Kale Yeah! Why Kale Still Makes the Superfood List

As a high school nutrition teacher, kale became a running joke to several of my students. If I asked for any food that contained fiber, the answer was kale. A food that provides vitamin C? Kale. A green leafy vegetable that helps prevent cancer? You guessed it- kale. What’s not to love about this versatile green superfood? Lettuce take a look at all the ways to be kaleful.

Your brain on kale

One of the main reasons I’m a big kale fan is brain health. Several nutrients, including folate, tryptophan, vitamin B6 and B12 impact mental health. These in addition to multiple amino acids are needed to make neurotransmitters such as serotonin, dopamine, and norepinephrine, which aid in regulating mood, appetite, and cognition. 1

Kale provides folate, which impacts the risk of depression. One study of over 150 adults found that subjects with normal levels of folate and B12 (versus low levels) had lower rates of depression.2

A systematic review of studies also found that higher intakes of green leafy vegetables (including kale) may promote higher levels of optimism and self-efficacy, in addition to a reduced level of psychological distress, ambiguity, and cancer fatalism. They may also protect against depressive symptoms. 3

As part of the MIND diet, kale is a source of lutein, zeaxanthin, and alpha-carotene. Participants in a MIND study with higher circulating levels of alpha-carotene had better global cognition. Those with a higher circulating level of a combination of lutein and zeaxanthin showed higher semantic memory scores. 4 More reasons to eat this leafy green.

Kale for your heart

Kale’s not only great for your noggen but also for your ticker. A recent meta-analysis of studies found that per 100 gm daily intake of green leafy vegetable intake, a 25% decreased risk of all-cause mortality, coronary heart disease, and stroke was observed. 5 This is equivalent to roughly one and a half cups of kale daily. Easy peasy!

Another review of studies revealed that the intake of green, leafy vegetables was linked with a reduced incidence of cardiovascular disease. An inverse relationship was observed for cerebral infarction, heart disease, and other cardiovascular disease events. 6

Finally, kale is part of the cabbage family, a rich source of isothiocyanates.  A review of several human studies found that intake of cruciferous vegetables (including kale) was linked with a reduced risk of all-cause mortality, cancers, and depression. Just one and a half cups per day provide a 10% reduction in the risk of all-cause mortality. 7

Tips to Be More Kaleful

If you’re having trouble convincing your clients to eat more of this powerful green, here are some simple tips:

·         Massage clean kale for 5 minutes prior to ripping it up to use in salads. This wilts the green and reduces its bitterness.

·         Top grain bowls with chopped kale and other veggies.

·         Pair ripped kale with strawberries and balsamic vinaigrette in a seasonal salad.

·         Try greens and beans- sauteed kale in olive oil with navy beans and garlic

·         Add chopped kale to soups and stews

·         Use cooked kale in scrambled eggs, omelets, and frittatas

• Don’t toss the ribs! They can be chopped and sauteed just like celery for soups and stews.

Lisa Andrews, MEd, RD, LD

Free Handout: Kale Yeah!

References

1.       Calderón-Ospina CA, Nava-Mesa MO. B Vitamins in the nervous system: Current knowledge of the biochemical modes of action and synergies of thiamine, pyridoxine, and cobalamin. CNS Neurosci Ther. 2020 Jan;26(1):5-13. doi: 10.1111/cns.13207. Epub 2019 Sep 6. PMID: 31490017; PMCID: PMC6930825.

2.       Liu X, Dhana K, Furtado JD, Agarwal P, Aggarwal NT, Tangney C, Laranjo N, Carey V, Barnes LL, Sacks FM. Higher circulating α-carotene was associated with better cognitive function: an evaluation among the MIND trial participants. J Nutr Sci. 2021 Aug 16;10:e64. doi: 10.1017/jns.2021.56. PMID: 34527222; PMCID: PMC8411267.

3.       Głąbska D, Guzek D, Groele B, Gutkowska K. Fruit and Vegetable Intake and Mental Health in Adults: A Systematic Review. Nutrients. 2020 Jan 1;12(1):115. doi: 10.3390/nu12010115. PMID: 31906271; PMCID: PMC7019743.

4.    Khosravi, M., Sotoudeh, G., Amini, M. et al. The relationship between dietary patterns and depression mediated by serum levels of Folate and vitamin B12. BMC Psychiatry 20, 63 (2020). https://doi.org/10.1186/s12888-020-2455-2

5.       Li N, Wu X, Zhuang W, Xia L, Chen Y, Wang Y, Wu C, Rao Z, Du L, Zhao R, Yi M, Wan Q, Zhou Y. Green leafy vegetable and lutein intake and multiple health outcomes. Food Chem. 2021 Oct 30;360:130145. doi: 10.1016/j.foodchem.2021.130145. Epub 2021 May 18. PMID: 34034049.

6.       Ojagbemi A, Okekunle AP, Olowoyo P, Akpa OM, Akinyemi R, Ovbiagele B, Owolabi M. Dietary intakes of green leafy vegetables and incidence of cardiovascular diseases. Cardiovasc J Afr. 2021 Jul-Aug 23;32(4):215-223. doi: 10.5830/CVJA-2021-017. Epub 2021 Jun 10. PMID: 34128951; PMCID: PMC8756059.

7.       Li N, Wu X, Zhuang W, Wu C, Rao Z, Du L, Zhou Y. Cruciferous vegetable and isothiocyanate intake and multiple health outcomes. Food Chem. 2022 May 1;375:131816. doi: 10.1016/j.foodchem.2021.131816. Epub 2021 Dec 14. PMID: 34929422.