chapter 3: infectious diseases, autoimmune conditions and allergies

‘The constancy of the internal environment is the condition for a free and independent life.’

Claude Bernard, French physiologist

The human immune system is undeniably highly complex, and our precious immunity is threatened every day by suppressors, including inadequate nutrition, inappropriate levels of exercise, chronic stress, air pollution, lack of sunlight and environmental toxins. Left to decline and weaken, it can go haywire, resulting in us being more susceptible to infections, allergies and autoimmune diseases. This chapter takes a look at what can happen when things get out of control.

Infectious diseases

Until the end of the twentieth century, infectious diseases were responsible for the greatest global burden of premature death. Over the last 500 years, worldwide pandemics of infectious diseases, such as influenza, cholera and smallpox placed whole populations in danger of being completely wiped out. However, in high-income countries, improved sanitation and living conditions began to reduce the toll of infectious disease, and by the mid-twentieth century vaccines and the accessibility to antibiotics decreased the burden of infectious diseases even further.

Bacteria, along with viruses, are the most common source of infectious diseases, with antibiotics often used to combat bacterial infection. However, emerging pandemic viral infections are a continual threat, and while antibiotics can treat bacterial infections, comparatively few antiviral drugs have been developed to treat these emerging viral infections. Our first line of defence against a viral infection is the interferon system. Interferons are cytokines, and they’re named for their ability to ‘interfere’ with viral replication by protecting cells from virus infection. This system is designed to block the spread of virus infection in the body, and is highly dependent on adequate vitamin C and the mineral manganese. Unfortunately, some viral infections aren’t able to be eliminated by the immune system, and the viruses hide in cells. These hidden viruses are able to be re-activated, which leads to repeated attacks, such as the recurring cold sores of the herpes virus.

Epidemics and pandemics have always had major social and economic impacts on affected populations, but in the modern world the impacts are truly global. Despite major advances in infectious disease research and treatment, the control and elimination of these diseases face significant challenges.

More men than women die of infectious disease

Fatality rates of infectious diseases are often higher in males than females17. This has also been observed in data concerning Covid-19, where data from the Centers of Disease Control and Prevention indicated that, in England and Wales, men account for 60 per cent of all deaths and in Malaysia 78 per cent¹⁸. According to findings from past respiratory disease studies, it could be due to the role that testosterone and oestrogen play. Alternatively, it may be due to the fact that the X chromosome (of which females have two, but males have only one), has more immune-related genes, thus providing females with stronger immunity to defend against certain infections, such as Covid-19. Generally, females tend to mount a stronger immune response, which helps them to clear infections quicker. However, while this more robust immune response helps to combat unwanted invaders, it does make women more susceptible to immune disorders¹⁹.

Autoimmune conditions

Autoimmune disease occurs when the immune system mounts an attack against healthy tissue. In autoimmunity, the immune system recognizes, targets and causes damage to normal tissues, such as skin, kidneys, pancreas, the nervous system and the body’s joints. There are over 80 autoimmune conditions, each affecting different parts of the body. For example, in Type 1 diabetes, the immune system destroys the cells that make insulin; in rheumatoid arthritis, the lining of the joints are attacked; and in multiple sclerosis, the coating around nerves is damaged.

While no exact figure exists in the UK for the total number of people affected by the 80 or more identified autoimmune disorders, it has been estimated that approximately four million people have an autoimmune condition – which is more than 6 per cent of the population²⁰. The US National Institutes of Health (NIH) estimates that approximately 23.5* million Americans live with an autoimmune disease and that its prevalence is on the rise, while the American Autoimmune Related Diseases Association (AARDA) says that approximately 50 million Americans live with an autoimmune disease. (*The NIH only includes 24 diseases for which they had epidemiology studies they considered appropriate available.)

Furthermore, having one autoimmune condition makes developing another more likely, with up to a third of the four million people affected by autoimmunity living with more than one autoimmune condition²⁰. This can result in extremely complicated and multifaceted health needs and, ultimately, makes everyday life significantly more difficult.

• According to Diabetes UK, there are around 400,000 people in the UK with Type 1 diabetes and this rate is growing at a rate of 3 per cent per annum. Whilst in the US approximately 1.6 million have Type 1 diabetes, including 187,000 children and adolescents (ADA, 2020).
• Rheumatoid arthritis (RA) affects roughly 700,000 people in the UK, according to the British Society for Rheumatology. RA also affects over 1.3 million Americans (Rheumatology Org, 2020).
• At least 115,000 people in the UK live with Crohn’s disease. Whilst in the US, around 780,000 people are currently living with this debilitating disease (Crohn’s Colitis Foundation, 2020).
• A 2014 study estimated a UK-wide figure of 127,000 for prevalence of MS, with the number of people affected by the condition growing at a rate of 2.4 per cent per year. And, nearly 1 million American adults have been diagnosed with MS (National MS Society, 2020).
• Lupus is thought to affect up to 50,000 people in the UK. The Lupus Foundation of America, believes that approximately 1.5 million Americans, and 5 million people worldwide have a form of lupus (Roper, 2012).

Disturbingly, autoimmune conditions are on the rise, with treatments to manage them already costing billions. Unfortunately, they are poorly understood. Research has indicated that genetic predisposition explains approximately 30 per cent of all autoimmune disorders, while 70 per cent are owing to environmental factors, including dietary issues, gut dysbiosis, infections, and exposure to toxic chemicals²¹. As we know, in general, women tend to have a stronger immune response, which helps to clear infections quickly, but it also increases vulnerability to immune disorders¹⁸. In the United States alone, women represent 80 per cent of all cases of autoimmune disease.

While it is evident that genetics play a role in autoimmunity, we still don’t know exactly how genes are involved. Having a family member with lupus, for example, does increase your risk of also getting lupus, but some families have several family members who all have different autoimmune disorders. Additionally, it appears there are lots of genes involved in the immune response on the X chromosome, and because, as we saw earlier, women have two X chromosomes while men have only one, women have more of those immune genes. Genetics alone isn’t enough to cause autoimmune disease. Professor Johann E. Gudjonsson of the University of Michigan discovered that females have more of a molecular switch called VGLL3 in their skin than males, and that more of this VGLL3 may be what provokes an increased immune response in females.

Nearly 50 per cent of women who develop an autoimmune disease do so in the first year after pregnancy. Then, as a woman enters menopause, the reduction in female sex hormones leads to a considerable decrease in immune function, leaving it similar to, or even less capable than that of a male²². This can be a period when autoimmunity symptoms improve or, due to a reduction in immune function, symptoms may worsen. Thus, as we get older, we need to focus on supporting our immunity more than ever.

While we know that certain genes or being exposed to certain environmental factors can make some autoimmune conditions more likely, that’s not the whole picture – something is going wrong with the immune system, and we don’t fully know why, as yet. Currently, autoimmune conditions cannot be cured, which means that for many people who develop an autoimmune disease, a lifetime of daily management and potential health complications lies ahead.

Allergies

Like autoimmune conditions, incidence of allergies is increasing. In fact, allergy is the most common chronic disease in Europe, with up to 20 per cent of patients affected by an allergy living with an incapacitating or life-threatening form, and fighting daily with the anxiety and distress of a potential asthma attack, anaphylaxis, or even death²³. In addition, more than 50 million Americans have experienced various types of allergies each year, and up to 2 million, or 8 per cent, of children in the US are estimated to be affected by food allergies²⁴.

Similarly to autoimmune disease, allergy is caused by an inappropriate immune response, and results when the body alters its normal immune response to an offending allergen (a substance that provokes an antibody response). An allergic response can be a result of a variety of different stimuli, such as pollen, medications (such as the antibiotic penicillin), or a particular food. Allergic responses are very specific because they are adaptive immune responses. Thus, a hay fever sufferer’s condition is caused by one type of pollen, not just by any pollen, and a patient with an allergy to penicillin may be safe taking other kinds of antibiotic. While in the instance of contact allergies, such as sensitivity to nickel or washing detergents, it is the lymphocytes and macrophages that over-react, in most other allergies it is the antibody response that is over-reactive.

Allergies are the most common type of acquired immune disease, and they usually depend on an IgE-mediated immune response to the antigen.

IgE antibodies attach themselves to ‘mast cells’ and, when the allergen combines with its specific IgE antibody, the IgE molecule triggers the mast cell to release granules containing histamine and other chemicals that cause the symptoms of allergy, such as asthma, eczema, hay fever and hives.

The reasons for the rising rate in allergies are not fully understood, but we do know that genetics plays a role, since allergies have a tendency to run in families. Another theory is that it may be the result of living in a cleaner, more sterile and germ-free environment, which decreases the number of germs our immune systems have to deal with. It is thought this may cause our immune system to then over-react when it comes into contact with harmless substances. The ‘hygiene hypothesis’ proposes that modern standards of public health, which have had a significant effect on the timing and type of infections that children encounter as they grow up, have altered the balance of the immune response. On a positive note, childhood mortality is considerably reduced due to improved public health, but on the other hand, immune systems, which develop in this sterile world may be less ‘educated’, and potentially more inclined to make a mistake. Such hypotheses are very tricky to prove, but various findings have confirmed the intricate and highly complex relationship that exists between the immune system and the environment.

Atopic conditions

Atopic diseases tend to occur in a progression, termed the ‘atopic march’, which refers to the natural history of allergic diseases as they develop over the course of infancy and childhood25. The initial manifestation of atopic disease in infancy or early childhood is often eczema, followed by the staggered development of food allergy, hay fever and asthma²⁶.

ATOPHY or BEING ATOPIC means having a genetic tendency for your immune system to make increased levels of IgE antibodies to certain allergens. An atopic individual is likely to have more than one allergic condition during their lifetime, such as eczema, asthma, hay fever or food allergy.

Contact with an allergen can bring about various forms of eczema and involves an over-active response by the immune system. While the exact cause of developing an atopic condition like eczema is unknown, it is not down to one single thing, and often food allergies can play a part, as may inadequate food choices, obesity, exposure to stress, air pollution, infections, antibiotics and vitamin D deficiency. Further, research has shown that vitamin D has confirmed effects on immunity, which may be significant in the progression, severity and course of eczema, asthma and food allergies²⁷. Deficiency in vitamin D is a global issue, which could be a reason why there has been a keen rise in allergic diseases that have resulted over the last sixty years.

Food allergies

Food allergies are on the rise, and some of the most common offenders include foods such as cow’s milk, egg, peanuts, tree nuts, soy, wheat, shellfish and fish. A true food allergy causes an immune-system reaction involving IgE antibodies, which affects numerous organs in the body, causing a range of symptoms, such as hives, digestive upsets, swelling in the face or throat or itching. In some cases, an allergic food reaction can be life-threatening, resulting in anaphylaxis. If you have an immediate reaction after eating a food, it is most likely to be an allergic response. In contrast, food intolerance symptoms can result fairly quickly, but are often delayed by up to 48 hours and last for hours or even days28. They are also generally less serious and often limited to digestive issues.

Food allergy facts

• It is estimated that between 1 and 10 per cent of adults and children have a food hypersensitivity. However, as many as 20 per cent of the population experience some reaction to foods that make them think they have a food hypersensitivity²⁹.
• Around 11–26 million members of the European population are estimated to suffer from food allergy. If this prevalence is projected onto the world’s population of 7 billion, it converts into 240–550 million individuals with potential food allergies⁹.
• Food allergy tends to affect approximately 3–6 per cent of children in the developed world³⁰. However, in the UK, it is estimated that the prevalence for food allergy is 7.1 per cent in breast-fed infants, with 1 in 40 developing peanut allergy and 1 in 20 developing egg allergy³¹.

Correct diagnosis of a food allergy is crucial to identify individuals who could have critical and deadly allergic reactions, and also to eliminate potential allergies that may result in avoidable dietary restrictions. Medically supervised oral food challenges (OFC) remain the most definitive test in the diagnosis of food allergy, with the majority of oral food challenges being carried out openly, so the individual and medical professional conducting the challenge are aware of what food is being tested. However, OFCs that are blinded can follow two different forms: single-blinded is when the individual may not know what they are eating; and a double-blind OFC is when both the medical professional and patient are unaware if it is a ‘placebo’ or ‘test food’ that is being eaten. (If testing a potential allergy for soy, and soy is hidden in a cracker – this is a test food. Another cracker that tastes and looks just the same, but without the soy, is the placebo.) The American Academy of Allergy, Asthma and Immunology (AAAAI) considers the double-blind oral food challenge as the best test, as it reduces potential anxiety-associated reactions. However, blinded challenges are seldom conducted in clinical practices, and are generally performed in research studies³². If a subject is found to have a true food allergy, treatment is usually complete exclusion of that food.

Food intolerances

As we have seen, it is the immune response that determines whether an individual may have a true food allergy. Where the immune system causes the reaction in food allergy, it is the digestive system that triggers the reaction in a food intolerance. This is when your body can’t properly break a substance down, or your body reacts to a food you’re sensitive to; for example, lactose intolerance is when your body can’t break down lactose – a sugar found in dairy products. Symptoms of food intolerance may include gas, bloating, diarrhoea, constipation, digestive cramping and nausea. There are lots of reasons why you may experience a food intolerance:

• lacking the digestive enzyme you need to break down a particular food
• reacting adversely to substances added to food, such as additives and preservatives
• a chemical sensitivity reaction to food components, such as caffeine
• sensitivity to naturally occurring dietary components, such as fructans (found in artichokes, cabbage and leeks), that may cause IBS symptoms.

Keeping a food diary can be useful in helping you narrow down food intolerances. If you still can’t pinpoint the culprit, you may wish to try an elimination diet (see chapter 5). This strategy involves removing foods that are most commonly associated with intolerances for about two weeks, at which point foods are then re-introduced, one at a time. You may wish to undertake a guided elimination diet with the support of a nutritionist or dietician who can advise you, thus avoiding any potential nutrient deficiencies.

Allergies are especially common in children, with some disappearing as the child gets older; however, many are lifelong. Adults can also develop allergies to things they weren’t previously allergic to, which is exactly what happened to me in 2015.

My story

I have had numerous operations in my life, but only twice in 43 years have I been bedridden by an illness. The first was when I contracted the Epstein-Barr virus (EBV), which is responsible for glandular fever, at the age of 15.

The second time occurred in 2015, shortly after the birth of my second child. I had been working hard the months before I got ill, but what started as a minor cold developed into viral chest pneumonia, which left me bedridden for two weeks. That was bad enough, but it was what I developed immediately afterwards that completely derailed me.

It was a cold December day, and I remember being delighted that I was well enough to go outside for a walk with my 12-week-old son. However, after less than two minutes outside, I felt as though I was burning and itching all over, but especially in my face. My face was inflamed and covered in red and white patches, as if I had been wearing a ski-mask. I also had welts all over my body. At that stage, I knew I had had an allergic reaction, and went through what I had eaten or drank prior to going outside, but there was nothing out of the ordinary. After about an hour, the welts and swelling started to subside. Unfortunately, it happened the next day, and the next… I dreaded going out. Even for the daily drop-off and pick-up, I would take an antihistamine prior to leaving the house. This didn’t reduce the burning, swelling and itching, so I booked in to see my GP. It emerged that I had ‘cold urticaria’, which affects about 0.05 per cent of the population.

The cause of most cases of cold urticaria is unknown, but it is thought in some cases to be triggered by an infectious disease, an insect bite, certain medications or blood cancers³³. My doctor advised that the allergy could last for a minimum of five years, and the only treatment available was a daily antihistamine, which didn’t improve my symptoms at all.

I realized that the pressure of recently giving birth, of being mum to two children under three, working hard, and also writing up a substantial research paper had taken their toll and pushed my immune system to the limit. I believed I had contracted a minor virus that my body would normally have fought off with ease, but excess stress and severe lack of sleep meant that my immunity at that point was unable to fight it off.

Back to basics

During my son’s birth, I had had a C-section and also underwent a two-hour bowel operation. Afterwards, I had been given antibiotics to prevent infection. It was therefore very likely that much of my ‘good’ bacteria had been wiped out. As we know, antibiotics can reduce gut bacteria diversity in just three days, with the effects of a short course lasting for years. In the days following the frantic activity of having a new-born and a longer-than-intended hospital stay, I hadn’t thought about addressing my gut health. For 12 weeks following my son’s birth, sleep had been non-existent, while my emotional and physical stress was the highest it had ever been. Therefore, I decided to go back to basics, and followed exactly the same programme I outline in Chapter 5. After six weeks, my allergy had gone.