"Eat to Live, Not Live to Eat"
John H Weisburger, 2000
We know the classic micronutrient deficiency diseases such as scurvy, rickets, beriberi and pellagra have existed throughout history. But effective remedies in the form of dietary practices were not established until relatively recent times, leading on subsequently to identification of the individual vitamins and minerals involved, and then biochemical understanding of their mechanisms. In the affluent developed countries, supply of these substances either in the diet or through supplements has long since been possible, whereas in the developing world deficiency states are still all too common. In industrialised countries where government and public health agencies provide recommended minimum daily intakes and affordable foods that are rich sources and are available all year round, there is little excuse for not meeting the goals.
However, results from the USDA’s 1994-96 Continuing Survey of Food Intakes by Individuals and the 1994-96 Diet and Health Knowledge Survey on two day average intakes revealed that the percentages of individuals aged 2 or more years in the US not meeting 100% of the 1989 recommended dietary allowances were: Vitamin B12 - 17.2, Niacin - 25.9, Phosphorus - 27.4, Riboflavin - 30.0, Thiamine -30.2, Folate - 33.2. Vitamin C - 37.5, Iron - 39.1, Vitamin B6 - 53.6, Vitamin A - 56.2, Magnesium - 61.6, Calcium - 65.1 and Zinc - 73.3. A large proportion of these nutrients comes from fruits and vegetables, and the following study (American Journal of Preventive Medicine (2007), 32, 257–263) details lamentably low intake, with the result that many people can be seriously micronutrient deficient. Furthermore, it seems the situation did not improve over the period 1988 to 2002.
Previous research indicates that few Americans meet the USDA guidelines for fruit and vegetable consumption, and that adequate fruit and vegetable consumption may decrease the risk for chronic disease. Twenty-four-hour dietary recall data from the National Health and Nutrition survey, NHANES III, 1988–1994 (n = 14,997) and NHANES 1999–2002 (n = 8910) were used to assess adult (18 or more years old) trends in daily fruit and vegetable consumption (number of servings and types). In 1988–1994, an estimated 27% of adults met the USDA guidelines for fruit (two or more servings) and 35% met the guidelines for vegetables (three or more servings). In 1999–2002, 28% and 32% of adults met fruit and vegetable guidelines, respectively. There was a significant decrease in vegetable consumption over time. Only 11% met USDA guidelines for both fruits and vegetables in 1988–1994 and 1999–2002, indicating no significant change in consumption. In both data sets, non-Hispanic blacks were significantly less likely to meet USDA guidelines compared to non-Hispanic whites. Higher income and greater education were significantly associated with meeting the guidelines in both data sets. Despite the initiation of a national fruit and vegetable campaign in 1991, the findings indicated that Americans’ fruit and vegetable consumption did not increase in 1999–2002, and only a small proportion met the related dietary recommendations. Greater public health efforts and approaches are needed to promote healthy eating in the United States.
These figures and comments concern the US. Although in Australia we generally follow the US in most trends, are we doing any better here in WA? The answer is - perhaps marginally but, like the US, without signs of major improvement and maybe even deterioration. Australian Government Dietary Guidelines recommend a better level of at least 2 and 5 fruits and vegetables per day, consisting of at least two 150g servings of fruit and five 75g servings of vegetables, giving a total of 675g or more per day. A recent study (American Journal of Public Health (2009) 99, 355-361) monitored self-reported fruit and vegetable consumption for a single day in 2854 Perth adults in 1995, 1998, 2001 and 2004. The Nutrition Monitoring Surveys were conducted by the Health Dept of WA, and during this period the Dept also ran a ‘Go for 2 and 5’ promotion campaign from 2002 to 2005.
There were no significant changes in the average number of fruit pieces consumed per day between 1995 and 2004, varying between 1.85 and 2.14. Although these figures appear to be in the range of desired levels, like income distributions, the means were skewed to higher values by a minority who consumed much more (11-18% reported 4-6 pieces/d). In 2004, 41% of people said they consumed zero or one piece of fruit on the survey day. Even though women have a smaller calorie and nutrient requirement than men, they ate significantly more pieces than men (+20%), with the higher levels being reported amongst those with higher education and income.
Average number of cups of vegetables consumed on the four survey days was also low, varying from 2.55 to 2.81. As seen in the US study looking at trends over several years, the number of cups of vegetables consumed in the Perth study actually decreased significantly from 1995 to 2004 (-12%). This was despite participants becoming increasingly aware of the recommended level of ‘at least 5 servings of vegetables/d’ following the promotion campaign (34% in 1995 to 67% in 2004), suggesting that lack of compliance is not due to a lack of knowledge; 65 -71% had not tried to change their vegetable intake in the previous 12 months.
The perceived adequacy of fruit and vegetable intakes among the survey participants was 34% and 59% respectively, and 27% said that time and effort involved in vegetable preparation made it difficult to eat more. This latter factor supports the value of fruit as a simple and convenient food that needs little or no preparation and can therefore more easily be squeezed into busy lifestyles in modern society. This time-poor scenario probably isn’t going to improve any time soon, and it’s one of the key factors underlying deficient diets that rely increasingly on ready-made supermarket products and fast food outlets. The particularly high proportion of people who thought their vegetable intake was satisfactory in the Perth study shows just how far we have to travel to favourably impact on general well-being and prevention of chronic diseases in our community.