Nutrition Bytes

Vitamin b12 (cobalamin) deficiency has been associated with multiple neurological and psychiatric symptoms such as peripheral neuropathy, myelopathy, altered mental status, depression and dementia. Potentially irreversible neuropsychiatric changes due to low cobalamin levels are avoidable. Despite some controversy over the effectiveness of cobalamin therapy, there is growing evidence that subjects with low serum cobalamin levels suffering from dementia, displayed significant cognitive improvement and/or resolution of their cognitive defects after prolonged cobalamin therapy. Early detection of low levels of cobalamin is imperative for cobalamin replacement therapy to be effective. Treatment of the deficiency, however late may prevent the symptoms from getting worse.

Oral ingestion of monosodium L-glutamate, particularly when used as a seasoning in Chinese restaurant meals, has been implicated in a growing number of adverse reactions. These range from the classic Chinese Restaurant Syndrome triad of symptoms (facial pressure, chest pain, and a burning sensation) to documented cases of MSG-induced asthma. A number of double-blind, placebo-controlled studies have confirmed a relationship between MSG dose and CRS symptom duration and intensity, with a challenge threshold around 2.5 gm. Studies have also confirmed MSG-provoked asthma attacks in susceptible individuals, which exhibit a reproducible time delay. While the existing data are not overwhelming, they do suggest the existence of certain subgroups within the general population that are predisposed to MSG-induced symptoms, both the CRS and asthma. Current mechanisms under consideration involve the effects of elevated serum glutamate level mediated through central and/or peripheral glutamate receptors. Much research remains to be done.

Obesity is a major health problem in the United States affecting one in every three individuals. As a result, a number of diets, regimens, herbs and drugs have been introduced over the past number of years to combat obesity. However, none have been as potent as the combination drug therapy commonly known as "fen-phen". Fen-phen is a combination of fenfluramine or dexfenfluramine and phentermine, which have all individually been approved by the FDA as appetite suppressants. In 1992, a study by Weintraub showed that fen-phen may be successful in the long-term management of obesity. This study resulted in an upheaval in both the medical community and the media, which led to 18 million prescriptions being written for fen-phen by 1996. Weintraub s study, however, failed to adequately assess the long-term side effects associated with fen-phen therapy in patients. In August of 1997, a study by Connolly et. Al. resulted in another upheaval because it associated fen-phen therapy with valvular heart disease, especially in women. As a result of this study, further reports of valvulopathy began to pour into the FDA, and by September of 1997 manufacturers and the FDA announced the withdrawal of fen-phen from the market. Presently, the U.S. Department of Health and Human Services recommends that all individuals exposed to fen-phen therapy for any period of time to be seen by their physicians for a complete cardiovascular assessment. These sequences of events should, thus, serve as a lesson to the entire health-care community to analyze treatments comprehensively and not just prescribe the "quick fix" without adequate corroborative evidence.

Recent studies have shown that there exists an inverse relationship between coronary heart disease(CHD) and alcohol consumption. Separate studies have been done on men and women showing similar effects of alcohol consumption on CHD risks. Most studies agree that light to moderate drinkers have a decreased risk of CHD as compared to nondrinkers. However, there is some disagreement as to whether light or heavy drinkers benefit from a greater protective effect for CHD. Also, there is some conflict as to which alcoholic beverage(beer, wine, or distilled spirits) is more beneficial in reducing the risk of coronary heart disease. Results from recent studies suggest that all provide a protective effect, but different studies provide different alcoholic beverages as being the one with the greatest risk-reducing effects. The mechanism by which alcohol reduces CHD risk is not completely understood, but most studies agree that it is due to alcohol s effect on increasing high-density lipoproteins(HDLs) in the body. Also, some studies suggest that alcohol may also stimulate clot-dissolving factors and decrease platelet aggregation which lower the risk for coronary artery obstruction. Despite the agreement that alcohol may reduce CHD risk, the findings do not justify heavy drinking since large quantities of alcohol consumption are correlated to numerous health problems and diseases.

The Effects of Ginkgo biloba extract on memory enhancement in healthy subjects was examined. It was found that Ginkgo biloba is widely used in Western Europe for the treatment of peripheral vascular diseases such as intermittent claudication and cerebral insufficiency. The extract components and the research of Ginkgo biloba’s most studied physiological mechanisms of action were described. Research most closely implicating the use of Ginkgo biloba on cognitive enhancement was also examined, along with the adverse side effects associated with its use. The findings reveal a safe and suitable role of Ginkgo biloba in enhancing the cognitive performance of people who suffer from various mental dysfunction’s associated with aging, specifically those arising from decreased cerebral blood flow. Presently there is no evidence to support the role of Ginkgo biloba in enhancing cognitive function in young healthy subjects. Further studies in this domain are necessary to characterize such a role.

Garlic has been touted for its medicinal properties in almost all ancient cultures. It belongs to the Allium family all members of which contain sulfur. Garlic contains an abundance of sulfur amino acids and their derivatives. The processing of these compounds through various preparations is what causes the odor of garlic. These garlic constituents have been shown to influence both initiation and promotion phases of cancer in several animal and cell culture methods. It has been found that these components exert antiproliferative activity on normal and malignant cells. Furthermore garlic compounds have been shown to block the synthesis of N-nitroso compounds that function as potential carcinogens. In this review, several carcinomas have been examined with respect to garlic’s ability to produce prevention. These include colon, esophagus, lung, prostate, and breast. On a side note, selenium enriched food products have been shown to be effective in cancer prevention. Interestingly enough, garlic has a great capacity to concentrate selenium when grown in a selenium-fertilized condition, which makes it a great candidate for food fortification. There are many other benefits to regular garlic consumption, some of which are mentioned at the end of this review.