Physicians and patients – well, people – constantly struggle with understanding how important certain things are or how impactful they might be in our lives. In medicine, we might appreciate that both quitting smoking and eating more fruits and vegetables are both associated with a positive impact on overall health and longevity. But which one is more important? How important is either? In most cases, if something adds several years to your life or improves the quality of life that you have, it’s going to be worth doing. But what if something were associated with only one week of extra life? This thing might be worth doing if it comes at a low cost or at only a small amount of time or pleasure expense. For example, if I knew for sure that eating steaks was associated with a reduction in my life span of only week, I would still eat steaks.

Part of good communication is the ability to communicate risk and benefit in a way that is rational and understandable. We often judge risk disproportionately when the risks being compared are different in terms of immediate impact versus a slow accrual of risk. In the same way, we rarely see benefits the same way when it comes to comparing a sudden benefit versus a slow accrual of benefit. For example, a lot of people buy lottery tickets even though there is virtually no chance of winning but those same folks do not save money for retirement. They believe it is more advantageous to spend money on the thing that is unlikely to happen but has a perceived major impact rather than spend money on something that is guaranteed but doesn’t have an immediate payoff.

In terms of risk, many patients fear the one in 1 million chance of a major reaction to a vaccine (the big, immediate impact) and completely negate the slow accrual of benefit over a season or a period of years (avoiding the disease). The psychology that underlies this irrational view of risk and benefit also leads people to look for the simple yet miraculous treatments or cures. Many billions of dollars are spent every year on gimmicks and con-games while patients are often reluctant to spend a few dollars on a prescription. It is more appealing to think that organic honey and turmeric can cure cancer, even though there is zero evidence that it can, than to believe that surgery and chemotherapy can cure cancer.

We must work hard to communicate the actual magnitude of effect of the things we do for patients and the things we recommend for patients. Understanding magnitude of effect is also the key to interpreting literature in a more rational way. It might be statistically significant that one person will benefit from an intervention for every 10,000 that were treated, but your common sense tells you that this is not a very important intervention compared to something that benefits one out of two people treated. In fact, your common sense tells you that the observed effect is probably not even true.

I have written before about the concept of micromorts and microlives as a tool for better understanding and communicating risk and benefit or magnitude of effect. Recall that a micromort is a one in a million chance of death while a microlife is equal to 30 minutes of life expectancy. We can use these concepts as an exchange currency to understand the relative risks and benefits of virtually any activity or intervention.

Understanding this, one question that we might ask is, What are the five most meaningful things we can do that affect life expectancy and, to a lesser degree, quality of life? Using good risk and benefit communication tools can help us sort through all the nonsense offered up on the Internet in the form of life hacks and health tips, the vast majority of which actually offer almost no benefit whatsoever or such a small benefit that doing the intervention is not worthwhile for the vast majority of people.

If you are a patient, and you are not doing the things listed below, then almost nothing else is worth your time considering in terms of the quality and quantity of your life and health. If you are a physician, these things should be your priorities when discussing beneficial interventions with your patients.

1. Quit smoking.
2. Exercise
3. Maintain a normal body weight.
4. Stay current with your immunizations.
5. Don’t abuse substances.

Quitting smoking. If you smoke a pack of cigarettes per day, you will lose 10 microlives per day, or 300 minutes. This is equivalent to 76 days lost per year of smoking. This will result in a roughly 21% reduction in lifespan, and smoking impacts the quality-of-life in a profound way. Smoking kills about a half million people in the United States each year. This equates to nearly one in five deaths. In addition to causing 90% of lung cancers, it also impacts quality-of-life through diseases like COPD, heart disease, stroke, blindness, pneumonia and other respiratory illnesses, asthma, osteoporosis, reduced fertility and poor pregnancy outcomes, and an increased risk of cancers of the head and neck, stomach, liver, esophagus, kidney, pancreas, colon, bladder, cervix, and a few other organs. Smoking increases the risk of preterm delivery, stillbirth, low birth weight, SIDS, ectopic pregnancy, and orofacial cliffs and newborns.

I could go on, but you get the idea that smoking is the most common, worst thing that you can do for your health. Yet nearly one in five adults in the United States smoke, and while that number has declined over the last several years, the number of marijuana smokers is increasing. There is not the same perception of the risks of daily marijuana use as of daily cigarette use, which in and of itself poses a public health hazard. In other words, many folks who would never touch a cigarette see no risks associated with smoking marijuana. This is patently unscientific, but we can talk about that later.

For most patients, quitting smoking is more valuable to them than is treating all their other chronic illnesses with medicines combined; yet, many physicians who are quick to write prescriptions for statin drugs and blood pressure medications do no more than pay lip-service to tobacco cessation with their patients.

There are many good ways of helping patients quit smoking; but it takes time and commitment and good communication skills to make these methods effective.

Exercise. Another benefit of quitting smoking is that it will allow a person to more easily exercise. Twenty minutes of exercise adds one hour to the average person’s lifespan. Remember that number the next time someone tells you that they don’t have time to exercise: they don’t have time to not exercise. Exercise is an investment not just into life span, but quality-of-life. Exercise reduces the risk of cardiovascular disease, type 2 diabetes, breast cancer, colon cancer, endometrial cancer, and lung cancer.

Exercise reduces the risk of osteoporosis, hip fracture, and arthritis. Exercise leads to better quality sleep, clearer thinking, an increased ability to learn, improved judgment, and decreases the risk of depression. Exercise decreases daytime somnolence and improves energy levels and heightens self-esteem.

As with quitting smoking, there are no excuses to not exercise. It doesn’t take much to see significant benefit, and with time more exercise and therefore more benefit will accrue. The chart below shows that for most people, especially those seeking to use exercise to lose weight, less is more. You should probably exercise at least 20 minutes per day 3 to 4 times per week, but an hour per day 4-5 times per week is not unreasonable.

In addition to the benefits associated with exercising itself, an active plan of exercise will likely reduce sedentary behavior such as television watching, which is associated with a loss of 30 minutes of lifespan for every two hours.

Maintain a normal body weight. A person loses 30 minutes of lifespan each day for every 5 kg they are above optimum weight, which is equivalent to a BMI of about 23. So let’s say that you are a woman who weighs 210 pounds and your optimum body weight is 135 pounds; this is equivalent to roughly 35 kg or seven microlives per day. Every pound lost is lifespan gained, and because losing weight is likely associated with increased exercise activity, then those effects are synergistic.

In fact, the magnitude of the effect for losing weight in this scenario I just gave is greater than the benefit of exercising alone; I listed maintaining a normal body weight third after exercise simply because not everyone is obese, but almost no one exercises. There are plenty of people who maintain a normal body weight but who do not exercise and smoke a pack of cigarettes per day; for those folks, quitting smoking and exercising are the most important things that they can do.

Also intimately tied to maintaining a normal body weight is eating a good diet. When I say the words “good diet,” most people will assume that that means a lot of things that it does not. A good diet has nothing to do with the eating whole foods or macronutrients, organic food or pesticide free food, or any other variety of restrictive diets. In fact, it means simply eating a well-rounded diet that includes normal proportions of all the major food groups including vegetables and fruits each day, and maintaining portion control necessary to maintain a normal body weight. There’s really no magic to it. But a good diet that includes more than five servings of fruits and vegetables each day will buy you another four microlives per day, and obviously it will make it easier for you to maintain normal body weight and exercise.

Let’s talk about that 210 pound woman again. Let’s assume she smokes a pack of cigarettes per day while maintaining a sedentary lifestyle with no exercise, eating a high caloric diet that disproportionately excludes fruits and vegetables. If she were to quit smoking, exercise an hour a day for five days out of the week, become more active, eat a balanced diet, and get to an optimum bodyweight, she will gain 169 microlives per week or about 84 hours of lifespan per week. This means that for every year spent living this way, the woman in question will live six months longer if she makes these three changes. If she had 30 years of life expectancy left at the time of making these changes, she will now have a new life expectancy of 45 years. The magnitude of effect of these interventions cumulatively is greater than anything else we can offer to patients and represents 90% of preventative medicine.

Those 45 years will also be associated with a significantly better of quality of life, as she will be burdened with less disease and disability, and achieve more health, happiness, and prosperity.

Stay current with your immunizations. Vaccinations have reduced the incidence of numerous diseases, with a greater than 95% reduction in the rates of measles, diphtheria, mumps, whooping cough, smallpox, rubella, haemophilus influenza, polio, and tetanus. In fact, many of those diseases have been virtually eradicated with a greater than 99% reduction. Each year, these vaccines, plus the vaccines against flu and pneumonia, prevent about 33,000 premature deaths in the United States; countless others are prevented from the suffering caused by these diseases. Therefore, the quality-of-life for the average person is made greatly better through immunization. There is really no more cost-effective intervention ever invented by medicine than vaccinations and they are almost single-handedly responsible for the doubling of life expectancy observed in the United States over the last 150 years.

Since most adults in the United States have received their childhood vaccinations, I have listed this intervention fourth. For a person who has not received her childhood immunizations, this intervention would be listed first. Staying current with booster shots and receiving flu and pneumonia vaccines, and other vaccinations as indicated by risk factors, is still supremely important for even immunized adults. It’s certainly true, for example, that the flu shot doesn’t prevent every case of the flu; but not getting the flu shot because of this fact would be like not quitting smoking because not every case of lung cancer is prevented by not smoking.

We are entering an era where vaccinations will become even more important in helping to reduce burdens of disease that we have not previously considered. Already, vaccines like Gardasil have a potential to reduce the rates of cervical cancer by over 90% in the next generation. Vaccines against CMV, HIV, rotavirus, malaria, Ebola, GBS, RSV, the Zika virus, and countless other burdensome diseases are just around the corner. They are and will remain our most effective tool against infectious diseases.

Don’t abuse substances. Beyond tobacco, other illicit and prescribed drugs as well as alcohol contribute to roughly another 100,000 people in the United States dying per year. This includes only direct deaths, like overdoses. There are also indirect deaths associated with drug use, for example, through violent crime associated with drug procurement. For every death from drugs or alcohol, there is a much larger burden of disease risk, mental health issues, and poverty. As many as 8% of US adults currently abuse alcohol or prescription/illicit drugs and one person in seven will at some point in his lifetime. Substance abusers are at an increased risk of STIs, HIV and HCV from needle-sharing, hypertension, liver disease, cancer, birth defects, and deaths from violent crimes and accidents. They are at an increased risk of poverty, imprisonment, interpersonal violence, depression, economic non-productivity, etc.

If you personally do abuse substances or alcohol, then getting treatment and getting clean is the single most important thing you can do. This doesn’t just include drugs like cocaine and opiates; it also includes marijuana. Unfortunately, marijuana is the subject of countless false claims. It is presented as the miracle cure or treatment for almost every ailment with little to no good scientific evidence. At the same time, the risks of marijuana use are presented as practically non-existent. It certainly is not the danger that opiates and cocaine are; it likely is safer than alcohol and certainly safer than tobacco. Just because it might be safer than the currently legal alcohol and tobacco doesn’t mean it’s safe; remember, alcohol and tobacco kill over half a million people in the United States each year. Don’t confuse arguments about legalization for arguments about safety.

Just because something is legal, like guns or cars or alcohol, doesn’t mean that it is safe. And before you get too carried away with hate emails, understand that I am mostly talking about daily users, not casual and occasional users of marijuana. Marijuana use is associated with cognitive disabilities, some of which are irreversible (particularly if use is started in adolescence). It is also associated with increased risk of pulmonary complications including lung cancer, higher rates of mortality from accidents and impaired driving, and a dependence syndrome. It is unfair to compare marijuana use to alcohol directly, since normal rates of alcohol consumption are actually beneficial. One drink per day actually adds 30 minutes of life expectancy, but subsequent drinks subtract 15 minutes each (this means 3 drinks makes you even). But marijuana doesn’t have a similar beneficial effect in small quantities.

These five interventions together account for almost every beneficial effect that we can offer to our patients. Notice some of the things I did not mention: a daily aspirin, statin drugs, antihypertensive drugs, cancer screening tests, cancer treatments, coronary artery bypass grafts, routine lipid screenings, angioplasties, etc. All of these things have some value, but the cumulative value of all of them is far less than just these five interventions alone. In other words, these five things are more important than everything else we do in medicine added together.

Unlike most articles with a title similar to this one’s, I also didn’t mention naturopathy, aromatherapy, massage therapy, herbology, meditation, Ayurveda, homeopathy, traditional Chinese medicine, acupuncture, reflexology, chiropractic, or Reiki. I didn’t discuss “clean foods,” raw foods, Paleo diet, or any other dietary fad; I didn’t mention colon cleansers or detox programs; nor was there one word about essential oils or incense candles. I am not dismissing some minor benefits that no doubt exists from a couple of these interventions. But none of them are some magical intervention and none of them are the key to a good life. Whatever small benefit some of them might afford, the magnitude of effect is so little that it is likely not worth any of your time.

I will also point out that it costs very little money to stop smoking, exercise, eat a better diet, maintain a normal body weight, get vaccinations, and avoid substance abuse. There clearly is a cost and we are likely not doing enough in terms of drug treatment programs and mental health interventions, for example. But this is a case of poor priorities. With 1/10 of the cost spent on non-effective medical interventions in the United States each year, we could fully finance even our most imaginative needs to address these five interventions. The truth is, the best healthcare and preventative medicine is practically free; but it requires education and some personal responsibility and accountability for the patient. It also requires physicians who are good at communicating risk and benefit and motivating patients to change. You would be right to conclude that these are the most important skills of any physician.