The Effect of Tart Cherry Juice on Risk of Gout Attacks

The Effect of Tart Cherry Juice on Risk of Gout Attacks: a Randomised Controlled Trial

The purpose of this study is to determine whether consuming tart cherry juice daily for 12 months reduces the risk of gout attacks during this period. Individuals with an existing gout diagnosis and who have experienced at least one gout flare in the past year will be recruited to participate in this study.

Study Overview

• Status: Unknown
• Conditions: Gout Flare; Gout Attack
• Intervention / Treatment: Dietary supplement: Tart cherry juice; Other: Fruit-flavoured placebo drink

Detailed Description

Gout is a painful and often debilitating condition affecting around 3% of adults in the UK. It is a type of inflammatory arthritis caused by high levels of uric acid which is deposited as crystals in joints, resulting in painful gout flares. Cherries and cherry products have received attention for their possible role in gout management owing to their anti-inflammatory and anti-oxidant properties. Their consumption has been associated with a lower risk of gout attacks in one observational study. The consumption of cherries is also endorsed by several gout information websites and in the British Society of Rheumatology's 2017 guidelines for the management of gout. However, there is limited evidence underpinning these claims and existing studies tend to be short in duration and have small participant numbers. Gout attacks are sporadic in nature and so a long-term trial is required to clarify the therapeutic effect of cherries on gout attack risk.

The investigators are aiming to recruit 120 participants who have had at least one gout flare in the previous 12 months. Using the work of Rothenbacher et al., 2011, the chance of these individuals experiencing at least one attack in the next 12 months has been calculated at 11%. It is predicted that treatment with daily cherry juice consumption will reduce gout flare recurrence (primary outcome measure) to 1/4 of the rate of the actual recurrence i.e. to 2.7%. Using these figures, a sample size of 93 participants would provide power of 0.95 at a significance level of 0.05. A sample size of 120 participants allows for an approximate 20% attrition rate.

Participants will consume either 30 mL tart cherry juice (CherryActive) diluted to 250 mL with water or a fruit-flavoured placebo drink daily with breakfast for 12 months. Participants will be followed up at 6 and 12 months at the investigators' laboratory to study changes in gout flare frequency and intensity, uric acid levels and levels of inflammation. This will help determine if tart cherry juice could help reduce or even prevent gout attacks. Additionally, as gout is associated with increased cardiovascular disease (CVD) risk, changes in CVD risk markers, including blood pressure, arterial stiffness and cholesterol levels, will also be assessed.

Participants will be recruited through the use of posters, advertising on the UK Gout Society website, emails to large organisations and through letters sent from General Practitioners' (GP) surgeries to eligible patients. Potentially eligible patients will be identified by surgery staff using their patient database before contact information is passed to the research team at the surgery to prepare and send out invitation letters. As this method of recruitment involves accessing patient identifiable data (name and home address) prior to patient consent being given, an application to the Confidentiality Advisory Group (CAG) will be submitted for consideration.

A general linear mixed model analysis will be used to assess the effect of treatment allocation, time and their interaction on both primary and secondary outcome measures.

• Study Type: Interventional
• Enrollment (Anticipated): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Sheffield, United Kingdom, S1 1WB
    • Food and Nutrition Group, Sheffield Hallam University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 78 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• existing diagnosis of gout
• have experienced at least one gout flare in the previous 12 months
• able and willing to participate in the study and provide written informed consent

Exclusion Criteria:

• frequently consume cherries or cherry products e.g. cherry supplements and juice (more than once a week)
• severe renal impairment (estimated glomerular filtration rate of <30ml/min)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Tart cherry juice; 30 mL tart cherry concentrate (CherryActive, UK) diluted with 220 mL of water once per day (250 mL total volume per day). According to available manufacturers data, this is equivalent to consuming 90-100 fresh cherries per day.	Dietary supplement: Tart cherry juice; 30 mL tart cherry juice concentrate (CherryActive, UK), diluted with water to 250 mL. This is consumed daily by participants, with breakfast, for 12 months.
Placebo Comparator: Fruit-flavoured placebo drink; Matched for sensory characteristics and energy (with the addition of glucose). once per day (250 mL total volume per day)	Other: Fruit-flavoured placebo drink; Consumed daily by participants, with breakfast, for 12 months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in gout flare frequency	Difference in gout flare frequency in tart cherry juice group versus placebo group from baseline to 12 months. Recorded as number per month.	Measured at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in gout flare intensity	Difference in gout flare intensity in tart cherry juice group versus placebo group from baseline to 12 months. Using a 0-10 Likert pain scale. The scale measures the pain of any gout flare. The possible score ranges from 0 for no pain through to 10 for worst pain imaginable. Change in pain scores between treatment and placebo groups will be compared throughout the duration of the intervention.	Measured at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 months
Changes in serum urate (in millimoles per litre (mmol/l))	Difference in serum urate in tart cherry juice group versus placebo group from baseline to 12 months.	Measured at 0, 6 and 12 months
Change in fractional excretion of uric acid (as a percentage, %)	Difference in fractional excretion of uric acid in tart cherry juice group versus placebo group from baseline to 12 months. Measured from 24 hour urine sample.	Measured at 0, 6 and 12 months
Change in inflammatory markers (in milligrams per litre (mg/l))	Difference in inflammatory markers (c reactive protein (CRP), inter leukin-6 (IL-6) and tumour necrosis factor- alpha (TNF-alpha)) in tart cherry juice group versus placebo group from baseline to 12 months. Measured using an enzyme-linked immunosorbent assay (ELISA).	Measured at 0, 6 and 12 months
Change in oxidative damage (in percentage (%) of tail DNA)	Difference in markers of oxidative stress in tart cherry juice group versus placebo group from baseline to 12 months. Measured using single-cell electrophoresis 'comet assay' as 8-oxo-dg levels in lymphocytes.	Measured at 0, 6 and 12 months
Change in antioxidant status (in percentage (%) of tail DNA)	Difference in antioxidant status in tart cherry juice group versus placebo group from baseline to 12 months. Measured using single-cell electrophoresis 'comet assay' as resistance of DNA lymphocyte to H202-induced DNA strand breaks.	Measured at 0, 6 and 12 months
Change in blood pressure (in millimetres of mercury (mmHg))	Difference in brachial and central blood pressure in tart cherry juice group versus placebo group from baseline to 12 months. Measured using a Vicorder.	Measured at 0, 6 and 12 months
Change in arterial stiffness (in meters per second (m/s))	Difference in arterial stiffness in tart cherry juice group versus placebo group from baseline to 12 months.	Measured at 0, 6 and 12 months
Change in lipid profile (in millimoles per litre (mmol/l))	Difference in total cholesterol, HDL cholesterol, LDL cholesterol and triacylglycerides) in tart cherry juice group versus placebo group from baseline to 12 months.	Measured at 0, 6 and 12 months
Height (in meters (m))	Height and weight will be combined to report BMI in kg/m^2. Difference in BMI in tart cherry juice group versus placebo group from baseline to 12 months.	Measured at 0, 6 and 12 months
Weight (in kilograms (kg))	Height and weight will be combined to report BMI in kg/m^2. Difference in BMI in tart cherry juice group versus placebo group from baseline to 12 months.	Measured at 0, 6 and 12 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in habitual diet	4 day diet diaries will be used to assess any changes in habitual diet as a result of, or over the course of, the study.	Measured at 0, 6 and 12 months
Changes in habitual physical activity levels	4 day physical activity logs will be used to assess any changes in habitual activity levels as a result of, or over the course of, the study.	Measured at 0, 6 and 12 months

Collaborators and Investigators

• Sponsor: Sheffield Hallam University
• Collaborators: Cherry Research Committee
• Investigators: Principal Investigator: Margo Barker, Sheffield Hallam University

Publications and helpful links

General Publications

• Jacob RA, Spinozzi GM, Simon VA, Kelley DS, Prior RL, Hess-Pierce B, Kader AA. Consumption of cherries lowers plasma urate in healthy women. J Nutr. 2003 Jun;133(6):1826-9. doi: 10.1093/jn/133.6.1826.
• Zhang Y, Neogi T, Chen C, Chaisson C, Hunter DJ, Choi HK. Cherry consumption and decreased risk of recurrent gout attacks. Arthritis Rheum. 2012 Dec;64(12):4004-11. doi: 10.1002/art.34677.
• Kuo CF, Grainge MJ, Mallen C, Zhang W, Doherty M. Rising burden of gout in the UK but continuing suboptimal management: a nationwide population study. Ann Rheum Dis. 2015 Apr;74(4):661-7. doi: 10.1136/annrheumdis-2013-204463. Epub 2014 Jan 15.
• Cea Soriano L, Rothenbacher D, Choi HK, Garcia Rodriguez LA. Contemporary epidemiology of gout in the UK general population. Arthritis Res Ther. 2011 Mar 3;13(2):R39. doi: 10.1186/ar3272.
• Rothenbacher D, Primatesta P, Ferreira A, Cea-Soriano L, Rodriguez LA. Frequency and risk factors of gout flares in a large population-based cohort of incident gout. Rheumatology (Oxford). 2011 May;50(5):973-81. doi: 10.1093/rheumatology/keq363. Epub 2011 Jan 12.
• Dalbeth N, Ames R, Gamble GD, Horne A, Wong S, Kuhn-Sherlock B, MacGibbon A, McQueen FM, Reid IR, Palmano K. Effects of skim milk powder enriched with glycomacropeptide and G600 milk fat extract on frequency of gout flares: a proof-of-concept randomised controlled trial. Ann Rheum Dis. 2012 Jun;71(6):929-34. doi: 10.1136/annrheumdis-2011-200156. Epub 2012 Jan 23.
• Lamb KL, Lynn A, Russell J, Barker ME. Effect of tart cherry juice on risk of gout attacks: protocol for a randomised controlled trial. BMJ Open. 2020 Mar 15;10(3):e035108. doi: 10.1136/bmjopen-2019-035108.

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2019
• Primary Completion (Anticipated): March 1, 2021
• Study Completion (Anticipated): April 1, 2021

Study Registration Dates

• First Submitted: July 30, 2018
• First Submitted That Met QC Criteria: August 3, 2018
• First Posted (Actual): August 8, 2018

Study Record Updates

• Last Update Posted (Actual): December 19, 2020
• Last Update Submitted That Met QC Criteria: December 17, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Keywords: gout; cardiovascular disease risk; tart cherries; gout attack; gout flare
• Additional Relevant MeSH Terms: Metabolic Diseases; Genetic Diseases, Inborn; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Metabolism, Inborn Errors; Crystal Arthropathies; Purine-Pyrimidine Metabolism, Inborn Errors; Gout; Arthritis, Gouty
• Other Study ID Numbers: ER7166682; AA4736173 (Other Grant/Funding Number: Cherry Research Committee/Cherry Marketing Institute)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No