Early in the New Year is the traditional time for setting ambitious goals for better health, fitness and, often, a slimmer body. This resolve commonly reflects guilt stemming from the dissipation of the preceding festive season – and it often starts with a detox.

It’s unclear where the idea of an in-depth body cleanse or “the detox cure” comes from, but it’s worth noting that many traditional and complementary medicine practices describe cleansing and detoxification as a way to avoid illness, or engender wellness.

They’re based on the idea that “toxins” accumulate and the body needs regular purification. They cover everything from enemas and colonic irrigation, lemon juice detox or water fasts to exclusion of certain food groups, purging with herbs, large-dose nutrient supplementation and sweat lodges, among other things. And they’re generally a waste of money and effort.

Detoxing from what?

In medical terms, detoxification means removing poisons or the build-up of toxic substances, when large amounts have been consumed or have come into the body through inhalation or skin exposure. It’s only used when the amount or type of substance is such that our body’s natural detoxification systems are unable to clear it.

The body’s detoxification system uses the skin (via sweat and sebum), liver and gall bladder (bile), kidneys (urine), lungs, lymphatic system (lymph) and intestines (faeces) to get rid of toxins.

The toxins can be from both internal and external sources. Internal sources include the by-products from usual physiological processes and cells' waste products. The process of breaking down food components to produce energy uses oxygen, for instance, and results in unstable molecules called free radicals. These molecules must be neutralised or converted to avoid build-up to toxic levels.

External sources of toxins can come from food and beverage-related compounds – molecules resulting from baking, deep-frying and char-grilling, as well as alcohol and additives in processed foods. Then there’s medication, tobacco smoke and exposure to environmental pollutants, among other things.

Toxic life

Many toxins from external sources (also known as xenobiotics) are fat-soluble and can accumulate in fatty tissue. Exposure to these has considerably increased with modern lifestyles because of industrial waste contaminating soil and water and, in turn, agriculture products and seafood.

Agriculture practices also use a variety of chemicals, resulting in residues in food products. And cosmetics, body care products, as well as plastic food and beverage packaging, all increase our exposure to a variety of chemicals.

These kinds of exposure are often used as the main rationale for commercial detox programs. In the absence of robust human data on acceptable non-harmful ranges for all the chemicals in our environment, the argument goes that any small amount may be toxic and should be removed. But our bodies are purging these chemicals all the time.

Anyway, no one-off detox regimen can “erase” the effects of weeks' worth of excess and years of sluggish lifestyle habits. There’s no scientific basis or high-level evidence showing the benefits of commercial short-term detox programs.

Still, there’s good news too: your internal detoxification system, which includes numerous organs and enzymes coded for in your DNA, works around the clock to process toxins as needed.

Not consuming any alcohol, or masses of chocolate and fried food, for a few weeks may (depending on what you’re eating in their stead) reduce the amount of detoxification your body needs to perform. But real good happens over the long term. And anyway, all the alcohol you’ve drunk in the last few weeks has already been dealt with – principally by your liver – to avoid harmful effects.

Natural detoxification

Among its over 500 functions, the liver metabolizes and detoxifies any dietary constituents (including caffeine or herbal teas and supplements) and any external toxins entering the body from a variety of exposure.

Detoxification is a three-step process. In the first two phases, fat-soluble compounds are converted to water-soluble compounds. And the third facilitates transport of the converted products out of the cells, then out of the body via the bile and faeces, or urine.

The internal production of toxins, such as free radicals, is kept under tight control by a sophisticated mechanism involving genes that code for antioxidant enzymes. Indeed, enzymes play a key role in detoxification and when there’s more to detoxify, the body produces more enzymes.

While the liver is the star of the show, most tissues in the body also participate in detoxification. But the differences between individual genetic profiles mean there can be large variation in responses to toxin exposure.

Vitamins and minerals in food are crucial for the optimal function of detoxification pathways and the function of enzymes. But this doesn’t mean you should consume large doses as that can also result in toxicity.

The crux of the story is that the human body is a comprehensive, self-mending, self-detoxing apparatus. It will perform its detoxification tasks regardless of whether you’re undertaking a rigid detox cure, or a gourmet food and wine tasting marathon. But providing the right ingredients for optimal function daily, rather than opting for a quick-fix detox, is the key.

Veronique Chachay, Research&Teaching Academic , The University of Queensland. This article was originally published on The Conversation. Read the original article.