The truth about detox diets: Science vs. myth

Guest article by our nutrition expert Dr. Dorothea Portius

The first warm rays of sunshine tickle the skin, the birds are chirping and flowers are beginning to bloom everywhere - spring is here! Now is the perfect time for a fresh start. Just as we are sprucing up our homes, cleaning out the cellar and banishing the winter dust, many of us also want to give our bodies a refreshing treatment. Detox diets promise exactly that: to "cleanse" the body, rid it of toxins and provide it with new energy. But does it really work? Does our body even need a special detox diet, or is it just a clever marketing ploy?

Is there a scientific definition of "detox diets"?

The term "detox" is not clearly defined in medicine. While "detoxification" describes the treatment of drug or alcohol addiction in clinical medicine, the term is often used unspecifically in the wellness and nutrition sector. Many detox programs claim to eliminate environmental toxins, heavy metals or metabolic waste from the body - but usually without clearly stating exactly which substances are involved and the mechanisms by which they are to be eliminated. There is also usually a lack of clinical evidence for most detox promises.

Detoxification - a physiological body process

Our body has highly developed, endogenous detoxification systems that work around the clock. The most important organs for detoxification are:

• Liver: Converts fat-soluble toxins into water-soluble substances so that they can be excreted via urine or bile.
• Kidneys: Filter water-soluble degradation products from the blood and excrete them in the urine.
• Intestine: Fibre and commensal gut bacteria in our microbiome bind harmful substances and eliminate them via the bowel movements.
• Lungs: Removes volatile substances such as carbon dioxide.
• Skin: Small amounts of heavy metals and other substances can be excreted through sweat.

The body's own detoxification takes place in two main phases:

1. Phase I reactions: Enzymes (e.g. cytochrome P450 system) chemically modify toxic substances so that they can be processed further.
2. Phase II reactions: These substances are coupled with other molecules (e.g. glutathione, sulphates or amino acids) to make them water-soluble and excrete them.

Detox diets in the fact check: hype or real help?

Despite the popularity of detox diets, there is hardly any scientific evidence of their effectiveness. There are only a few studies that prove that commercial detox diets actually increase detoxification.

1. Elimination of environmental toxins

A few studies suggest that certain foods such as coriander, chlorella or citrus pectins may have a detoxifying effect. However, these effects were mainly observed in animal studies, not in human clinical studies.

2. detoxification through fasting?

Many detox programs sometimes involve greatly reduced calorie intake, fasting programs or the elimination of certain food groups, which can promote nutrient deficiencies. Paradoxically, this can inhibit the body's own detoxification, as important micronutrients for phase II detoxification are missing (e.g. Vitamin B12, folic acid and certain amino acids). In addition, harmful substances stored during the breakdown of body fat can enter the bloodstream and increase the burden on the body in the short term.

3. Detox diets and weight loss

Many people go on detox diets in the hope of losing weight quickly. In fact, there may be visible weight loss in the short term - but this effect is mostly due to the loss of water and stored carbohydrates, not body fat. As carbohydrates bind water in the form of glycogen, their deprivation initially leads to dehydration of the body. However, as soon as the normal diet is resumed, the stores are replenished and the weight increases again.

In the long term, restrictive detox diets are even problematic: They can promote food cravings and often lead to weight gain later on. Sustainable weight loss is therefore better achieved with a balanced, nutrient-rich diet than with short-term detox diets.

Risks of detox diets

• Nutrient deficiencies: Deficiencies in proteins, vitamins and minerals can disrupt metabolic processes.
• Electrolyte imbalances: Excessive water intake or the use of laxatives can lead to sodium or potassium imbalances.
• Muscle wasting: A very low calorie intake leads first to a loss of muscle mass.
• Increased exposure to pollutants: When fatty tissue is broken down, stored environmental toxins can enter the bloodstream.

How to support natural detoxification

Instead of relying on questionable detox cures, a healthy diet and a sustainable lifestyle can optimally support the body's natural detoxification mechanisms:

1. drink plenty of water

• The kidneys filter around 200 liters of fluid every day, of which around 1.5-2 liters are excreted as urine.
• Inadequate fluid intake can impair kidney function and slow down the excretion of harmful substances.
• Recommended: Drink at least 1.5 to 2 liters of water per day - more if you exercise or are hot.
• Tip: Herbal teas and diluted lemon or ginger water also support hydration.

2. Dietary fiber for healthy digestion

• Fibre binds toxins in the intestines and promotes their elimination via the stool.
• A high-fibre diet also supports the intestinal flora, which plays an important role in detoxification.
• Empfohlen: 30-40 g of fiber daily from whole grains, vegetables, legumes, nuts and seeds.
• Tip: Start the day with a portion of oatmeal with flaxseed and enrich your salad with some chickpeas for lunch.

3. Sufficient protein to support the detoxification process

Proteins play a central role in the body's detoxification process. Certain protein building blocks (amino acids), particularly sulphur-containing amino acids such as methionine and cysteine, are essential for the synthesis of glutathione, one of the body's most important antioxidants and detoxification factors. They also play a role in proteostasis - a molecular hallmark of ageing.

The decisive factor here is not only the quantity, but also the quality of the proteins ingested. High biological value proteins contain all essential amino acids in an optimal ratio and therefore promote efficient detoxification.

• High-quality protein sources:
  • Animal: eggs, fish, lean meat (e.g. chicken, beef fillet), dairy products (z.B. low-fat quark, feta).
  • Plant-based: Quinoa, soy products (e.g. Tofu, tempeh), lupin and combinations of cereals and pulses (e.g. beans with rice, chickpeas with sesame seeds (hummus)) to ensure a complete supply of amino acids.
• Recommended intake: Depending on the activity level, a daily protein intake of 0.8-1.2 g per kg body weight is recommended. Athletes or people with increased metabolic stress may have a higher requirement.
• Tip: Make sure that every meal contains a high-quality source of protein. Add some nuts and yogurt to your oatmeal breakfast or supplement your salad with chickpeas and a whole grain bread and hummus, feta or chicken strips.

4. Antioxidant-rich foods to support liver function

• Antioxidants are essential to neutralize free radicals produced during detoxification.
• Important antioxidants are vitamin C, vitamin E, selenium and secondary plant substances (z.B. Phenolic acids, glucosinolates, carotenoids).
• Recommended: Lots of colorful fruits and vegetables (berries, peppers, spinach), as well as herbs such as turmeric and ginger.
• Tip: Your plate should never look colorless, half of it should be filled with seasonal and preferably regional fruit and vegetables. How about apples and berries in your porridge or carrots, tomatoes or radishes in your salad

5. Exercise gets the metabolism going

• Exercise improves blood circulation and helps the liver to detoxify and the kidneys to filter toxins.
• Sweating excretes small amounts of heavy metals such as arsenic and cadmium.
• Recommended: At least 150 minutes of moderate exercise per week (e.g. walking, cycling, yoga) and/or 75 minutes of intensive training (e.g. jogging, weight training).
• Tip: No time for sport? How about walking a few stops instead of taking the bus or train?

6. Avoid exposure to heavy metals

• Heavy metals such as mercury and lead can accumulate in the body and overload the detoxification systems.
• Plastic packaging often contains plasticizers such as bisphenol A (BPA), which can have hormonal effects.
• Empfohlen:
  • Choose fish with a low mercury content (e.g. salmon, trout, herring instead of tuna).
  • Use glass instead of plastic for food storage.
  • Prefer organic food to minimize pesticide residues.
• Tip: Choose unpackaged fruit and vegetables in the supermarket. This not only reduces plastic waste, but also allows you to buy exactly the amount you actually need - so you avoid food waste.

Conclusion - detox diets

Detox diets are not scientifically sound and are often more marketing than medicine. The body has effective detoxification mechanisms that can be optimally supported by a healthy diet and lifestyle. If you want to stay healthy in the long term, you should focus on sustainable nutritional strategies - and not on short-term detox trends.