The Great Pumpkin is Not Just for Decoration

pumpkinsMany of us associate pumpkin with autumn, especially Thanksgiving. That’s a shame because there’s a wealth of goodness in that winter squash, and it deserves more than mere seasonal entertainment. It’s low in calories and fat, and provides vitamins, minerals, fiber, and phytochemicals essential to a healthy diet. A cup has only 83 calories and one gram of fat, which is just enough to allow its use in recipes that call for shortening or oil. Measure for measure, you can use canned pumpkin puree for half the fat in a cake or cookie recipe. Some people even add it to their morning oatmeal with cinnamon and a little, like a teaspoon, of brown sugar. Here we’re talking about the nutritive value of canned pumpkin, which is denser than what you would get from spending a few hours trying to hatchet out and distill the flesh from a fresh pumpkin.  The only virtue realized from a fresh squash is the potential to roast the seeds for a snack later on… if you have the composure to separate the seeds from the stringy fibers in the core.

The Color of Vitamin A
Because of its color, pumpkin is immediately identified as being a source of beta-carotene, the precursor to vitamin A that has no measurable level of liver burden. Beta-carotene is a molecule that the body easily changes to vitamin A in the intestine, and is found in plants, as opposed to pre-formed vitamin A common to animal products, as from butter and eggs. This fat-soluble vitamin is known to fight infections, to help treat skin disorders, to improve night vision and to ameliorate dry eyes, all the while performing anti-oxidant functions. Although beta-carotene does not, pre-formed vitamin A can lead to orange skin and yellow eyes, a state that disappears when levels are adjusted or intake is temporarily discontinued. The bioavailability of beta-carotene—the proportion that can be absorbed, transported and utilized by the body—is influenced by a few factors: supplemental beta-carotene is better absorbed that that from foods; food processing and cooking can enhance availability; the presence of fat in the gut aids absorption (only about three grams per meal is needed).

One cup of pumpkin yields more than 500 milligrams of potassium, an essential mineral in which most North Americans are shallow, often getting much less than the RDI of 4700 milligrams. In the body, potassium helps to keep blood pressure under control (Barri, 1997) (Hajjar, 2001) (Geleijnse, 1996), may help to encourage positive bone mineral density (New, 1997, 2000) (Tucker, 1999), and may reduce risk of stroke (Ascherio, 1998) (Fang, 2000) (Bazzano, 2001). Epidemiological evidence indicates that potassium intake and blood pressure are inversely correlated, with the greatest hypotensive effect found in those with the highest blood pressure. Inclusion of potassium in the management of hypertension was suggested in the late 90’s (Barri, 1997).  Knowing your potassium intake might be more important than you think.

Another of the vision-friendly carotenoids in pumpkin is lutein, a pigment for which spinach has been lauded. Concentrated in the macula, the part of the retina responsible for central vision, lutein rescues the eye from oxidative stressors and the high-energy photons of blue light that are known to increase risk for macular degeneration (Richer, 2004). Naturally combined with its isomer, zeaxanthin (the yellow pigment also in corn, saffron and paprika), lutein may also lower the risk of cataracts (Barker, 2010) (Moeller, 2008) (SanGiovanni, 2007).

Hypoglycemic Activity of Pumpkin
Though the foregoing is reason enough to eat pumpkin more often than once a year, another virtue was made public earlier in this century. China has received some bad publicity in the recent past, with melamine in baby formula, toxic bean sprouts and contaminated pet foods, but its scientific community looks less toward dollar signs and more toward humanitarian ventures. While examining the medicinal properties of plants, pharmaceutical researchers in Shanghai found pumpkin to be among the species that exhibit hypoglycemic activity. Specific polysaccharides in pumpkin and a few other plants apparently are able to restore the function of pancreatic cells and cause an increase in insulin output by the functional beta cells. Scientists noticed that lower dosages of anti-diabetes drugs were needed when the plant compounds were concomitantly administered. Frequency of drug administration and its unwelcome side effects were also reduced (Jia, 2003). As with many natural approaches to the management of disease, dose makes the difference. Later study in Beijing found that 1000 mg/kg doses of protein-bound pumpkin polysaccharide were considerably more effective than half that amount (Quanhong, 2005).

Much of what we all learn as students is based on prior knowledge, using it as a springboard for additional investigation. One of the active pumpkin factors that eventually “sprang from the board” and found to be most effective in lowering glucose is trigonelline (TRG), an alkaloid also appearing in coffee, sea urchins and jellyfish, the latter two not being suggested as complementary to the pie. A derivative of vitamin B6, trigonelline is believed also to have anti-migraine, antiseptic, and anti-carcinogenic properties. If roasted at temperatures greater than 230° C (446° F), this alkaloid yields nicotinic acid—niacin. Experimental use of TRG attenuated triglycerides as well as serum glucose in laboratory animals bred to mimic human disorders (Yoshinari, 2009).  Anti-oxidant status is severely compromised in diabetes, causing an increase in damage by free radicals. TRG was seen to ameliorate oxidative stress and to return related blood markers to near normal levels (Zhou, 2011, 2012).

The Gentle Giant
You’d think that, as big as they can get, pumpkins are rough and tough. They’re actually very tender, starting with seeds that don’t do well in cold soil and seedlings that succumb to frost. If planted too early, they often rot before you’re ready to pick them.  What is truly surprising about pumpkins’ cultivation is that they fare poorly if fertilized with the typical N-P-K fertilizers used in the garden. To ascertain initial results, researchers duplicated experiments five more times in order to remove doubts that high fertilizer rates decrease anti-oxidant concentrations in the fruits (Oloyede, Apr 2012 and May 2012).

Preparing fresh pumpkin is more work than fun unless you do it once a year, and just for the novelty of it. Uncut pumpkins can be stored for weeks in a well-ventilated space, but once you cut ‘em you got to use ‘em. Canned keeps seemingly forever. Fruit, leaves, flowers and seeds are edible. But we think of the flesh in pies, pancakes, muffins, custards, soups, soufflés, and yes, even ravioli. Now you can eat for health as well as flavor.

References

Age-Related Eye Disease Study Research Group, SanGiovanni JP, Chew EY, Clemons TE, Ferris FL 3rd, Gensler G, Lindblad AS, Milton RC, Seddon JM, Sperduto RD.
The relationship of dietary carotenoid and vitamin A, E, and C intake with age-related macular degeneration in a case-control study: AREDS Report No. 22.
Arch Ophthalmol. 2007 Sep;125(9):1225-32.


Ascherio A, Rimm EB, Hernán MA, Giovannucci EL, Kawachi I, Stampfer MJ, Willett WC.
Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men.
Circulation. 1998 Sep 22;98(12):1198-204.


Bakuradze T, Lang R, Hofmann T, Stiebitz H, Bytof G, Lantz I, Baum M, Eisenbrand G, Janzowski C.
Antioxidant effectiveness of coffee extracts and selected constituents in cell-free systems and human colon cell lines.
Mol Nutr Food Res. 2010 Dec;54(12):1734-43.


Barker FM 2nd.
Dietary supplementation: effects on visual performance and occurrence of AMD and cataracts.
Curr Med Res Opin. 2010 Aug;26(8):2011-23.


Barri YM, Wingo CS.
The effects of potassium depletion and supplementation on blood pressure: a clinical review.
Am J Med Sci. 1997 Jul;314(1):37-40.


Bazzano LA, He J, Ogden LG, Loria C, Vupputuri S, Myers L, Whelton PK
Dietary potassium intake and risk of stroke in US men and women: National Health and Nutrition Examination Survey I epidemiologic follow-up study.
Stroke. 2001 Jul;32(7):1473-80.


Czok G.
Coffee and health
Z Ernahrungswiss. 1977 Dec;16(4):248-55.


Fang J, Madhavan S, Alderman MH.
Dietary potassium intake and stroke mortality.
Stroke. 2000 Jul;31(7):1532-7.


Geleijnse JM, Witteman JC, den Breeijen JH, Hofman A, de Jong PT, Pols HA, Grobbee DE.
Dietary electrolyte intake and blood pressure in older subjects: the Rotterdam Study.
J Hypertens. 1996 Jun;14(6):737-41.


Hajjar IM, Grim CE, George V, Kotchen TA
Impact of diet on blood pressure and age-related changes in blood pressure in the US population: analysis of NHANES III.
Arch Intern Med. 2001 Feb 26;161(4):589-93.


Huang XE, Hirose K, Wakai K, Matsuo K, Ito H, Xiang J, Takezaki T, Tajima K.
Comparison of lifestyle risk factors by family history for gastric, breast, lung and colorectal cancer.
Asian Pac J Cancer Prev. 2004 Oct-Dec;5(4):419-27.


Jia W, Gao W, Tang L.
Antidiabetic herbal drugs officially approved in China.
Phytother Res. 2003 Dec;17(10):1127-34.


Jian L, Du CJ, Lee AH, Binns CW.
Do dietary lycopene and other carotenoids protect against prostate cancer?
Int J Cancer. 2005 Mar 1;113(6):1010-4.


Jiang Z, Du Q.
Glucose-lowering activity of novel tetrasaccharide glyceroglycolipids from the fruits of Cucurbita moschata.
Bioorg Med Chem Lett. 2011 Feb 1;21(3):1001-3. Epub 2010 Dec 10.


Mishkinsky J, Joseph B, Sulman FG.
Hypoglycaemic effect of trigonelline.
Lancet. 1967 Dec 16;2(7529):1311-2.


Moeller SM, Voland R, Tinker L, Blodi BA, Klein ML, Gehrs KM, Johnson EJ, Snodderly DM, Wallace RB, Chappell RJ, Parekh N, Ritenbaugh C, Mares JA; CAREDS Study Group; Women’s Helath Initiative.
Collaborators (88)
Associations between age-related nuclear cataract and lutein and zeaxanthin in the diet and serum in the Carotenoids in the Age-Related Eye Disease Study, an Ancillary Study of the Women’s Health Initiative.
Arch Ophthalmol. 2008 Mar;126(3):354-64.


Mohamed Makni, Mediha Sefi, Hamadi Fetoui, El Mouldi Garoui, Nabil K. Gargouri, Tahia Boudawar, Najiba Zeghala
Flax and Pumpkin seeds mixture ameliorates diabetic nephropathy in rats
Food and Chemical Toxicology. Vol 48, Iss 8–9, Aug–Sept 2010, Pp 2407–2412


New SA, Bolton-Smith C, Grubb DA, Reid DM.
Nutritional influences on bone mineral density: a cross-sectional study in premenopausal women.
Am J Clin Nutr. 1997 Jun;65(6):1831-9.


New SA, Robins SP, Campbell MK, Martin JC, Garton MJ, Bolton-Smith C, Grubb DA, Lee SJ, Reid DM.
Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health?
Am J Clin Nutr. 2000 Jan;71(1):142-51.


Oloyede FM, Agbaje GO, Obuotor EM, Obisesan IO.
Nutritional and antioxidant profiles of pumpkin (Cucurbita pepo Linn.) immature and mature fruits as influenced by NPK fertilizer.
Food Chem. 2012 Nov 15;135(2):460-3. Epub 2012 Apr 30.


Oloyede FM, Obisesan IO, Agbaje GO, Obuotor EM.
Effect of NPK fertilizer on chemical composition of pumpkin (Cucurbita pepo Linn.) seeds.
ScientificWorldJournal. 2012;2012:808196. Epub 2012 May 2.


Quanhong L, Caili F, Yukui R, Guanghui H, Tongyi C.
Effects of protein-bound polysaccharide isolated from pumpkin on insulin in diabetic rats.
Plant Foods Hum Nutr. 2005 Mar;60(1):13-6.


Richer S, Stiles W, Statkute L, Pulido J, Frankowski J, Rudy D, Pei K, Tsipursky M, Nyland J.
Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial).
Optometry. 2004 Apr;75(4):216-30.


Suzuki K, Ito Y, Nakamura S, Ochiai J, Aoki K.
Relationship between serum carotenoids and hyperglycemia: a population-based cross-sectional study.
J Epidemiol. 2002 Sep;12(5):357-66.


Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP.
Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women.
Am J Clin Nutr. 1999 Apr;69(4):727-36.


van Dijk AE, Olthof MR, Meeuse JC, Seebus E, Heine RJ, van Dam RM.
Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance.
Diabetes Care. 2009 Jun;32(6):1023-5. Epub 2009 Mar 26.


Carolina Médici Veronezi, Neuza Jorge
Bioactive Compounds in Lipid Fractions of Pumpkin (Cucurbita sp) Seeds for Use in Food
Journal of Food Science. Volume 77, Issue 6, pages C653–C657, June 2012


Yoshinari O, Sato H, Igarashi K.
Anti-diabetic effects of pumpkin and its components, trigonelline and nicotinic acid, on Goto-Kakizaki rats.
Biosci Biotechnol Biochem. 2009 May;73(5):1033-41. Epub 2009 May 7.


Zhou J, Zhou S, Zeng S.
Experimental diabetes treated with trigonelline: effect on β cell and pancreatic oxidative parameters
Fundam Clin Pharmacol. 2011 Dec 16. doi: 10.1111/j.1472-8206.2011.01022.x. [Epub ahead of print]


Zhou J, Chan L, Zhou S.
Trigonelline: a plant alkaloid with therapeutic potential for diabetes and central nervous system disease.
Curr Med Chem. 2012 Jul 1;19(21):3523-31.

*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.

Print Friendly, PDF & Email