Are detox diets a myth? Do they really help our bodies to detoxify? The human body is constantly in a state of detoxification each and every day. If it were not detoxing continuously, we would die. It is that simple. So do we need additional detox protocols to provide a helping hand to our detox systems? Lets take a look at how the liver plays a critical role in the detox process. The liver is critically important to our health playing a major role in metabolism, regulating glycogen storage, hormone production, plasma protein synthesis, immunity and detoxification.
If the liver is not working optimally, then these functions will be compromised resulting in poor health outcomes. When the liver becomes overburdened with processing toxins, you’ll feel sluggish and tired as it is having to work harder to eliminate these toxins. At the same time, it has less capacity for it’s other important tasks of producing nutrients the body needs. Common sense tells us to minimise the toxins we put into the body so that the liver doesn’t have to work so hard on detoxification so that it can function optimally on producing the nutrients we need. An example of this is excessive consumption of alcohol as the liver has to work hard to clear this from the system.
An example of this is excessive consumption of alcohol. Even though research shows that there are some health benefits to moderate alcohol consumption, your liver doesn’t buy into this and considers all alcohol as a toxin. The liver will use a large amount of metabolic energy processing the alcohol to eliminate the toxin and purify the blood. Have you noticed how you can feel tired and sluggish the next day even after moderate amounts of alcohol? There is a process going on in the liver that contributes to this and it is directly related to how much one drinks.
Its not just alcohol though that needs to be detoxified by the liver. In fact, the past 50 years have seen tens of thousands of new synthetic compounds introduced into the environment. Artificial substances, drugs, pesticides or heavy metals ingested through food, air pollutants such particulate matter from diesel engines or industrial manufacturing plants, as well as indoor pollution from a myriad of cleaning chemicals and personal care products. Many of these come under the umbrella of xenobiotics.
These are chemical substances found within an organism that are not naturally produced by or expected to be present within. It can also cover substances that are present in much higher concentrations than are usual. All of these contribute to the toxic load the liver has to deal with on a daily basis. Indeed, there is compelling evidence that all of the various chemical agents we are potentially exposed to are a clear risk to our health. With this in mind, it is easy to see why the body may need some assistance with the detox process. We are living in an age of toxic overload and this can take its toll on our inbuilt detox systems. The liver takes on a large part of this burden but can only do so much before it start to get a backlog!
How Does the Liver Detoxify?
In general terms, the detoxification process involves two phases.
Phase 1 Detox
Many of the toxins that enter the body are fat-soluble, which means they dissolve only in fatty or oily solutions and not in water. This makes them difficult for the body to excrete. Fat soluble toxins have a strong attraction to fat tissues and cell membranes, which are made of fatty substances. In these fatty parts of the body, toxins may be stored for years, being released during times of exercise, stress or fasting. The first phase of the detox process involves enzyme activities that include oxidation, reduction, and hydrolysis reactions during which the toxin is ‘activated’ to a more reactive form. The cytochrome P450 is the family of enzymes responsible for phase 1. Essentially, the phase 1 pathway converts a toxic chemical into a less harmful chemical, however, this process generates free radicals. These free radicals are further metabolized in phase 2, becoming water-soluble molecules that can then can be excreted through urine or bile.
Excessive amounts of toxic chemicals can disrupt the P-450 enzyme system by causing over activity or what is called 'induction' of this pathway. This results in high levels of damaging free radicals being produced. If these free radicals are not fully metabolised in phase 2, they can cause damage to liver cells and to DNA within the cells.
Antioxidants such as vitamin C, vitamin E and natural carotenoids can help to reduce the damage caused by these free radicals. We covered the antioxidant system in a previous article on free radicals.
Phase 2 Detox
This is called the conjugation pathway, whereby the liver cells add another substance such as cysteine, glycine or a sulphur molecule to a toxic chemical or drug, to render it less harmful. This process converts chemical toxins and drugs to into a water soluble substances that can be excreted from the body. In order for the phase 2 process to work effectively, the liver requires sulphur containing amino acids (proteins) such as taurine and cysteine. Other nutrients such as glutamine, glycine, choline and inositol are also required.
If high toxic loads are detected in the body, or high xenobiotic loads as it is sometimes called, phase 1 and phase 2 enzymes are normally activated so that more enzymes are present and detoxification occurs at an increased rate. However, some toxic compounds like those in cigarette smoke and charbroiled meats (grilled on a rack over charcoal), increase phase 1 but not phase 2 enzymes. This results in high levels of unstable intermediate molecules that can trigger free radical damage. This increase in circulating free radicals may be part of the mechanism linking the cancer-promoting toxins in cigarette smoke to increased cancer risk.
Looking at it another way, if Phase 1 is working at normal or accelerated rates, but Phase 2 is running slow, we end up with a lot of reactive substances building up in the body that have no way of being excreted from the body. Ideally, we need Phase 2 to be working optimally at all times.
Can Diet Help the Liver to Detox?
So how do we help the liver with the detoxification process and keep it in working optimally? There are plenty of so called ‘liver detox’ diets out there that recommend some type of starvation regime. However, I don’t subscribe to these diets as there is no evidence that they work and can, in some cases lead to negative consequences. In my view, it really comes down to eating a balanced, healthy diet and minimising refined, processed, sugary foods.
Eating organic vegetables and fruit packed with polyphenols, flavonoids, carotenoids, vitamins and minerals will help us to maintain optimal liver health. Eating the right fats will also help your liver so avocados, nuts and olive oil are all good sources of healthy fats. These kinds of foods have been found to be associated with the upregulation, or inducing, of the detoxification enzymes that we discussed above. This leads to more enzymes being present and a faster rate of detoxification. Lets take a closer look.
In general, B vitamins including riboflavin and niacin, glutathione (the body’s main detoxifying antioxidant), magnesium and flavonoids have been shown to assist phase 1 detoxification. Foods rich in B vitamins include eggs, wholegrains, brown rice, chicken, fish and vegetables. Fruits and vegetables are rich in flavonoids that have potent antioxidant properties.
In phase 2 we saw how sulphur containing amino acids are required for efficient detox. Eggs and cruciferous vegetables such as broccoli, cabbage, Brussels sprouts, cauliflower, as well as raw garlic, onions, leeks and shallots are all good sources of natural sulphur compounds to enhance phase two detoxification. Indeed, broccoli has long been considered to play a role in a healthy diet. Broccoli contains significant amounts of a phytonutrient called glucoraphanin, which is metabolized to the biologically active sulforaphane. Research indicates that sulforaphane has the ability to increase the capacity of the liver to detoxify harmful, cancer-causing compounds. Specifically, sulforaphane increases the activity of the liver's Phase 2 detoxification enzymes. As we can see, broccoli is a nutritional powerhouse, however, its worth noting that broccoli sprouts can contain up to 50 times the level of some of the antioxidants found in full-grown broccoli. Sprouts are a particularly excellent source of sulforaphane glucosinolate and indole-3-carbinol, known for their protective effects against carcinogens.
Phase 2 also requires micronutrient coenzymes, including glycine, N-acetylcysteine (NAC), glutamine, glycine, B vitamins, choline and inositol. As mentioned above, efficient phase two detoxification also requires sulphur-containing amino acids such as taurine and cysteine. NAC is a supplement that acts as a precursor to glutathione, which is the master antioxidant in the body and chief detoxifier! There are glutathione supplements available but it is thought that these may not survive the digestive process, therefore, taking NAC could be a better strategy to support phase 2 detox.
Antioxidants such as C, E and beta-carotene as well as minerals such as selenium, zinc can help in the alcohol metabolism if you enjoy the odd glass of wine. There is some research into milk thistle and dandelion root that might help protect liver cells when ridding the body of toxins. Lab studies suggest that silymarin, an extract of milk thistle, acts on biochemical pathways to help with detoxification.
Having said this, it is early days and there have been no large scale, clinical trials on milk thistle so the jury is still out on this. However, milk thistle has been shown to support glutathione production.
MSM is another interesting supplement that has many health benefits. MSM is a good source of sulphur and research has shown that MSM supplementation has been shown to protect the liver from oxidative damage and chemically induced toxicity. In healthy men ten days of MSM supplementation at 50mg/kg body weight reduced markers of oxidative damage and enhanced glutathione levels following exhaustive exercise. Its worth noting that ten days of supplementation is optimal before achieving these results. The ability of MSM to mitigate toxin-induced liver damage and support detoxification is due in large part to the sulfur it provides with cysteine availability being the main rate-limiting step in glutathione synthesis.
Fibre intake is important too as it supports regular elimination, which is crucial for excreting toxins. Brown rice fibre may be particularly beneficial in eliminating fat-soluble toxins.
Interestingly, grapefruit juice decreases the rate of elimination of drugs from the blood and has been found to substantially alter their clinical activity and toxicity. Eight ounces of grapefruit juice contains enough of the flavonoid naringenin to decrease cytochrome P450 activity by 30%.
When considering taking any supplements to assist in the detoxification process it is wise to seek medical advice, particularly if you are on any medication. If you have the all clear, it is wise to take it slowly and introduce any supplement into the diet at lower doses at first.
In summary, your liver looks after you by cleaning up the toxins you put into your body and producing nutrients essential to good health. Modern day life doesn’t help in this respect with the amount of low quality, processed food that is consumed, environmental toxins, excessive alcohol and so on. We really need to look after our liver to support these critical functions it diligently carries out behind the scenes.
Modulation of Metabolic Detoxification Pathways Using Foods and Food-Derived Components: A Scientific Review with Clinical Application
J Nutr Metab. 2015; 2015: 760689.
Induction of Phase 2 Antioxidant Enzymes by Broccoli Sulforaphane: Perspectives in Maintaining the Antioxidant Activity of Vitamins A, C, and E
Front Genet. 2012; 3: 7.
Induction of Phase 2 Antioxidant Enzymes by Broccoli Sulforaphane: Perspectives in Maintaining the Antioxidant Activity of Vitamins A, C, and E.
Published online 2012 Jan 24. doi: 10.3389/fgene.2012.00007
Sports & fitness nutritionist, researcher and author on a mission to improve the human condition. Focusing on evidence-based and outcome-based nutrition, training, mindset & environment