We’ve all heard of “cleanses” or “detox” diets. Maybe you’ve even tried one (or a few). Many people think that a good way to kickstart a healthy lifestyle change is to do a cleanse. Others look to cleanses for weight loss, increased energy, or to rid their bodies of toxins.
Unfortunately, “cleansing” or “detoxing” is based on a misunderstanding of human physiology.
One of the best ways to find out whether a certain concept in the health and fitness field has any validity is to look up peer-reviewed journal articles on the topic. Peer-review is a process whereby a panel of professionals evaluates research to ensure it was conducted well and is up to professional standards. Scientific journals are specialized publications in which researchers publish findings from their studies. So, we’re not talking about websites written by hobbyists, or even books written by PhD’s. If there is no – or limited – good quality published research from clinical studies to support a certain claim, you can be pretty sure it’s B.S., or you’re ahead of the game and your topic hasn’t been researched yet, but that’s unlikely. Google Scholar is a great resource for finding peer-reviewed journal articles.
In the case of dietary cleanses, which have been around for a long time, extensive research has been conducted. And guess what? Not only is there no evidence that detox diets actually do anything beneficial, but there’s also no evidence to support the very basis of detoxing. Detoxing is based on a misunderstanding of how our bodies work. And, ironically enough, going on a detox diet can actually increase toxins in our bodies. Of course, nobody actually ever defines what a “toxin” is.
Melanie Hackett, who has a B.Sc. in Biomedical Physiology and Kinesiology (and a whole host of other health-related certifications, and also happens to be my sister) is here to share her expertise and to set the record straight on so-called “cleanses” or “detox diets”. Importantly, she has a specific definition of a toxic effect in the body caused by detox cleanses. Let’s turn things over to her!
If you are interested in health you have probably heard of “cleansing” diets aimed at ridding your body of toxins by reducing what you consume to a very limited selection of healthy products for two or three weeks. Unfortunately, our physiology is not nearly that straightforward, and these diets simply don’t do what they are intended for. In fact, more toxins are created during these diets! Of course, there are many different types of detox diets. Like all fad diets, most of these are merely a tool for companies to earn money off unwary consumers and aren’t based on science at all. Even my mother, a very health-conscious and active 61-year-old who generally looks for the science, used to do annual “cleansing” diets consuming nothing but elderberry juice for several weeks in an attempt to “flush away” toxins. I will focus on these types of “cleanses”.
In a normal human body with a healthy diet where caloric intake equals caloric expenditure, blood sugar levels are well regulated by two hormones: insulin and glucagon. Insulin, released by the pancreas after a meal, takes the blood glucose and helps it enter all body cells where it can be used as energy for all cell function. Extra glucose combines forming a substance called glycogen, which gets stored in muscle and the liver. These stores are crucial for maintaining blood glucose levels. They can be completely depleted after only a couple of hours of exercise at a heart rate 80% of your maximum heart rate, and do not build back up unless a diet high in carbohydrates (fruits, veggies, quinoa, rice, whole grain bread, etc.) is eaten. These stores can also be depleted within a couple days of consuming much less than you are expending, or not having a diet consisting of about 60% carbohydrates.
When glycogen runs out, fatty acids and proteins are broken down instead in the liver. The by-products of this process are three types of ketone bodies, two of which the heart and brain use. The third is a waste product stressing the kidneys. Ketones also lower the pH of the blood. To correct this acidic blood, the respiratory system starts to hyperventilate to expel more carbon dioxide. In the blood, carbon dioxide combines with water and forms bicarbonate and a hydrogen ion (the latter makes the blood more acidic). If there is less carbon dioxide available, fewer hydrogen ions will be produced. However, less carbon dioxide also means less stimulus for breathing, and in extreme cases this can be fatal.
Excess ketones and the physiological effect they have can be considered toxic in the human body. These effects are pretty much identical to what happens both during starvation and during a diabetic coma when a diabetic’s blood sugar is extremely high because they lack insulin to help shuttle the sugar from the blood to the starved cells. This is also what happens during the Atkin’s diet, one that should only be tried in morbidly obese people who are at alarming risk of fatality if they don’t lose weight. In general, if a diet is not healthy or is impossible to maintain permanently, it probably should not be done at all.
Additionally, the net breakdown of proteins to provide energy (either in a high protein diet or when the body is starved of carbs) causes a negative nitrogen balance, and taxes the liver, which tries to rid itself of the nitrogenous waste products that are produced. The immune system is weakened, and the levels of cortisol, our long-term stress hormone, may increase, further weakening the immune system.
The physiological effects discussed above merely state what toxins build up in the body and the negative effect on health during “detox” diets. This doesn’t take into account the nutrient deficiencies that can occur during such limited diets, which have a cascade of harmful effects in the body.
Of course, some cleansing diets instruct you to eat lots of dark green veggies, a variety of plant-based foods, limited processed foods, legumes and nuts instead of meat and a healthy caloric intake for you. To me, this sounds like a diet that might as well be maintained permanently.
Melanie Hackett
B.Sc. Biomedical Physiology and Kinesiology
Certificate in Health and Fitness Studies
Certificate in Human Nutrition
The article above appears in my book Vegan Vitality. Check it out for more than 100 easy recipes made for active vegans, interviews with vegan athletes, daily living tips, and more.
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