Juice Plus: A Critical Look
Stephen Barrett, M.D.
National Safety Associates (NSA) president Jay Martin likes to turn simple ideas into megamillion-dollar sales. An NSA brochure states by 1997, his company had generated over $3 billion in sales by "developing and introducing innovative new products that are on the leading edge of whole new industries": home fire detectors in the 1970s, water filters in the early 1980s, and air filters in the late 1980s. But its "biggest hit yet," is a line of "natural food-based products designed to help prevent disease."  Its flagship product —Juice Plus+®—was introduced in 1993 and reportedly hit $6 million per month by the end of its first year .
The Juice Plus+ recipe for success is very simple: Fruits and vegetables are good for us. Capture their goodness in convenient products. Add endorsements, testimonials, a pinch of fear, a scientific veneer, and several dollops of deception. And harness the power of multilevel marketing (MLM) to spread the word. All of these ingredients have been around for many years. But NSA has developed a winning mix.
It is well established that dietary strategies can help prevent certain cancers and reduce the risk of cardiovascular disease. Popularization of the diet-cancer link began during the early 1980s when the National Academy of Sciences (NAS) reported that people who eat lots of whole-grain cereals, fruits, and vegetables have a lower incidence of certain cancers . Since that time, research has shown that emphasizing these foods can also help prevent heart attacks and strokes. These ideas were quantified in the Food Guide Pyramid System (1992), which recommended 6-11 servings of grain products, 2-4 servings of fruit, and 3-5 servings of vegetables per day, depending on the individual's caloric level . Since it was not known which dietary factors, if any, might be helpful, the NAS report specified that supplementation with individual nutrients was not advisable. Within a few months after the report was issued, however, several products containing dehydrated vegetables and/or various nutrients were marketed as though the report had supported their use for cancer prevention. Government regulatory actions drove some of the early products from the marketplace, but new studies (particularly of antioxidants), new marketing techniques, and lax federal enforcement have enabled many more to take their place.
NSA would like you believe that everyone should take Juice Plus+. This article explains why I disagree.
The Power of MLM
MLM is a form of direct sales in which independent distributors can make money not only from their own sales but also from those of the people they recruit. Its roots date back to the 1930s when a California businessman began offering friends a commission for selling a food supplement to their friends. The operation evolved into Nutrilite Products in 1939 and began significant interstate distribution in 1945. In 1959, two highly successful distributors formed a new company that evolved into the multibillion-dollar, international conglomerate now called Amway. Shaklee Corporation, another MLM giant, was founded in 1956 by a retired chiropractor. Since that time, hundreds of other companies and millions of "independent distributors" have joined the fray.
Until the mid-1980s, claims made for health-related MLM products were conveyed mainly through direct personal contact in which the salesperson's personal success story (health or financial) played an important role. Since that time, however, many companies have added slick videotapes and audiotapes to spread their story, telephone conferences to train large groups of salespeople, a scientific advisory board to seem more authoritative, company-sponsored research to appear more authentic, and endorsements from prominent persons to lend prestige. Many companies use scare tactics and cite scientific research to suggest that their products will prevent disease. NSA does all of these things effectively.
Testimonials Are not Reliable Evidence
The "success" of network marketing lies in the enthusiasm of its participants. Most people who think something has helped their health enjoy sharing their success with their friends. Testimonial-givers are usually motivated by a sincere wish to help their fellow humans. Since people tend to believe what others tell them about personal experiences, testimonials can be powerful persuaders. An NSA distributor manual notes that "as people use the product, they begin to build their own Juice Plus+ story to share with others." Although NSA literature has stated, "We do not make any claims . . . involving the prevention, cure, mitigation of any disease," NSA distributors have circulated statements that Juice Plus+ products have relieved a wide variety of discomforts. In 1994, I even even acquired a 69-page booklet of endorsements and testimonials which stated:
These are some of the benefits found by people taking Juice Plus+. Some noticed these signs after a few days, others after weeks or months. These benefits may not apply to you, but you may want to look out for them: general sense of well-being; more alert; more energy; more regular; better digestion; better appetite; sleep better; need less sleep; wake up easier; wake up earlier, less urge to snack; less craving for sweets; crave fruit, vegetables & salad; weight loss; weight gain (if desired); loss of inches from waist & hips; better skin tone; nails grow stronger and faster; hair grows stronger and faster; look better; clearer eyes; easier to quit smoking; easier to start exercise program; handle stress more easily; better recovery after workout; able to work harder; higher athletic performance; faster recovery from injury; reduced allergies & sinusitis; reduced arthritis pain; fewer headaches; less pain; lower blood pressure; improved blood sugar .
Testimonials, of course, should not be regarded as valid evidence. Without well-designed tests, it is usually impossible to tell whether changes that take place after taking a product are the result of the product, a placebo effect, or other factors such the fact that symptoms often change with the passage of time. Nor is it possible to tell whether enthusiastic, financially motivated salespeople accurately report what they experience.
The unreliability of testimonials was dramatically illustrated by the case of former football star O.J. Simpson, who was charged with stabbing his wife and her friend Ronald Goldman. In March 1994, shortly before these murders took place, he was videotaped telling 4,000 distributors at a sales meeting that Juice Plus+ had cured his arthritis. Testimony in the murder case indicated that he was also taking sulfasalazine, a standard anti-inflammatory drug that could have relieved his symptoms . Subsequently, his defense attorneys presented medical testimony that Simpson was so crippled by arthritis that he could not have committed the murders .
What's in Juice Plus+?
NSA's Guide for New Distributors, a 94-page loose-leaf manual dated October 1997, stated that 17 foods were juiced to extract their nutritional essence and then reduced to powders using a proprietary process that avoids high temperatures. During the process, sugar, salt, and most of the calories and fiber are removed. "Orchard Blend" capsules are derived from acerola berries, apples, cranberries, oranges, papaya, peaches, and pineapple. "Garden Blend" capsules contain barley, beets, broccoli, cabbage, carrots, kale, oats, parsley, spinach, and tomato. Both products are also said to contain corresponding soluble and insoluble fibers, phytochemical "food actives," vitamins, minerals, and enzymes. Additional fiber and enzymes are added, and the products are encapsulated by a company called Natural Alternatives International (NAI) .
Neither the product labels nor the product literature I have seen indicate the quantities of these ingredients in Juice Plus+ capsules. The 1997 manual advised taking Orchard Blend and Garden Blend at separate times because "fruits are digested differently from vegetables and your system can handle them more efficiently if they're dealt with separately." However, Juice Plus+ "Better Bars" combined both concentrates with "real fruits, oats, bran, and a host of other natural ingredients." NSA has also marketed a meal-replacement drink, Juice Plus+® Lite, each serving of which provided 110 calories, 4 grams of dietary fiber, and significant amounts of 12 vitamins and a few minerals. The current (2006) products include a chewable pill for children, JP+ Gummies® (said to be a healthy alternative to candies), and Juice Plus Thins®, said to be a snack "specially designed and formulated to help curb your appetite." The Juice Plus+ Web site contains no data showing that taking the product helps curb appetite. In 2016, I noticed that ingredients for ten products marketed in Australia are specified in a database maintained by the Australian Register of Therapeutic Goods.
NSA stresses that government guidelines recommend eating 5-9 servings of fruits and vegetables per day. However, it fails to put this recommendation into proper perspective. The primary purpose is not to ensure adequate vitamin intake (which is achieved with fewer servings) but to (a) get adequate fiber intake and (b) create a dietary mix that is low to moderate in fat. Juice Plus+ provides the nutrients in fruits and vegetables, but includes far more beta-carotene than most experts would recommend. In addition, it lacks the fiber and people who think it substitutes for fruits and vegetables might wind up with a higher dietary fat content.
In 2005, the National Advertising Division of the Council of Better Business Bureaus advised NSA to modify certain advertising claims to avoid the implication that Juice Plus+ Gummies® are an alternative for or are nutritionally comparable to fruits and vegetables .
In 2007, the Complaints Resolution Panel for the Therapeutic Goods Administration Advertising Code Council ruled that statements on NSA's Juice Plus website were in breach of Australia's Therapeutic Goods Advertising Code. According to the panel, the "clear message" in the ads was that Juice Plus tablets/capsules are "equivalent to fruits and vegetables" and that "consuming Juice Plus tablets would help Australians to consume the 'recommended 5-7 servings' of fruits and vegetables." The council ordered NSA to withdraw any representations that the products "are equivalent to fruits and vegetables or that their consumption can aid in meeting dietary recommendations relating to fruits and vegetables." 
Pages 41 and 42 of the 1997 manual suggested that each food source offered a special health benefit. Apples, for example, were said to "contain boron a trace mineral that affects the electrical activity of the brain, increasing mental alertness." Oranges are said to "contain every class of cancer inhibitor known." Acerola cherries were "a source of vitamin C, known to relieve symptoms of osteoarthritis." Carrots were said to lower cholesterol, parsley to be "good for the heart and immune system," kale to be a "powerful cancer fighter," and cabbage was "thought to block breast cancer." Even if these claims were true, there is no reason to conclude that taking Juice Plus+ capsules could provide the same benefit.
Page 43 stated, "The food enzymes in Juice Plus will facilitate digestion of your food, making it more usable to your body. This also conserves the body's own enzyme supply to do other important things like fighting off disease." This statement is false because: (a) most people have enough enzymes in their intestinal tract to digest their food; (b) most of the enzymes in food are destroyed during digestion; and (c) the body's production of metabolic enzymes does not depend upon the amounts of enzymes in the digestive tract.
Such enzymatic nonsense reflects the ideas of Humbart "Smokey" Santillo, author of Food Enzymes: The Missing Link to Radiant Health , to whom NSA attributes the Juice Plus+ concept. Santillo's credentials include a bachelor of science degree from Edinboro State Teacher's College; a doctor of naturopathy degree from a nonaccredited correspondence school (the Anglo-American Institute of Drugless Therapy), an iridology "certificate of merit," a master herbalist certificate from the herbalist John Christopher's School of Natural Healing, and eight years of study at the Concept Therapy Institute (which teaches a biotheistic chiropractic technique). One of NSA's audiotapes featured Santillo claiming that whole fruits and vegetables should not be eaten closely together as foods but are safely combined but in Juice Plus+. He also claimed that Juice Plus+ Lite helped people manage their weight because. "It has so much food value and is so easy to digest. Once they start absorbing all that food, they just don't have the same hunger . . . and lose weight automatically." 
Santillo's basic concepts of health, disease, and treatment include a hodgepodge of naturopathy and traditional Chinese medicine. His book Natural Healing with Herbs, spouts the naturopathic dogma that most diseases are "really the result of an overtaxed eliminative system" and that "by using a cleansing diet and short fasts, cleaning the colon by using enemas, aiding eliminative processes and purifying the blood through the proper choice of herbs, and by other methods," disease can be quickly cleared up by "clearing the underlying toxic state." [13:3] But he also states that "diseases can be classified as either hot or cold, yin or yang, excess or deficient, internal or external." [13:5]. Varro E. Tyler, Ph.D., a world-renowned herbal authority who was professor of pharmacognosy at Purdue University, concluded that the book was riddled with errors and was a "nearly perfect example" of irrational advice about herbs .
The Aetna U.S. Health Care "Endorsement"
In 1998, Aetna U.S. Health Care (the largest HMO) began offering a "Natural Alternatives Program," under which subscribers could obtain discounts of 20% or more for various products and services . Several Juice Plus+ distributors notified me that Aetna U.S. Health Care was "recommending" Juice Plus+ under this program. However, the site describing the program stated otherwise:
Natural Alternatives is a discount pass-through program. . . . Participating Natural Alternatives providers and vendors are solely responsible for the products and services they provide. Providers or vendors offering discounts under Natural Alternatives may not have been credentialed or reviewed by Aetna U.S. Healthcare. By making these discounts available, Aetna U.S. Healthcare does NOT endorse these providers or vendors or their services or make any guarantee as to availability or quality of providers or discounts under this program. Aetna U.S. Healthcare gives no warranty, expressed or implied, as to description, quality, merchantability, fitness for any particular purpose, or any other matter for any product or service purchased by you using a Natural Alternatives discount .
The Scientific Veneer
Juice Plus+ promoters also claim there is scientific proof that Juice Plus+ is good for people's health. NSA's most powerful sales aids are tape-recordings by Richard DuBois, M.D., a board certified internist who is described as "one of the world's leading authorities on infectious disease." Citing scientific studies, DuBois correctly notes that:
- Considerable research shows that diets high in grains, fruits, and vegetables are associated with lower rates of certain cancers, cardiovascular disease, and several other types of degenerative disease
- Many Americans do not eat the recommended number of servings
- Epidemiologic studies have found that these diseases are associated with low blood levels of certain phytonutrients
- An NSA-sponsored study of 15 healthy individuals found that supplementation with Juice Plus+ for 28 days raised the blood levels of five phytonutrients: beta-carotene, alpha carotene, lutein/zeaxanthin, lycopene, and vitamin E. The study found, for example, that beta-carotene levels were five times as high and lycopene levels were 20 times as high .
To further support his argument, DuBois correctly describes how clinical trials have found that supplementation with individual nutrients sometimes does more harm than good. But he then asserts that the Juice Plus+ nutrients are safe and more effective, because the phytonutrient content of plants is "balanced." Based on all of the above assumptions, he concludes that everyone should take Juice Plus+.
The above reasoning is not valid. Nearly all of the evidence relating disease rates to dietary composition is epidemiologic. Epidemiologic studies do not prove cause and effect. And even if causal connections are established, they do not prove that dietary supplements will remedy a poor diet or that Juice Plus+ is an optimal supplement. (In fact, it is not likely to be optimal because it lacks vitamin B12 and most of the minerals included in full-spectrum multivitamin/multimineral pills.) Nor is there any logical reason to conclude that Juice Plus is "balanced" simply because its ingredients were extracted from foods. Only well-designed, long-term clinical trials can determine whether taking Juice Plus+ or any other pill or potion can actually prevent disease.
But that's not all. Much of the protective effect of fruits and vegetables is due to their fiber content. Juice Plus+ pills have nearly all the fiber removed. Moreover, eating the recommended portions of grains, fruits, and vegetables does not merely provide high levels of phytochemicals. It usually means that the overall diet is low or moderate in fat. Nobody knows whether adding a product like Juice Plus+ to a high-fat or low-fiber diet would provide much benefit. The bottom line is that if someone's diet is low in fruits, vegetables, or grains, the most prudent action is fix the diet.
Curiously, in 1986, two authors of NSA's phytonutrient study were associated with United Sciences of America (USA), a multilevel company that sold supplements with illegal claims that they could prevent many diseases. Lead author John A. Wise, Ph.D., was USA's vice president of science and data information; and second author Robert J. Morin, M.D., was a scientific advisor who helped design the products. State and federal enforcement actions drove the company out of business in 1987 . USA's main product was its Master Formula, which included large amounts of beta-carotene and vitamin E . Today, Wise subsequently became president, science and technology and is a stockholder of Natural Alternatives International (NAI), of San Marcos, California, which manufacturers the Juice Plus+ products. NSA was responsible for at least 16% of NAI's sales during the year ending June 30, 1999 .
Even more curiously, DuBois himself has cast doubt on his claim that Juice Plus+ provides "balanced nutrition." In the 1998 NSA videotape, "Homocysteine, Oxidative Stress, Pathogenesis and Prevention of Disease," he states extra carotenoids are stored in the skin and that his own skin has turned orange from the pills. Beta-carotene supplements have been associated with increased cancer rates in two large clinical studies [21,22] and have been found to increase precancerous changes in ferrets exposed to cigarette smoke . The highly respected Medical Letter on Drugs and Therapeutics—a peer-reviewed newsletter for physicians—has concluded that "no one should take beta-carotene supplements."  But rather than noting the risk, DuBois claims that "When you turn orange, you have neutralized your oxidative stress" (a purported measure of harmful free-radical activity) and therefore reduced your odds of getting certain diseases. He even describes how his patients say, "I want to look like you. I want that carotenoid gloss."  How could he possibly know that years of living with orange skin will do more good than harm?
NSA has also used testimonials from pediatrician William Sears, M.D, and others to promote Juice Plus+ Gummies as low in sugar and a nutritional alternative to fruits and vegetables. In 2005, after the Better Business Bureau's National Advertising Division concluded that the ads were misleading, the company promised to stop saying that Gummies contain "less sugar" than a can of soda and are “the next best thing to fruits and vegetables.” 
The Research Veneer
Many studies sponsored by Juice Plus+ have been completed and many more are underway. The vast majority were funded and/or authored by NSA or NAI. Here are some examples plus my comments.
- One study showed that taking Juice Plus+ increased a few markers of immune activity. Another study concluded that giving Juice Plus+ to healthy men and women helped protect DNA from oxidative as measured in the the nuclei of white blood cells. However, neither of these studies involved measurement of health outcome.
- Two studies have found that taking Juice Plus+ decreased the blood level of homocysteine, a substance thought to contribute to coronary artery disease. The results of these studies were predictable because Juice Plus+ contains folic acid, which is known to reduce homocysteine levels. However, extensive clinical trials have found that lowering homocysteine has not been proven beneficial so that homocysteine-lowering is no longer considered as part of standard cardiac care . Even if lowering homocysteine level were useful, using Juice Plus+ for this purpose would be silly because the standard regimen would cost less than $2 per month and would be more effective for people who need B12 to achieve the desired levels.
- Another study found that Juice Plus+ reduced the adverse effect of a high-fat meal on the functioning of a wrist artery. Many studies have shown similar effects with supplementation with antioxidant supplements, but whether this has practical value is not known and the effect can be achieved with very inexpensive products.
- One study found that taking Juice Plus+ provides a benefit in patients with gum disease. The study was preliminary and did not include an assessment of the patient's nutrient blood levels to see whether the benefits were related to taking the products. But even if these findings hold up to further scrutiny, I believe that any such benefit will be equally achievable with inexpensive vitamin supplements.
A Wikipedia report has examined whether the research findings support claims that Juice Plus+ (a) reduces oxidative stress, (b) promotes cardiovascular wellness, (c) supports a healthy immune system, and (d) helps protect DNA. In January 2008, the report concluded that "multiple studies of varying standards have produced conflicting results as to the truth of these claims." 
Many Juice Plus+ distributors believe that these studies "prove" that taking Juice Plus+ makes people healthier. Real proof, however, would require that people taking the product have a better specific health outcome (fewer colds, for example) than comparable people who don't take the product. Even if a study found a better health outcome, it would not make sense to use Juice Plus+ if dietary modification or a less expensive supplement could do the same thing. This point is illustrated by an 8-month study in which nurses received either Juice Plus+ or a placebo. Both groups had the same number of sick days, but the Juice Plus+ group reported 20% reduction in days in which they had moderate to severe cold symptoms . These findings are neither new nor significant. It is well established that vitamin C supplementation does not prevent colds but, when taken at the onset of a cold, may provide a modest reduction in symptom severity . Taking a daily 250 mg vitamin C pill for 7-10 days when a cold strikes would cost about 24 cents per episode. Taking Juice Plus for six months would cost about $240—about 1,000 times as much!.
Over the years, experts at Memorial Sloan-Kettering Cancer Center have looked closely at the Juice Plus+'s research output . Their most recent summary states:
- Studies on bioavailability suggest that consumption of JP can increase serum levels of alpha-carotene, vitamin C, and folate, but studies with other markers, such as lutein, alpha-tocopherol yielded mixed results.
- JP was shown comparable to standard vitamin C and E supplements but it remains unclear if this product is nutritionally superior to fresh produce.
- Studies on cardiovascular effects, such as changes in blood pressure and cholesterol levels are inconclusive.
- While there is ongoing research using Juice Plus+ in cancer patients, it has not been proven to prevent or treat cancers
- Gastrointestinal distress and hive-like rash have been associated with intake of JP in clinical trials. .
- Due to its antioxidant effects, JP may interfere with the actions of some chemotherapy drugs.
- Juice Plus+ is not a substitute for fresh fruits and vegetables.
In April 2016, the Juice Plus+ Web site listed 27 research studies with links to their abstracts or full reports. As previously noted, most merely reported changes in blood levels of various substances and/or other laboratory findings that are associated with improved body functions. In addition, many of the studies involved small numbers of participants and/or didn't last very long. However, to be clinically significant, a study would have to demonstrate an improved health outcome. The only studies I found that might fit this description were the one about cold symptoms (described above) and another that reported a short-term improvement in skin thickness and texture that the authors said might have some relevance to skin aging .
In 1999, NSA launched the Juice Plus+® Children's Health Study, which it described as a large, multi-year health survey that would help determine whether adding Juice Plus+® fruit and vegetable supplements to the family diet can affect the health and well-being of children ages 6 to 15. In the study, each child participant is paired with an adult participant, usually a parent. The children under 12 are given products free or charge, but payment is required for the other participants. Completed questionnaires were tabulated by the Juice Plus Children's Research Foundation, which was set up to support programs that "advance the principle that improved nutrition leads to healthier lifestyle and overall better health in children." . The "preliminary report"—said to have been based on the first 25,000 responses—contained many claims that the regimen led to improvements in the child's health status and interest in health promotion. However, the questionnaire is poorly designed, no control groups were used, and the resultant data are meaningless.
In 2010, the Foundation's Web reported results based on the responses or more than 150,000 families. The report includes eight bar graphs that compare things reported after 4-8 months, 1 year, and 3 years: (1) eating more fruits and vegetables, (2) consuming less fast food and soft drinks, (3) drinking more water, visiting the doctor less, (4) missing fewer days of school or work, (6) taking fewer medications, (7) more aware of their health and wellness, and (8) reaping a health benefit of some kind. In each case, the numbers allege a benefit that rises with time. Nothing in this report indicates that the study's design had improved. Thus, as far as I can tell, the study is just a gimmick to promote sales .
Libel ActivitiesIn an attempt to counter my criticisms, some Juice Plus+ distributors have circulated false statements suggesting that my medical license was revoked. I retired from psychiatry in 1993 with my license in good standing and have never been subjected to any regulatory activity. The false claims about my license are part of a vicious libel campaign by people whose activities I have criticized .
The Bottom Line
NSA sales aids acknowledge that taking Juice Plus+ is not as good as eating the recommended amounts of grains, fruits, and vegetables. But they also state that everyone should take Juice Plus+, including people whose diets contain adequate amounts of the nutrients in Juice Plus+. NSA's "Preferred Customers" who buy a four-month supply of Juice Plus+ capsules at a time, pay about $480 per year. If every American did this, the total annual cost would exceed $100 billion. Do you think this would be a wise allocation of our national resources?
- NSA profile. Brochure, March 1997.
- Company of the month: National Safety Associates, Inc. Money Makers Monthly, Aug 1994.
- NAS Committee on Diet, Nutrition, and Cancer. Diet, Nutrition, and Cancer. Washington, DC: National Academy Press, 1982.
- USDA Human Nutrition Service: The Food Guide Pyramid:. House and Garden Bulletin No. 252. Washington, D.C., 1992, US Departments of Agriculture and Health and Human Services.
- Juice Plus+: Letters, Testimonials and Articles. Undated booklet, distributed in 1994.
- Transcript, cross-examination of Dr. Robert Huizenga, July 18, 1995.
- Switzer J. Unofficial summary of the Russ Limbaugh Show for Wednesday July 19, 1995.
- NSA's Guide for New Distributors. Memphis, TN: National Safety Associates, Oct 1997.
- NSA, Inc. participates in NAD self-regulatory forum. NAD News, April 25, 2005.
- Complaint 19-0607 Juice Plus. Complaints Resolution Panel; Therapeutic Goods Advertising Code Council, Oct 4, 2007.
- Santillo H. The Missing Link to Radiant Health. AZ: Holm Press, 1987.
- Santillo H. NSA Audiotape.
- Santillo H. Natural Healing with Herbs. Prescott, AZ: Holm Press, 1990.
- Tyler VE. Book review: Natural Healing with Herbs. Nutrition Forum 8(4):32, 1991.
- Aetna U.S. Healthcare announces Natural Alternatives Program. Press release, Dec 31, 1998.
- Natural Alternatives Provider Listing, Accessed April 21, 2000. The wording in 2006 was slightly different.
- Wise JA, Morin RJ and others. Changes in plasma carotenoid, alpha-tocopherol, and lipid peroxide levels in response to supplementation with concentrated fruit and vegetable extracts: A pilot study. Current Therapeutic Research 57:445-461, 1996.
- Barrett S. The Rise and Fall of United Sciences of America. Quackwatch, Sept 19, 1999.
- Barrett S. Health or Hype? A Report on United Sciences of America. New York: American Council on Science and Health, 1987.
- Natural Alternatives International. Annual 10-K report to the Securities and Exchange Commission. Filed Sept 28, 1999. Page 41 of the report indicated that three companies (NSA, NuSkin International, and Pharmavite were responsible for 16%, 23%, and 32% of NAI's sales during the reporting period. However, the report did not indicate which company was responsible for which number.
- Why megadoses of beta carotene may promote lung cancer. USDA Agricultural Research Service Food & Nutrition Research Briefs, Jan 1999, p. 1.
- Vitamin supplements. The Medical Letter on Drugs and Therapeutics 40:75-77, 1999,
- DuBois R. Homocysteine, Oxidative Stress, Pathogenesis and Prevention of Disease. NSA Videotape, 1998.
- NSA, Inc participates in NAD self-regulatory forum. NAD press release, April 25, 2005.
- Barrett S. Does lowering homocysteine prevent cardiovascular disease? Quackwatch, June 26, 2010.
- Juice Plus. Wikipedia Web site, accessed Jan 27, 2008.
- Roll S. and others. Reduction of common cold symptoms by encapsulated juice powder concentrate of fruits and vegetables: a randomised, double-blind, placebo-controlled trial. British Journal of Nursing 105:18-22, 2012.
- Marshall CW. Does vitamin C prevent colds? Quackwatch, May 18, 2002.
- Juice Plus. About Herbs database, Memorial Sloan-Kettering Cancer Center Web site, Nov 27, 2012.
- De Spirt S and others. An encapsulated fruit and vegetable juice concentrate increases skin microcirculation in healthy women. Skin Pharmacology and Physiology 25:2-8, 2012.
- Juice Plus Children's Research Foundation. IRS Form 990 (Return of organization exempt from income tax), 1999.
- Barrett S. Questionable research by the Juice Plus Children's Research Foundation. MLM Watch Web site, Feb 12, 2013.
- Barrett S. A response to Tim Bolen. Quackwatch, updated July 2, 2010.
This article was revised on April 24, 2016.