Sprout nutrition and vitamins

Sprouts

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.

Anti-sprouts?

Please don't misinterpret my aims. I'm not "anti-sprouts". If you want to eat sprouts, then go ahead - but don't do so on the basis of questionable claims about sprout nutrition or sprout vitamin content. If you decide to eat sprouts for some other reason, e.g. you like the taste of them, then that's fine with me.

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).

Claims about sprout nutrition

There is an abundance of claims that sprouts are some kind of "superfood", and have almost magical nutritional qualities, for example this quote from sproutnet.com: "Sprouts are considered as wonder foods. They rank as the freshest and most nutritious of all vegetables available to the human diet." (full text is here) When you look at the facts, you soon find these claims can't be justified with real evidence and you start to wonder if the exaggerated statements are actually just a marketing ploy by those selling the sprouts and related products.

So, let's deal with one of the most-often quoted (and misunderstood) nutritional properties of sprouts: their vitamin content.

Vitamin content of sprouts

Here are some of the claims, taken from Gillian McKeith's books and articles:

"A study conducted at Yale University by Dr Paul Barkholden found that B vitamins increased in sprouts by as much as 2000 per cent" (from "You Are What You Eat", p212, Gillian McKeith)
"Another study, at the University of Pennsylvania by Dr Barry Mack reported a general overall average vitamin increase of more than 500 per cent when seeds are sprouted" (from "You Are What You Eat", p212, Gillian McKeith)
"a superfood with enormous levels of proteins, vitamins, minerals... which have all multiplied anywhere from 300 to 1200 percent" (from this article from the (now defunct) Bonasana site. Original URL: http://www.bonasana.com/woh/artman/publish/article_41.shtml)

Similar claims of large increases of the vitamin content of sprouted seeds are quoted on a variety of internet sites, and percentage increases of between 500% and 2000% are often quoted. Sprout enthusiasts often see this vitamin increase as something remarkable, almost magical. A few examples of the types of claims made are given below:

"vitamin B2 increase of 2000% ...vitamin C increase of 600%" (from http://www.rosneath.com.au/ipc6/ch05/swindell/ - no longer on-line but archived here)
"There is an amazing increase in nutrients in sprouted foods... remarkable increase in vitamins" (from this site)
"The increase of vitamin content in sprouts during the sprouting period is tremendous... Germinated seeds and grain showed an increase in vitamins, minerals, proteins and enzymes of 25 to 4,000 percent!" (from http://www.chefnoah.com/sprouts.htm - no longer on-line but archived here)

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.

Vitamin C - sprouts, fruits and vegetables

So, how does the vitamin C content of sprouts compare to that from other food sources?

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)
Blackcurrant	fruit	155-215
Sweet red peppers	vegetable	189 (142mg for 75g)
Kiwifruit	fruit	98 (75)
Broccoli (cooked)	vegetable	65 (51mg for 78g)
Strawberry	fruit	57 (58)
Red cabbage	vegetable	57 (51mg for 89g)
Orange	fruit	53 (53)
Lemon juice	fruit	46
Kale	vegetable	42 (27mg for 65g)
Kidney beans sprouts	sprout	39
Grapefruit	fruit	34 (34)
Radish sprouts	sprout	29
Mango	fruit	28 (28)
Pinto bean sprouts	sprout	22
Navy bean sprouts	sprout	19
Lentil sprouts	sprout	17
Soy bean sprouts	sprout	15
Mung bean sprouts	sprout	13
Pea sprouts	sprout	10
Alfalfa sprouts	sprout	8
Wheat sprouts	sprout	3

Data sources:

Sprout nutrition data from: http://www.sproutnet.com/nutritional_analysis.htm. The figures for sprouts available from http://waltonfeed.com/grain/sprtnutr.html appear to be taken from the same data source.
Fruit data from http://www.naturalhub.com/natural_food_guide_fruit_vitamin_c.htm, second figure in brackets from: http://www.dole5aday.com/ReferenceCenter/NutritionCenter/Chart/R_NutrChart.jsp?topmenu=1
Vegetable data from http://www.dole5aday.com/ReferenceCenter/NutritionCenter/Chart/R_NutrChart.jsp?topmenu=1

Summary

From 10 types analysed, only one type of sprout has more than 30mg per 100g (kidney bean sprouts with 39mg). The average value for sprout vitamin C content is 17mg/100g. The data clearly show that there are many fruits and vegetables with considerably higher levels of vitamin C, some with 3 or 4 times more than in the "best" sprouts. In other words, if you were choosing a food for high vitamin C content, sprouts wouldn't be top of the list.

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.

Vitamin A - sprouts, fruits, vegetables and animal sources

What about the vitamin A content of sprouts compared to other food sources? Data from this page (note: the original page no longer shows all the data) gives a variety of data for vitamin content of sprouts and vegetables. Note that some of the tables from this page incorrectly give the unit of vitamin A as milligrams per 100g food - in fact all vitamin A figures are quoted in international units (IU) per 100g food. The figures for sprouts range from around 10 to 700 IU. The sprouts with the highest vitamin A content are radish (391) and red pea (712).

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)
radish sprouts	sprout	391
pea sprouts	sprout	166
alfalfa sprouts	sprout	155
Whole milk (3.25% fat)	animal	122 (305 for 1 cup, ~250g)
lentil sprouts	sprout	45
soybean sprouts	sprout	11
mung bean sprouts	sprout	21
navy bean sprouts	sprout	4
pinto bean sprouts	sprout	2
kidney bean sprouts	sprout	2
wheat sprouts	sprout	0

Data sources:

Sprout nutrition data from http://www.sproutnet.com/nutritional_analysis.htm
Vegetable data from http://www.dole5aday.com/ReferenceCenter/NutritionCenter/Chart/R_NutrChart.jsp?topmenu=1
Fruit data from http://www.dole5aday.com/ReferenceCenter/NutritionCenter/Chart/R_NutrChart.jsp?topmenu=1
Animal source data from http://ods.od.nih.gov/factsheets/cc/vita.html#table4 and http://www.metzerfarms.com/nutri.htm

Summary

Again it's clear that if you were selecting a food on the basis of high vitamin A content, sprouts would not be top of the list. There are many other vegetables and fruits (not to mention animal sources such as milk, eggs, liver) that have a vitamin A content more than 10 times greater than the "best" sprouts.

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").

Vitamin E - sprouts, fruits, vegetables and other sources

Now lets look at the vitamin E content of sprouts and other food sources. I've used the same colours to highlight the different food sources (vegetables in blue, fruit in red, sprouts in green, other items in yellow). All vitamin E figures quoted are in mg and the amounts of each food source are given in the table.

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

Data sources:

Sprout nutrition data from http://www.sproutnet.com/nutritional_analysis.htm
Vegetable data from: http://www.askdrsears.com/html/4/T045300.asp#T045307
Fruit and other data from: http://ods.od.nih.gov/factsheets/vitamine.asp#h2

Summary

Once again the vitamin content of sprouts is shown to be far lower than other food source. In other words, if you're looking for a food source that's high in vitamin E, you shouldn't choose sprouts. Based on the available data, the "best" sprouts have vitamin E levels that are over a hundred times lower than other common foud sources.

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