Product Rating Criteria
This chapter explains
the Health Support Profile, a set of mathematical models based on the 18 Health
Support criteria described below. The Health Support Profile provides an
overall ranking for each product included in this guide in accordance with the nutrient
intake recommendations as described in the Blended Standard. Together, the
Blended Standard and the 18 Health Support criteria form the basis of our
analysis. For a detailed explanation of the Blended Standard, please refer to
the previous chapter.
To evaluate a product,
its rating for each Health Support criterion is calculated mathematically. This
rating is determined by the nutrients and their potencies present in the
product in relation to the requirements for each criterion. Next, these 18 individual
ratings for each product are pooled to provide a raw product score for that
product. These scores, separated statistically into percentile ranks, represent
a product's rating relative to all products evaluated. Final product ratings
are displayed as star ratings, shown in half-star increments from zero to five
stars.
The five-star scale is,
at once, both visual and intuitive: a five-star rating represents a product of
the highest quality relative to all products evaluated in accordance with the
comprehensive NutriSearch Health Support Profile used in our analysis.
Conversely, a one-star rating or less represents products possessing few, if
any, of the characteristics for optimal nutrition as reflected in the Blended
Standard.
This Health Support
Profile is described in detail below. For a more detailed explanation of each
criterion and the science supporting its development, the reader is referred to
the NutriSearch Comparative Guide to Nutritional Supplements,™ 5th
(Professional) Edition. Our website also includes the complete description of
each criterion, along with the relevant scientific references. Please visit us
online at www.nutrisearch.ca.
The NutriSearch Health Support Profile
To receive a full point
for any single Health Support criterion, the product must meet or exceed the
benchmark established for that criterion. Each criterion uses a sliding scale,
from 0% to 100%, where partial points are awarded for the partial fulfillment
of the criterion. The last criterion, Potential Toxicities, penalizes the
product if the formulation exceeds defined limits of daily intake for those
nutrients (vitamin A and iron) that demonstrate potential cumulative
toxicities.
The following discussion
provides an overview of each criterion used in our Health Support Profile. For
each criterion, we address the fundamental question posed; in turn, each
question presents the logical argument that forms the basis of our mathematical
model for that criterion.
1. Completeness
The human body requires
several vitamins and vitamin-like substances, a diverse group of plant-based
antioxidants, numerous trace elements and minerals, and several essential fatty
acids. Many of these substances can only be obtained through the diet. In all,
47 essential nutrients and nutrient categories comprise our Blended
Standard—the definitive benchmark upon which our analysis is built. This
criterion assesses whether the product contains all of the Blended Standard
nutrients.
Does the product contain
the full spectrum of nutrients and nutrient categories listed in the Blended
Standard and considered essential for optimal health? To qualify, a nutrient or
nutrient category must be present at a dosage that is at least 20% of the value
in the Blended Standard.
2. Potency
The potencies for the 47
essential nutrients and nutrient categories used in our Blended Standard
reflect the need for supplementation with some nutrients at levels considerably
higher than their Dietary Reference Intakes (DRIs). This criterion assesses how
much of each nutrient the product contains compared to the Blended Standard.
For each nutrient in the
product, what is the level of potency relative to the potency for that nutrient
in the Blended Standard?
3. Mineral Forms
Minerals are essential
components of our cells and serve as cofactors in the thousands of
enzyme-controlled reactions that power the machinery of the cell. Throughout
the body, minerals also form critical structural components, regulate the
action of nerves and muscles, maintain the cell's osmotic (water) balance, and
modulate the pH (acidity) of the cell and extracellular fluids. While minerals
comprise only 4% to 5% of our total body weight, life would not be possible
without them. This criterion examines mineral forms (mineral salts, chelated
minerals, or organic-acid/mineral complexes), which affect the ability of the
minerals to be absorbed into the blood, making them available to our cells.
For those minerals
included in a formulation, how many are found in their most bioavailable forms
as amino-acid chelates or organic-acid complexes?
4. Vitamin E Forms
Vitamin E comes in many
different forms, each of which has important benefits in cellular function. In
its natural form, the most common type of vitamin E is d-alpha tocopherol;
synthetic vitamin E (commonly found in supplements as d/l-alpha tocopherol) is
only half as effective as the natural form. Another form of vitamin E, gamma
tocopherol, possesses distinctive chemical properties that differentiate it
from alpha tocopherol. Studies show that gamma tocopherol reduces chronic
inflammation and protects against cancers of the colon and prostate better than
its alpha analogue. This criterion assesses the product for the various forms
of vitamin E and their bioactivity.
Does the product contain
the natural (d) isomer of alpha tocopherol or does the product contain the less
useful synthetic (d/l) isomers of alpha tocopherol? Does the product contain
gamma tocopherol (or a mixture of gamma, beta, and delta tocopherols) at a
potency of up to one-half the potency of alpha tocopherol in the same product?
What is the potency of gamma tocopherol or mixed tocopherols in the product,
compared to the potency for gamma tocopherol in the Blended Standard?
5. Immune Support
An explosion of research
over the past decade has uncovered vitamin D as a vital component to our immune
systems. Working in conjunction with other micronutrients, vitamin D can help
protect us against many of the most common degenerative diseases, including
heart disease, stroke, cancer, multiple sclerosis, dementia, and many others.
Unfortunately, this new research coincides with a dramatic downturn in vitamin
D intake amongst North Americans. Many other nutrients, particularly other
vitamins, are also essential to a healthy immune system. This criterion assesses
the product for vitamin D levels and the presence of other nutrients that boost
immune response.
Another nutrient
recently discovered as vital to immune support is iodine. The high iodine
concentration of the thymus gland is prima facia evidence of the important role
played by iodine in the immune system—a role likely related to the element's
innate antioxidant powers.1-3
Many other nutrients,
including vitamin A, vitamin C, vitamin E, zinc, selenium, and the B-vitamins
B1, B2, B5 (pantothenic acid), B6, B12 and folic acid, are also essential to a
healthy immune system.4 This criterion assesses the product for vitamin D and
iodine levels and for the presence of these other nutrients that boost the
immune response.
Does the product contain
vitamin D and iodine at the potencies described in the Blended Standard? Does
the product also contain beta carotene and vitamin A, vitamin C, vitamin E,
zinc, selenium, and the B-vitamins B1, B2, B5 (pantothenic acid), B6, B12 and
folic acid at the potencies established in the Blended Standard?
6. Antioxidant Support
The weight of scientific
evidence supports supplementation with antioxidants in the prevention and
treatment of many of today's common ailments. As was anticipated decades ago by
leading researchers,5 high-dose supplementation with antioxidants has gained a
significant role in the prevention and treatment of many of today's common
ailments. However, antioxidants do not work in isolation. For this reason, it
is vital to supplement with a wide spectrum of antioxidants—an approach that is
reflective of what occurs in nature. This criterion examines the nutrients that
help to prevent or repair cellular damage caused by oxidation.
Does the product contain
vitamin C, vitamin E (including alpha-tocopherol and gamma-tocopherol, or mixed
tocopherols), vitamin A, beta-carotene, alpha-lipoic acid, lycopene, coenzyme
Q10, selenium and iodine at potencies up to 100% of the potencies for these
nutrients in the Blended Standard?
7. Bone Health
As living tissue,
healthy bones require at least 24 bone-building materials, including several
vitamins, minerals, trace elements, and protein. The most important minerals
are calcium, magnesium, phosphorus, and potassium; equally important is the
balance between these minerals. This criterion examines the nutrients in a
product that assist in bone remodeling, a process vital in warding off
osteoporosis and other diseases that weaken the skeletal framework.
Does the product contain
vitamin D, vitamin K, vitamin C, vitamin B6, vitamin B12, folic acid, boron,
calcium, magnesium, silicon, and zinc at potencies up to 100% of the potencies
for these nutrients in the Blended Standard?
8. Heart Health
Individuals with high
dietary intakes of antioxidant vitamins, certain minerals, and several
plant-based flavonoid compounds exhibit a lower-than-average risk of
cardiovascular disease. This criterion examines several nutrients, including
the recently discovered cardioprotective powerhouses—iodine and vitamin D—that
are known to benefit the heart and cardiovascular system by reducing oxidative
stress and suppressing inflammation.
Does the product contain
vitamin D, iodine, vitamin E (including alpha-tocopherol and gamma-tocopherol,
or mixed tocopherols), beta-carotene, coenzyme Q10, calcium, magnesium,
l-carnitine or acetyl-l-carnitine, procyanidolic oligomers (PCOs), phenolic
compounds, and lycopene at potencies up to 100% of the potencies for those
nutrients and nutrient categories in the Blended Standard?
9. Liver Health (detoxification)
Intracellular
glutathione status is a sensitive indicator of cellular health and of the
cell's ability to resist toxic challenges. An important water-phase
antioxidant, glutathione is one of three vital free radical scavenging
mechanisms in the cell. It is also the body's pre-eminent detoxicant in the
liver. While dietary glutathione is efficiently absorbed in the gut, the same
is not the case for nutritional supplementation.
Iodine is another
important nutrient for liver health and detoxification. Iodine's ability to
staunch the potential damage of hydrogen peroxide provides support for the work
of the glutathione peroxidase enzyme system in helping to remove these toxic
agents from the body. This criterion examines those nutrients that optimize
levels of glutathione and enhance liver function.
Does the product contain
iodine, vitamin C, n-acetyl-cysteine (including cysteine), selenium, vitamin
B2, and vitamin B3 (including niacin and niacinamide), at potencies up to 100%
of the potencies for these nutrients in the Blended Standard?
10. Metabolic Health (glucose control)
Diabetes is a chronic
disorder of carbohydrate, fat, and protein metabolism. The disease begins as a
constellation of metabolic changes associated with chronically high insulin
levels and elevated blood-sugar levels, a condition known as Insulin
Resistance. The development of insulin resistance is multi-factorial; however,
complications associated with this pre-diabetic disorder can be resolved
effectively through conscientious dietary and lifestyle changes, including
supplementation with several vitamins and minerals essential for metabolic
support and the close regulation of glucose metabolism. This criterion examines
those nutrients that help the body handle its daily sugar load, keeping systems
responsive to insulin and restoring lost insulin sensitivity.
Does the product contain
vitamin B3 (including niacin and niacinamide), vitamin B6, vitamin B12, vitamin
C, vitamin E (including alpha-tocopherol and gamma-tocopherol, or mixed
tocopherols), vitamin D, iodine, biotin, coenzyme Q10, chromium, magnesium,
manganese, and zinc at potencies up to 100% of the potencies for these
nutrients in the Blended Standard?
11. Ocular Health
Good eyesight and the
prevention of cataracts and macular degeneration require adequate levels of
several nutrients known to reduce the level of oxidative stress in the retina
and lens of the eye.
Does the product contain
the antioxidants, vitamin C, vitamin E (including alpha and gamma tocopherol,
or mixed tocopherols), vitamin A (including beta-carotene) and the carotenoids,
lutein and zeaxanthin, at potencies up to 100% of the potencies for these
nutrients in the Blended Standard?
12. Methylation Support
Over 40 major clinical
studies confirm that high homocysteine levels are a predictive marker for heart
disease, stroke, and peripheral artery disease. In fact, up to 40% of patients
with heart disease express elevated levels of homocysteine. Deficiencies in
certain B-complex vitamins are known to increase circulating levels of
homocysteine; conversely, supplementation with these nutrients can
significantly reduce circulating homocysteine by converting it to harmless
methionine and cysteine. This criterion looks at those nutrients required for
the body to reduce homocysteine levels in the blood
Does the product contain
vitamin B2, vitamin B6, vitamin B12, folic acid, and trimethylglycine at
potencies up to 100% of the potencies for these nutrients in the Blended
Standard?
13. Lipotropic Factors
The liver and the brain
are two primary targets for the accumulation of fat-soluble toxins, including
pesticides and heavy metals (such as lead). Within the liver, choline and
inositol assist with the elimination and removal of these noxious compounds
through their ability to mobilize fats and bile. Known as lipotropic
(fat-moving) factors, these agents have a long history of use within the
naturopathic community, helping to restore and enhance liver function and treat
a number of common liver ailments. This criterion examines those lipotropic
agents that help the liver mobilize fats stores and remove toxins.
Does the product contain
the important lipotropic factors, choline or lecithin (phosphatidylcholine),
and inositol at potencies up to 100% of the potencies for these nutrients in
the Blended Standard?
14. Inflammation Control
Chronic inflammation,
frequently induced by uncontrolled oxidative stress, is a principal mechanism
by which degenerative disease takes root. Changing the balance within the body
to favour the production of anti-inflammatory chemical messengers and lower the
levels of inflammation is therefore an important preventive measure. This
criterion examines the nutrients responsible for reducing inflammation at the
cellular level, such as the omega-3 oils—particularly those found in fish oil
(eicosapentaenoic and docosahexaenoic acids, or EPA and DHA) and
alpha-linolenic acid (flaxseed and other oils).
Recent evidence shows
that Vitamin D also expresses potent anti-inflammatory actions. The hormone
activates several genes controlling the manufacture of an
inflammation-suppressing chemical, Interleukin-10 (IL-10), produced in
specialized white blood cells. IL-10, in turn, dampens the body's over-response
that can often precipitate allergic reactions. As well, iodine—likely in its
molecular form—exhibits anti-inflammatory and anti-proliferative activities
that are important factors in determining cardiovascular health,6-9 and in
reducing the risk of inflammatory cancers of the breast, stomach, endometrium,
and ovaries.10; 11
Does the product contain
eicosapentaenoic and docosahexaenoic acids, linolenic acid, gamma-tocopherol,
alpha-lipoic acid, vitamin C, vitamin D, iodine, flavonoids, procyanidolic
oligomers, and the phenolic compounds from green tea, olive and turmeric
extracts, at potencies up to 100% of the potencies for these nutrients or
nutrient categories in the Blended Standard?
15. Glycation Control
Aging—the outcome of the
conflict between chemistry and biology in living systems—introduces chronic,
cumulative chemical modifications that compromise the structure and function of
important biomolecules within our cells. We now know that changes to these
molecular structures, driven by unrelenting oxidative stress, can render them
dysfunctional. Their accumulation, the detritus of an ongoing oxidative war
within the cell, is a hallmark of the aging process. This criterion examines
those nutrients that help slow the progress of glycation.
Does the product contain
l-carnosine, vitamin E (including alpha-tocopherol and gamma-tocopherol, or
mixed tocopherols), vitamin C, and alpha-lipoic acid at potencies up to 100% of
the potencies for those nutrients or nutrient categories listed in the Blended
Standard?
16. Bioflavonoid Profile
The flavonoids are known
as "nature's biological response modifiers" because of their ability
to alter the body's reactions to allergens, viruses and carcinogens, and to
protect cellular tissues against oxidative attack. Flavonoids, found in the
edible pulp of many fruits and vegetables, impart a bitter taste when isolated.
Citrus fruits, such as oranges, lemons, limes, grapefruit, and kiwi, are
particularly rich sources of flavonoids. This criterion examines the
bioflavonoid family of nutrients, which works throughout the body to attack
free radicals, suppress inflammation, and support a myriad of bodily functions.
Does the product contain
a mixture of bioflavonoids (including citrus and other flavonoids, billberry
flavones and related extracts, hesperidin, quercetin, quercitrin, rutin, soy
isoflavones, and silymarin and related milk thistle extracts) and PCOs
(including grape seed and grape seed extract, hawthorne berry and hawthorne
berry extract, pine bark and pine bark extract, pycnogenol and resveratrol) at
potencies up to 100% of the recommended potencies for mixed bioflavonoids and
PCOs in the Blended Standard?
17. Phenolic Compounds Profile
The weight of scientific
evidence supporting the health benefits of polyphenols is immense. They are
powerful free radical antagonists, recognized for their ability to reduce
cardiovascular disease and cancer, and they demonstrate potent anti-inflammatory,
anti-viral, anti-bacterial, anti-allergic, anti-hemorrhagic, and
immuno-enhancing properties. The most intensely studied of the phenolic
compounds include those isolated from: turmeric, a perennial herb of the ginger
family and a major ingredient in curry; green tea, a rich source of compounds
called catechins; and extracts from the fruit of the olive tree. This criterion
examines these specific phenolic compounds, all of them known to be
exceptionally potent free radical antagonists.
Does the product contain
phenolic compounds (polyphenolic acids and their derivatives, including
cinnamon bark and cinnamon bark extract, cranberry and cranberry extract,
curcumin, fenugreek, ginger and gingerols, green tea leaf and green tea
extracts, olive fruit and olive extracts, papaya, pomegranate fruit and
pomegranate extract, rosemary, and turmeric rhizome) at the potency for this
nutrient category established in the Blended Standard?
18. Potential Toxicities
In order to optimize its
preventive benefits, the strategy of nutritional supplementation is to
encourage long-term use. Consequently, there exists a potential risk for
consumers with regard to the cumulative toxicity of particular nutrients. Most
nutrients used in nutritional supplements have a high degree of safety;
however, some nutrients require a degree of prudence when it comes to long-term
use. Both iron and vitamin A (retinol) can become toxic when taken in high
doses over a long period. Accidental overdose of iron-containing supplements
is, in fact, a leading cause of fatal poisoning in children, and too much
vitamin A during pregnancy can cause birth defects. Vitamin A is available,
safely, as beta carotene, while adequate iron is easily obtained, for most
people, from a variety of foods. This criterion examines the levels of
pre-formed vitamin A (retinol) and iron in the product and penalizes the
product rating if it contains too much of either nutrient.
Does the nutritional
supplement contain vitamin A and iron (which is no longer included in the
Blended Standard)? Does the potency of vitamin A exceed 100% of the potency for
that nutrient in the Blended Standard? Does the potency of iron exceed 5
mg/day?
Summary
The 18 individual Health
Support ratings, as described above, are pooled for each product to provide a
raw product score. These scores are then separated statistically into a
percentile rank, which represents a product's rating relative to all products
evaluated. Final product ratings are displayed as star ratings, shown in
half-star increments from zero to five stars. The five-star scale is, at once,
both visual and intuitive: a five-star product represents a product of the
highest quality relative to all products evaluated in accordance with the
comprehensive NutriSearch Health Support Profile used in our analysis.
Conversely, a one-star rating or less represents products possessing few, if
any, of the characteristics for optimal nutrition as reflected in the Blended
Standard.
