The origin, nutrient composition, phytochemicals, health benefits and clinical studies of green beans

1. FOOD AS MEDICINE:
GREEN BEAN
PHASEOLUS VULGARIS
By
Kevin KF Ng, MD, PhD.
Former Associate Professor of Medicine
Division of Clinical Pharmacology
University of Miami, Miami, FL., USA
Email: kevinng68@gmail.com
A Slide Presentation for HealthCare Providers Mar 2022

2. Presentation Outline
▪ History of green bean
▪ World production
▪ Scientific classification
▪ Anatomy of a green bean
▪ Nutrient composition
▪ Phytochemicals
▪ Scientific studies
▪ Commercial products
▪ Summary

3. A green bean is a legume
Legume = Pod containing seeds
https://www.kitchenstories.com/en/stories/everything-to-
know-about-cooking-and-shopping-for-in-season-green-beans

4. Domestication, distribution, and production of
common bean worldwide (2016)
https://www.researchgate.net/figure/Domestication-distribution-and-production-of-
common-bean-worldwide-A-Geographic_fig1_301796175

5. Origin and cultivation of green beans (1977)
http://www1.biologie.uni-hamburg.de/b-online/schaugarten/PhaseolusvulgarisL/Common_bean.html

6. Countries by String Bean Production (2018-2022)
https://www.atlasbig.com/en-us/countries-string-bean-production

7. • CLASSIFICATION OF GREEN BEAN
• VARIETIES
• SCIENTIFIC PUBLICATIONS

8. Scientific classification of green beans
Green beans are young, unripe fruits of various cultivars of the common bean (Phaseolus vulgaris)
https://en.wikipedia.org/wiki/Green_bean#/media/File:A_green_bean.jpg

9. Some varieties of green beans commonly used in the diet (2020)
https://www.researchgate.net/publication/343648502_Green_Beans

10. Number of articles on “Green Bean” in PubMed from
1946 to 2021
https://pubmed.ncbi.nlm.nih.gov/?term=green+beans%2C+

11. • ANATOMY OF A GREEN BEAN
• NUTRIENT COMPOSITION

12. Anatomy of a green bean
https://www.kitchenstories.com/en/stories/everything-to-know-about-cooking-and-shopping-for-in-season-green-beans

13. Nutrient composition of raw, green beans
©DRKEVINKFNG
Raw
Green beans
Macronutrients
Micronutrients
Vitamins
Micronutrients
Minerals
Micronutrients
Phytochemicals

14. Nutrient composition of raw green bean per 100g
Adapted from https://fdc.nal.usda.gov/fdc-
app.html#/food-details/1103337/nutrients

15. PHYTOCHEMICALS

16. Nutrient composition of raw green beans
©DRKEVINKFNG

17. Phytochemical Characterization of Green Beans (Phaseolus vulgaris L.)
by Using High-performance Liquid Chromatography Coupled with
Time-of-flight Mass Spectrometry (2012)
▪ 72 phytochemical compounds were tentatively characterised by
HPLC–ESI–TOF–MS.
▪ These compounds were classified as,
▪ 10 phenolic acids,
▪ 59 flavonoids,
▪ two lignans and
▪ an iridoid.
▪ Out of the 72 compounds, 54 are new and their isomers have
been characterized for the first time in green beans.
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/pca.2385#:~:text=The%20
phytochemicals%20that%20were%20tentatively,lignans%20and%20other%20polar%20compounds

18. Major phytochemicals in green beans
(10)
(59)
Adapted from
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/pca.2385#:~:text=The%2
0phytochemicals%20that%20were%20tentatively,lignans%20and%20other%20polar%20compounds
Major phytochemicals

19. How much beta-carotene is in green beans (μg/100g)?
https://www.soupersage.com/compare-nutrition/carrots-vs-green-bean

20. Comparison of flavonoids in carrots and green beans (mg/100g)
https://www.soupersage.com/compare-nutrition/carrots-vs-green-bean

21. Comparison of nutrients in green beans and carrots
https://www.soupersage.com/compare-nutrition/carrots-vs-green-bean

22. • HEALTH BENEFITS OF GREEN BEANS
• ACTIONS OF PHYTOCHEMICALS
• CLINICAL STUDIES

23. Health benefits of green beans
Water 90.3 g
Energy 31 kcal
Protein 1.83 g
Total lipids 0.22g
Total fiber 2.7g
©DRKEVINKFNG

24. Bioactivity of Major Phytochemicals in Green Beans
Phenolic acids
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/pca.2385#:~:text=The%20p
hytochemicals%20that%20were%20tentatively,lignans%20and%20other%20polar%20compounds
(10)
(59)
Bioactivity
Phytochemicals

25. CLINICAL STUDIES

26. Clinical studies with green beans
▪ Studies on the effects of green beans on hypertension, Type 2 diabetes
mellitus, lipids and obesity are limited and inconsistent.
▪ However, there are reports on the beneficial effects of green beans on
the prevention of cardiovascular disease and stroke:

27. Metabolic effects of onion and green beans on
diabetic patients (1983)
▪ A comparative study, using a crossover design, was carried out on 260-well controlled diabetic out-
patients to investigate the metabolic effects of the A (50% cal carbohydrate, 30% cal fat, and 20% cal
protein) and the B-diets (Study I), since the adherence of diabetic patients to the A-diet is very poor, and
uncontrolled diabetes ensues.
▪ In Indonesian rural areas traditional medicines are still widely preserved; onion and green beans
represent two of the frequent ones. Being faced with such facts, two separate randomized crossover
studies were performed on 20 cooperative diabetic outpatients each; paired t-test was used for statistical
analysis.
▪ Half of the patients were assigned to the B-diet (68% cal carbohydrate, 20% cal fat, 12% cal protein) plus
3 X 20 g fresh onion per day (Study II), or plus 3 X 200 g green beans per day (Study III) in the first week,
and the B-diet only in the second week; the other half was assigned the other way around.
▪ Well and poorly controlled diabetics were used as experimental patients of Study II and Study III,
respectively.
▪ Study I demonstrated that the B-diet showed potent hypocholesterolemic effect (31.75 mg%, p less than
0.001), maintained diabetic state, and did not raise the fasting serum triglyceride level.
▪ Study II resulted in significant decrease in blood sugar level (4.37 mg%, p less than 0.05) in the onion
treated group, however, no blood lipid levels-changes occurred during both diets.(ABSTRACT TRUNCATED
AT 250 WORDS)
https://pubmed.ncbi.nlm.nih.gov/6393443/

28. The effect of Pinto Beans and Green Beans on fasting glucose,
postprandial glucose and HbA1c concentrations
in adults with Type 2 diabetes
(n=8, Duration 12 weeks , double blind cross-over trial) 2020.
https://www.researchgate.net/publication/340309778_Pinto_Beans_and_Green_Beans_Result_
in_Comparable_Glycemic_Control_in_Adults_with_Type_2_Diabetes_A_Randomized_Pilot_Trial
No statistically significant changes (p<0.05) in fasting glucose, HbA1c or
average postprandial glucose values between the two interventions.

29. Relation between legume consumption and total CVD incidence (comparing highest with lowest
categories of consumption) in 163,974 participants. (2019)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6855964/
Pooled risk was estimated with the inverse variance method,
using fixed-effects meta-analyses. CVD, cardiovascular disease.

30. Relation between total legume consumption and CHD (comparing highest with lowest categories
of consumption) in 184,129 participants. (2019)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6855964/
Pooled risk was estimated with the inverse variance method, using
random-effects meta-analyses. CHD, coronary heart disease.

31. Relation between total legume consumption and stroke (comparing highest with lowest
categories of consumption) in 342,079 participants. (2019)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6855964/
Pooled risk was estimated with the inverse variance method, using random-
effects meta-analyses.

32. • SIDE EFFECTS
• COMMERCIAL PRODUCTS
• DELICIOUS CUISINES

33. Side effects of green beans
▪ No serious side effects of green beans have been reported.
▪ Phytic acid in green beans may cause nutrient deficiencies as it binds with
calcium, zinc and other minerals and do not allow them to be absorbed by
the body.
▪ Lectins, present in small quantities in beans can cause the proteins to
bind up the intestinal system and this may cause intestinal disorder.
▪ Oxalates also in small quantities may accumulate in the kidney and cause
kidney stones.
▪ .Allergy to green beans is rarely encountered.

34. Commercial green bean products
▪ Fresh green beans
▪ Frozen green beans
▪ Canned green beans

35. Some delicious cuisines

36. Summary
▪ Green bean originated in Peru. It is now cultivated and spread to many
parts of the world.
▪ Green bean is rich in fiber, vitamins and minerals beneficial for health.
▪ The phytochemicals such as phenolic acids and flavonoids have been
shown to have antioxidant, immuno-modulatory, anti-inflammatory and
anticancer properties which may reduce the risks for cardiovascular
disease, stoke and cancer.
▪ Clinical studies are limited. More research is needed

37. ANY QUESTION?
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