Please note: This article has been updated with the release of the NutriSearch Comparative Guide to Nutritional Supplements™, 5th US Consumer edition. A similar criteria was used for the Australian and New Zealand Edition.
There are, in fact, two things, science and opinion; The former begets knowledge, the latter ignorance.
~ Hippocrates (460 BC – 377 BC)
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.
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.
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?
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.
- Kupper FC, Carpenter LJ, McFiggans GB et al. Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry. Proc Natl Acad Sci U S A 2008;105:6954-6958.
- Patrick L. Iodine: deficiency and therapeutic considerations. Altern Med Rev 2008;13:116-127.
- Venturi S, Venturi M. Iodine in evolution of salivary glands and in oral health. Nutr Health 2009;20:119-134.
- Murray MT and Pizzorno J. Immune Support. Encyclopedia of Natural Medicine. Prima Health, Rocklin CA; 1998;145-160.
- Crary EJ, McCarty MF. Potential clinical applications for high-dose nutritional antioxidants. Med Hypotheses 1984;13:77-98.
- Cacace MG, Landau EM, Ramsden JJ. The Hofmeister series: salt and solvent effects on interfacial phenomena. Q Rev Biophys 1997;30:241-277.
- Hatefi Y, Hanstein WG. Solubilization of particulate proteins and nonelectrolytes by chaotropic agents. Proc Natl Acad Sci U S A 1969;62:1129-1136.
- Hoption Cann SA, van Netten JP, van NC. Iodized salt and hypertension. Arch Intern Med 2002;162:104-105.
- Hoption Cann SA. Hypothesis: dietary iodine intake in the etiology of cardiovascular disease. J Am Coll Nutr 2006;25:1-11.
- Clur A. Di-iodothyronine as part of the oestradiol and catechol oestrogen receptor–the role of iodine, thyroid hormones and melatonin in the aetiology of breast cancer. Med Hypotheses 1988;27:303-311.
- Thomas BS, Bulbrook RD, Goodman MJ et al. Thyroid function and the incidence of breast cancer in Hawaiian, British and Japanese women. Int J Cancer 1986;38:325-329.