By Dr. Mercola

Many studies support the belief that having an upbeat and positive attitude will translate into living a longer, healthier life, and conversely, that a pessimistic outlook promotes ill health and can shave years off your life.

For example, in one study,¹ the tendency to always expect the worst was linked to a 25 percent higher risk of dying before the age of 65.

Perhaps one of the most well-known forerunners of "the science of happiness" was Norman Cousins, who in 1964 was diagnosed with a life-threatening autoimmune disease.

After being given a 1 in 500 chance of recovery, Cousins created his own laughter therapy program, which he claims was the key to his ultimate recovery. He went on to write the book, "Anatomy of an Illness," and established the Cousins Center for Psychoneuroimmunology² in Los Angeles, California.

Your Brain and Immune System Are Linked

As noted by Medical News Today:³

"Over the last few decades, the intriguing and pervasive links between neuroscience and the immune system have slowly been uncovered.

What might seem, at first, like an uneasy marriage between the brain and immunity has steadily grown into a fully fledged interdisciplinary area of study.

This field is known as psychoneuroimmunology (PNI).

It is well-established ... that stress can induce illness and that, conversely, a fun-filled occasion with loved ones can soothe aches and pains and stave off the very same illness ...

PNI has deep ramifications for the future of medical research, the treatment of diseases and our attitude toward handling stress."

Research conducted in the 1980s and early 1990s revealed that your immune system and brain are actually wired together,⁴ and connections between your nervous system and immune-related organs such as your thymus and bone marrow allow for crosstalk between the two systems.

Revealingly, your immune cells also have neurotransmitter receptors, suggesting that what goes on in your brain impacts your immune system, for better or worse. For example, stress has been shown to reduce activity of virus-fighting immune cells.

Stress also increases levels of antibodies for common viruses such as Epstein-Barr, suggesting that stress can reactivate otherwise latent viruses in your body. Ruminating on a stressful incident has also been shown to increase your levels of C-reactive protein, a marker of inflammation in your body.⁵

Sociable, Outgoing People Tend to Have Stronger Immune Function

Positive emotions also have a decided impact on your health. Steve Cole, Ph.D. a professor at Cousins Center for Psychoneuroimmunology, has done a number of studies investigating the genetic effects of various mental states.⁶

For example, he and his team found that chronic loneliness tends to upregulate genes involved in the regulation of inflammatory response while downregulating genes involved with antiviral control — the combination of which results in decreased immune function.

In sociable people, the reverse gene activation took place, leading to improved immune function. Other research⁷ has shown that happiness, optimism, life satisfaction, and other positive psychological attributes are associated with a lower risk of heart disease.

Different Kinds of Happiness Produce Different Health Results

In one of Professor Cole's happiness studies, participants answered questions about the frequency of certain emotional states, covering two different categories or types of happiness known to psychologists as:

• Hedonic well-being (characterized by happiness gleaned from pleasurable experiences, such as sex and shopping)
• Eudaimonic well-being (originating with Aristotle, this form of happiness comes from activities that bring you a greater sense of purpose, life meaning, or self-actualization )

Interestingly, while both are positive emotional states associated with happiness, the gene expressions they produced were not identical.

Those whose sense of happiness was rooted in the eudaimonic camp had favorable gene-expression profiles, while hedonic well-being produced gene profiles similar to those seen in people experiencing stress due to adversity.

Professor Cole's theory⁸ as to these differences is that when you're driven by materialistic values, your happiness depends on circumstances that may or may not be within your control. If you run into adversity, it can cause a great deal of stress because it impedes your perceived ability to be happy.

On the other hand, those driven by a sense of "purpose" are largely buffered against the uncertainty that comes with adversity, and their happiness is not dependent on having or experiencing anything in particular that can at any moment be taken away.

Different Kinds of Stress Affect Different Components of Your Immune System

In a similar way, research⁹ has shown that different types of stress alter different parts of your immune system.

• Brief stress, such as making a speech or taking a test, tends to suppress cellular immunity (acquired immunity mediated by antigen-specific T-cell lymphosites; involved in resistance to infectious diseases) while preserving humoral immunity (which refers to antibody production and accompanying processes).

  As a result, you may find yourself more vulnerable to the common cold or flu

• Chronic stress, such as caring for a partner or parent with dementia, suppresses both components of the immune system, making you more susceptible not just to infectious diseases, but all disease

How Your Mind Influences Your Health

Medical News Today¹⁰ lists a number of examples where studies have shown a link between your psychology and your health, to which I've added a couple more:

Sudden death	Research shows that during the first week after the death of a spouse, mortality skyrockets to double the normal rate
Heart and cardiovascular disease, stroke, and heart attacks	Letting your anger out explosively may be harmful because it triggers surges in stress hormones and injures blood vessel linings. One study11 found that people over the age of 50 who express their anger by lashing out are more likely to have calcium deposits in their coronary arteries — an indication that you're at a high risk for a heart attack — than their mellower peers. A systematic review12 involving data on 5,000 heart attacks, 800 strokes and 300 cases of arrhythmia also revealed that anger increases your risk of heart attack, arrhythmia and stroke — and the risk increases with frequent anger episodes.
Gastrointestinal (GI) problems	Sustained or chronic stress has been linked to a number of GI problems, including inflammatory bowel disease and irritable bowel syndrome. It's becoming increasingly clear that your brain, your immune system and your gut microbes are intricately linked. Autism, for instance, is associated with gastrointestinal problems and potentially an over-reaction in the immune system
Cancer	Your outlook has an effect on your ability to recover from cancer. The quality and quantity of psychological support also makes a difference in survival rates
HIV	Heightened stress and dwindling support from family and friends has been shown to accelerate the progression of HIV infection
Allergies	Skin complaints like psoriasis and eczema have psychological underpinnings. Ditto for asthma. All tend to worsen when stress is elevated
Wound healing	The psychological state of the patient has been shown to affect their rate of healing. As noted in the featured article: "For instance, increased levels of fear or distress before surgery have been associated with worse outcomes, including longer stays in the hospital, more postoperative complications and higher rates of re-hospitalization. In one study on patients with chronic lower leg wounds, those who reported the highest levels of depression and anxiety showed significantly delayed healing."
Inflammation	Stress-relieving strategies such as meditation has been shown to promote antiviral gene activity and reduce inflammatory gene expression

The Psychology of Immune Function

Robert Ader is another psychoneuroimmunology (PNI) pioneer. In the mid-1970s he stumbled upon a link between the brain and the immune system while studying conditioning behavior in rats. The animals were fed varying quantities of saccharin in water, while being injected with a drug (Cytoxan) that causes gastrointestinal distress and immune suppression. By administering the drug, the rats were conditioned to avoid the solution, despite its sweet allure.

Surprisingly, when he stopped injecting the rats with the drug, not only did they still avoid the sugary solution, some of them died. Moreover, the rate of mortality corresponded with the level of saccharine they received. Ader hypothesized that, in addition to conditioning the avoidance response, the rats' immune function had also been conditioned.

In essence, even though the rats no longer received the immunosuppressant drug, their immune function dropped in response to the taste of sweetened water alone.

As noted in the featured article:

"If the immune system was in cahoots with the nervous system, there must be points where they intersect. Soon, this too was demonstrated. In 1981, David Felten made the next major discovery. He uncovered a network of nerves that led to blood vessels and, importantly, cells of the immune system.

Felten's team found nerves in the thymus and spleen that terminated near clusters of important immune system components: lymphocytes, macrophages and mast cells.

In 1985, Candace Pert, Ph.D. found neurotransmitter and neuropeptide receptors on the cell walls of the immune system and the brain. This discovery showed that the communication chemicals of the nervous system could also speak directly to the immune system."

The brain was once considered to lack normal immune surveillance. This was assumed to be the case because normal immune responses like swelling do not regularly occur inside the brain. If they did, people would be dying from it on a regular basis. However, considering the brain "immune privileged" turned out to be overly simplistic.

As noted above, research shows that your brain does in fact interact with your peripheral immune system, albeit in unique ways. In 2015, researchers discovered lymphatic vessels in the brain,¹³ again showing the connection between the brain and the immune system.

Neuropeptides may also be part of the puzzle, as they've been implicated in a number of functions involving emotions. For example, they play a role in social-, reproductive-, and reward-seeking behaviors. More than 100 neuropeptides are also used by your central nervous system; they influence both gene expression and the building of new brain synapses.

The Hypothalamic-Pituitary-Adrenal Axis

As noted in the featured article, the hypothalamic-pituitary-adrenal (HPA) axis plays an important role in stress-induced immune-brain interactions. Your hypothalamus, pituitary, and adrenal glands all secrete hormones related to biological processes such as digestion, immune function, sexuality and mood. Medical News Today explains:¹⁴

"One chemical of note involved in the HPA axis' work is corticotropin-releasing hormone (CRH). The hypothalamus releases CRH in response to stress, illness, exercise, cortisol in the blood and sleep/wake cycles. It peaks soon after waking and slowly declines throughout the rest of the day. In a stressed individual, however, cortisol levels are elevated for prolonged periods of time.

During stress, the body believes it is in imminent danger, so cortisol triggers a number of metabolic changes to ensure that enough energy is available in case a fight or flight is necessary. One of these energy-saving tactics is to suppress the metabolically expensive immune system, saving vital glucose for the approaching life-threatening event ...

In this way, ongoing stress can reduce the capabilities of the immune system as the body saves its energy for a physical exertion that never comes."

On the other hand, oxytocin — a hormone that has long been associated with physical and emotional closeness — helps suppress the HPA axis, thereby promoting healthy immune function and improved wound healing.

Meditation Eases Pain and Anxiety

Considering the detrimental effects of stress, it should come as no surprise that stress-relieving strategies like meditation can have direct, beneficial health effects. One recent study found meditation helps ease pain and anxiety during breast biopsies. A total of 121 women undergoing breast cancer diagnosis were randomly assigned to participate in one of three approaches as they went through their biopsies:

• A recorded loving-kindness meditation
• Music (their choice of instrumental jazz, classical piano, harp and flute, nature sounds or world music)
• Standard care, which includes casual conversation and emotional support

As reported by Duke Cancer Institute:¹⁵

"Patients in the meditation and music groups reported significantly greater reductions in anxiety and fatigue after biopsy than those receiving standard care. The standard-care patients reported increased fatigue after biopsy. The meditation group also showed significantly lower pain during biopsy when compared to the music group."

Meditation has also been shown to have a distinct impact on gene expression, reduces inflammation,¹⁶ and can help relieve stress-related diseases such as:

High blood pressure	Sleep disturbances and fatigue
Chronic pain	Gastrointestinal distress and irritable bowel syndrome
Headaches	Skin disorders
Respiratory problems such as emphysema and asthma	Mild depression and premenstrual syndrome (PMS)

Your Psychological Health Cannot Be Divorced From Your Physical Health

By activating the relaxation nervous system, which allows you to "rest and digest," you can ease a variety of health symptoms and restore your body to an anti-inflammatory state. You can start with something as simple as listening to a guided meditation for several minutes a day and working up to 20 minutes twice a day for a therapeutic effect.

Remember, the relationships between your gut, brain, immune, and hormonal systems are impossible to untangle. So for optimal health and effective disease prevention, it's important to communicate to your body the message that it is not being attacked; it's not in danger.

You also need to nourish and support your body — both emotionally and physically. In short, restoring mental calm, increasing your sense of joy, and maintaining an optimistic outlook helps lay the foundation for a long, healthy life.