Strategic nutrition: a vision for the twenty-first century.

It is now widely accepted that poor nutrition plays a major role in the epidemic of various diseases, including obesity, type 2 diabetes and CVD. There has also been much research regarding the role of related factors such as advertising and food prices. Many intervention studies have been carried out where attempts have been made to persuade people to modify their behaviour, such as by making dietary changes, in order to enhance health (health promotion). There has also been much debate on the potential of government policy as a tool for achieving these goals. Various proposals have been made, such as a tax on sugary drinks, the redirection of food subsidies and how the salt content of food can be reduced. However, the great majority of previous papers have considered only single aspects of the topics discussed here. The present paper reviews strategies for improving public health, both health promotion interventions and the use of government policy approaches. Topics discussed include providing advice for the general population and the design of food guides and food labels. This leads to the conclusion that we need an overall strategy that integrates this diverse body of information and formulates a comprehensive action plan. I propose the term 'strategic nutrition'. The implementation of this plan opens up a path to a major advance in public health.

The marketing of dietary supplements in North America: the emperor is (almost) naked.

BACKGROUND: Many different dietary supplements are being sold in North America. The quality of the evidence supporting their efficacy covers a wide spectrum: Some are based on solid science (such as vitamin D and fish oil), whereas with most supplements there is little or no supporting evidence. Types of supplements commonly sold include exotic fruit juices (such as goji juice) and single herbs or mixture of herbs. Common claims made in support of particular supplements are that they are rich in antioxidants, induce detoxification, stimulate the immune system, and cause weight loss. Supplements are commonly sold through health food stores and by multilevel marketing. Sales may be promoted using bulk mail ("junk mail"), spam e-mails, and Web sites. A large part of marketing is based on claims that are blatantly dishonest. CONCLUSIONS: Whereas supplements for which good supporting evidence exists generally cost around $3-$4 per month, those that are heavily promoted for which there is little supporting evidence cost about $20-$60 per month. The major cause of this problem in the United States is weakness of the law. There is an urgent need for stricter regulation and for giving better advice to the general public.

Advice on dietary supplements: a comparison of health food stores and pharmacies in Canada.

OBJECTIVES: Our first objective was to determine the accuracy of information provided to customers in health food stores (HFS) in Canada. The second objective was to compare the accuracy of this information with that provided to customers in pharmacies. METHODS: Undergraduate students visited 192 HFS and 56 pharmacies, located across Canada. In approximately half of the stores, they asked whether a specific supplement would help to prevent a particular condition or enhance health in a particular way. In the rest of the stores, they asked for advice on particular health concerns. RESULTS: On 88% of times that questions were asked in HFS, the recommendations made were either unscientific (6%) or were poorly supported by the scientific literature (82%). By contrast, this occurred for only 27% of visits to pharmacies (p < 0.01). Conversely, on two thirds of visits to pharmacies, staff gave advice considered to be fairly accurate or accurate, but this seldom occurred in HFS (68% vs. 7%, p < 0.01). CONCLUSIONS: The vast majority of information provided in HFS in response to questions has little scientific support. Pharmacies are a far more reliable source of information, although they still have significant scope for improvement.

Fruit, vegetables, and the prevention of cancer: research challenges.

OBJECTIVE: A great deal of epidemiologic evidence has indicated that fruits and vegetables are protective against numerous forms of cancer. However, there are many gaps in our knowledge. METHODS: In this pilot study we reviewed more than 200 cohort and case-control studies to determine the shape of the dose-response relationship (i.e., how the risk reduction per extra serving of fruits and vegetables changes with the actual intake of these foods). We found major barriers to investigating this. As part of this pilot study we also investigated whether specific fruits and vegetables are responsible for the anticancer action of these foods or whether a wide variety is required for optimal protection. If the former is correct, then fruits and vegetables may contain one or a small number of "magic bullets"; if the latter is correct, then a "teamwork" concept may be valid. RESULTS: Different findings suggested that the teamwork concept is much more likely. Many studies, especially older ones, have ignored potential confounding variables such as energy intake, alcohol consumption, physical activity, body mass index, smoking, and socioeconomic status (although many recent studies have adjusted for education). Other potential confounders that have generally been ignored are consumption of whole grain cereals and the use of vitamin and mineral supplements. CONCLUSIONS: The inverse association between intake of fruits and vegetables and the risk of cancer of the colon, breast, and stomach has generally been much stronger in case-control than in cohort studies. We have no clear explanation for this.

Nutrition and disease: challenges of research design.

This review discusses research methodology in the relation between diet and disease. Medical research can be divided into two types: complex research (the detailed study of disease mechanisms using such methods as biochemistry and molecular genetics) and simple research (the investigation of the factors that cause or prevent disease using methods such as epidemiology, intervention trials, and analagous studies on animals). Although complex research has received the bulk of resources, the large majority of our information of practical value has come from simple research. This general principle is illustrated in the area of diet and disease by examples from various areas: selenium, carotenoids, and cancer; vitamin E, omega-3 fatty acids, and coronary heart disease; dietary fat and obesity; dietary sodium and hypertension; and alcohol and stroke. Discussion then turns to aspects of the design of cohort (prospective) studies. Because of problems of sample size and relative lack of diversity, previous studies often failed to give clear-cut results. Suggestions are made concerning the design of cohort studies, notably the use of much larger numbers of subjects and with greater diversity in their diets. The problem of confounding also is discussed. Lifestyle factors often cluster together but cohort studies may not have fully unraveled this.