Nutritional supplements and your health

Nutritional supplements (NS) are a hot topic in the Canadian media at the moment. Both the FifthEstate and Marketplace aired programs looking at the effectiveness and quality of NS sold in Canada. After watching the information presented it would certainly make you question whether NS should be effective and safe part of improving maintaining your health.

Do NS help?

In clinical practice, it is important to look at what evidence there is to show that something works. This can come in two forms, scientific research, and clinical observation. When looking at the scientific data it is commonly agreed among researchers that the best source to derive any truly meaningful evidence that something works is from research papers that review and analysis the data from some studies. These are called systematic reviews with meta-analysis  (SRMA). When looking at the most recent SRMAs looking at Vitamin and mineral supplements, the conclusions are varied between NS may give benefit, no benefit or even harm to health. Table 1 below shows a summary of the latest SRMAs. I have used some NS throughout the vast majority of clinical practice, beginning in 1997. From my observations of my clients, which have come to me already taking NS I would have to agree with scientific data that results are mixed. When prescribing any NS are am a big believer in using some form of testing to determine whether to recommend a client takes something. When adopting this approach in the majority cases, I have seen both objective and subjective benefits.

The case for food and exercise

While I have seen some remarkable results from prescribing supplements, these benefits have been limited to resolving specific problems and not overall health. From my 18 years of clinical practice, the most effective therapeutic approach I have observed has been from diet and exercise modification. This observation is pretty much in line with the scientific data from the most recent SRMA’a on the effect of diet and exercise on overall health. Diet and lifestyle modifications may have benefits in the management of Alzheimer's, Chronic Disease, Diabetes, obesity, visceral fat and overall health. Table 2 below shows a summary of the latest SRMAs looking at the effect of diet and exercise on health. There seems to be a particularly heavy weight of evidence suggesting that consuming more fruits and vegetables and incorporating exercise can have benefits for overall health.

In conclusion

I see NS very much in the same light as drugs they are simple solutions used to try and solve complex problems. Humans are complex beings and as such you need complex solutions to prevent and resolve health issues. Real food provides that complex solution, and this is born out from my clinical observations and current scientific research. If you are searching for that magic pill you are probably going to be disappointed.

Table 1

Supplement	Conclusions
Multivitamin and minerals	There is no evidence to support the use of vitamin and antioxidant supplements for prevention of cardiovascular diseases.
	There is sufficient evidence to substantiate the role of dietary multivitamin/mineral supplements for the decreasing the risk of age-related cataracts.
	Unlike observational epidemiological studies, this meta-analysis of RCTs suggests that there is no clinical evidence to support the efficacy of vitamin and antioxidant supplements in the prevention of esophageal cancer.
B Vitamins	B vitamin supplementation, when used for primary or secondary prevention, is not associated with a reduction in MACE, total mortality, cardiac death, MI, or stroke.
	A meta-analysis of 10 RCTs showed a borderline significant increase in the frequency of overall cancer in the folic acid group compared to controls.
Vitamin D	Continuing widespread use of vitamin D for osteoporosis prevention in community-dwelling adults without specific risk factors for vitamin D deficiency seems to be inappropriate.
	The effect size for Vitamin D in depression demonstrated in this meta-analysis is comparable with the effect of anti-depressant medication, an accepted treatment for depression.
Calcium	Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD, which are unlikely to lead to a clinically significant reduction in risk of fracture.
	Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.
Chromium	Data from RCTs show no effect of chromium on glucose or insulin concentrations in nondiabetic subjects. The data for persons with diabetes are inconclusive. RCTs in well-characterized, at-risk populations are necessary to determine the effects of chromium on glucose, insulin, and Hb A1c.
Zinc	Zinc supplementation has favorable effects on plasma lipid parameters. Zinc supplementation significantly reduced total cholesterol, LDL cholesterol, and triglycerides. Therefore,  it may have the potential to lessen the incidence of atherosclerosis-related morbidity and mortality.
Antioxidants	Treatment with beta carotene, vitamin A, and vitamin E may increase mortality.

 Table 2

Diet	Conclusion
Diet and Exercise	Moderate-quality evidence from the present network meta-analysis suggests that D + E can be highly recommended for long-term obesity management.
	Results suggest that an aerobic exercise program, without hypocaloric diet, can show beneficial effects to reduce visceral adipose tissue.
Mediterranian Diet	The Mediterranean diet was associated with better glycemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes.
	The Mediterranean diet in children may prevent asthma or wheeze.
Fruits and Vegetables	Sub-types of vegetables, such as root vegetables or green leafy vegetables may be beneficial for the prevention of diabetes while total FVI may exert a weaker overall effect.
	Green leafy vegetables may help prevent bladder cancer.
	This meta-analysis showed several inverse associations between fruit and vegetable intake and prospective improvements in anthropometric parameters, and risk of adiposity.
	This critical review of the associations between the intake of vegetables and fruit and the risk of several chronic diseases shows that a high daily intake of these foods promotes health.
	The evidence reviewed provides additional support for increased consumption of a wide variety of vegetables, in particular, dark-green leafy, cruciferous, and deep yellow-orange ones, and a wide variety of fruits, in particular, citrus and deep yellow-orange ones. Continued attention to increasing fruit and vegetable consumption is a practical and important way to optimize nutrition to reduce disease risk and maximize good health.
Exercise	Decreased physical activity were particularly strong predictors of incident AD.