Chapter 10: Stress (Genome)

•The genome is a record of our ancestors’ struggles with plagues, and our resistance to disease is pre-programmed in our genes.

• However, genetic resistance is not the only factor in whether or not we catch an infection. There are many other things that are relevant, such as sleeping under a mosquito net, maintaining good hygiene, and having a strong immune system.

• Cholesterol is an essential ingredient of the body which helps to produce hormones that are necessary for survival. It has been unfairly demonized as being the cause of heart disease.

• The hormone Cortisol is produced from cholesterol and it influences many different bodily functions. It also plays a role in stress response.

•The mind and body are not separate entities, but are part of the same system.

• Psychological stress can affect the body in various ways, including reducing the responsiveness of the immune system.

• Genes need to be switched on in order for them to have an effect, and external events (or free-willed behaviour) can switch on genes.

•People are very like monkeys.

• The discovery that monkeys low in the hierarchy get heart disease came soon after the far more startling discovery that British civil servants working in Whitehall also get heart disease in proportion to their lowliness in the bureaucratic pecking order.

• In a massive, long-term study of 17,000 civil servants, an almost unbelievable conclusion emerged: the status of a person’s job was more able to predict their likelihood of a heart attack than obesity, smoking or high blood pressure.

• Somebody in a low-grade job, such as a janitor, was nearly four times as likely to have a heart attack as a permanent secretary at the top of the heap. Indeed, even if the permanent secretary was fat, hypertensive or a smoker, he was still less likely to suffer a heart attack at given age than thin non-smoking janitor with normal blood pressure.

• Exactly same result emerged from similar study of million employees Bell Telephone Company in 1960s

•The conclusion of the study undermines everything previously thought about heart disease.

• Cholesterol is a risk factor, but only for those with genetic predispositions to high cholesterol.

• Diet, smoking and blood pressure are secondary causes of heart disease.

• Stress and heart failure come from busy, senior jobs or fast-living personalities.

• The lower someone is in the pecking order, the less control they have over their lives.

•Heart disease is often caused by a lack of control in one’s life, which can lead to high levels of stress.

• Cortisol, a hormone released during periods of stress, suppresses the immune system.

• Testosterone also suppresses the immune system, but is necessary for sexual selection.

• Darwin proposed that females choose mates based on the quality of their genes, and this idea has been supported by subsequent studies.

•Testosterone has immune-suppressive effects that are unavoidable.

• This means that when an animal raises its testosterone level, it becomes more vulnerable to infection, cancer and heart disease.

• Scientists do not have a good explanation for this link between steroids and immune suppression.

"A gilded No is more satisfactory than a dry yes" - Gracian