Knowing what foods are healthful these days can be a challenge.  Should I eat certain types of fish because of their high levels Omega-3 Fats or avoid them because of their concentration of heavy metals such as mercury?  Should I eat more fiber rich grains or will such carbohydrates just make me fat?  Are “Free-range” chickens any better for me than those raised in confinement?  These are the types of nutrition topics for which there are often conflicting – even confusing – claims and counter claims.

In this article I will explain some of the reasons for the endless series of conflicting diet advice and how to separate fiction from fact.  Let’s begin by accepting that there will always be some amount of misinformation promoted by people or organization with profit or political motives.  Companies, industry organizations, and individuals wishing to sell us there products will always be tempted to twist the facts to make the sell.  Can you envision the National Pork Board promoting research suggesting that you should eat less pork?

Setting aside the normal propaganda, there are legitimate challenges to providing clear and conclusive “Scientific” answer regarding what foods are more health promotion than others.

Nutrition researchers encounter many difficulties in studying food’s effects on our health.  The main challenges include issues with collecting data, separating multiple variables, and determining cause when correlations are discovered.

Collecting research data for nutrition studies often requires participants to complete lengthy surveys or maintain logs regarding what they eat.  The two biggest issues with these methods are that subjects may have a hard time recalling or documenting with accuracy the foods they consume.

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Although studies with animals and live cells in test tubes allow for a more controlled laboratory environment, it is hard to say with certainty that the outcomes of these types of studies mirror the reactions in the human body.

Assuming researchers have a supply of useful data, the next major hurdle is determining how to isolate the variable(s) that are being studied.  One major problem in this area is the fact that when study participants eat more of one food they naturally consume less of another.  For example, if one sets out to determine the effect of eating fresh spinach on cholesterol levels,  it is very likely that people eating significantly large quantities of spinach leaves everyday will also eat less of something else such as meat.  Hence, is the outcome a result of more spinach or less meat?  This is an inherent challenge of dietary research.

Let’s say a researcher manages to collected a substantial amount of reliable data and has been able to isolate an important variable.  One additional challenge is being able to say with scientific certainty that the isolated variable caused whatever effect took place.

The ongoing research with tomatoes and the antioxidant Lycopene illustrates this challenge.  In studies with men, who ate large amounts of tomato sauce, the subjects were noted as having high levels of Lycopene in their bodies.  They also experienced lower incidence of prostate cancer.  The immediate conclusion and media headline was “Lycopene Prevents Prostate Cancer”.  Unfortunately, follow-up studies focusing specifically on Lycopene consumption did not demonstrated any lower rates of  prostate cancer.  The follow-up research suggests that something other than Lycopene alone was responsible for the original lower rate of cancer.

Considering just this hand-full of challenges in the world diet research, it is easy to understand how so much confusing information leaks into magazines, books, news casts, and onto the internet.

In light of all it takes to make a truly valid food health claim, how does one navigating the maze of questionable nutrition advice?  Here at a few useful tips when shifting through the sea of “Diet Information” :

Consider who is making the claim:  If an organic farming organization is promoting the wisdom of spending twice as much for produce because it’s “Healthier”, it would best to verify the claim with an independent source.
Scrutinize the specific health claim:  It is not enough to simply except, for example, “Red Wine is good for you” .  How much red wine must I drink to receive any benefit?  At what amount does the extra calories out weight the other benefits?  What nutrients are makes it healthful?  Are there other source for acquire the nutrient?  Is the claim supported by long-term scientific studies?  Asking yourself these types of questions will help to expose weak claims.
Determine if the claim passes the Common Sense Test:  When presented with a new food health claim ask the question, how does this claim square with the current information on this topic?.   Does the explanation accompanying the claim make good sense?

In the end, be weary of health claims made by sources with questionable motives, that don’t hold up to basic scrutiny, and that don’t make sense on the surface.

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