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Issue # 63: Do Vegetarians Live Longer
Do vegetarians live longer? Meat products represent a major source of protein in the Western diet and so findings on whether meat intake significantly contributes to the burden of fatal disease have important clinical and public health implications. Literature promoting the health benefits of a vegetarian diet often cites historical accounts of longevity among populations with a low consumption of meat. It has been shown that the life expectancy of adults in Japan and certain Mediterranean countries is up to two years longer than that of their Western peers, who tend to have a significantly higher level of meat consumption. A recent review examined whether a very low meat intake was associated with an increased life expectancy. The data from six prospective cohort studies were reviewed and the authors reported new findings on the life expectancy of long-term vegetarians. After a review of the six studies, the following trends were reported:
Am J Clin Nutr. 2003 Sep;78(3 Suppl):526S-532S A recent pilot study investigated the effects of supplementation with cod liver oil on the symptoms of rheumatoid arthritis. 43 patients with rheumatoid arthritis were supplemented with cod liver oil (in a capsule form) at a dosage of 1000mg per day over a period of three months. The results showed significant decreases in morning stiffness (52.4%), joint pain (42.7%), joint swelling (40%) and intensity of pain (67.5%). The patients reported their experiences of supplementation with cod liver oil with regard to efficacy and tolerability. Ratings of 'good' or 'very good' were awarded by 68% of patients for efficacy and by 95% for tolerability. It was concluded that cod liver oil can be recommended for the treatment of arthritis. Adv Ther. 2002 Mar-Apr;19(2):101-7. Elevated levels of plasma homocysteine (tHcy) are identified as independent risk factors for coronary heart disease and foetal neural tube defects. tHcy levels are negatively associated with folic acid intakes but increase as a result of coffee consumption. The ability of folic acid supplementation to eliminate the tHcy-elevating effect of coffee was investigated in a recent randomised, blinded study. A total of 121 healthy non-smoking subjects (male and female, aged 29-65 years) participated in the trial. The effects of consuming 600ml coffee per day in combination with placebo were compared with the effects of consuming 600 ml per day in combination with a folic acid supplement (200ug per day). It was concluded that supplementation with 200ug of folic acid eliminates the tHcy increasing effect of 600ml of filtered coffee. Eur J Clin Nutr. 2003 Nov;57 (11):1411-7. The association between the self-selected use of multivitamin supplements and the risk of myocardial infarction was examined in a recent epidemiology program. The study included 1296 cases with a history of a first non-fatal myocardial infarction and 1685 matched healthy controls. The use of nutritional supplements among the study population was investigated and it was found that use of multivitamin supplements was significantly higher in the control group (women = 57%; men = 35%) than in the myocardial infarction group (women = 42%, men = 27%). The results of the study showed that the use of a multivitamin supplement was associated with a reduction in the occurrence of myocardial infarction. It was concluded that the use of multivitamin supplements may aid in the prevention of myocardial infarction. J Nutr. 2003 Aug;133(8):2650-4. Ultra-violet (UV) light is involved in the initiation of almost all types of skin cancer via damage to the cells’ DNA. 25 human subjects were used in this study to assess the capacity of an antioxidant complex (AOC) composed of lycopene, beta-carotene, alpha-tocopherol and selenium to reduce UV induced damage. The results showed that many parameters of the epidermal defence against UV-induced damages improved significantly, following the oral intake of an antioxidant complex. It was concluded that the oral intake of an antioxidant complex could provide a safe, daylong and efficient complement to photo-protective measures provided by topical and physical agents and may contribute to reduce the DNA damages leading to skin ageing and skin cancers during exposure to UV light. Photodermatol Photoimmunol Photomed. 2003 Aug;19(4):182-9. The effects of conjugated linoleic acid (CLA) supplementation after weight loss were investigated in a recent placebo-controlled randomised trial. Subsequent to weight loss a total of 26 men and 28 women (age 37.8 years +/- 7.7 years) participated in the trial, which was undertaken over a period of 13 weeks. Each subject was assigned to either CLA (1.8g/day), CLA (3.6g/day) or placebo. The results showed that feelings of hunger were decreased after 13 weeks intervention with CLA compared to placebo. It was concluded that appetite (hunger, satiety and fullness) was favourably affected by consumption of 1.8g or 3.6g of CLA per day. Eur J Clin Nutr. 2003 Oct;57(10):1268-74. Diet is a major influence on the development of cardiovascular disease, the commonest cause of death in most industrialised countries. Tomatoes are widely produced and consumed, they are also a rich source of lycopene, beta carotene, folate, potassium, vitamin C, flavonoids and vitamin E. A recent review examined the role of tomatoes in protecting against heart disease. It was reported that many of the nutrients present in tomatoes may function individually or in concert to protect lipoproteins and vascular cells from oxidative damage, a major step in the development of atherosclerosis. Other reported benefits included the reduction of LDL cholesterol, homocysteine, platelet aggregation and blood pressure. Crit Rev Food Sci Nutr. 2003;43(1):1-18. Elevated plasma homocysteine has been reported to be inversely related to cognitive function in patients with Alzheimer,s disease and community-dwelling older adults. The cross-sectional relationship between total plasma homocysteine levels and cognitive functions among an elderly study population (aged at least 60 years) was recently investigated. Global cognitive function and specific cognitive functions were assessed and then the associations between the cognitive function scores and homocysteine levels were measured by multiple-regression analysis. It was concluded that homocysteine might be a predictor of cognitive function in the elderly and that reducing homocysteine levels through supplementation with B vitamins might protect against cognitive decline in elderly populations. Am J Clin nutr 2003;78:441 - 7. Vitamin D is a fat-soluble vitamin. The vitamin is made in the skin by the action of sunlight on cholesterol. Vitamin D is also present in certain foods and is stable to normal cooking procedures. What does it do? Vitamin D is converted in the body into a calcium-controlling hormone (1,25-dihydroxycholecalciferol) and its functions are all related to the effects of this hormone. Its principle function is to regulate the level of calcium in the blood. It does this by controlling the amount of calcium and phosphorous absorbed by the intestine or released from bones. To maintain the correct ratio of Calcium to Phosphorus it can regulate the amount of Phosphorous excreted by the kidney. What are the deficiency signs? Rickets: Developed during childhood, rickets can begin to show at just 2 months when craniotabes (areas of softening on the skull) are noted. Production of first teeth can be delayed and posture affected. Enlargement at the end of long bones can cause the child to develop a characteristic bowing of legs when beginning to walk. Osteomalacia: Develops in adults, similar to rickets but different in that the bones are no longer developing. There is thinning and weakening of bone and spontaneous fractures may occur. Osteoporosis and Hip Fracture: Incidence of brittle bones and hip fracture may be increased in post-menopausal women with an inadequate vitamin D supply. Is it Toxic? There are some reports f hypercalcaemia (high blood calcium levels) in infants at an intake of 50μg. Signs of toxicity appear in adults at a daily intake of 625μg. Who should supplement? There are certain categories of people who are more susceptible to a Vitamin D deficiency, and who may thus need to supplement their diets. These groups include: vegetarians and vegans, Asian women (who may not consume adequate vitamin D, or choose to cover their skin), lactating women (whose breast-milk may be low in vitamin D especially during the winter), and the housebound or elderly (who tend to eat poorly). Intake Levels: micrograms (μg) RDA = 5 Upper Safe Level = 10 (Long Term) 50 (Short Term) Which Foods? Micrograms (μg) / 100g Cod Liver Oil 212.5 Herring and Kipper 22.4 Salmon, canned 12.5 Milk, evaporated 4.0 Eggs 1.6 Butter 0.8 Liver 0.8 Cheese, cheddar 0.3 Milk, whole 0.03 Milk, skimmed 0 1. Vitamin and mineral safety council for responsible nutrition: 1997 2. Handbook of dietary supplements: 1995 3. Med Hypotheses, 1995, 44;6:490-492 4. Health Essentials vitamin guide: 1994 |