“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.
