Promoting Cultural Competence Using a Heart Healthy Diet to Lower Cardiovascular Risk Factors
Cultural competence in dietetics is an important aspect of cultivating trust and connection with clients seeking to improve dietary outcomes. Dietary recommendations need to reflect the unique culture of individuals and population(s). For example, the widely accepted Mediterranean Diet is recommended to lower the risk of cardiovascular disease (CVD) and stroke and the DASH diet shows meaningful reductions in blood pressure (1,2). However, limiting the recommendations to Mediterranean and DASH dietary patterns not only neglects how other cultural cuisines can promote cardiovascular health, but further marginalizes people from non-white cultures (3). The PEN Team decided to look at a recent study that explored the effects of a Chinese heart healthy diet in lowering blood pressure among adults in China, which may have implications to adapting Chinese cuisine around the world.
A multi-centre, patient- and outcome-assessor, blinded, randomized feeding trial was conducted among 265 participants (men and women aged 25 to 75 years) with mild hypertension (130 to 159 mmHg systolic blood pressure (SBP)) representing four major Chinese cuisines (Shangdong, Huaiyang, Cantonese and Szechuan) (4). For seven days, participants consumed a control diet matching the usual local diets, based on the most common foods and modified to ensure the participants' food and flavour preferences were incorporated. Participants were then randomized to continue with the control diet or the cuisine-based Chinese heart healthy (CHH) diet for another 28 days. The study authors looked at SBP as the primary outcome and diastolic blood pressure (DBP) and food preference scores as secondary outcomes.
The generalizability and acceptability of the diets were considered in the study design to reflect the diversity of regional cuisines (4). Each recipe was developed jointly by study nutritionists, dietitians and chefs. All four CHH intervention diets shared the same nutrient targets with a focus on increased intakes of nuts, seeds, beans/bean products, vegetables and fruit. All meals for control and intervention diets were provided to participants who were asked to consume them onsite. Compared to control diets, participants' average intake on CHH diets was similar for total kcal, lower in energy from fat (-12%) and higher in energy from carbohydrate (10%) and protein (4%). In addition, participants on CHH diets consumed more dietary fibre (+13 g/day), calcium (+430 mg/day) and potassium (+1448 mg/day) and less sodium (+2733 mg/day) than those on control diets (4,5). Using a linear regression analysis, the study results were:
- Changes in SBP from baseline to the end of the intervention in the Chinese Heart Healthy Group were greater than those in the control group (-15.0 (95%CI -16.5 to -13.5) mmHg and -5.0 (95%CI -6.5 to -3.5) mmHg, respectively), with a net difference from baseline to the end of the intervention of -10.0 mm Hg (95%CI -12.1 to -7.9) (P<0.001). The effect size was more than expected and applicable across the major Chinese cuisines.
- The effects in the Chinese Heart Healthy Group occurred soon into the intervention, with differences in the SBP readings noted in the first week, and the difference widening by the end of the intervention. The mean DBP showed a similar trend and a smaller difference at the end of the study (-3.8 mmgHg, 95%CI -5.0 to -2.5). No difference in food preference score was observed between groups.
The study’s findings provide evidence for a heart healthy diet as a compatible lifestyle treatment that can have a direct effect on blood pressure for those at risk for CVD.
Blinding both the patients and outcome assessors while randomizing participants among the intervention and control groups and providing all meals to participants strengthened the study conclusions. Furthermore, the baseline characteristics including the type of cuisine, demographics, lifestyle, blood pressure, history of hypertension, antihypertension medication use, nutrient intake and food pattern were similar between the intervention and control groups (all P values >0.05), suggesting more variables were controlled when comparing the outcomes between the two groups.
Study limitations identified by the authors that could impact the size and effect of their findings included (4):
- The study did not reach its recruitment target, limiting the power to detect the effect of cuisine type on the effect.
- The short intervention period and lack of follow up may have impacted the effect size if the intervention continued (and if participants were permitted to self-select foods).
- The study could not separate the effect of reducing sodium intake alone from other dietary changes.
What this means
According to the study authors, this study may be the first study to develop a heart healthy diet that fits Chinese food culture (defined by authors as diets that incorporate character[istics] of major Chinese cuisines relating to palatability, affordability and health efficacy) and emphasizes the importance of palatability and acceptance of “food as medicine” to support Chinese adults with high BP (4).
While the study focuses on Chinese adults, the findings could be generalized more globally. As dietitians continue to advocate for cultural safety and competence in working with a diverse client population, this study provides further impetus to explore a variety of cultures and adapt the dietary recommendations. Dietary recommendations should be as diverse as the population they serve to ensure a more culturally competent profession and overall improved nutritional and health outcomes (3).
See Additional Content
- Dietitians of Canada. What is the effectiveness of a Mediterranean-style diet for the primary prevention of cardiovascular disease (CVD)? In PEN: Practice-based Evidence in Nutrition. 2019 Jul19. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2671&pqcatid=146&pqid=27816. Access by subscription only. Click Sign Up on PEN login page.
- Dietitians of Canada. What dietary patterns may affect blood pressure in individuals with or at risk for hypertension? In PEN: Practice-based Evidence in Nutrition. 2022 Aug 15. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=674&pqcatid=145&pqid=29539. Access by subscription only. Click Sign Up on PEN login page.
- Burt KG. The whiteness of the Mediterranean diet: a historical, sociopolitical, and dietary analysis using critical race theory. J Crit Diet. 2021 Mar;5(2):41-52. Available from: https://journals.library.ryerson.ca/index.php/criticaldietetics/article/view/1329/1328
- Wang Y, Feng L, Zeng G, Zhu H, Sun J, Gao P, et al. Effects of Cuisine-based Chinese heart-healthy diet in lowering blood pressure among adults in China: multicenter, single-blind, randomized, parallel controlled feeding trial. Circulation. 2022 Jul;(0):1-13. DOI: 10.1161/CIRCULATIONAHA.122.059045:1-13. Available from: https://www.ahajournals.org/doi/epdf/10.1161/CIRCULATIONAHA.122.059045
- Xie W, Wang Y, Sun J, Zeng G, Zhu H, Yang Z, et al. Protocol of a multicenter, single-blind, randomised, parallel controlled feeding trial evaluating the effect of a Chinese Healthy Heart (CHH) diet in lowering blood pressure and other cardiovascular risk factors. BMJ Open. 2020 Aug 20;10(8):e036394. doi: 10.1136/bmjopen-2019-036394. PMID: 32819944; PMCID: PMC7440703. Available from: https://pubmed.ncbi.nlm.nih.gov/32819944/