Will vitamin E help with blood-sugar control in diabetes?
It may, but there is not much human research in this area. One study suggests that high amounts of vitamin E, on the order of 900 mg per day, appeared to improve how the body manages glucose.1 It may benefit because of the way insulin handles glucose, or it may be because of vitamin E?s antioxidant qualities. As far as I know, there are no studies suggesting this amount is harmful.
Interestingly, it has been found that low blood levels of vitamin E are an independent risk factor for the development of diabetes. One study showed that the lowest levels of vitamin E were associated with a 3.9-fold increase in risk.2 Therefore, getting a reasonable amount of vitamin Eâsay 100 to 200 IU per dayâin a good multiple may be protective, particularly in someone with a strong family history or other risk factors. As a personal trial, large dosages of vitamin Eâup to the study?s 900 IU per dayâmight be tried for three to six months to assess if it?s helping blood-sugar control in a person with diabetes.
Which Indian spice may prevent Alzheimer?s disease?
You are probably referring to the research on the polyphenol curcumin, found in the rhizome turmeric (Curcuma longa). Turmeric is a spice that has been used for centuries in Indian cooking and Ayurvedic medicine. The herb contains many active compounds, and curcumin has been shown to have significant anti-inflammatory activity. Many holistic practitioners prescribe it for conditions such as rheumatoid arthritis and osteoarthritis.3
Now, new animal research suggests that its anti-inflammatory action may indeed be helpful in the prevention of Alzheimer?s disease. A recent study reported that in mice, curcumin is effective in inhibiting formation of the protein fragments associated with the development of AD.4 It appears the structure of curcumin allows it to penetrate the blood-brain barrier effectively and bind to beta-amyloid (which forms the disease-causing plaques) better then some anti-inflammatory drugs. (Beta-amyloid is formed when a particular brain protein, amyloid precursor protein, is broken down abnormally into shorter fragments. They stick together and form the plaques that are the hallmark of AD.)5 These animal studies have been so positive that UCLA?s Alzheimer?s Disease Research Center has begun recruiting for a trial to further evaluate its therapeutic effects in humans.
Given the apparent safety of this compound, one should continue to eat curry dishes with gusto. If you take curcumin regularly as a supplement, you should certainly continue to do so. However, while I don?t think it will hurt, it may be a little early to regularly supplement with curcumin in the prevention of Alzheimer?s.
Does the herb guggul have any side effects?
Anything can have side effects, and herbs are no exception. The resin of the Commiphora mukul (guggul) tree, termed gum guggul, has been used in Ayurvedic medicine for more than 2,000 years to treat a variety of ailments. Older studies of animals and humans have shown that guggul can decrease elevated cholesterol levels. Recently, however, a U.S. study cast some doubt as to its efficacy in that area. A double-blind, placebo-controlled trial showed no significant changes in levels of total cholesterol, high- and low-density lipoproteins, and triglycerides in response to treatment with guggulipid.6 Additionally, while generally well tolerated, six participants treated with guggulipid in this trial developed a hypersensitivity rash, compared with none in the placebo group.
Another recent report, this time an in vitro study, suggests guggulsterones (one of the active compounds found in guggul) affect a detoxification enzyme family called CYP3A. These enzymes are involved in metabolism and excretion of a variety of drugs, and guggul appears to increase the rate of detoxification. Therefore, drugs that go through CYP3A may be excreted more quickly and potentially lose some of their effectiveness. Lastly, guggulsterone stimulates cell receptors for the hormones estrogen and progesterone, having potential consequences for women, especially those on hormone replacement therapy.7
While guggul may be effective in some individuals with high cholesterol, it would not be the first herb I would turn to, given this recent research on its efficacy and potential side effects. I think we should be a bit cautious with this herb.
1. Paolisso G, et al. Pharmacologic doses of vitamin E improve insulin action in healthy subjects and noninsulin-dependent diabetic patients. Am J Clin Nutr 1993;57(5):650-6.
2. Salonen JT, et al. Increased risk of non-insulin dependent diabetes mellitus at low plasma vitamin E concentrations: a four-year follow up study in men. Brit Med J 1995;311(7013):1124-7.
3. Lodha R, Bagga A. Traditional Indian systems of medicine. Ann Acad Med Singapore 2000;29(1):37-41.
4. Yang F, et al. Curcumin inhibits formation of Abeta oligomers and fibrils and binds plaques and reduces amyloid in vivo. J Biol Chem. 2004; Dec 7. www.jbc.org/cgi/content/short/M404751200v1 [Epub ahead of print].
5. Frautschy SA, et al. Phenolic anti-inflammatory antioxidant reversal of Abeta-induced cognitive deficits and neuropathology. Neurobiol Aging 2001;22(6):993-1005.
6. Szapary PO, et al. Guggulipid for the treatment of hypercholesterolemia: a randomized controlled trial. J Amer Med Assn 2003;290(6):765-72.
7. Brobst DE, et al. Guggulsterone activates multiple nuclear receptors and induces CYP3A gene expression through the pregnane X receptor. J Pharmacol Exp Ther 2004;310(2):528-35.