Fresh tomato consumption can enhance antioxidant biomarkers and reduce metabolic syndrome risks in postmenopausal women, according to researchers of the RCT conducted in Taiwan.
“Fresh tomato intervention for 8 weeks significantly lowered serum total cholesterol, triglyceride, systolic blood pressure and blood sugar, and higher high-density lipoprotein cholesterol and antioxidant biomarkers. Therefore, fresh tomato intervention could improve metabolic syndromes in overweight postmenopausal women,” wrote researchers in Biology.
Metabolic syndrome refers to a series of cardiovascular risk factors, including hypertension, hyperlipidemia, high blood sugar, and abdominal obesity.
Studies suggest that the consumption of tomato-based foods might reduce cardiovascular risks by 30% when patients consume seven servings of tomato-based products every week.
Additionally, a previous human clinical study showed there is a clear connection between tomato supplementation and positive effects on human biochemical parameters – such as blood glucose, harmful lipid profile, inflammatory markers, and free radicals), which is likely to reduce obesity, diabetes, and cardiovascular events.
However, the beneficial effects of consuming fresh tomato – Lycopersicon esculentum Mill., a native Taiwan variety – remains unclear for overweight menopausal women.
To investigate the impact of tomato consumption on reducing metabolic syndrome risk factors in overweight postmenopausal women, researchers conducted a randomised controlled trial with an eight-week dietary intervention.
The study
Sixty overweight postmenopausal women aged 45–70 years were part of the study. They had a body mass index (BMI) of more than 24 kg/m2. Participants were recruited from the community of Xinyi District, Taipei.
Participants were divided into two groups of 30. One group was asked to consume a control diet for eight weeks, while the other group consumed a tomato diet for the same period.
The control group ate sprouts during the meal intervention treatments, while the tomato group had two servings of tomato per day, or a minimum of about 11 mg lycopene per day.
Both groups consumed 1500 kcal a day, consisting of 18% protein, 28% lipids, and 54% carbohydrates.
Two servings of vegetables in the tomato group were replaced with about 200 g a day of tomatoes, and raw tomatoes were eaten with breakfast and lunch. Tomatoes were provided weekly from the laboratory.
The control group used sprouts as an intervention. They consumed a regular diet, and the tomatoes and tomato-made product intakes were restricted. The control group contained no vitamin A or lycopene.
Dietary intake was assessed using seven-day food diaries before and during the start of the trial, as well as during the intervention.
Dietary diaries were analysed using a nutrition professional software.
Twelve-hour fasting blood samples were collected at the start of the trial, and during the fourth and eighth weeks.
The tomato diet group showed significant improvements. These included a smaller waist circumference, lower blood glucose levels, lower fat percentage, and an increase in antioxidant biomarkers.
In the control group, the starting point of the waist circumference was an average of 90.9 cm, which decreased to an average of 89.2 cm at week eight.
In the tomato group, it was an average of 89.0 at the start, and decreased to an average of 86.2 cm by week eight. Compared with the starting point, there was a significant decrease of around 2.9 cm – a significant decrease compared with the control group.
They also had significantly lower serum total cholesterol, triglycerides, systolic blood pressure, and blood sugar levels.
For example, by week eight, the average blood sugar level for the control group was 103.0 mg/dl, and 98.5 mg/dl for the tomato group.
The fat percentage also showed an average decrease of 0.3% in the tomato group – at the start of the trial, the percentage of fat was an average of 35.0, and decreased to an average of 34.7 by week 8.
Additionally, antioxidant biomarkers such as ferric-reducing ability of plasma (FRAP), were significantly higher in the tomato diet group.
FRAP is used to measure antioxidant power.
At week eight, FRAP was significantly decreased from an average of 627.61 μM/L to 485.6 μM/L in the control group.
However, FRAP increased from an average of 611.81 μM/L to 1066.4 μM/L in the tomato group.
The study therefore showed positive effects of fresh tomato consumption in overweight postmenopausal women.
“These findings suggest that fresh tomato consumption can enhance antioxidant biomarkers and reduce metabolic syndrome risks in postmenopausal women,” concluded the researchers.
Source: Biology
“Fresh Tomato (Lycopersicon esculentum Mill.) in the Diet Improves the Features of the Metabolic Syndrome: A Randomized Study in Postmenopausal Women”
https://doi.org/10.3390/biology13080588
Authors: Chein-Yin Chen and Yi-Wen Chien