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 one in 500 chance of recovery, Cousins created his own laughter therapy program, which he claims was the key to his ultimate recovery.
Cousins went on to establish the Cousins Center for Psychoneuroimmunology  in Los Angeles, California, and his book, Anatomy of an Illness, was made into a TV movie in 1984 that you can see in the video above. It's an old grainy movie. However, you can watch it if you are in a tough spot and feel you would benefit from some happy support.
Still, conventional medicine is reluctant to admit that your emotional state might have any major impact on your overall health and longevity. Perhaps this is understandable, as “happiness” is not something that can be bottled and sold at your local pharmacy.
The featured article in Scientific American  discusses some of the latest advancements in the field of psychoneuroimmunology (PNI), conducted by researchers at the Cousins Center and elsewhere.
Fortunately, despite being ridiculed and rejected by mainstream science, there are still a brave few who are willing to stick their necks out to investigate how and why emotions, such as happiness, affect your physical health. As stated by Stephen Smale, an immunologist at the University of California:
“If you talk to any high-quality neurobiologist or immunologist about PNI, it will invariably generate a little snicker. But this doesn't mean the topic should be ignored forever. Someday we need to confront it and try to understand how the immune system and nervous system interact.”Your Brain Is Wired to Your Immune System
According to the featured article, studies done in the 1980s and early 1990s revealed that your immune system and brain are actually wired together:
“[P]ortions of the nervous system connect with immune-related organs such as the thymus and bone marrow, and immune cells have receptors for neurotransmitters, suggesting that there is crosstalk.”In some ways, this discovery can be likened to the revelation that your gut has far broader impact on your health than previously imagined—including your psychological health, as your gut and brain are actually made from the same tissue. In a very real sense, you have TWO brains; one inside your skull, and one in your intestines.
When you get down to it, why wouldn’t your emotions and mental state affect your health? It’s already well-known that stress can take a tremendous toll on your health, for example. Yet conventional scientists frown on the idea that emotions such as “happiness” or “joy” would make any difference. As reported in the featured article:
“[I]t has proved difficult to explain how this happens at the molecular level — how subjective moods connect with the vastly complex physiology of the nervous and immune systems. The field that searches for these explanations, known as psychoneuroimmunology (PNI), is often criticized as lacking rigour.Stress Takes a Toll on Your Immune System
[Cousins Center professor, Steve] Cole's stated aim is to fix that, and his tool of choice is genome-wide transcriptional analysis: looking at broad patterns of gene expression in cells. ‘My job is to be a hard-core tracker,’ he says. ‘How do these mental states get out into the rest of the body?’”
Cole and his colleagues have published a number of studies investigating the genetic effects of various mental states. Not surprisingly, they’ve discovered that different emotional states tend to alter gene expression in different ways.
For example, they found that chronic loneliness tends to result in certain types of genes being either up- or downregulated.  Genes involved in the regulation of inflammatory response were upregulated, while genes involved with antiviral control were downregulated. The end result? Decreased immune function. According to the featured article:
“In sociable people, the reverse was true. It was a small study, but one of the first to link a psychological risk factor with a broad underlying change in gene expression.”Through the years, studies have also been able to show the effects of stress on various biological functions. Such effects include:
- Reduced activity of virus-fighting immune cells
- Increased levels of antibodies for common viruses such as Epstein-Barr, suggesting that stress can reactivate otherwise latent viruses in your body
To do so, they asked 34 healthy young women to give a speech about her candidacy for a job in front of two stone-faced interviewers wearing white lab coats. Afterward, half the group was asked to contemplate their performance while the other half were asked to think about neutral things like going to the grocery store. Blood samples were drawn from each participant, showing that the C-reactive protein levels were significantly higher in those who kept ruminating on their speech. According to Medical News Today: 
“For these participants, the levels of the inflammatory marker continued to rise for at least one hour after the speech. During the same time period, the marker returned to starting levels in the subjects who had been asked to focus on other thoughts.What Happens in Your Body When You’re Happy?
The C-reactive protein is primarily produced by the liver as part of the immune system's initial inflammatory response. It rises in response to traumas, injuries or infections in the body, [lead author, Peggy] Zoccola explained. C-reative protein is widely used as a clinical marker to determine if a patient has an infection, but also if he or she may be at risk for disease later in life. ‘More and more, chronic inflammation is being associated with various disorders and conditions,’ Zoccola said. ‘The immune system plays an important role in various cardiovascular disorders such as heart disease, as well as cancer, dementia and autoimmune diseases.’"
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:
1. Hedonic well-being (characterized by happiness gleaned from pleasurable experiences, such as sex)
2. 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 were found to have favorable gene-expression profiles, while hedonic well-being produced gene profiles similar to those seen in people experiencing stress due to adversity. According to the featured article: 
“One interpretation is that eudaimonic well-being benefits immune function directly. But Cole prefers to explain it in terms of response to stress. If someone is driven purely by hollow consumption, he argues, all of their happiness depends on their personal circumstances. If they run into adversity, they may become very stressed.Stress-relieving strategies have also been shown to have direct, beneficial health effects. Meditation, for example, has been shown to promote antiviral gene activity and reduce inflammatory gene expression. Laughter yoga is also becoming increasingly popular around the world.
But if they care about things beyond themselves — community, politics, art — then everyday stresses will perhaps be of less concern. Eudaimonia, in other words, may help to buffer our sense of threat or uncertainty, potentially improving our health. ‘It's fine to invest in yourself,’ says Cole, ‘as long as you invest in lots of other things as well.’”
What Comes First—Health or Happiness?
For many, happiness can be a poorly defined, elusive goal. One way to think about happiness is to define it as “whatever gets you excited.” Once you’ve identified that activity, whatever it is, you can start focusing your mind around that so you can integrate more of it into your day to day life. If you feel stuck and don’t know where or how to start, I suggest reviewing my previous article “13 Tips for Living Happy, Wild, and Free.”
I also believe that factors such as diet and exercise can play a significant role. It’s tough to feel exuberant when you’re not feeling well physically. As mentioned earlier, the state of your gut can have profound implications for your mental well-being, and is an oft-overlooked aspect of depression and other psychological problems. The following lifestyle strategies can help you create a firm foundation of good health, which will support your psychological and emotional being as well.
1. Eat a healthy diet focused on fresh, whole foods (ideally organic and/or locally grown). Eat a large portion of your food raw. You want to pay careful attention to keeping your insulin levels down, which means avoiding sugars and grains of all kinds, and replacing the lost carbs with healthful fats. Also be mindful of your protein sources, making sure they’re of high quality (ideally organically-raised and pasture-fed). A high-fat, moderate-protein, low-carb diet is likely to improve the health of most people. My optimized Nutritional Plan can guide you, whether you’re at a beginner’s or advanced level.
2. Consume healthy fat. The science is loud and clear on this point: omega-3 fats are essential for optimal health. Other healthy fats include coconut oil, avocados, olives, olive oil, butter, and macadamia nuts. All these fats are low in protein and carbs and will not impair your insulin or leptin.
3. Make clean, pure water your primary beverage, and steer clear of all sweetened and/or flavored beverages, including those that contain artificial sweeteners.
4. Manage your stress.
5. Exercise regularly. Ideally, you want a comprehensive fitness regimen that includes stretching, high intensity interval training, core strengthening exercises, and strength training.
6. Get plenty of appropriate sun exposure to optimize your vitamin D levels naturally. UV exposure also has additional health benefits beyond vitamin D production.
7. Get grounded. Grounding or Earthing is defined as placing one's bare feet on the ground whether it be dirt, grass, sand, or concrete (especially when humid or wet). When you ground to the electron-enriched earth, an improved balance of the sympathetic and parasympathetic nervous system occurs. Studies have shown that grounding improves blood viscosity, heart rate variability, inflammation, cortisol dynamics, sleep, autonomic nervous system (ANS) balance, and reduces effects of stress. Earthing also decreases the effect of potentially disruptive electromagnetic fields.
8. Limit your exposure to toxins of all kinds. The number of toxic chemicals and their sources is so large, addressing them all could easily require an entire library, but I believe you can help you keep your toxic load as low as possible by becoming an informed and vigilant consumer. This includes tossing out your toxic household cleaners, soaps, personal hygiene products, air fresheners, bug sprays, lawn pesticides, and insecticides, just to name a few, and replacing them with non-toxic alternatives.
9. Get plenty of quality sleep. Scientists have discovered that your circadian rhythms regulate the energy levels in your cells. In addition, the proteins involved with your circadian rhythm and metabolism are intrinsically linked and dependent upon each other. Therefore, when your circadian rhythm is disrupted, it can have a profound influence on your health. For example, research has also linked disrupted sleep cycles to serious health problems like depression, coronary heart diseases, and even cancer. If you have any kind of sleep problem, whether you’re having trouble falling asleep or staying asleep, my article “33 Secrets to a Good Night's Sleep” is packed with great tips to help you finally get some good rest.
1 Mayo Clinic Proceedings 2000 Feb;75(2):133-4
2 Cousins Center for Psychoneuroimmunology
3 Scientific American November 27, 2013
4 Genome Biology 2007, 8:R189
5 See ref 2
6 See ref 2
7 Scientific American November 27, 2013