Flaxseed Lowers Cholesterol in Postmenopausal Women
Postmenopausal women who consume ground whole flaxseed may reduce their total cholesterol and risk of heart disease, according to a new study in the Journal of Clinical Endocrinology and Metabolism.1 Elevated blood levels of total cholesterol and low-density lipoprotein (LDL) cholesterol (known as "bad" cholesterol) are known risk factors for heart disease, and can ultimately lead to blocked arteries, heart attack, or stroke.
Thirty-six postmenopausal women were randomly assigned to add 40 grams of either ground flaxseed or a wheat-based product to their regular diet every day for three months. Additionally, all the women received 1,000 mg of elemental calcium and 400 IU of vitamin D per day. Measurements of blood lipids and specific markers of bone turnover were taken initially and at the conclusion of the trial.
The women who consumed flaxseed had a significant decrease in total cholesterol (6%) at the end of the study. LDL cholesterol and triglycerides were also slightly reduced, but the result was not statistically significant, suggesting that the drop in these lipids may have occurred by chance. However, the women consuming the wheat-based product had no change in any lipid marker. None of the women in either group had significant changes in any marker for bone turnover, indicating that flaxseed has no effect on bone metabolism and will likely not protect against osteoporosis.
Other nutritional supplements in addition to flaxseed have been shown to lower cholesterol. Policosanol, a substance derived from sugar cane, has been shown in several controlled studies to lower total cholesterol by 21% and LDL cholesterol by 29%, while raising HDL cholesterol by 15%.2 3 4 Other trials have demonstrated that 10 to 20 mg of policosanol per day is as effective as conventional prescription medications,5 without significant side effects.
Taking large amounts of niacin (such as 3,000 mg or more per day) is a well-established treatment for high cholesterol. However, such large amounts, in addition to often producing an uncomfortable flushing sensation, can on rare occasions cause liver damage or peptic ulcer. Smaller levels of intake, such as 1,000 to 1,500 mg per day, are safer but not as effective for lowering cholesterol. Because of the potential side effects, it is important to consult a doctor before using niacin as a cholesterol-lowering agent. Niacin should not be confused with another form of vitamin B3, niacinamide, which is ineffective in lowering cholesterol.
Research shows that 1,500 mg per day of gugulipid (Commiphora mukul), a traditional herb from India, can reduce total cholesterol by 12% and LDL cholesterol by 17%.6 Garlic has a mild cholesterol-lowering effect, when taken in amounts of 900 mg per day.7 8 Smaller trials suggest soy protein,9 tocotrienols (special forms of vitamin E),10 and calcium may also reduce high cholesterol.11 Supplementation to treat any medical condition should always be undertaken with the supervision of a healthcare professional.
1. Lucas EA, Wild RD, Hammond LJ, et al. Flaxseed improves lipid profile without altering biomarkers of bone metabolism in postmenopausal women. J Clin Endocrinol Metab 2002;87:1527–32.
2. Gouni-Berthold I, Berthold HK. Policosanol: clinical pharmacology and therapeutic significance of a new lipid-lowering agent. Am Heart J 2002;143:356–65.
3. Castano G, Mas R, Fernandez L, et al. Effects of policosanol 20 versus 40 mg/day in the treatment of patients with type II hypercholesterolemia: a 6-month double-blind study. Int J Clin Pharmacol Res 2001;21:43–57.
4. Castano G, Mas R, Fernandez L, et al. Effects of policosanol on postmenopausal women with type II hypercholesterolemia. Gynecol Endocrinol 2000;14:187–95.
5. Castano G, Mas R, Arruzazabala ML, et al. Effects of policosanol and pravastatin on lipid profile, platelet aggregation and endothelemia in older hypercholesterolemic patients. Int J Clin Pharmacol Res 1999;19:105–16.
6. Nityanand S, Srivastava JS, Asthana OP. Clinical trials with gugulipid: a new hypolipidemic agent. J Assoc Physicans India 1989;37:323–8.
7. Mader FH. Treatment of hyperlipidaemia with garlic-powder tablets. Evidence from the German Association of General Practitioners’ multicentric placebo-controlled double-blind study. Arzneimittelforschung 1990;40:1111–6.
8. Silagy CA, Neil HA. Garlic as a lipid lowering agent—a meta-analysis. J R Coll Physicians Lond 1994;28:39–45.
9. Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med 1995;333:276–82.
10. Qureshi AA, Bradlow BA, Brace L, et al. Response of hypercholesterolemic subjects to administration of tocotrienols. Lipids 1995;30:1171–7.
11. Bell L, Halstenson CE, Halstenson CJ, et al. Cholesterol-lowering effects of calcium carbonate in patients with mild to moderate hypercholesterolemia. Arch Intern Med 1992;152:2441–4.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of Garlic and Cholesterol: Everything You Need to Know (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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