Can drinking pomegranate juice help lower my cholesterol level?
The literature I have seen suggests that pomegranate juice may indeed have an effect on cholesterol. Pomegranate (Punica granatum) originated as a native fruit in the Middle East, but is now grown in many areas around the world. The fruit holds hundreds of seeds in a juicy red pulp and, like many fruits, contains a variety of phytonutrients that act as antioxidants.
In an uncontrolled study of 22 diabetic patients who drank 40 g of pomegranate juice per day for eight weeks, participants showed significant reductions in both total cholesterol and low-density lipoprotein cholesterol.1
Pomegranate juice not only may lower cholesterol levels, but also may protect the cholesterol already in a person's blood from becoming more atherogenic (prone to forming lipid deposits in the arteries). Free radicals that come in contact with cholesterol in the bloodstream alter the cholesterol molecule through the process of oxidation. This oxidized cholesterol is a much-more dangerous molecule and appears to greatly speed atherosclerosis (hardening and thickening of the arteries). Pomegranate juice appears to inhibit this process in animal experiments.2
In human studies, patients who drank eight ounces of pomegranate juice per day for three months showed improvement in how well blood flowed through the heart,3 suggesting that atherosclerosis may have been improved. In a longer-term study, 10 patients were supplemented with an unspecified amount of pomegranate juice for one year, and five of them continued for up to three years. Compared with a control group that did not consume pomegranate juice, carotid wall thickness was reduced, again suggesting improved blood flow. Interestingly, blood pressure also improved.4 It appears pomegranate juice may have an effect on angiotensin-converting enzyme,5 a key enzyme in blood pressure regulation.
In addition to its effect on cholesterol, the antioxidants in pomegranate juice may have an effect on prostate cancer. While this work has not yet reached human trials, in vitro studies suggest pomegranate juice may inhibit the growth of prostate cancer cells.6,7
Will magnesium help with the heart condition mitral valve prolapse?
Possibly. The mitral valve separates the left atrium from the left ventricle, allowing blood to flow in the proper direction. With prolapse, the mitral valve bulges slightly back into the left atrium when it closes. This may allow a tiny amount of blood to leak backward and cause symptoms. Mitral valve prolapse is a very common heart problem; though not usually serious, it can be quite discomforting. Symptoms include weakness, chest pain, shortness of breath, palpitations and anxiety. MVP occurs far more often in women than men, and may be present from birth or develop later in life.
It is not entirely clear how magnesium helps, but it may have to do with the mineral's ability to promote collagen synthesis in the heart muscle itself. There have been a number of human clinical studies using magnesium for MVP. One double-blind, placebo-controlled study showed that after six months on 500 mg of magnesium/day, more than half the patients had a complete or partial reduction in symptoms such as those listed above.8 It is likely that those who respond well have some level of magnesium deficiency. In fact, in a study of people with severe MVP symptoms, blood levels of magnesium were low in 60 percent of the cases. Those people with low magnesium participated in a double-blind trial, in which they received a placebo or magnesium (500 mg per day for one week, then about 335 mg per day for four weeks). People receiving magnesium experienced a significant reduction in symptoms.9
Can zinc supplementation really help with canker sores?
It is unclear what causes canker sores (also called aphthous ulcers or aphthous stomatitis). The condition is not contagious. The ulcers seem to be triggered by various factors such as stress, poor nutrition, food allergies and menstrual periods. Zinc is a nutrient that has been tested with mixed results.10,11 One thought about these conflicting responses is that the people who respond to zinc may have a general zinc deficiency or a defect in zinc metabolism in the first place.
Some studies support this idea, showing those who are deficient in zinc—at least as measured by a blood zinc level—respond to zinc supplementation the best,12,13,14 and their canker sore outbreaks decrease in frequency. People who suffer with recurrent canker sores and are unable to get a serum zinc test may consider a trial of zinc (25 mg two to three times a day taken with food to avoid nausea) for eight weeks. This is a high level of zinc to supplement with over the long term, however, so if there is no decrease in recurrence after that time, zinc supplementation should stop. If the canker sores seem to improve, dropping down to a maintenance dose of zinc (10 to 20 mg/ daily) should be sufficient to maintain a normal zinc level.
1. Esmaillzadeh A., et al. Concentrated pomegranate juice improves lipid profiles in diabetic patients with hyperlipidemia. J Med Food 2004;7(3):305-8.
2. Aviram M, et al. Pomegranate juice flavonoids inhibit low-density lipoprotein oxidation and cardiovascular diseases: studies in atherosclerotic mice and in humans. Drugs Exp Clin Res 2002;28(2-3):49-62.
3. Sumner MD, et al. Effects of pomegranate juice consumption on myocardial perfusion in patients with coronary heart disease. Am J Cardiol 2005;96(6):810-4.
4. Aviram M, et al. Pomegranate juice consumption for 3 years by patients with carotid artery stenosis reduces common carotid intima-media thickness, blood pressure and LDL oxidation. Clin Nutr 2004;23(3):423-33.
5. Aviram M and Dornfeld L. Pomegranate juice consumption inhibits serum angiotensin converting enzyme activity and reduces systolic blood pressure. Atherosclerosis 2001;158(1):195-8.
6. Malik A., et al. Pomegranate fruit juice for chemoprevention and chemotherapy of prostate cancer. Proc Natl Acad Sci U S A 2005;102(41):14813-8.
7. Albrecht M, et al. Pomegranate extracts potently suppress proliferation, xenograft growth, and invasion of human prostate cancer cells. J Med Food 2004;7(3):274-83.
8. Martynov AI, et al. New approaches to the treatment of patients with idiopathic mitral valve prolapse. [Russian] Ter Arkh 2000;72(9):67-70.
9. Lichodziejewska B, et al. Clinical symptoms of mitral valve prolapse are related to hypomagnesemia and attenuated by magnesium supplementation. Am J Cardiol 1997;79(6):768-72.
10. Wang SW, et al. The trace element zinc and aphthosis. The determination of plasma zinc and the treatment of aphthosis with zinc. [Chinese] Rev Stomatol Chir Maxillofac 1986;87(5):339-43.
11. Wray D. A double-blind trial of systemic zinc sulfate in recurrent aphthous stomatitis. Oral Surg Oral Med Oral Pathol 1982;53(5):469-72.
12. Merchant HW, et al. Zinc sulfate supplementation for treatment of recurring oral ulcers. South Med J 1977;70(5):559-61.
13. Endre L. Recurrent aphthous ulceration with zinc deficiency and cellular immune deficiency. Oral Surg Oral Med Oral Pathol 1991;72(5):559-61.
14. Orbak R, et al. Effects of zinc treatment in patients with recurrent aphthous stomatitis. Dent Mater J 2003;22(1):21-9.
Natural Foods Merchandiser volume XXVII/number 9/p. 45