December 2009 Issue

Evidence on 2009’s ‘Super’ Supplements
By Jasmin Ilkay, MPH, RD
Today’s Dietitian
Vol. 11 No. 12 P. 16

Walking through the supplement section of a health food store, shoppers may think they can find a cure for just about anything that ails them. With hundreds of choices before them, they may feel overwhelmed trying to decide which supplements work and which are simply a new craze.

Dietitians are often the first to field questions concerning the efficacy and safety of dietary supplements, and therefore need to keep current with the evidence. This article provides background information on a variety of popular and emerging supplements currently on the market. Some have been around for years, while others are new and awaiting further research.

Kudzu and Metabolic Syndrome
Kudzu is generally regarded as a fast-growing vine and botanical nuisance. However, according to a recent report of a preclinical rodent study published in the Journal of Agricultural and Food Chemistry, it may curb symptoms of metabolic syndrome, which is defined by three or more of the following medical conditions: high blood pressure, high insulin levels, excess fat around the waist, and high cholesterol. Human clinical trials are required to confirm these finds.

Researchers studied the effects of kudzu root extract in female rats with high blood pressure that were prone to strokes and showed symptoms of metabolic syndrome.1 The rats were divided into two groups. One group received a standard diet, while the other group received additional supplementation with kudzu root extract for two months.

At the study’s conclusion, rats in the kudzu group gained less weight and had significantly lower blood pressure, blood sugar levels, and total cholesterol than the control group.1 The researchers concluded that a dietary supplement of kudzu may decrease the risk of stroke and cardiovascular disease in at-risk individuals.

Based on this rodent study, scientists find kudzu’s potential as a treatment for metabolic syndrome promising. However, kudzu should not be recommended for people with metabolic syndrome until it has undergone human trials to prove safety and effectiveness.

I3C for Cancer Prevention and Treatment
Indole-3-carbinol (I3C) is a phytochemical found in cruciferous vegetables such as broccoli, kale, and cauliflower. Research has indicated that it may decrease cancer risk and slow cancer growth. To date, it has shown promise in preventing or slowing breast, colon, prostate, and cervical cancers.

I3C works by stimulating cytochrome P450 detoxification enzymes in the gut and liver.2 Other studies have further demonstrated that I3C can cause cell cycle arrest and apoptosis.3 These findings have motivated scientists to investigate I3C’s potential as a cancer treatment.

A majority of I3C research has focused on the phytochemical’s ability to reduce estrogen-related cancer risk through altering estrogen metabolism.2 For example, I3C has shown some effectiveness in decreasing lesions associated with cervical intraepithelial neoplasia (CIN), a premalignant lesion associated with the development of cervical cancer.

In a double-blind study, researchers randomly assigned 27 women with CIN to receive a placebo or 200 or 400 mg of oral I3C daily for 12 weeks. None of the subjects in the placebo group showed regression of their premalignant lesions. However, 50% of those receiving 200 mg/day of I3C and 44.4% of those receiving 400 mg/day of I3C demonstrated complete regression of the lesions at 12 weeks. The important findings of this study suggest that even short-term supplementation with I3C may have the potential to prevent cervical cancer.1

Another small study found that women taking 400 mg of I3C for three months had a significant change in urinary 2-OH-estrone:estriol:estrogen ratio toward increased 2-OH.2

A daily dose of 200 to 400 mg of I3C, which is available in tablet form, has been used in estrogen-related cancer research. Up to 800 mg/day has been used in phase 1 chemoprevention studies.2 According to the Linus Pauling Institute, these doses are well above usual dietary levels, which range from 20 to 120 mg daily.

Some research has indicated that I3C has tumor-promoting capabilities. Individuals who choose to take I3C should do so only under the supervision of a qualified physician. For the general population, daily consumption of cruciferous vegetables is safe and recommended.

Fewer Migraines With Feverfew
For thousands of years, Tanacetum parthenium, or feverfew, has been believed to possess medicinal properties. The word feverfew is derived from the Latin word febrifugia, which translates as “fever reducer.” In addition to treating fevers, feverfew has been used to treat allergies, labor difficulties, menstrual irregularities, infertility, and migraines. Of the claims listed, feverfew’s ability to manage migraine headaches has shown promise, according to research.

The exact cause of migraines is unknown; however, they are associated with blood vessel constriction. While there is no cure for migraine headaches, there are medications available to prevent them or manage pain. Some individuals have success handling their migraines with medication, while others choose to identify and avoid triggers related to their onset (eg, stress, alcohol, certain foods, lack of sleep).

According to the University of Maryland Medical Center, feverfew’s migraine-relieving activity is believed to be due to parthenolide, an active compound that helps relieve smooth muscle spasms, thus preventing blood vessel constriction in the brain.

A double-blind, randomized, placebo-controlled trial investigated the efficacy of feverfew in migraine prophylaxis in three phases. In the first phase, subjects were given 100 mg of feverfew daily for 60 days. The second phase gave a placebo to one half of the subjects, while the remainder continued to receive feverfew for 30 more days. Finally, in the third phase, the subjects switched groups and continued for another 30 days. In 57 subjects, feverfew use led to a significant reduction in pain intensity compared with the placebo; this trend was reversed after the switch of the placebo.2 The study indicated that after placebo treatment, feverfew did indeed improve migraine prophylaxis.2

The clinical trials have not reported any serious side effects with short- or long-term use.2 However, feverfew has been shown to decrease the effectiveness of cytochrome P450 substrates. Patients taking these substrates who want to take feverfew should do so under the advice of a qualified physician. Withdrawal symptoms, such as headaches, anxiety, and insomnia, may also occur with sudden feverfew cessation.

Açaí or Maqui?
The Brazilian açaí berry has been one of the top-selling antioxidants for the past couple of years. Açaí is touted as a “super” antioxidant supplement that slows aging, aids in weight loss, decreases cholesterol, and increases energy.

In 2008, the first human research study published in the Journal of Agricultural and Food Chemistry proved that antioxidants from açaí pulp and juice are absorbed in the human body. Another study conducted at the University of Florida showed that açaí berries triggered a self-destruct response in up to 86% of leukemia cells tested.

Açaí’s successful debut has since encouraged the introduction of several other antioxidant-rich exotic fruits. Maqui is an example of a newly introduced supplement that comes from a “super” berry grown in the Patagonia region. Maqui supplement makers claim that it’s the next “miracle” for weight loss and that it has more antioxidants than açaí. Maqui berry products are also reported to have anti-inflammatory, antimicrobial, and pain-relieving properties.

Both of these super berries have strong antioxidant properties; however, neither has been extensively researched for effectiveness in aiding weight loss, increasing energy levels, or treating any other specific conditions. Most of the guarantees promised by “super berry” supplement manufacturers appear to be more effective marketing claims than actual outcomes from taking the supplements.

In short, feverfew and I3C appear to be effective treatments for migraines and cancer, respectively. Scientists have yet to confirm whether kudzu can manage metabolic syndrome. Super berries such as açaí and maqui show promise in terms of their antioxidant levels but require further evaluation.

While this article touches on only a few dietary supplements and herbs, there are a variety of valid Web sites where professionals can learn about others:

• ConsumerLab:

• Medline Plus:

• National Institutes of Health Office of Dietary Supplements:

• Quackwatch:

• University of Maryland Medical Center:

— Jasmin Ilkay, MPH, RD, is a professor in the human nutrition and food science department at California State Polytechnic University in Pomona and a freelance writer specializing in dietary supplements, child and family nutrition, and eating disorders.

1. Natural Standard. Kudzu for metabolic syndrome. September 2009. Available at:

2. Sarubin Fragakis A, Thomson C. The Health Professional’s Guide to Popular Dietary Supplements, 3rd ed. American Dietetic Association; 2006.

3. Memorial Sloan-Kettering Cancer Center. Indole-3-carbinol. Last updated June 17, 2009. Available at: Accessed October 2009.