Introduction Poor diet is the leading cause of poor health in USA, with fresh vegetable consumption below recommended levels. We aimed to assess the impact of medical prescriptions for fresh (defined as picked within 72 hours) vegetables, at no cost to participants on cardiometabolic outcomes among adults (predominantly Mexican-American women) with or at risk of type 2 diabetes (T2D).
Methods Between February 2019 and March 2020, 159 participants (122 female, 75% of Mexican heritage, 31% with non-insulin treated T2D, age 52.5 (13.2) years) were recruited using community outreach materials in English and Spanish, and received prescriptions for 21 servings/week of fresh vegetable for 10 weeks. Pre-post comparisons were made of weight; waist circumference; blood pressure; Hemoglobin A1c (HbA1c, a measure of long-term blood glucose control); self-reported sleep, mood and pain; vegetable, tortilla and soda consumption. After obtaining devices for this study, 66 of 72 participants asked, agreed to wear blinded continuous glucose monitors (CGM).
Results Paired data were available for 131 participants. Over 3 months, waist circumference fell (−0.77 (95% CI −1.42 to 0.12) cm, p=0.022), as did systolic blood pressure (SBP) (−2.42 (95% CI −4.56 to 0.28) mm Hg, p=0.037), which was greater among individuals with baseline SBP >130 mm Hg (−7.5 (95% CI −12.4 to 2.6) mm Hg, p=0.005). Weight reduced by −0.4 (−0.7 to –0.04) kg, p=0.029 among women. For participants with baseline HbA1c >7.0%, HbA1c fell by −0.35 (-0.8 to –0.1), p=0.009. For participants with paired CGM data (n=40), time in range 70–180 mg/dL improved (from 97.4% to 98.9%, p<0.01). Food insecurity (p<0.001), tortilla (p<0.0001) and soda (p=0.013) consumption significantly decreased. Self-reported sleep, mood and pain level scores also improved (all p<0.01).
Conclusions Medical prescriptions for fresh vegetables were associated with clinically relevant improvements in cardiovascular risk factors and quality of life variables (sleep, mood and pain level) in adults (predominantly Mexican-American and female) with or at risk of T2D.
Trial registration number ClinicalTrials.gov Identifier: NCT03940300.
- diabetes mellitus
- dietary patterns
- metabolic syndrome
- nutritional treatment
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Contributors DK conceived the idea for the study and is guarantor. AL, WB and NG contributed to the protocol development, IRB approval and the conception and design of the work. MK, AL and CC were involved in the recruitment and retention of participants, and data collection. WB, DK, AS and SB performed data analyses. AS supervised SB in the design of the CGM analysis framework. SB built the CGM analysis framework, performed statistical analysis and created the figures. AS and SB undertook analyses of the CGM data. DK drafted the manuscript. All authors contributed to manuscript review and revisions.
Funding Funding for Farming for Life during the study period was provided by the US Department of Agriculture (Grant number: 2018-33800-28404). We would also like to acknowledge funding support from the Hearst Foundation, the Mosher Foundation, Sun Life Financial, the St. Francis Foundation and the Blooming Prairie Foundation. AS and SB were supported by the NSF Engineering Research Center for Precise Advanced Technologies and Health Systems for Underserved Populations (PATHS-UP) (Award #1648451).
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval Independent Review Board (Advarra IRB).
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request. The investigators agree to share de-identified individual participant data that underlie the results reported in this article, the statistical analysis plan and the study protocol with academic researchers beginning 3 months after publication and ending 5 years following article publication. Proposals should be directed to dkerr@ sansum.org. To gain access, data requestors will need to sign a data access agreement.
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