I?ve heard that homocysteine levels may be important in preventing osteoporosis as well as heart disease. Could you please comment on this?
You heard correctly. High blood homocysteine levels—which may be related to low intake levels of certain B vitamins, especially folic acid—recently have been associated with bone fractures.
As you mentioned, many people are aware of the relationship between homocysteine and cardiovascular disease, although that association is a bit murky at this point. Two recent meta-analyses came to somewhat different conclusions in this regard: One suggested there is only a modestly increased CVD risk with elevated homocysteine; the other suggested the risk is more significant.1,2 However, this new connection with bone health adds another reason to consider homocysteine. It has been observed that there is an increased prevalence of osteoporosis among people with homocystinuria (a rare, autosomal recessive disease of excessively high levels of homocysteine in the blood). The question was thus raised whether modestly elevated levels may lead to some risk as well.
Two recent studies support this hypothesis. In one study looking at hip fractures in men and women ages 59 to 91, elevated homocysteine levels that were assessed 12 to 15 years prior showed a causal relationship with fractures of the hip in ensuing years. There was an almost four-times higher risk for men with the highest homocysteine levels and an almost two-times higher risk for women in such cases.3 In a second study, it was noted that associations between homocysteine levels and the risk of fracture appeared to be independent of bone mineral density and other potential risk factors for fracture.4 Thus, for just pennies a day, it seems like a prudent idea to supplement with relatively high levels of B6 (25 to 50 mg), B12 (75 to 100 mcg), and folic acid (800 to 1,000 mcg), three nutrients important in keeping homocysteine levels low.
Can eating almond butter help lower my cholesterol?
It has actually been known for some time that nuts, and particularly almonds, can lower cholesterol and have a positive effect on CVD risk. Human feeding studies have demonstrated reductions in low-density lipoprotein cholesterol (the ?bad? cholesterol) when almonds and walnuts, containing both poly- and monounsaturated fats, were substituted for more traditional poly- and monounsaturated fats. Epidemiological studies have repeatedly reported that eating nuts frequently is associated with a 30 percent to 50 percent decreased risk of coronary heart disease.5
Recent controlled clinical trials have supported these observations. In one study, adding almonds to a standard heart-healthy diet markedly improved the serum lipid profile of healthy and mildly hypercholesterolemic adults. Total and LDL cholesterol concentrations declined with progressively higher intakes of almonds, which suggests a dose-response relation.6 And it doesn?t appear to be just the addition of monounsaturated fat that you would get from, say, increasing olive oil. Because when compared to an olive-oil based diet, an almond-supplemented diet was superior in terms of cholesterol.7 Another study suggested the magnitude of the change one might achieve with the addition of almonds or almond oil was a decrease of 14 percent in triglycerides, 6 percent in LDL cholesterol and a 6 percent increase in protective high-density lipoprotein cholesterol.8 Nuts are good for you. They are nutrient-dense; are perhaps the best natural source of vitamin E; and are relatively concentrated repositories of dietary fiber, magnesium and potassium.
Should I be concerned about white spots under my fingernails?
Possibly. For years, naturopathic practitioners have associated white spots underneath fingernails as an indication of low zinc status. There are, however, many reasons for white spots (called leukonychia), most of them due to mild trauma—such as hitting a fingernail with a hammer.
Additionally, a significant zinc or protein deficiency can cause a pattern of white bands across the width of the nail or even a nearly total whiteout of the nail. Cirrhosis, a form of chronic liver disease usually brought about by alcoholism, can also result in nails that are almost completely white. Or else white spots may be a fungal, yeast or bacterial infection that attacks the substance of the nail directly, leaving a whitish streak or spot behind. White spots can also occasionally accompany psoriasis and eczema.
Having said all that, after other causes such as those listed above are ruled out, I think that white spots under the nails should make one consider zinc. Another common sign that may lead in the direction of zinc deficiency is poor taste sensation. Zinc deficiency is rampant in the United States. The third National Health and Nutrition Examination Survey National performed by the Center for Health Statistics, Centers for Disease Control and Prevention, in Hyattsville, Md., found that adequate zinc intake for all study populations was 55.6 percent (based on total intakes of greater than 77 percent of the 1989 recommended dietary allowance). Young children (1 to 3 years old), adolescent females (12 to 19) and older adults (71 years or older) were at the greatest risk of inadequate zinc intakes.9
Dan Lukaczer, N.D., is director of clinical research at the Functional Medicine Research Center, a division of Metagenics Inc., in Gig Harbor, Wash.
1. Wald DS, et al. Homocysteine and cardiovascular disease: evidence on causality from a meta-analysis. BMJ 2002 Nov;325(7374):1202.
2. Homocysteine Studies Collaboration. Homocysteine and risk of ischemic heart disease and stroke: a meta-analysis. JAMA 2002 Oct;288(16):2015-22.
3. McLean RR, et al. Homocysteine as a predictive factor for hip fracture in older persons. N Engl J Med 2004 May;350(20):2042-9.
4. Van Meurs JB, et al. Homocysteine levels and the risk of osteoporotic fracture. N Engl J Med 2004 May;350(20): 2033-41.
5. Fraser GE. Nut consumption, lipids, and risk of a coronary event. Clin Cardiol 1999 Jul;22(7 Suppl III):11S-15S.
6. Sabate J, et al. Serum lipid response to the graduated enrichment of a Step I diet with almonds: a randomized feeding trial. Am J Clin Nutr 2003 Jun;77(6):1379-84.
7. Hyson DA, et al. Almonds and almond oil have similar effects on plasma lipids and LDL oxidation in healthy men and women. J Nutr 2002 Apr;132(4):703-7.
8. Spiller GA, et al. Nuts and plasma lipids: an almond-based diet lowers LDL-C while preserving HDL-C. J Am Coll Nutr 1998 Jun;17(3):285-90.
9. Briefel RR, et al. Zinc intake of the U.S. population: findings from the third National Health and Nutrition Examination Survey, 1988-1994. J Nutr 2000 May;130(5 Suppl):1367S-1373S.
Natural Foods Merchandiser volume XXV/number 9/p. 60