The Goji

What it is.... and isn't

Part 3 of 4 -- The Nutrient Story

Sorting harvested goji berries, Ningxia, China

[follow the Wikipedia links]

 

As world economies merge, plant foods once considered exotic

and mystical are becoming more commonly available

in stores around the world .... and better understood by science.

For those of us watching the global markets for berry commerce, wolfberries (Lycium barbarum L.) -- known more popularly today as goji berries -- first were noticeable on the internet beginning around 1999 -- mainly for their unusual antioxidant strength.

 

Why should we be interested in goji now ?

 

  • simple, ready-to-eat foods like dried berries rich in nutrients and antioxidants are needed to help overcome the poor dietary practices so common in today's industrialized countries
  • buyers are becoming interested in novel foods that provide nutrient, taste, aroma and application experiences different than they've had before
  • pleasant tasting fruits rich in nutrients, antioxidants and potential health benefits, including goji, açaí, blueberries, cranberries and pomegranates -- a group sometimes called superfruits -- are forecast to become a $6 billion industry worldwide by 2009
  • as goji is new to large markets like those of North and South America, Europe and Japan, how it is received as a superfruit will affect the commerce of other current and future natural health foods new to established markets
  • goji has attracted such significant recent interest that some 100 medical research studies have been completed over the past 20 years, with 40 research papers and two books published since 2005. By comparison, no science-based books exist for common berries, such as blueberry, cranberry or strawberry
  • in 2005-6, 54 new food or beverage products using goji were introduced across the world. In 2006-7, this number is expected to triple!
  • with such intensive industrial development, goji is being called "Darling" of the 2007 superfruit industry...

 

                                            

                             Goji juice concentrate                            Soluble goji juice powder

 

With the above as introduction,

let's get some goji FAQs straight !

[follow the Wikipedia links]

*  Part 1, FAQ 1-5 - names and uses

* Part 2, FAQ 6-10 - origins of the goji

 

Part 3  -- Exceptional in Nutrient Density and Antioxidant Pigments

When scientists first look at an unknown plant with potential as a health food, they ask four main questions

  1. what nutrients does it have and how concentrated and diverse are those nutrients?
  2. does it have pigmentation (color) giving it a rich complement of antioxidant phytochemicals?
  3. what expert scientific studies have been conducted on it and published in world literature?
  4. is there a scientific basis to believe this plant could benefit human health?

Continuing with the FAQ on goji...

 

11. What extent of nutrients does goji have and how diverse are those nutrients?

First, let's establish a guideline for comparing goji's nutrient content to what is recommended by a public regulatory agency like the United States FDA

How To Understand and Use a Nutrition Facts Label (click)

What we're looking for are nutrient levels at the

"Good" (10% of DRI) or "Excellent" (>20% of DRI) level

in this single food source

Goji contains an exceptional nutrient content compared not just to other berries but to many nutritious "superfoods" (e.g., spinach, blueberries, flax seeds, soy, papaya)

  • good to excellent levels of carbohydrates, dietary fiber, and linoleic acid, an omega-6 fatty acid (mainly in seeds)
  • excellent source of dietary fiber via high density of polysaccharides
  • excellent levels of vitamin A (carotenoid provitamins), B vitamins - thiamin, riboflavin, niacin – and vitamin C
  • excellent content of 11 essential minerals
  • 18 amino acids with total content of 11 g per 100 g of dried fruit, an exceptional amino acid concentration giving excellent protein value for a plant food

Goji's content of essential micronutrients is among the densest found in one plant food, as the few examples below illustrate (100 g dried fruit)

  • potassium, 1,132 mg, 24% of the Recommended Dietary Allowance (excellent)
  • iron, 9 mg (100% of the Dietary Reference Intake (DRI, US Institute of Medicine)
  • copper, 2 mg (100% DRI)
  • zinc, 2 mg (18% DRI, an excellent source)
  • riboflavin (vitamin B2), 1.3 mg (100% DRI)

 

Let's compare goji with the US Dietary Reference Intake (DRI)

and two berry superfoods -- a 3-berry faceoff !

 

Nutrients
DRI
Goji %DRI
Goji
Açaí
Blueberry
Protein
50
24
12
10
1
Fiber
30
33
10
25
2
Calcium
1000
11
112
286
6
Potassium
4700
24
1132
932
77
Vitamin C
80
91
73
trace
10
Vitamin B2
1.2
100
1.3
0.02
0.1
Vitamin B3
15
29
4.3
0.07
0.4

DRI is for one day's total food intake

Protein and fiber in grams per 100 g sample; Micronutrients in milligrams per 100 g sample

See References below for source information

Although other data could have been selected, these nutrient contents for goji are unusual for a single plant food, and show a trend consistent across nutrients:

Goji is a high-density and diverse source of nutrients -- almost a complete whole food!

 

Check out the complete nutrient description for goji on Wikipedia!

Other nutrient comparisons of açaí and goji --

two exotic superfruits! -- with blueberry

The Berry Doctor's Face-Off Between Açaí and Goji (click)

 

How Does Goji Achieve Such Nutrient Quality?

  • soils where it is grown in China are mineral-rich and fertile
  • optimal cultivation methods have been applied for more than 600 years
  • day-night temperature variation during the ripening season intensifies nutrient content (conjecture)
  • probably of greatest importance: its botanical derivation and genetics are from high-nutrient plant foods in the family Solanaceae

Dispelling Myths

On the internet and in promotional literature for some manufacturers of goji products, you'll see

> "goji contains 500 times the vitamin C of an orange!" Truth: it contains about the same amount of vitamin C per gram as a raw navel orange, yet is certainly a high-content source of vitamin C

> "goji has twice as much beta-carotene as a carrot!" Truth: goji has about half the amount of beta-carotene per gram as a carrot; this is still high content for a plant food and is unusual for a berry to have this level

> "goji polysaccharides are master control molecules, working in the body by serving as directors and carriers of instructions that cells use to communicate with each other"! Truth: was this author dreaming?

Polysaccharides have never been shown to have such a function in living cells (they are passive molecules serving as dietary fiber and prebiotics for intestinal bacteria); certainly, goji polysaccharideas have not been shown to have such functions after being consumed in juice or whole berries as food entering the human digestive tract.

Polysaccharides are valuable mainly for the byproducts they yield when fermented. Here are some industrial applications (click).

 

Other references describing nutrient density:

 

12. Does goji have pigmentation (color) giving it a rich complement of antioxidant phytochemicals?

Courtesy of Timpanogos Nursery

Can you see the resemblance with tomato, its cousin?

Simple answer: Yes! Goji has excellent content of both antioxidant pigment classes, i.e., water-soluble phenolics and fat-soluble carotenoids, unusual among plant foods.

This combination of pigments provides goji with one of the highest measured ORAC values.

Review reports from the Berry Doctor's Journal

 

13.  What expert scientific studies have been conducted on goji nutrients and published in world literature?

Is there a scientific basis to believe goji could benefit human health?

Facts

  • over 100 studies have been published on goji but none has specifically validated a food value for humans unique to goji (in other words, as with all nutritious plants, we eat them because they provide a good source of nutrients and are enjoyable to eat!)
  • goji contains an exceptional content of interesting phytochemicals that scientists are just beginning to understand for their potential health and anti-disease effects
  • none of these studies has developed sufficiently toward human clinical trials
  • conclusion: goji is an exceptionally enriched whole food high in nutrient value... but this is all we can say about its importance in a human diet

 

Next Topics on Goji

  • Myths, fraud and government surveillance in goji marketing
  • Goji health claims?
  • What to expect for goji products in the future

 

References

  • Goji data from Gross PM, Zhang X, Zhang R, Wolfberry: Nature’s Bounty of Nutrition and Health, Booksurge Publishing (Amazon.com), 2006.

 

Archives (click!)

 

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Dr. Paul
The Berry Doctor