Moderate Tomato Consumption is Associated with a Lower Risk of New-Onset Hypertension

by | Jan 11, 2023 | 2022, Blood Pressure, Cardiovascular Health, Carotenoids, Fruits and Vegetables, Lycopene

Written by Taylor Woosley, Staff Writer. Results of this observational study using data from CHNS, a large-scale prospective cohort study, shows that eating around 10-13 g/day of tomatoes versus no consumption of tomatoes was associated with a 49-58% lower risk of new-onset hypertension. 

tomatoesHypertension is one of the main contributing factors for cardiovascular disease and all-cause mortality1. Raised blood pressure levels result from complex interactions between genetics and environmental factors2. Hypertension leads to adverse cardiovascular and renal outcomes and is a major risk factor for ischemic stroke, heart failure, chronic kidney disease, and cognitive decline3. Evidence shows that this disease is modifiable and well-controlled blood pressure can enhance quality of life, improve prognosis, and prevent clinical complications4.

Research has reported that lifestyle factors play an important role in cardiovascular disease prevention, with the inclusion of sufficient fruits and vegetables in the diet5. Compounds occurring in plants display diverse bioactivities with therapeutic potential to exhibit effects counteracting cardiovascular disease and hypertension6. One example is tomatoes which contains carotenoids such as lycopene with potent antioxidant abilities that can improve vascular function and aid in blood pressure regulation7.

Zhao et al. conducted an observational study using data from the China Health and Nutrition Survey (CHNS), an ongoing, prospective cohort study that began in 1986. Data from 7 waves of CHNS from 1997 to 2015 were used in the current study. Study exclusion consisted of anyone not regarded in the general population, who were less than 18 years old, and had prior cardiovascular disorders. Final analysis consisted of 11,460 subjects.

Covariates such as demographic and lifestyle information, smoking status, anthropomorphic measures, systolic (SBP) and diastolic blood pressure (DBP), and physical activity levels were included in analysis. The primary outcome was new-onset hypertension. Dietary nutrient intake was assessed for three consecutive days by nutritionists, with 24-h recalls being included to calculate the average intake of vegetables, fruits, and tomato consumption. Dietary tomato intake was categorized into four groups, group 1: no tomato intake; group 2: 0 to ≤13.3 g/day; group 3: 13.3 to ≤33.3 g/day; group 4: >33.3 g/day.

A multivariable Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals for the association between dietary tomato intake and new-onset hypertension. The final Cox models adjusted for the potential confounders of age, sex, BMI, smoking and drinking status, education, physical activity, and cumulative average vegetables, fruits, and average energy intake. Furthermore, dose-response relationships were analyzed with restricted cubic spline (RCS) Cox regression between tomato intake and new-onset hypertension.

Of the 11,460 participants included, 7075 (61.7%) did not consume tomatoes. The average participant age was 41.7 (SD, 13.9) years. Significant findings of the study are as follows:

  • During a median follow-up duration of 6 years (interquartile range, 4 to 13 years), 4015 participants developed new-onset hypertension. Multivariable HRs for the risk of new-onset hypertension with increasing tomato consumption were 0.42 (95%CI, 0.37-0.47), 0.51 (95%CI, 0.46-0.57) and 0.82 (95%CI, 0.74-0.92), compared with those who did not consume tomatoes.
  • A J-shaped relation between dietary tomato intake and new-onset hypertension was noted, with the nadir at approximately 10-13 g/day (p for non-linearity < 0.001).
  • The association between dietary tomato intake and hypertension was not modified by any other factors, including age, BMI, baseline SBP, fat intake, protein consumption, or carbohydrate consumption (p interaction > 0.05).

Results of the study show that moderate tomato intake reduced the risk of new-onset hypertension compared to subjects who did not consume tomatoes. A J-shaped association was observed between new-onset hypertension and tomato intake, particularly around 10 to 13 g/day. Further research should continue to explore the potential anti-hypertensive effects of tomatoes. Study limitations include the inability to determine a causal relationship due to the study design, the potential possibility of residuals or confounding, and the lack of generalization of study participants.

Source: Zhao, Dan, Zezhong Tian, Ying Liang, Hong Chen, Zhiying Fan, Zhihao Liu, Suming Dai, Meitong Liu, Huiying Kuang, and Yan Yang. “J-Shaped Association of Tomato Intake with New-Onset Hypertension in General Adults: A Nationwide Prospective Cohort Study.” Nutrients 14, no. 22 (2022): 4813.

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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Posted January 11, 2023.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

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