We all know that what we eat greatly affects our health. We know from medical studies, for example, that high blood cholesterol is associated with heart disease. We know that if we eat too much food, we put on weight and that obesity brings with it many health problems.
And since we buy the food we consume, our beliefs about our diet and nutrition directly affect our spending activity. It is therefore an irresistible target for marketers and advertisers. If food consumers can be made to believe that their nutrition requires a particular supplement, or products with particular characteristics, that makes money for the producers. The more concern that can be generated about the adequacy of the normal diet, the more marketing space there is for new products, and therefore increased profits. Food marketers have a vested interest in creating doubt, confusion, and uncertainty about our nutrition.
We have seen a massive growth in the number of nutritionists who claim to have expertise in human nutrition. One way in which professions promote the skills of their members is to insist on certain recognised qualifications, obtained through regulated examination. That is the case with dieticians in the UK, who have to complete a degree course in a university, or if they already possess a degree in a relevant subject, complete postgraduate study. Without this very strict and exacting training, you cannot practice as a dietician. By contrast, a nutritionist does not have to have any qualifications at all. In fact, you or I can put up a plate and start practising as a nutritionist any time we like, whether or not we know anything at all about human nutrition.
Sometimes nutritionists claim to have qualifications but often these are paid for on short courses in institutions that are taught by similarly self-declared experts. Without the rigorous regulation of exacting scientific standards, nutritionist qualifications are worthless.
There are many foodies foraging in the land of Woo. They talk about dietary supplements, detox, an enormous range of diets, and seem to possess arcane knowledge about the importance of various elements such as zinc and selenium. They offer scare stories about free radicals and the importance of antioxidants. If they are nutritionists, it is quite possible that they have little or no understanding of any of this stuff.
Human nutrition – the basics
Our food contains what we need to survive but not in a form we can use immediately. It has to be processed first into simpler chemicals that the body can use. That is what our alimentary canal is for. It consists of an elaborate pipe that passes through the body from the mouth to the anus.
As food passes through, it is treated by being mixed with biological chemicals called enzymes. These chemicals are actually proteins that chop up the large chemicals in food into smaller pieces. Our food consists of basically three types of chemicals: carbohydrates, proteins, and fats. Different parts of the alimentary canal have different enzymes, some working in a very acid environment (like the stomach) and some in mildly alkaline (like in the mouth and small intestine). Different components of the food are digested in different places.
Sugars are broken down in the mouth by an enzyme called ptyalin (enzymes often have strange names...) and proteins are broken down in the stomach and small intestine by enzymes such as renin, pepsin, and trypsin. Fats are broken down in the small intestine by enzymes called lipases.
Nutrients are absorbed into the bloodstream from the gut, along with water. Anything that isn't absorbed that way, is removed from the body through the anus. Inside the gut, there are colonies of bacteria. The majority (around 85%) are beneficial whereas the remainder can in some circumstances be harmful. The balance is maintained because the harmful bacteria are starved of nutrients preventing their growth beyond a safe level.
The process of burning up those simpler chemicals to produce energy, also produces bi-products which need to be removed from the body. These unwanted chemicals are produced in the body tissues. The lymph system feeds them into the bloodstream which carries them to the liver and the kidneys.
The liver will store unused carbohydrate sources of energy as a chemical called glycogen where it provides a reserve energy store for use during starvation. The liver does a number of jobs. It breaks down old red blood cells, makes protein for the blood plasma, makes bile to help in fat digestion, and it even makes some hormones. It also breaks down any chemicals which are toxic. It is the body's very own detox mechanism.
The other breakdown products are removed by the kidneys and will be excreted as urine.
The body takes the simple products of digestion such as glucose, amino acids and simple fats, and makes the larger chemicals we need, such as proteins. But there are some chemicals we need which we cannot synthesise inside our bodies. For example, every red blood cell contains a protein called haemoglobin which binds to oxygen so it can be carried around the body. In the centre of the haemoglobin molecule is an atom of iron. We need to eat that iron in some food or other. Fortunately iron is available in very many foods such as meat, fish, poultry, beans, and lentils. Unless we suffer from an illness, it is hard to produce iron deficiency (anaemia) in humans. We also need tiny amounts of other chemicals called vitamins. But if we eat a balanced diet, we get all the nutrients we need.
Now let's take a look at some of the claims and see if there's any basis for them.
Oxidation, antioxidants and free radicals
We are often told in advertising and the associated articles that our health is at risk from oxidation and free radicals and that therefore we need to increase the amount of antioxidants in our diet. Certain foods, we are told, are rich in antioxidants and these will prevent the harm caused by those free radicals.
Unless we understand this vocabulary, we only get the message that we are at risk and should eat something recommended to offset the danger. For food Woo marketers, a little ignorance goes a long way. So here's the low-down.
Oxidation and reduction are two sides of the same coin – you don't get one without the other. Oxidation refers to the loss of hydrogen or electrons, or the gain of oxygen. So for example carbon can be oxidised to carbon dioxide (addition of oxygen). Reduction refers to the gain of hydrogen or electrons, or the loss of oxygen. So for example, an atom of carbon can be reduced with four atoms of hydrogen to make methane (adding hydrogen).
Most biological processes involve oxidation-reduction. Our bodies oxidise glucose to carbon dioxide and at the same time reduce oxygen to water. That's an absolutely vital process for all of us. Without oxidation we wouldn't be able to extract energy from our food nor breathe out our carbon dioxide and we'd die. So oxidation itself is not a problem, it's a normal part of human metabolism. Similarly reduction is not a problem either.
Free radicals are molecules that have an unpaired or spare electron, which makes them highly reactive. They are looking for anything to restore themselves to a more stable state. Not all free radicals are that reactive. For example two atoms of oxygen together form a free radical that is perfectly stable.
The reactivity of free radicals is essential for some of our biochemical reactions including those involved in the breakdown of harmful bacteria and in nerve transmission. But they can also be a problem if they are not contained. They have been associated with ageing, with some cancers, with Parkinson's disease, and many others. Uncontrolled, the free radicals can cause a great deal of harm. And that's where the antioxidants come in.
The human body has a number of mechanism to control the actions of free radicals including the enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase as well as vitamins C and E.
Should we then be worried about getting enough antioxidants to cancel out the harmful effects of those free radicals? Fortunately, we can get a plentiful supply of antioxidants without really trying. They are readily available in fruit and vegetables.
But does adding additional antioxidants improve our health? The trials that have been done so far show no benefit in the case of heart disease and cancer incidence nor with the progression of existing illness.
But it's worse than that. Trials have shown that people taking beta-carotene, vitamin A and vitamin E as supplements actually have worse health. Beta-carotene increased death rates by 7 per cent, vitamin A by 16 per cent, and vitamin E by 4 per cent. Check it out for yourself.
Adding extra antioxidants affects the body's own mechanism for balancing the effects of the free radicals, so it is not even yet known that it is a safe procedure. Many scientists now believe the whole hype about extra antioxidants in the diet was misguided from the beginning and that there is no evidence of any benefit. But we do know that it's a $20 billion industry in the USA.
Toxins and detox
When we talk about toxins and detox, we are assuming that there are chemicals in the body which we need to remove for our health. We already know about the breakdown products of digestion which our body naturally removes but we are also drawn into thinking that there are other harmful chemicals which get into our bodies. There may be contaminants in our food, perhaps pesticides, antibiotics, poisonous metals, or the products of harmful bacteria, and it is claimed that these too need to be removed. The assumption is that the human body's own way of eliminating these toxins is inadequate.
The range of toxins listed in detox web adverts found in just two minutes include: ammonia, lead, food additives, cigarette smoke, carcinogens, arsenic, herbicides, fertilisers, plastic packaging (seriously), aluminium, mercury, preservatives and hormones. Suggested mechanisms for detoxing your body included taking pills, changing your diet, wearing foot pads, colonic irrigation, and a variety of high speed products including drinks and chewing gum.
But if we have such toxins within us, they will be within tissues, possibly bound to other molecules, involved in chemical reactions, having a metabolic effect. When people are poisoned by industrial chemicals such as fertilisers and pesticides, there is always an initial process of identification because without understanding the nature of the poisoning, we cannot know how to go about removing the poison. The complexity of the metabolic reaction makes this investigation essential. Those who offer generic solutions to the problem of toxins clearly don't realise this, or else believe one solution fits all.
Can eating things detox you?
Clearly you can restrict the entry of certain substances into your body by choosing your diet carefully. You can avoid alcohol or caffeine if you want to, and you can adjust the composition of your food, perhaps adopting a deliberately unbalanced diet to eliminate certain foodstuffs, but it is wise to consult a qualified dietician before doing anything radical. Unbalanced diets can lead to dietary deficiency and even malnutrition. But gently restricting calorie intake will slow down weight gain or may even reduce weight and that is more likely to be beneficial than harmful.
Proactively changing your diet, despite it being recommended by most detox marketers, is not the same as removing toxins from the body. The detox marketers claim that they have dietary supplements that can remove toxins from the body. If they do not identify the toxins, their claims can never be tested, and therefore never be disproved. They therefore avoid the charge of fraud.
If a dietary mechanism for the elimination of toxins is to work, there must be some agent which gets to the tissues around the body which can bind to the toxin (a process known as conjugation) or denature it (through oxidation). If it binds, then the composite molecule has to be eliminated using the body's own mechanisms.
These specific claims are testable if and when the toxin is identified. But there is no scientific evidence for the accumulation of toxins in the body. So eating something to eliminate them is a nonsense. They are not there in the first place.
Cholesterol, fats and fatty acids
Cholesterol is one of those chemicals which occur naturally in the body and without it, we wouldn't be able to synthesise certain hormones called steroids. Steroids form part of a larger group of biological chemicals called lipids, which also includes fats. These steroid hormones are vitally important to us and it is their fatty characteristic that allows them to pass through cell membranes easily. If we didn't have any cholesterol, we couldn't make those hormones inside our bodies. So cholesterol, far from being really bad, is actually essential. But like many things in the body, an excess can be harmful.
Fats are chemically different from both carbohydrates and proteins because they have a different structure. Just like other foodstuffs, our gut breaks down fats into simpler components which are then used to build up the chemicals we need. Fats come in different varieties and they have different properties. Steroids for example, have a complex ring structure, whereas fatty acids are much simpler. Within the fatty acids, we have saturated and unsaturated which simply refers to the type of chemical bonds holding them together. Some fatty acids are made inside the body, but others we need to get through our food and we call those essential fatty acids. There are only two of these: linoleic acid and alpha linoleic acid. All the other fatty acids we can make ourselves.
The terms LDL and HDL are touted around as well. LDL refers to low density lipoprotein in contrast to HDL which refers to high density lipoprotein. All lipoproteins enable fats and cholesterol to be transported around the water-based blood system (because they are soluble) but HDL has often been incorrectly referred to as “good cholesterol” on the grounds that a high LDL level is often associated with cardiovascular disease. LDL is sometimes even used as a test for it. The issues are confused further because it is known that until oxidised, LDLs are pretty harmless and it's those dreaded free radicals which can do the oxidation. That led to claims that to counter the LDLs you needed to eat more antioxidants but the research is inconclusive. So rather than modifying your diet to increase antioxidants, by far the most sensible thing to do is to limit the amount of animal fats and full-fat dairy products you eat.
The term polyunsaturated fatty acid simply refers to the structure of these essential fatty acids contrasting them with saturated fatty acids. We also hear the term omega used frequently, for example omega 6 fatty acid. What this refers to is the position of an unsaturated chemical bond in position 6 of the fatty acid chain. There are also omega 3 and omega 9 fatty acids though we don't need the 9 variety because the body can make it itself. Omega 3 and 6 are important to us because they are necessary for the production of biological chemicals we need.
The language of chemistry is used to describe the structure of these chemicals but that doesn't stop the advertisers makings use of them too. Nowadays it is common to see milk enriched with omega 3, and there are many health products advertising these supplements. Omega 3 and 6 comes from a variety of foodstuffs particularly oily fish, but also soya and rapeseed oil, and leafy vegetables.
It is still controversial whether or not dietary supplements of omega 3 and 6 makes a significant difference to health and research is ongoing. Nevertheless it is clear that the quantity of these fatty acids in the diet has declined over the centuries and some scientists argue that this change in diet may affect the incidence of inflammatory diseases such as arthritis. Research is continuing into these hypotheses.
Taking omega 3 supplements is unlikely to lead to excess since the body simply excretes what it doesn't need.
Although cholesterol is found in foodstuffs, generally we get our cholesterol by synthesising it in the liver. We make around 75% of the body's cholesterol and get the rest from our diet. It gets recycled with the liver excreting it into the bile that flows into the small intestine to help with the digestion of fats, then a lot of it is reabsorbed later in the gut. All foods containing animal fats contain some cholesterol and it's the continual high level of cholesterol which is harmful, leading to congestion of the arteries. Saturated fats are particularly associated with high cholesterol levels and that means foods like full-fat dairy products and animal fats.
There is no doubt that high cholesterol levels are associated with heart disease and that reducing cholesterol is a recommended good health strategy. It is therefore important to realise that if you undertake a low carbohydrate diet, your relative proportion of fats may increase and you are therefore likely to increase your intake of cholesterol.
So where does all this leave us? Since we can manufacture internally almost all the cholesterol we need, then as long as we have a balanced diet containing the two essential fatty acids, we can safely avoid full-fat dairy products and animal fats, keeping our cholesterol down to a safe level. There is some evidence that the omega 3 and 6 fatty acids are helpful but we can get those through a balanced diet. If we choose to take extra, it won't harm us unless we suffer from specific medical conditions so it's fairly safe. Mention of the chemical jargon is almost always there to increase sales by providing them with scientific respectability but as with other branches of Woo, the effect is to confuse and cast doubt in order to encourage sales.
Colonic irrigation
This involves pumping water into the large intestine (colon) through a pipe inserted into the anus with the intention of flushing out material from the gut. This process will certainly remove material from the gut, but the Woo claim goes beyond this to argue that it also removes dangerous toxins which build up in the body. But there is no evidence that toxins accumulate in the gut. This is a remnant of a disproved scientific hypothesis from the nineteenth century.
The gut, by necessity is largely waterproof. Absorption of water from the gut takes place through a tightly-controlled biological mechanism. Nothing pumped into the colon will cause any chemicals in the bloodstream to be flushed out. If there are any toxins in the blood, they will still be there after colonic irrigation has finished.
Chelation therapy
This is a routine clinical medical treatment for poisoning with heavy metals such as mercury or lead, or metalloids such as arsenic, and it was initially developed to treat gas attack victims from World War I. The chemicals in the chelating agent were injected into the patient and they bound tightly to the arsenic atoms, forming a water soluble compound. Because it was water soluble, it could then be eliminated from the body through the liver and kidneys, the body's own mechanism.
Some detox marketers now offer such chemicals as a possible treatment for coronary artery disease but there is no scientific evidence to support it. Although chelation therapy is a recognised clinical treatment for certain forms of poisoning, its use has been usurped by the marketers of Woo to treat non-existent poisoning.
There are safety concerns about the introduction of such powerful chemicals into the body as they have the potential seriously to disrupt our finely balanced metabolism.
Metals
There are many metals that are essential for the body to function. These include iron, zinc, magnesium, calcium, sodium, potassium and copper. Each of these metals is ingested in chemical combinations in food.
Iron is essential for the formation of haemoglobin in the blood. It is abundant in meat, fish, poultry, beans, and leafy vegetables. Its level in the human body is self-regulating and excessive iron leads to toxicity. Unless a person is suffering from a medical condition, it is difficult to develop iron deficiency.
Zinc is enormously important to human biochemistry and is found throughout the body but especially in the brain, kidney, liver, bones and muscles. It is involved in the regulation of the nervous system. It is abundant in all red meats but also beans, wheat and nuts. It is difficult to be zinc deficient but too much additional zinc in dietary supplements carries the risk of toxicity.
Magnesium is essential for the production of nucleic acids, the building blocks of DNA. Magnesium is at the centre of the chlorophyll molecule, the pigment in all green vegetables. Although through poor or deliberately modified diet, it is possible to experience magnesium deficiency, it is abundant in tea, coffee, green vegetables, nuts, and even spices. It is almost impossible to produce an excess of magnesium because, since almost all magnesium salts are soluble, the kidneys will filter it out very efficiently. High concentrations of magnesium though have a laxative effect.
Calcium is essential for bones and teeth and is plentiful in dairy products, nuts, oranges, and even seaweed. It requires vitamin D for absorption through the gut. However, adding extra calcium in the form of dietary supplements can paradoxically slow down the rate of calcium absorption itself.
Sodium is enormously important in human biology helping to regulate body fluids, blood pressure, and in enabling nerve transmission and muscle contraction. Because of the common use of salt as a seasoning most people take in more than ten times their daily requirement and although salt is excreted through the skin, excess sodium intake can be harmful to people with high blood pressure. In hot climates, insufficient sodium intake can result in cramps.
Potassium is a metal very similar to sodium and it too is involved in nerve transmission and in fluid balance. It is extremely difficult to generate a potassium deficiency with a balanced diet because it is very common in fruit, vegetables and meats. An unbalanced diet, or one unbalanced by design, can lead to potassium deficiency. Potassium deficiency is most commonly seen in patients undergoing treatment for renal failure in which potassium is lost along with sodium. Healthy individuals need no additional potassium.
Copper is essential to human metabolism and is found in muscle, liver and bone and it is used in the metabolism of fats. Copper is common in the normal diet in green vegetables, potatoes, beans, nuts and shellfish.
All of these metals are self-regulating in the human body, are abundant in a balanced diet, and far from being toxins, are essential to metabolism.
Dietary supplements
It is only necessary to supplement our diets when we have a known deficiency. The blanket intake of additional vitamins and minerals will not only be filling any particular deficiency, but may also lead to toxicity. For example, although the B vitamins are easily excreted, it is possible to produce toxicity by excessive intake of niacin, pyridoxine or folic acid.
An interesting exercise is to compare the compositions of typical dietary supplement pills and say, a potato! A medium -sized potato already supplies 45% of the daily need for vitamin C (an orange will make up the rest), and a good chunk of all the other vitamins. You also get thrown in calcium, iron, magnesium, phosphorus, potassium and sodium. A balanced diet is by far the best source of nutrients.
The essential elements of Food Woo
The customer has to be convinced that his or her existing diet is inadequate in some way and that it needs to change in the direction of a product. The inadequacy takes two forms: a dietary deficiency, or a failure to remove toxins.
The customer is presented with some well-known dietary information, perhaps tables of recommended daily intake of carbohydrates, proteins and fats, or lists of vitamins, or the composition of various foodstuffs.
The very real health risks of obesity and poor diet are stressed, but whereas the science points to the need for a balanced diet and exercise, Woo marketers bring in additional requirements. As well as eating sensibly and exercising, you are told you also have a need to remove toxins, and to supplement your diet with their products.
Having used the real science to set the scene and convince the customer that they are receiving good advice, they get some good advice (eat properly, exercise) and some bad advice (that they need detox and/or supplements). Science is used to put the customer at ease before they are (sometimes literally) sold a lemon!
Summary
We need to look at how human nutrition really works and not trust the self-appointed nutritionists with their fanciful stories. We now know a bit about the important metals, the vitamins, the enzymes, how the gut functions, and we know that claims about toxins are unfounded. We understand about oxidation and reduction, and what free radicals are, and we know that the detox brigade are misrepresenting science.
We've looked at some of the science behind the vocabulary of cholesterol and fatty acids and seen that there is some inconclusive evidence in support of the significance of omega-3 and omega-6 fatty acids. But more than anything else, the clear message is that eating sensibly without recourse to supplements gives us the best chance of a healthy digestion.
So now we can dispense with the food fads, the nonsense diets, the supplements, the scares about toxins and free radicals and trust in a sensible balanced diet.
Goodbye to the land of Food Woo.
Bob Lloyd has studied in four universities and has degrees in Biochemistry, Mathematics, and Computer Science. After a long career in publishing, teaching, and software engineering, he is now retired and lives in Andalucia in the South of Spain with his wife and rather ancient cat.
