Research Shows Functional Medicine and Nutrition Improve Reported Quality Life and Health

Last week was a big win for the field of functional medicine. It was the first time that a research study was published comparing reported quality of life related to health in patients who went to the Cleveland Clinic Center for Functional Medicine compared to those that saw a primary care doctor at a Cleveland Clinic Family Health Center. The conclusions of the study indicate that a functional medicine model of care demonstrated beneficial and sustainable health-related quality of life.

What is Functional Medicine?

Before I get into the study, let’s back up and give some context to functional medicine as a whole. This way of practicing medicine is a new operating system that focuses on seven principles:

1-Make personalized recommendations that are based on the needs of each individual patient. Health is not one size fits all. Nutrition is not one size fits all. Therefore, medical interventions should not be one size fits all.

2-Get to the root cause of disease rather than just treating symptoms. This means patients are asked in-depth questions about their environmental exposure, food intake, stress levels, history of trauma, travel abroad, long-term antibiotic use, and more. More advanced testing is also used to determine genetics, gut health, nutrient deficiencies and more.

3-Disease does not manifest overnight. You did not randomly wake up one morning with Hashimoto’s or Pre-Diabetes. By the time a person gets to the point of a diagnosis, the physiological imbalances that are drivers have usually been brewing below the surface for years. In functional medicine, the practitioner reviews a person’s timeline to better understand possible contributing factors. One major question regularly asked in functional medicine is: “When was the last time that you felt well?”. Why is this an important question? Because it helps to understand possible triggering events that played a role in the onset of a person’s symptoms. For instance: divorce, a car accident, birth of a child, living in a moldy home, and more.

4-Take a patient-centered rather than disease-centered. This means practitioners look at the whole picture of you, as a person and your emotional, spiritual and mental health, in addition to the symptoms that you are experiencing. The Father of functional medicine, Dr. Sidney Baker explains that “it is the individual, not the disease that is the target of our therapeutic efforts”.

5-Use food as medicine. Food and lifestyle are the primary contributors to our chronic disease epidemic and therefore, can no longer be ignored in medicine. We aren’t just talking about calorie restriction for weight loss. We are talking about a true comprehensive approach to using nutrient-dense, whole foods to modulate inflammatory pathways and improve cellular function.

6-Emphasize health creation rather than just disease management. A lot of conventional doctors appointments are focused on one problem or one set of symptoms and how to improve that, often with drugs. There is little focus on the primary ingredients that are essential for the foundation of health like sleep, stress reduction, movement, connection, and nutrition. As Dr. Mark Hyman has been saying for years, “When you focus on creating health, disease often goes away as a side effect”.

7-Leverage a team-based approach to optimizing outcomes. This is not the case for all functional medicine clinics but it is the case at the Cleveland Clinic Center for Functional Medicine and practices like Parsley Health. At the Cleveland Clinic, your doctor oversees your healthcare team but you also have other specialists like Registered Dietitians, Health Coaches, and Behavioral Health Therapists working on your team to help you do the hard work–make necessary behavior changes.

When you think about these seven principles, you can pretty much conclude that functional medicine is medicine that makes sense. It creates an opportunity for patients to feel heard and supportive. For them to spend more time with their practitioners to develop a therapeutic relationship. It helps them understand that they have much of the power to improve their state of health. And while it seems like this should be the way of the future, it needs to be substantiated by research and this is the first step to doing that.

The Momentum that We Experienced in Functional Medicine

I’m sure most of you know that I was part of the original team that started by Dr Mark Hyman at the Cleveland Clinic Center for Functional Medicine exactly five years ago this month, in October 2014. We had six healthcare practitioners (3 doctors, 2 dietitians, and 1 nurse). Although I was a dietitian by training, I started as the health coach. But after the first six weeks, I also began running the nutrition appointments because we experienced extremely fast and massive growth.

We could not keep up with the high demand of patients that wanted to be seen in functional medicine. At any given time there were thousands of patients on the waitlist. And within three years of starting the department, I trained seven additional dietitians in functional nutrition, as we built out our healthcare team. Why was there so much demand? Because so many people were getting better! We also slowly established relationships with other departments at the Cleveland Clinic, as other specialists began to see the improved results their patients were getting from working with the Center for Functional Medicine.

I tell you this for two reasons: 1) A primary objective for the department since the inception was to conduct research to demonstrate the effectiveness of this approach. Because it had never been done before. Five years later, this is the first study that was conducted to demonstrate the results that our patients experienced. 2) There were 1,595 functional medicine patients that were seen in this study between 2015-2017. Many of the patients enrolled, I personally saw for their nutrition and witnessed first-hand the life changing improvements that they experienced.

The Difference Between the Functional Medicine Group and the Primary Care Group

The study included 7,252 patients, 1,595 were from the Center for Functional Medicine and 5,657 were from the primary care group. They ended up using propensity score matching, which allowed for a more even comparison of the two groups, with 398 patients in each group. This was a retrospective, cohort study, which means that unlike some of the other randomized control trials that were conducted when I was at the clinic, this study just looked at individuals who were already seeing functional medicine compared to people who were already seeing their primary care doctor. They were not randomly assigned to a specific group.

The primary care patients had a typical primary care experience. The functional medicine patients received the following care:

1-A 60 minute initial appointment with the functional medicine doctor to get an in depth look at the patient.

2-An initial 60 minute nutrition appointment with a Registered Dietitian or a group nutrition appointment that was led by a Registered Dietitian.

3-A 15 minute health coach appointment with a health coach or a group health coaching appointment that was led by a health coach.

4-A 45 minute doctors follow up visit every three months and the option to also schedule appointments with their dietitian and/or health coach. Whether a person scheduled a follow up with the dietitian or health coach was up to them.

No patient seen in functional medicine was put on the same plan. They were given a plan that was unique to them. So the study compared the total functional medicine experience rather than whether one diet or one supplement protocol worked better compared to something else.

The Study Method & Results

The study tracked functional medicine and primary care patient outcomes using an NIH validated tool called Patient-Reported Outcome Measurement Information System (PROMIS) that looked at Global Physical Health (GPH) scores and Global Mental Health S(GMH) scores. The patients completed this test at baseline, 6 months and 12 months. This is a self-reported measurement of patient quality of life and health across several different domains. The GPH scores include physical health, physical functioning, pain intensity and fatigue and the GMH scores include overall quality of life, mental health, satisfaction with social activities and emotional problems.

They study found that the functional medicine model was associated with better PROMIS GPH scores in patients after 6 months (point change of 1.59 in functional medicine vs. 0.33 in primary care, p=0.004) and they remained significant up to 12 months (point change of 1.60 in functional medicine vs 1.09); however the results at 12 months were not statistically significant (p=0.41). They also found that patients from the Center for Functional Medicine were more likely to have clinically meaningful change, which meant a 5 point improvement in their PROMIS GPH score after 6 months, which were less likely to decrease over time.

Study Takeaways

Based on the findings of the study, it appears that functional medicine was beneficial and may also be more sustainable for the healthcare system by lowering chronic disease and improving quality of life. However, larger and more robust studies are needed to truly prove this for more widespread insurance-reimbursement to be applied to a functional medicine setting.

I want to point out a few major wins:

1-The fact that this paper was published is such a major win for functional medicine! This was the first research study ever published comparing a functional medicine group to any other group or intervention.

2-I am so proud of the clinical team that worked in functional medicine at the time that this study was conducted. I have to say, it was the most passionate, caring group of healthcare practitioners that I have ever been surrounded by. We worked tirelessly to support every patient that walked through the door, make them feel heard and cared for and we worked extremely collaboratively as a team to try to make a difference.

3-The patients got better! I am so thankful to all of the wonderful patients that walked into the doors of the Cleveland Clinic Center for Functional Medicine and left as their own advocate and the advocate of others. It’s because of them and their commitment to improving their own health and making behavior change that this study even exists.

4-Lastly, this study is also a win for the need for team-based approaches in healthcare and the use of Registered Dietitians and Health Coaches. The study notes the lack of nutrition training that is provided in medical school and the lack of time that doctors have during appointments to help patients make lasting lifestyle change. The study states “Dietitians and health coaches are integral because they address the nutritional, psychological, and social aspects of patients’ illnesses and promote long-term self-management, which are components needed for the treatment of various chronic conditions.”

Whether you are a functional medicine patient, functional medicine doctor, dietitian or health coach or someone just interested in learning more about this movement, there is an exciting future ahead for medicine and nutrition! In order to best serve patients, improve clinical outcomes and optimize quality of life, and decrease healthcare costs, we must address nutrition and we must address each individual’s persons mind, body, and spiritual health.

To find a functional medicine practitioner that has done their training through the Institute for Functional Medicine, visit

To find a dietitian that has done their Integrative and Functional Nutrition training, visit are the two advanced trainings that I complete in functional medicine and nutrition and I could not speak more highly of them both. If you are a dietitian or healthcare practitioner, this is the route that I would suggest taking to truly master functional medicine.

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