expert opinion

The role of micronutrients in healthy aging

January 1, 2012

file

Carrie Ruxton, PhD RD, Dietitian, Nutritionist, and Health Writer, UK

“The National Diet and Nutrition Survey (NDNS) offers the best quality and most representative micronutrient intake data for the UK. While the reference nutrient intake (RNI) is designed to meet the needs of 97.5% of the normal, healthy population, the lower reference nutrient intake (LRNI) only meets the needs of the remaining 2.5%. Therefore, those with intakes below the LRNI are deemed to be at risk of deficiency according to the Dietary Reference Values (1), although actual deficiency can only be determined using biochemical markers. In the NDNS, inadequate intakes were seen for vitamin A, vitamin D, folic acid, iron, calcium, magnesium, zinc and iodine (2), as well as long-chain omega-3 fatty acids (3). Markers of nutritional status gave a different picture showing low blood levels of vitamins C and D, iron and folate (4). These data suggest that a significant proportion of older people are failing to consume adequate amounts of vitamins, minerals and omega-3 fatty acids. Those most at risk of deficiency include people in their 80s and people in institutions. It is thus called for that older people take multi-nutrient supplements (5), as they appear to be a useful way to boost micronutrient intakes in this age group (6).

Poor diet is known to contribute to the development of type 2 diabetes, heart disease, stroke, osteoporosis and certain cancers (7). While public health messages often focus on reducing intakes of fat, saturated fat, sugar and salt, equal concern is deserved for inadequate intakes of vitamins, minerals and omega-3 fatty acids. Insufficient calcium and vitamin-D intakes throughout adulthood accelerate bone loss in later life, greatly increasing the risk of osteoporosis, fracture and falls (8). A growing number of studies report significant associations between a poor vitamin D status in later life and a greater risk of type 2 diabetes, cardiovascular disease (CVD) and cancer (9), and with faster aging in the DNA of cells, estimated by telomere length (10). Mortality rates from all causes are significantly higher in older people with a poor vitamin D status (11). Studies reveal that cognitive function in later life declines faster and the risk of dementia increase, when intakes of long-chain omega-3 fatty acids are low (12). A longitudinal survey of 1,091 UK adults found better cognitive performance in 70-year-olds who had higher intakes of vitamins B12, C, riboflavin and folate. However, the significance of this association was attenuated when childhood IQ was accounted for (13). Longitudinal studies have associated low B-vitamin status with faster cognitive decline (14), while low intakes of B vitamins have been linked with a higher risk of depression (15). Higher blood levels of antioxidant nutrients, e.g. carotenoids, vitamins C and E, may reduce the risk of CVD, diabetic complications and cancer (16). Two longitudinal surveys in older populations (17, 18) found a lower risk of
all-cause and cancer mortality when blood carotenoid levels were high. A meta-analysis of 15 cohort studies found a 16-24% lower risk of CVD when intakes of vitamins C and E and beta-carotene were high (19). These studies show the disadvantage of micronutrient insufficiency. Researchers suggest that supplements containing vitamins C and E, carotenoids, zinc and selenium could help prevent accelerated aging and reduce the risk of age-related diseases (20).

The research includes a number of long-term supplementation studies in elderly populations. Two of these found improvements in antioxidant capacity following supplementation of zinc, or a combination of zinc, selenium, vitamin C, beta-carotene and vitamin E (21, 22). This may have implications for disease risk as a low antioxidant status has been associated with a greater risk of cancer and CVD (17, 18). Other studies have reported improvements in nutritional status and a reduced risk of micronutrient deficiency with various combinations of vitamin and mineral supplements (23, 24). Other studies considered cognitive function. One long-term study demonstrated improved verbal fluency in older or ‘at risk’ participants following supplemen-tation with 11 vitamins and five minerals (25). Several trials have looked at heart health, revealing benefits for blood pressure, blood lipids, serum homocysteine, anti-inflammatory markers and heart function after the intake of fish oil or multi-nutrient supplements (26-29). These studies suggest improvements in nutritional status and disease markers when older populations take multi-nutrient supplements over the medium to long term. The findings are supported by systematic reviews and meta-analyses of the relationship between bone health and vitamin D supplementation (30, 31), CVD and folic acid supplementation (32), as well as age-related macular degeneration and supplementation with beta-carotene, vitamins C, E and zinc (33). For other conditions, such as atherosclerosis and cancer, the benefits of supplementation are inconsistent.

A varied diet including plenty of fruit, vegetables, whole grains, fish, lean meat and poultry, low-fat dairy foods and starchy carbohydrates should be the bedrock of dietary intervention. However, successive dietary surveys in the UK suggest that the rate of progress towards dietary targets is slow. Poor cooking skills, poor dentition, disabilities and loss of appetite or the sense of taste in older people may also hamper efforts to eat more healthily. As energy-intake requirements decline in old age, in part due to a loss of muscle mass, the diets of older people must remain nutrient-dense in order to meet the recommended requirements. Dietary supplements have an important role in helping older people maintain optimal nutrient intakes, thus reducing the risk of deficiency. Evidence on supplementation in this age group suggests consistent benefits to nutritional status and, in the case of some studies, markers of disease risk. Multi-nutrient supplements, such as multivitamin and multi-mineral formulations, are typically used in these studies, providing intakes close to recommendations. While standard supplements that provide 100% of the EU’s Recommended Daily Allowance are generally suitable, additional vitamin D will need to be provided for those over the age of 65 to achieve intakes of 10 mg per day, as advised by the Department of Health (1).”

Based on: Ruxton C. The role of micronutrients in healthy ageing. Nutrition & Food Science. 2011; 41(6): 420–429.

References

  1. Department of Health. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom, HM Stationery Office, London, No. 41. 1991.
  2. Henderson L. et al. The National Diet and Nutrition Survey: Adults Aged 19 to 64 Years, The Stationery Office, London. 2003.
  3. Gibbs R. A. et al. Postgraduate symposium: long-chain n-3 PUFA: intakes in the UK and the potential of a chicken meat prototype to increase them. Proceedings of the Nutrition Society. 2010; 69:144–155.
  4. Bates C. J. et al. Micronutrients: highlights and research challenges from the 1994-5 National Diet and Nutrition Survey of people aged 65 years and over. British Journal of Nutrition. 1999; 82:7–15.
  5. Toffanello E. D. et al. Ten-year trends in vitamin intake in free-living healthy elderly people: the risk of subclinical malnutrition. The Journal of Nutrition Health & Aging. 2011; 15:99–103.
  6. Anderson J. J. B. et al. Micronutrient intakes in two US populations of older adults: lipid research clinics program prevalence study findings. The Journal of Nutrition Health & Aging. 2009; 13:595–600.
  7. WHO. Global Strategy on Diet, Physical Activity and Health, World Health Organization, Geneva. 2004.
  8. Macdonald H. M. et al. Vitamin D status in postmenopausal women living at higher latitudes in the UK in relation to bone health, overweight, sunlight exposure and dietary vitamin D. Bone. 2008; 42:996–1003.
  9. Ruxton C. H. S. and Derbyshire E. Health impacts of vitamin D: are we getting enough? Nutrition Bulletin. 2009; 34:185–197.
  10. Richards J. B. et al. Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. American Journal of Clinical Nutrition. 2007; 86:1420–1425.
  11. Jia X. et al. Nutritional status and subsequent all-cause mortality in men and women aged 75 years or over living in the community. British Journal of Nutrition. 2007; 98:593–599.
  12. Morris M. C. et al. Consumption of fish and n-3 fatty acids and risk of incident Alzheimer disease. Archives of Neurology. 2003; 60:940–946.
  13. McNeill G. et al. Antioxidant and B vitamin intake in relation to cognitive function in later life in the Lothian Birth Cohort 1936. European Journal of Clinical Nutrition. 2011; 65:619–626.
  14. Vercambre M. N. et al. Long-term association of food and nutrient intakes with cognitive and functional decline: a 13-year follow-up study of elderly French women”, British Journal of Nutrition. 2009; 102:419–427.
  15. Sanchez-Villegas A. et al. Association between folate, vitamin B(6) and vitamin B(12) intake and depression in the SUN cohort study. Journal of Human Nutrition & Dietetics. 2009; 22:122–133.
  16. Mason P. and Ruxton C. Towards a Healthier Britain, PAGB, London. 2010. Available at: www.pagb.co.uk
  17. Buijsse B. et al. Plasma carotene and alpha-tocopherol in relation to 10-y all-cause and cause-specific mortality in European elderly: the Survey in Europe on Nutrition and the Elderly, a Concerted Action (SENECA). American Journal of Clinical Nutrition. 2005; 82:879–886.
  18. Lauretani F. et al. Low total plasma carotenoids are independent predictors of mortality among older persons: the InCHIANTI study. European Journal of Nutrition. 2008; 47:335–340.
  19. Ye Z. and Song H. Antioxidant vitamins intake and the risk of coronary heart disease: meta-analysis of cohort studies. European Journal of Cardiovascular Prevention & Rehabilitation. 2008; 15:26–34.
  20. Richard M. J. and Roussel A. M. Micronutrients and ageing: intakes and requirements. Proceedings of the Nutrition Society. 1999; 58:573–578.
  21. Girodon F. et al. Effect of a two-year supplementation with low doses of antioxidant vitamins and/or minerals in elderly subjects on levels of nutrients and antioxidant defense parameters. Journal of the American College of Nutrition. 1997; 16:357–365.
  22. Bao B. et al. Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: a potential implication of zinc as an atheroprotective agent. American Journal of Clinical Nutrition. 2010; 91:1634–1641.
  23. van der Wielen R. P. et al. Nutritional status of elderly female nursing home residents; the effect of supplementation with a physiological dose of water-soluble vitamins. European Journal of Clinical Nutrition. 1995; 49:665–674.
  24. McKay D. L. et al. The effects of a multivitamin/mineral supplement on micronutrient status, antioxidant capacity and cytokine production in healthy older adults consuming a fortified diet. Journal of the American College of Nutrition. 2000; 19:613–621.
  25. McNeill C. et al. Effect of multivitamin and multimineral supplementation on cognitive function in men and women aged 65 years and over: a randomised controlled trial. Nutrition Journal. 2007; 6:10–14.
  26. Cobiac L. et al. A low-sodium diet supplemented with fish oil lowers blood pressure in the elderly. Journal of Hypertension. 1992; 10:87–92.
  27. Farvid M. S. et al. The impact of vitamins and/or mineral supplementation on blood pressure in type 2 diabetes. Journal of the American College of Nutrition. 2004; 23:272–279.
  28. Witte K. K. A. et al. The effect of micronutrient supplementation on quality-of-life and left ventricular function in elderly patients with chronic heart failure. European Heart Journal. 2005; 26:2238–2244.
  29. Bekaert B. et al. Effect of selenium status and supplementation with high-selenium yeast on plasma homocysteine and B vitamin concentrations in the UK elderly. Molecular Nutrition & Food Research. 2008. 52:1324–1333.
  30. Shea B. et al. Meta-analyses of therapies for postmenopausal osteoporosis. VII. Meta-analysis of calcium supplementation for the prevention of postmenopausal osteoporosis. Endocrinology Reviews. 2002; 23:552–559.
  31. Papadimitropoulos E. et al. Meta-analyses of therapies for postmenopausal osteoporosis. VIII: meta-analysis of the efficacy of vitamin D treatment in preventing osteoporosis in postmenopausal women. Endocrinology Reviews. 2002. 23:560–569.
  32. Wang X. et al. Efficacy of folic acid supplementation in stroke prevention: a meta-analysis. Lancet. 2007; 369:1876–1882.
  33. Evans J. Antioxidant supplements to prevent or slow down the progression of AMD: a systematic review and meta-analysis. Eye (London England). 2008; 22:751–760.