US National Library of Medicine National Institutes of Health
Health benefits of fruit and vegetables are from additive and synergistic combinations of phytochemicals: https://www.ncbi.nlm.nih.gov/pubmed/12936943
Antioxidant effect of tea: https://www.ncbi.nlm.nih.gov/pubmed/14519827
Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men: https://www.ncbi.nlm.nih.gov/pubmed/15640470
Exploring the potential of black tea based flavonoids against hyperlipidemia related disorders: https://www.ncbi.nlm.nih.gov/pubmed/29592809
Antioxidant supplements and mortality: https://www.ncbi.nlm.nih.gov/pubmed/24241129
Multiple risk factors for cardiovascular disease and diabetes mellitus: https://www.ncbi.nlm.nih.gov/pubmed/17320520
The effect of black tea on risk factors of cardiovascular disease in a normal population: https://www.ncbi.nlm.nih.gov/pubmed/22198621
Black tea--helpful or harmful? A review of the evidence: https://www.ncbi.nlm.nih.gov/pubmed/16855537
Black tea consumption reduces total and LDL cholesterol in mildly hypercholesterolemic adults: https://www.ncbi.nlm.nih.gov/pubmed/14519829
Antihypercholesterolemic effect of Chinese black tea extract in human subjects with borderline hypercholesterolemia: https://www.ncbi.nlm.nih.gov/pubmed/19083445
Effect of cocoa and tea intake on blood pressure: a meta-analysis: https://www.ncbi.nlm.nih.gov/pubmed/17420419
Green and black tea consumption and risk of stroke: a meta-analysis: https://www.ncbi.nlm.nih.gov/pubmed/19228856
Black tea improves attention and self-reported alertness: https://www.ncbi.nlm.nih.gov/pubmed/21172396
Psychological effects of dietary components of tea: caffeine and L-theanine: https://www.ncbi.nlm.nih.gov/pubmed/18254874
Consuming large amounts of sugar has proven to increase blood sugar values and enhance the risk of type 2 diabetes.
Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis: https://www.ncbi.nlm.nih.gov/pubmed/20693348
The antimicrobial properties in black tea kills off harmful substances. This leads to improving gut bacteria and immunity, in turn repairing the lining of the digestive tract.
Influence of diet on the gut microbiome and implications for human health: https://www.ncbi.nlm.nih.gov/pubmed/28388917
JAMA Internal medicine
Effects of Black Tea on Blood Pressure: A Randomized Controlled Trial: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1108657
Individuals with high blood pressure may benefit by incorporating a healthy lifestyle and drinking black tea daily.
The beneficial effects of tea on immune function and inflammation: a review of evidence from in vitro, animal, and human research: https://www.sciencedirect.com/science/article/pii/S027153170700125X
The New England Journal of Medicine
High levels of blood sugar can increase risk of health complications.
Effects of Intensive Glucose Lowering in Type 2 Diabetes: https://www.nejm.org/doi/full/10.1056/NEJMoa0802743