The purpose of this study is to see if stress reduction can lead to less pain due to knee osteoarthritis. To do this the investigators will compare two types of stress reduction modalities, Mindfulness-Based Stressed Reduction (MBSR) and a Health Enhancement Program (HEP). Both include stress reduction techniques, but MBSR has a mindfulness component that includes meditation. MBSR will be provided either in-person or online and HEP will be in-person. The assignment to the stress reduction program will be determined by the Principal Investigator. In order to assess for stress reduction and pain reduction the investigators will use validated measuring tools before, during, and after the course instructions.

The current study is aiming to compare two stress reduction programs in order to see if stress reduction may lead to less pain due to knee osteoarthritis (OA). There are two stress reduction programs being compared, Mindfulness-Based Stress Reduction (MBSR) and a Health Enhancement Program (HEP). MBSR is a secular program that trains mindfulness meditation for stress reduction and to increase emotional regulation skills. It is defined as "paying attention in a particular way, on purpose, in the present moment, and non-judgmentally." Mindfulness refers to a set of meditation practices that develop a wide array of cognitive skills which include: attention regulation, response inhibition, and emotion regulation. HEP is an educational course intended to teach participants about their disease, factors influencing disease progression, nutrition, physical activity including walking and stretching, and functional movement. Key difference between these two is MBSR includes the mindfulness component, and MBSR will be taught either in-person or online. HEP will only consist of an in-person course.

The online MBSR course will be offered through: http://www.breathworks-mindfulness.org.uk/mindfulness-for-health. The investigators propose to use an active control training, the Health Enhancement Program (HEP), an intervention designed to isolate mindfulness as a testable active ingredient.

The duration of an individual subject's participation in the study will be at least 10 weeks starting from the screening visit all the way to the follow-up visit.

The in-person MBSR course consists of 8 weekly classes plus one all-day class between Weeks 6 and 7, and is sequential. Depending on when a participant is consented, they may have to wait until a new 8-week course is available in order to begin. The HEP course also consists of 8 weekly classes and will start when a group of 7-10 participants have been assigned to the HEP intervention. The online MBSR course is designed to last 8 weeks and can be started at any time.

Since initiation of the in-person MBSR or HEP courses will depend upon when subjects are enrolled, it is not possible to provide the maximum length of time for a subject's participation. However long the subject's participation, they are only expected to complete 2 in-clinic visits and 8 weeks of class (plus 1 all-day class for MBSR).

Weekly classes are 2.5 hours with the one-day retreat lasting from 10am to 5pm on a weekend day. The online MBSR course is roughly 20 minutes per day for 6-7 days of the week for 8 weeks.

HEP and MBSR are structurally equivalent, both using a group format that meets once a week for 2.5 hours for 8 weeks, plus home participation, but the in-person MBSR includes an "all day" component after week 6. The content of the HEP intervention meets the following criteria: (1) class activities match MBSR activities as closely as possible, (2) activities represent valid, active, therapeutic ingredients in their own right, and (3) these ingredients do not include mindfulness.

All participants will be assigned into one of the three courses by the Principal Investigator. Prior to the initial class of the participants' respective course, blood will be collected, and within two weeks after the final class, participants will return to collect the second set of blood samples. These collections prior and after treatment will be at the clinic, visits to the clinic may last from 1 to 2 hours.

Inclusion Criteria:

• Positive "Frequent Knee Pain" question
• Radiographically confirmed knee OA (Kellgren/Lawrence ≥ 2)

Exclusion Criteria:

• Scheduled to have knee replacement surgery within 6 months from enrollment
• Rheumatoid arthritis or another inflammatory arthritis
• Known avascular necrosis (death of bone due to lack of blood supply)
• Failure to comply with run-in procedures: poor attendance or non-compliant with completing the activity
• Major psychiatric illness, cognitive impairment or alcohol/substance abuse
• Non-English speaking

The investigators plan on making unidentifiable participant data for all primary and secondary outcome measures available. No information linking the data to the individual participant will be released, but measurements, averages, and statistical analysis will be made available.

Data will become available 6 months after study completion.

Data access requests will be reviewed by Principle Investigators.

The study will be structured as a parallel-group controlled trial. The Principal Investigator will assign participants into the three groups. This will allow for equalization of distribution of participants across the three groups. It will not be possible to blind the participants to which arm of the trial they are participating in, as the content or lack thereof of their activities will be obvious to them. For results analysis, collaborators at the UCD West Coast Metabolomics Center will be blinded to the treatment of the respective samples, thus eliminating potential bias during analysis.