Table 4.

Health benefits of carotenoids found in kale, determined through in vivo and in vitro studies.

Compound	Metabolic Effect	Main Findings	Reference
Lutein	Antiproliferative	Lutein induced a decrease in the proliferation of PC-3 cells (in vitro), modulating the expression of growth genes associated with prostate cancer cells.	[98]
	Antioxidant activity	Healthy subjects supplemented with 12 mg/d of lutein for 12 weeks showed improved visual function, particularly in contrast sensitivity.	[99]
	Neuroprotective	Rats supplemented with lutein (30, 15, and 7.5 mg/kg) significantly elevated the activities of superoxide dismutase, glutathione peroxidase, and catalase in brain and decreased the neurological deficit scores.	[100]
	Neuroprotective	Rats supplemented with lutein (50–100 mg/kg) for 14 days showed a fat loss, reduced neurobehavioral alterations, and reduced oxidative stress.	[101]
	Antidiabetic and obesity control	Rats supplemented with lutein significantly improved body weight, hepatic levels of lipid accumulation, and insulin sensitivity.	[102]
β-carotene	Apoptotic	β-carotene (1 μM) induced apoptosis in MCF cells by caspase-3 activity and inhibited the expression of the anti-apoptotic proteins, Bcl-2 and PARP.	[103]
	Antioxidant activity	Patients supplemented with 60 mg/d of β-carotene for 3 weeks showed a reduction in LDL susceptibility to oxidation.	[104]
	Antioxidant activity	The content of β-carotene in plasma was significantly and positively correlated with telomerase activity of Alzheimer disease patients, independent of gender.	[105]