Nutrition Q&A with Dan Lukaczer
Q: I heard that garlic doesn't work to lower cholesterol. Is that true?
A: Probably. The latest research in a line of studies concluded that various forms of garlic did not significantly lower cholesterol levels. This most recent study suggested that raw garlic, powdered garlic and aged garlic extract were no better than placebo for lowering low-density lipoprotein (the "bad cholesterol") over six months in a group of patients with moderately elevated LDL. Nor were there any statistically significant effects on high-density lipoprotein (the "good cholesterol"), cholesterol/HDL ratios or triglyceride levels.1
In general, trials evaluating garlic as a cholesterol-lowering agent in humans have been inconsistent and unimpressive. Most of the literature suggests that garlic's effects on cholesterol are modest at best.2
However, one shouldn't throw the clove out with the cooking water. Garlic does have cardiovascular benefits—just not likely by lowering cholesterol. It may act by scavenging oxidants or inhibiting lipid peroxidation, decreasing low-level inflammation or decreasing platelet aggregation.3 In fact, a recent study showed that crushing fresh garlic may increase the health benefits of the herb by preserving its healthy compounds during cooking. Crushing garlic may release certain agents in the clove that increase the antiplatelet activity, which helps decrease the risk of certain types of strokes.4 It's likely garlic also has a positive impact in the prevention of certain kinds of cancer.5 So keep garlic on your shelves.
Q: Can worms treat inflammatory bowel disease?
A: This is a case that's strange but likely true. Inflammatory bowel disease probably results from the failure to keep a chronic inflammatory intestinal process in check. It has been shown that certain intestinal worms may actually have a beneficial effect on the immune system and help regulate this inflammation. Animal tests have shown that helminths (worms) seem to prevent or improve colitis. There are also a few completed human studies using a worm called Trichuris suis, which is thought to be nonpathogenic in people.
In one preliminary, open-label study, T. suis eggs were given to patients with Crohn's disease. All patients ingested 2,500 live ova every three weeks for 24 weeks. Positive improvements occurred in 23 of 29 patients. There were no adverse events.6 In a follow-up, randomized, double-blind, placebo-controlled trial, patients with ulcerative colitis were randomly assigned to receive placebo or T. suis ova treatment for 12 weeks. Compared with 13 of 30 patients with ova treatment who improved, only four of 24 patients given placebo had improvements.7 Worms in the gut may explain, in part, why IBD is prevalent in highly industrialized Western countries, where helminths are rare and uncommon, compared to less-developed areas of the world where most people carry worms.8 However, a word of caution: While these are encouraging results, it seems long-term trials are needed because we are not sure of the potentially harmful effects of helminths on immunity.
Q: Can SAMe help with fibromyalgia?
A: Maybe. Fibromyalgia likely has a number of different causes. SAMe (S-Adenosyl-L-methionine) is a naturally occurring molecule distributed throughout almost all body tissues, and it plays an essential role in a variety of enzymatic reactions—particularly by affecting neurotransmitters involved in brain function.
SAMe is produced in the body from the metabolism of dietary protein, but deficiencies of vitamin B12 and folic acid can result in decreased SAMe concentrations. Two older trials using SAMe in fibromyalgia showed positive results.9,10 It also appears that SAMe has effects on pain and depression,11,12 and this may be how it works with fibromyalgia patients, who generally have both.
1. Gardner CD, et al. Effect of raw garlic vs. commercial garlic supplements on plasma lipid concentrations in adults with moderate hypercholesterolemia: a randomized clinical trial. Arch Intern Med 2007;167(4):346-53.
2. Stevinson C, et al. Garlic for treating hypercholesterolemia. A meta-analysis of randomized clinical trials. Ann Intern Med 2000;133(6):420-9.
3. Borek C. Garlic reduces dementia and heart-disease risk. J Nutr 2006;136(3 Suppl):810S-812S.
4. Cavagnaro PF, et al. Effect of cooking on garlic (Allium sativum L.) antiplatelet activity and thiosulfinates content. J Agric Food Chem 2007;55(4):1280-8.
5. Fleischauer AT and Arab L. Garlic and cancer: a critical review of the epidemiologic literature. J Nutr 2001;131(3s):1032S-40S.
6. Summers RW, et al. Trichuris suis therapy in Crohn's disease. Gut 2005;54(1):87-90.
7. Summers RW, et al. Trichuris suis therapy for active ulcerative colitis: a randomized controlled trial. Gastroenterology 2005;128(4):825-32.
8. Fiasse R and Latinne D. Intestinal helminths: a clue explaining the low incidence of inflammatory bowel diseases in Subsaharan Africa? Potential benefits and hazards of helminth therapy. Acta Gastroenterol Belg 2006;69(4):418-22.
9. Jacobsen S, et al. Oral S-adenosylmethionine in primary fibromyalgia. Double-blind clinical evaluation. Scand J Rheumatol 1991;20(4):294-302.
10. Tavoni A, et al. Evaluation of S-adenosylmethionine in primary fibromyalgia. A double-blind crossover study. Am J Med 1987;83(5A):107-10.
11. Bottiglieri T. S-Adenosyl-L-methionine (SAMe): from the bench to the bedside--molecular basis of a pleiotrophic molecule. Am J Clin Nutr 2002;76(5):1151S-7S.
12. Mischoulon D and Fava M. Role of S-adenosyl-L-methionine in the treatment of depression: a review of the evidence. Am J Clin Nutr 2002;76(5):1158S-61S.
Natural Foods Merchandiser volume XXVIII/number 7/p.40