Role of dietary phytochemical intake in cardiometabolic health.

Gamba Rincón, Magda Rocío (2023). Role of dietary phytochemical intake in cardiometabolic health. (Unpublished). (Dissertation, University of Bern, Faculty of Medicine and Faculty of Human Sciences)

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Background: Cardiometabolic diseases (CMDs) are the leading cause of death worldwide, with
cardiovascular diseases (CVD) at the top, responsible for 20.5 million deaths yearly. The epidemiological
transition faced by low and middle-income countries has raised the burden of
CMDs due to dietary changes, physical activity reductions, and high urbanization rates, while
in high-income countries, CMDs mainly affect populations of low socioeconomic status. Promoting
and adhering to high-quality diets have been considered effective measures to reduce
the burden of CMDs. Plant-based diets (PBD) have been associated with reduced cardiometabolic
risk factors (CRFs) and lower risk of metabolic syndrome (MetS), probably via phytochemical
interactions. However, dietary phytochemical content estimation is challenging as it
relies mainly on linking food frequency questionnaires (FFQ) to food composition databases
including phytochemicals, which is not always feasible due to high costs or accuracy as many
databases are outdated or incomplete. Therefore, an update on the bioactive compound's
composition of phytochemical-rich foods (PRFs) and using dietary indices that allow a practical
way to assess dietary phytochemical intake from these foods is warranted.

Aims: This thesis aims to increase the understanding of food's phytochemical composition and
explore the impact of total dietary phytochemical intake on cardiometabolic health as a potential
marker of a healthy diet and lifestyle. Specific aims were 1) to systematically review
and evaluate the nutrient and bioactive composition of Raphanus sativus (Radish) and report
the concentration of its bioactive components for the first time; 2) to systematically review
studies evaluating the presence and levels of nutrients and bioactive components in Swiss
chard; 3) to explore the association between Dietary Phytochemical Index (DPI) and CRFs and
MetS in a population-based study of middle age participants living in Switzerland, and 4) to
study the relation between DPI and CVD incidence, CVD mortality, and all-cause mortality in
a population-based cohort of middle age participants living in Switzerland.

Methods: The methods applied in the articles comprising this thesis are as follows: 1) and 2)
the available evidence on the nutrient and bioactive composition of Radish and Swiss chard
was systematically assessed. Four databases were searched for articles assessing the chemical
composition of Radish. Two independent reviewers screened selected articles and extracted
data; 3) A cross-sectional analysis of 2009-2012 data of the Colaus cohort study in Lausanne,
Switzerland, including 3879 participants. Dietary intake was assessed via a validated FFQ. DPI
was calculated as the total energy intake percentage obtained from PRFs consumption and
assessed as quartiles. Associations were determined using multivariable linear and logistic regression
for CRFs and MetS, respectively, and 4) A prospective analysis from a cohort study
conducted between April 2009 and April 2021 in Lausanne, Switzerland, including 3721 participants
exempt from CVD at baseline applying Cox-regression. Dietary intake was assessed
using a self-reportedFFQ. DPI and healthy dietary phytochemical index (hDPI) were calculated
as the total energy intake percentage obtained from phytochemical-rich foods consumption. As PBD are rich in phytochemicals, a healthy plant-based diet index (hPBD) was also estimated,
where healthy plant foods received positive scores, and less-healthy plant foods received negative
scores. Incident CVD, all-cause, and CVD-related mortality were the assessed outcomes.

Results: the analyses carried out in this doctoral thesis yielded the following results: 1) I identified
609 phytochemicals in Radish, with major constituents like flavonoids, nonflavonoid polyphenols,
fat and fatty-related compounds, terpenes, and derivatives, and glucosinolates being
reported in high concentrations in leaves and sprouts. However, this composition depends
on the radish variety and cultivar. Most of my findings are based on red, black, and white
radishes; 2) I identified 192 compounds. The most common chemicals reported in the literature
are betalains, fatty acids, flavonoids, minerals, non-flavonoid phenols, and terpenes.
However, most of my findings are based mainly on leaves of the cicla variety. I also identified
a lack of research using other parts of the plants, like stems/stalks/petioles and seeds, and for
compounds other than minerals, phenolics, and flavonoids; 3) In a middle-aged Swiss population,
DPI is inversely associated with waist circumference, body mass index (BMI), insulin, leptin,
and high-sensibility C reactive protein. Participants in the highest DPI quartile had lower
odds of central obesity. No other significant associations were observed, and 4) Besides a 30%
lower risk of CVD incidence for participants in the second tertile of hDPI that did not reach a
significative p-trend, no other associations were observed between hDPI, DPI, and hPBD and
incident CVD, CVD-related and all-cause mortality.

Conclusions: Through this doctoral thesis, I contributed to the role of dietary phytochemical
intake in cardiometabolic health. First, I concluded that Radish is a source of nutrients and
phytochemicals, particularly proteins, glucosinolates, flavonoids, β-carotene, and minerals.
Many of these phytochemicals are highly concentrated in leaves and sprouts; second, I found
that Swiss chard can be considered a good source of fiber, betalains, flavonoids, b-carotene,
vitamin K, and minerals like potassium and magnesium. Radish and Swiss chard should be
considered part of a healthy diet rich in phytochemicals. In a Swiss population-based cohort
of middle age participants, I discovered that third, high DPI modulates cardiometabolic health
by regulating waist circumference, BMI, insulin, leptin, and hs-CRP, as well as lowering the
odds of central obesity, particularly in women, and fourth, total phytochemical dietary intake
assessed via the hDPI, DPI, and hPBD was not associated with CVD incidence, all-cause, or
CVD-related mortality and further prospective studies with larger sample sizes are needed to
confirm or refute these findings.

Item Type:	Thesis (Dissertation)
Division/Institute:	04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Social and Preventive Medicine (ISPM) 04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Endocrinology, Diabetology and Clinical Nutrition
Graduate School:	Graduate School for Health Sciences (GHS)
UniBE Contributor:	Gamba Rincón, Magda Rocío, Bally, Lia Claudia
Subjects:	600 Technology > 610 Medicine & health 300 Social sciences, sociology & anthropology > 360 Social problems & social services
Language:	English
Submitter:	Doris Kopp Heim
Date Deposited:	17 Jul 2023 10:32
Last Modified:	06 Mar 2024 16:39
Additional Information:	PhD in Health Sciences (Epidemiology)
URI:	https://boris.unibe.ch/id/eprint/184873