Archive

Health Bits and Pieces
By Michael Janson, M.D.
April 09, 2008

A diet high in fruits, vegetables, whole grains, beans, nuts, and fish lowers the risk of developing Parkinson’s disease (PD). A compilation of data from the Health Professionals’ Follow-up Study of 49,692 men and the Nurses’ Health Study of 81,676 women showed that these dietary choices could lower the risk of PD by 30 percent, compared to a typical Western diet. (Gao X, et al., “Prospective study of dietary pattern and risk of Parkinson disease,” Am J Clin Nutr. 2007 Nov;86(5):1486-94.) The typical Western diet that they reported was high in saturated fat, refined grains, red meat, sweets, and fried foods. Most people realize that these foods are unhealthy, but this has not stopped their widespread consumption. The authors noted the great benefit of a plant-based diet, plus fish, in preventing PD, and this is the same diet that appears to protect from other degenerative diseases.

Low blood levels of markers for Vitamin-B12 function are associated with an increased rate of mental decline. A study in England evaluated 1648 participants over 65 years old for 10 years. Serum markers for B12 activity (holotranscobalamin and methylmalonic acid) were inversely associated with mental decline, while the level of B12 itself was not related to mental function, indicating that the B12 level is not as important as its activity. (Clarke R, et al., “Low vitamin B-12 status and risk of cognitive decline in older adults,” Am J Clin Nutr. 2007 Nov;86(5):1384-91.) The highest level of the markers was associated with a 30-percent reduction in loss of cognitive function over the 10 years. On the other hand, higher levels of homocysteine (a metabolite linked to loss of brain function and heart disease) were associated with a greater than 50-percent increase in the rate of cognitive decline. Vitamin B12 helps to lower levels of homocysteine, but this is not the only way it might help brain function. In another study with some of the same researchers, 195 subjects were given supplements of B12, folate, or a placebo for six months. B12 and folate supplements increased the level of betaine in the blood. Betaine is a methyl donor, and higher levels were associated with improved memory. (Eussen SJ, et al., “The association of betaine, homocysteine and related metabolites with cognitive function in Dutch elderly people,” Br J Nutr. 2007 Nov;98(5):960-8.)

Maintaining both a trim waist and upper body strength is one way to reduce the risk of dying early. In a study of 4107 men 60 to 79 years old, those with the largest biceps with waists less than 40 inches had the lowest mortality over a six-year period. (Wannamethee SG, et al., “Decreased muscle mass and increased central adiposity are independently related to mortality in older men,” Am J Clin Nutr. 2007 Nov;86(5):1339-46.) Neither waist size nor bicep size alone were as predictive, although bicep size did relate to lowered mortality. This indicates that it is most important to stay trim and maintain strength at the same time. Waist size greater than 40 inches and a high waist to hip ratio were both associated with an increased risk of mortality. A large bicep combined with a waist size over 40 inches was associated with a 36-percent higher mortality risk.

Chronic obstructive pulmonary disease (COPD, usually the result of smoking) is a contributor to early mortality. New research shows that eating cured meats – such as processed meats (bologna, salami), bacon, and hot dogs – increases the incidence of COPD, even independent of smoking. (Varraso R, et al., “Prospective study of cured meats consumption and risk of chronic obstructive pulmonary disease in men,” Am J Epidemiol. 2007 Dec 15;166 (12):1438-45.) In this research on 42,915 men in the Health Professionals Follow-up study, those who ate the most cured meats (4-6 servings per week) had more than 2.5 times the risk of COPD compared to those who ate the least (less than 1 serving per week). My negative opinion of eating meat is not based on bias or preconceived notions (I grew up eating lots of meat), but instead upon my observations of the overwhelming weight of the scientific research over the past 36 years.

Happiness appears to reduce inflammation and lower the risk factors for heart disease and hypertension. While a positive mood has long been associated with better health, it is not clear why this is so. New research suggests some possible reasons. In a study in England of 2873 healthy adult subjects, a positive mood appears to reduce the blood levels of cortisol, a hormone secreted in times of stress and associated with lowered immunity, increased obesity, and high blood pressure. (Steptoe A, et al., “Neuroendocrine and inflammatory factors associated with positive affect in healthy men and women,” The Whitehall II Study, Am J Epidemiol. 2008 January 1;167(1):96-102.) In other findings, in women but not men, positive moods were associated with reduced levels of the inflammatory markers, C-reactive protein (CRP) and interleukin-6 (IL6). Researchers asked the subjects to keep a record of their feelings and moods during the study – whether they were happy, excited, or content. High CRP is a known risk factor for heart disease. High levels of both IL6 and CRP are associated with increased cancer risks. The great benefits from positive feelings and an upbeat mood were reported decades ago by Norman Cousins in his book, Anatomy of an Illness. The great question, of course, is how to achieve it.