Sunday, August 22, 2010

What should We Eat?

Most of the illnesses that occur today are chronic like diabetes, heart disease, cancer or kidney disease. These stay with us for the rest of our lives, are debilitating, and are expensive to treat. But in many cases they are not all that difficult to prevent. Unfortunately, our dietary guidelines are of little or no help in this regard but could be.

In 1941, following studies that demonstrated that certain vitamin deficiencies caused specific diseases [thiamine and beriberi, niacin and pellagra, vitamin D and rickets, vitamin A and blindness, vitamin C and scurvy and iodine and thyroid disease], the US Department of Agriculture issued dietary guidelines for the minimum requirements for various vitamins along with those for protein, calcium, phosphorus and iron. These recommended dietary allowances, or RDAs, became the standard for nutrient targets to prevent deficiency diseases.

There followed the addition, for example, of vitamin D to milk and various vitamins like thiamine and niacin to prepared cereals in an attempt to avoid nutrient deficiencies. It was a successful approach but it is not adequate in today’s time for helping to prevent multiple serious chronic illnesses, many of which are beginning to develop in children and young adults.

An article in the Journal of the American medical Association [JAMA] on August 11, 2010 by Mozaffarian and Ludwig urges that we think in terms of “food” and not in terms of “nutrients.” They point our that we know full well that a diet of fresh fruits, vegetables, whole grains and nuts is associated with a lower incidence of chronic illnesses just as certain fish reduce the risk of heart disease.

We also know that processed foods such as lunch meats, fast foods, salty snacks, and sugared beverages increase disease risk. They argue that our “nutrient-based” current approach “may foster dietary practices that defy common sense.” For example, many packaged, processed foods substitute refined carbohydrates for fat and market them as fat free or low fat which they are but they are certainly not healthy. Similarly, many packaged foods such as soups are very high in sodium. “Taking the nutrient approach to self serving extremes, the food industry “fortifies” highly processed foods, like refined cereals and sugar-sweetened beverages, with selected micronutrients and re-characterizes them as nutritious.”

The authors recommend that we not drop our attention to nutrients levels but that we concurrently lessen the focus on nutrients and emphasize food-based targets such as fruits, vegetables, low fat meats and fish. These foods are inherently healthy, are low in saturated fats, have no trans fats, are low in salt, high in fiber and high in nutrients. This approach would be consistent with scientific data on what is healthful, what is likely to help prevent chronic illnesses, would “mitigate industry manipulation” and help us all to understand what a healthy diet can be.

The Department of Agriculture should take these recommendations and put them into action.

Praise for Dr Schimpff

The craft of science writing requires skills that are arguably the most underestimated and misunderstood in the media world. Dumbing down all too often gets mistaken for clarity. Showmanship frequently masks a poor presentation of scientific issues. Factoids are paraded in lieu of ideas. Answers are marketed at the expense of searching questions. By contrast, Steve Schimpff provides a fine combination of enlightenment and reading satisfaction. As a medical scientist he brings his readers encyclopedic knowledge of his subject. As a teacher and as a medical ambassador to other disciplines he's learned how to explain medical breakthroughs without unnecessary jargon. As an advisor to policymakers he's acquired the knack of cutting directly to the practical effects, showing how advances in medical science affect the big lifestyle and economic questions that concern us all. But Schimpff's greatest strength as a writer is that he's a physician through and through, caring above all for the person. His engaging conversational style, insights and fascinating treasury of cutting-edge information leave both lay readers and medical professionals turning his pages. In his hands the impact of new medical technologies and discoveries becomes an engrossing story about what lies ahead for us in the 21st century: as healthy people, as patients of all ages, as children, as parents, as taxpayers, as both consumers and providers of health services. There can be few greater stories than the adventure of what awaits our minds, bodies, budgets, lifespans and societies as new technologies change our world. Schimpff tells it with passion, vision, sweep, intelligence and an urgency that none of us can ignore.

-- N.J. Slabbert, science writer, co-author of Innovation, The Key to Prosperity: Technology & America's Role in the 21st Century Global Economy (with Aris Melissaratos, director of technology enterprise at the John Hopkins University).