Many sprout enthusiasts, including "Dr" Gillian McKeith, talk about the nutritional benefits of sprouts with an almost evangelical fervour. In particular, the seemingly high vitamin content of sprouts is often quoted as one of their main nutritional benefits. Is such enthusiasm really justified? Is there really hard evidence to back up their claims?
When you look into the claims, as this page does, you quickly find a lot of impressive-sounding statements, quite a bit of pseudo science, a lot of badly interpreted data but very little actual science. This page is an attempt to redress the balance, and present the facts.
My concern is specifically with the misleading or false claims made about sprout nutrition, and this page attempts to clarify some of the facts regarding the vitamin content of sprouts (as compared with other food sources).
So, let's deal with one of the most-often quoted (and misunderstood) nutritional properties of sprouts: their vitamin content.
What do all these claims actually tell us?
The plain truth is very simple: the seeds contain extremely small amounts of vitamins, the sprouts contain higher levels. Expressed as a percentage increase it looks impressive, but this figure is irrelevant. The vitamin content of the sprout is still fairly small, but it is bigger than the extremely small levels in the seed. Big deal!
It would be like saying the percentage change in size from the seed to the sprout is 2000%, and using this to imply that the sprout is really large. The percentage change looks impressive, until you realise it just means the seed starts small (say 3mm) and the sprout ends up a little bigger (say 60mm). The only thing that actually matters is what the vitamin content of the food you eat actually is. The percentage change to get to this level is irrelevant. Whether the large percentage increases are deliberately quoted with the intention of misleading people, or whether this just indicates a poor grasp of the science is another question.
So, ignoring the irrelevant percentage increase figures, when you compare the actual vitamin content of sprouts with other fruits and vegetables, things look much more ordinary, as shown below.
The table below ranks the vitamin C content of different food items, including sprouts. Data for sprouts is highlighted in green, fruits in red, vegetables in blue. Using this colour code, it means that there should be lots of green entries near the top of the table if sprouts are indeed such a good source of vitamin C. What do we see? No green entries at the top: the items with the highest vitamin C content are fruits and vegetables, and all the green entries are near the bottom of the table, showing that their vitamin C content is not as high as many fruits and vegetables.
All vitamin C figures are in mg (milligrams) per 100g, unless stated otherwise. All food items raw unless otherwise stated. Where two data sources give different values, the second value is given in brackets.
|Food item||Group||Vitamin C content|
|Green chilli peppers||vegetable||243 (182mg for 75g)|
|Sweet red peppers||vegetable||189 (142mg for 75g)|
|Broccoli (cooked)||vegetable||65 (51mg for 78g)|
|Red cabbage||vegetable||57 (51mg for 89g)|
|Kale||vegetable||42 (27mg for 65g)|
|Kidney beans sprouts||sprout||39|
|Pinto bean sprouts||sprout||22|
|Navy bean sprouts||sprout||19|
|Soy bean sprouts||sprout||15|
|Mung bean sprouts||sprout||13|
The best you can say is that there are one or two types of sprouts that have moderate levels of vitamins C (similar to the vitamin C levels of grapefruits and oranges). Most types of sprouts have vitamin C levels considerably lower than this, and so can't be considered as good source of vitamin C.
So how does this compare with the vitamin A content of other food items? The table below ranks the figures, so again we would expect lots of green entries at the top if sprouts were the best source of vitamin A. In fact, we again see that all the green entries are near the bottom, sothe facts on sprout nutrition show they are not a particularly good source of vitamin A.
All vitamin A figures in IU per 100g. Nutritional data for sprouts is highlighted in green, fruits in red, vegetables in blue, animal sources in yellow.
|Food item||Group||Vitamin A content|
|Beef liver||animal||35680 (30325 for 85g)|
|Sweet potatoes||vegetable||19218 (19218 for 100g)|
|Carrots||vegetable||17200 (13418 for 78g)|
|Chicken liver||animal||16376 (13,920 for 85g)|
|Kale||vegetable||13621 (8854 for 65g)|
|Butternut squash||vegetable||11100 (11434 for 103g)|
|Spinach||vegetable||10481 (9433 for 90g)|
|Sweet red peppers||vegetable||3111 (2333 IU for 75g )|
|Broccoli||vegetable||1967 (1534 for 78g)|
|Apricots fresh||fruit||1925 (1328 IU for 70g)|
|Papayas||fruit||1094 (766 for 70g)|
|Cheddar cheese||animal||1060 (300 for 28g)|
|Asparagus||vegetable||1005 (754 for 75g)|
|Grapefruit, pink/red||fruit||927 (1187 for 128g)|
|Mango||fruit||760 (631 for 83g)|
|Tangerines||fruit||681 (572 for 84g)|
|Watermelon||fruit||568 (438 for 77g)|
|Whole egg (medium)||animal||467 (280 for ~60g) (520 from metzerfarms site)|
|Whole milk (3.25% fat)||animal||122 (305 for 1 cup, ~250g)|
|mung bean sprouts||sprout||21|
|navy bean sprouts||sprout||4|
|pinto bean sprouts||sprout||2|
|kidney bean sprouts||sprout||2|
Indeed, this waltonfeed.com page openly admits this: "Even though sprouts have over 5 times the vitamin A of the seeds they came from, there is such a small amount of the vitamin that 100gm of sprouts doesn't even give 4 percent of the RDA." (Recommended Daily Amount).
(I'm sure Gillian McKeith would enjoy this quote from http://ods.od.nih.gov/factsheets/cc/vita.html: "Animal sources of vitamin A provide the best absorbed form of this vitamin").
Yet again, we find that when judged alongside other foods, sprouts do not come out as good sources of vitamin E - they rank at the bottom of the table, with many other food items (particularly nuts) providing vitamin E levels over 100 times greater.
It's interesting to note that vitamin E data was only available (from http://www.sproutnet.com/nutritional_analysis.htm) for 3 of the 10 types of sprout that were analysed. Does that mean the other 7 types of sprout have vitamin E levels that are too low to measure?
|Food item||Group||Vitamin E content|
|Almonds, dry roasted (1 ounce)||other||7.4|
|Sunflower seed kernels, dry roasted (1 ounce)||other||6.0|
|Corn oil (1 tablespoon)||other||1.9|
|Swiss chard (1/2 cup)||vegetable||1.6|
|Mustard greens (1/2 cup)||vegetable||1.4|
|Spinach (1/2 cup)||vegetable||1.4|
|Kiwi (1 medium fruit)||fruit||1.1|
|Mango (1/2 cup)||fruit||0.9|
|Wheat sprouts (100g)||sprout||0.05|
|Alfalfa sprouts (100g)||sprout||0.02|
|Mung bean sprouts (100g)||sprout||0.01|
Despite Gillian McKeith's claims that broccoli sprouts are "a good source of vitamin E" (Gillian Mckeith Newsletter 3/12/2004) I can find no data on the levels of vitamin E found in broccoli sprouts to support this. Broccoli as a vegetable is a reasonably good source of vitamin E (1/2 cup provides 1.2mg according to this site), but I can't find any data on broccoli sprout nutrition for comparison.
Last updated April 2011
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