or they happen at the same time.
Leaky gut and dysbiosis are associated with many health conditions:
Autoimmune conditions—where the body’s immune system mistakenly attacks healthy cells in the body—are on the rise, with some increasing by as much as nine per cent per year.
Researchers have found connections between the following autoimmune disorders and leaky gut:
Detoxification is part of our biology. Without it, we wouldn’t last very long: it functions continuously to keep us safe from the toxins in our environment and the ones our own body produces naturally.
The human body has evolved complex systems of detoxification enzymes, controlled by your genes. Everyone has their own set of detoxification genes that work differently to everyone else’s.
These genes play a vital role in your ability to detoxify, for example through a chemical pathway called methylation. The methylation pathway can be affected by a genetic mutation called MTHFR.
The MTHFR enzyme plays a key role in your body’s detoxification processes. Individuals with an MTHFR mutation may, therefore, have issues detoxifying, leaving them more susceptible to ill health. However studies show that with the right diet and sufficient nutrients like folate and vitamin B12, people with MTHFR mutations can ‘override’ this risk (Source: NCBI).
There are many lifestyle choices that can help or hinder our body’s ability to detoxify. For instance, initial research suggests that the current trend for fasting—at least for longer periods—might deplete intestinal alkaline phosphatase (IAP) levels (Source: HINDAWI).
IAP is a gut defence protein found in our gut epithelium (gut lining). It detoxifies some substances that bacteria produce and prevents intestinal inflammation. Recent research shows that IAP can also prevent a pathogenic type of E. coli bacteria from adhering to our gut walls (Source: NCBI).
So, although detoxification happens naturally, that doesn’t mean that we don’t need to worry about it. Your body’s own detoxing mechanisms don’t work properly without the right fuel: the nutrients in whole foods.
So while it’s not accurate to claim that certain types of food will detoxify your gut directly, a healthy diet definitely enhances the detoxification processes your body does by itself.
For example, toxic xenobiotics from drugs, food additives and environmental pollutants are metabolized by detoxification enzymes into less harmful compounds. Our cells then excrete them to our intestines which send them out of our body. This is our detoxification system in action, eliminating harmful chemical compounds while we go about our daily lives.
But the enzymes that zap those environmental pollutants are formed from ingredients that come from our food. To do their job well, they need the right building blocks.
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Some symptoms of an unhealthy gut are obvious, like diarrhoea, constipation, bloating and gut pain, along with conditions like coeliac disease, Crohn’s disease and IBS. As we’ve seen already, leaky gut and dysbiosis are associated with many conditions both inside and outside the gut.
An unhealthy gut can also make you feel generally unwell, with no specific condition or disease. Symptoms can fluctuate, so you may feel well one day and rubbish the next.
You might have:
These symptoms are all anecdotal, which means that they’re commonly reported alongside evidence of dysbiosis shown on a comprehensive stool test. There’s not currently any hard proof that dysbiosis causes them, so your doctor is unlikely to investigate dysbiosis as a cause.
The NHS doesn’t offer comprehensive stool tests so if you’d like to see what’s going on with your gut health you can order tests yourself, or go through a nutritional therapist or functional medicine practitioner.
There’s no food or protocol that will directly ‘cleanse’ your gut.
However, there’s plenty you can do to give your body’s own detoxification processes a helping hand.
Detoxification happens in all our cells, but most of the action happens in the liver. It’s a chemical process that’s split into two parts: phase 1 and phase 2. In phase 1, an electrical charge makes toxins ‘sticky’, to prepare them for phase 2 where they’ll be sent out of the body.
Some foods are especially helpful for either or both of these phases. For instance, crucifers contain compounds vital for both phases. In phase 1, those compounds dampen the toxic enzymes that our liver temporarily raises in order to start phase 2. Then once phase 2 begins, they activate the enzymes the body needs to usher those toxins away through bile, blood, sweat or urine via the gastrointestinal tract, kidneys or sweat glands. But what exactly is a crucifer?
You might not have ever heard the word crucifer, but it’s almost certain you’ve eaten them. It’s the name we give to a family of vegetables that includes:
As well as being a detoxification superstar, crucifers are anti-inflammatory and contain powerful antioxidants. They play a big part in producing energy and helping our immune system to prevent cancer and reduce the risk for autoimmune disease (Source: NCBI).
Crucifers are among the most powerful tools you can use to help your body to detoxify, but there are many more.
As we’ve seen, the best way to ‘cleanse’ your gut is to eat nutritious whole foods that support your body’s natural detox processes. Detoxification is made up of many, staggeringly complex biochemical processes, but it’s fair to say that the liver plays the leading role.
So bulk up on the foods your liver will love:
Avocados contain glutathione, which protects liver cells against oxidation and helps to get rid of heavy metals like mercury (Source: NCBI).
Spinach is full of inorganic nitrate, which has been found to reduce the buildup of fat in the liver (Source: NCBI).
The lycopene in tomatoes protects the liver from free radical damage. Tomato sauce, tomato paste and even ketchup contain high levels of lycopene (Source: NCBI).
Beetroot contains a group of phytonutrients called betalains that support phase 2 detoxification in the liver (Source: NCBI).
Carrots are very high in flavonoids and liver-supporting beta-carotene, as well as vitamin A which helps to prevent liver disease (Source: NCBI).
Research has shown that asparagus can actually reduce alcohol toxicity and helps to break down other toxins in the liver (Source: NCBI).
7. Green leafy vegetables
High amounts of chlorophyll in dark leafy greens like kale triggers the liver to eliminate toxins (Source: NCBI).
8. Cruciferous vegetables
As you learned above, cruciferous veggies like cauliflower and broccoli are phase 1 and phase 2 detoxification warriors, playing an active role in both downregulating the temporarily elevated toxins in phase 1 and producing the phase 2 liver enzymes that flush toxins out of the body.
The pectin in apples helps our guts sweep toxins away, which in turn helps the liver manage its own load of toxins (Source: NCBI).
Most nuts are high in arginine, an amino acid that helps the liver detoxify ammonia (Source: NCBI). They’re also high in glutathione and omega-3 fatty acids.
There are many bizarre yet popular diets that claim to cleanse or detox your gut. The potato diet, for instance, promises to help dieters lose weight, strengthen their immune systems, improve gut health and provide plenty of nutrients ‘to keep you energised while losing weight.
The rules are to only eat plain, cooked potatoes for three to five days. That’s it. While it probably won’t do you any harm over such a short space of time, it won’t do you any good either.
The Master Cleanse diet, made famous by Beyonce, will have you ‘eating’ nothing but lemon juice, maple syrup, cayenne pepper, laxative teas and salt water, for up to 40 days. Apart from being free of fibre, protein and fat, and dangerously low on vitamins and minerals, just one serving of the lemon drink contains over 23 grams of sugar.
Restricting your calorie intake to this level has been shown to increase levels of the stress hormone cortisol, which is actually associated with gaining weight in the long run. People on very low-calorie diets report bad breath, headaches, dizziness, fatigue, irritability, muscle weakness and cramps, hair loss, poor cold tolerance and nausea.
You may have also heard of a ‘colon cleanse’. A colon cleanse diet is usually very restrictive and accompanied by some kind of laxative to make your food pass through you more quickly. It goes without saying that if you eat less and give yourself diarrhoea that you’ll lose weight.
In the same way that your body has its own detox processes, your colon has its own cleansing processes. It’s called having bowel movement. If you’re doing that comfortably at least once a day, you don’t need to help your colon cleanse itself. If you’re not, you have constipation and you need to investigate why that’s happening.
However, you can certainly help your colon along by giving it the foods it—and the trillions of bacteria within it—needs. That means a varied, nutrient-dense, whole-food diet with plenty of fibre and healthy fats.
The best way to keep your gut running optimally is to eat the way nature intended. Our gut evolved over millions of years to eat natural, whole foods. There’s also growing evidence that we’re not designed to eat all day like many of us do. Giving your gut a break by not eating for a portion of the day could be a good idea (Source: NCBI).
The best colon cleanse is a natural colon cleanse: the one your colon performs on its own when it has the right tools to work with. However, many of us today start off at a disadvantage just by living in a modern environment with all its stressors, pollution and empty foods. If you’re constipated or suffering with other gut issues, you might need more than a good diet.
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There are endless different ways to fast, ranging from simply not snacking in between three square meals a day, to eating nothing at all for weeks. Although fasting has been practised for thousands of years, it’s considered an ‘alternative’ approach by conventional medicine and you should always ask your doctor before you start a fast.
Elimination diets are another growing trend that can be highly beneficial or a total disaster for your gut health, depending on what and how many foods you eliminate. Eliminating junk food, for example, is a great idea, whereas banning carbohydrates could be a huge problem. For instance, we know that the ketogenic diet, which almost eliminates carbohydrates, drastically changes the microbiome (Source: NCBI). Whether or not this is good news completely depends on the individual. Ask your doctor before eliminating foods, or nutrients—like carbohydrates—too.
Testing can reveal what’s going on behind your gut symptoms.
Diet is by far the most powerful way you can support your gut health.
The average person has over 1000 different types of bacteria in their intestines, and over 100 trillion individual bacteria. They all live and die by your diet.
Like people, each type of bacteria has its favourite foods. We’re still at the beginning of our exploration into the human microbiome but we know that most of the ‘good’ types of bacteria—that we want to encourage—like unprocessed plant foods.
Research backs these foods for gut health:
The science on what shapes our gut health and the impact that has on the rest of the human body is exploding. If you want to discover more about what you can do to look after your gut, check out our Gut Health Program.
Again and again, research reveals that the typical ‘Western’ diet is disastrous for our gut health (Source: NCBI).
We know that eating a high-fat, high-sugar diet starves our good bacteria, reduces diversity and tips us towards disease.
When researchers looked at the gut microbiomes of the Hadza hunter-gatherer people in Tanzania, they found them to be more diverse than those in the West (Source: NCBI). The Hadza eat as our ancestors did: they gather wild berries, honey, fibre-packed legumes and fruits, and hunt fresh game.
They found that many types of bacteria in the gut that depend on a diverse diet disappear with a Western diet.
The Hadza experience no diabetes, colon cancer, colitis or Crohn’s disease. Obesity is unknown, and as far as we know, they don’t do colon cleanses or gut detoxes.
Food for thought.
Alexandra Falconer MA (Dist) DipCNM mBANT is a Registered Nutritional Therapist specialising in IBS and related conditions. A graduate of Brighton’s College of Naturopathic Medicine, she is committed to fighting the root causes of chronic illness and bringing functional medicine to everyone who needs it.
Before her natural health career, Alex was a journalist and copywriter. She continues to write for magazines and media agencies, and now combines her two great passions—writing and health—by creating content that empowers people to claim their right to a healthy body and mind.
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