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Nutrition matters

BMJ 2014; 349 doi: (Published 27 November 2014) Cite this as: BMJ 2014;349:g7255

Nutrition matters far more than we know

A modern view of nutrition and health goes far beyond overweight, calories and nutritional requirements. The body is made of parts that come from food. We are what we eat; we function based on what we eat.

Through evolution, each species evolved to eat a narrow range of foods. Practically all species eat foods as they are, in their natural state. Humans are able to create new foods either by processing existing foods into new states (e.g., flour) or making new chemicals in large quantities (e.g., trans fats) or eating nutrients (in quantity or quality) far outside the evolution range.

Human bodies have vast regulatory capacities to manage wide range of foods. A combination of genetic changes and adaptive behavior allows humans to live almost anywhere on earth, and to process (digest, absorb, use) many different foods. But these regulatory abilities are likely different among individuals (meaning there is no optimal diet for everyone in any place, the best foods for Eskimos are not the best foods for natives in hot Africa or Latin America). Similar analysis apply to disease.

There are limits to regulation or adaptation. It is now easy to exceed the body’s regulatory system and cause disease. We can eat so many quantities of vitamins or minerals that exceed the body’s capacity to process them. Over time, we can eat so much of certain foods, such as fats (remember, we store as “fats” excess calories of any nutrient, which means that high calories from low fat high carbs or high fat low carbs are equivalent), or isomers of fats (e.g., trans) or calories that they accumulate in the body and cause disease (e.g., cardiovascular disease, diabetes type 2, immune disorders).

The body regulates itself and fights infection and disease via a wide range of “chemicals.” The production of these chemicals (and thus our ability to fight infection or cancer or prevent wear and tear with age) depends on what we eat. Production of eicosanoids and its derivatives (which influence inflammation, etc.) depend on the quantity and balance of fatty acids and calories. Thus, nutrition is the most powerful treatment; we need to understand better how it works. This is particularly important in children, whose bodies are being formed as they grow.

We now have adequate evidence that some disorders are best treated with specialized diets. Crohn’s disease improves dramatically using Exclusive Enteral Nutrition (EEN) with an elemental diet (treatment of choice in Europe, though not used enough in the US). Diabetes type 2, cardiovascular disease improve substantially on low calorie high essential fat diets (many published in journals, e.g., bmj). We know very little about accurately measuring individual nutrients and their effects on body function. We need to rethink medical education and clinical practice. We need a new theory of diseases that better connects to nutrition, and far greater emphasis on behavior modification instead of complex procedures. Doctors should look themselves in the mirror and start with themselves and their families. In the past 10 years, I noticed a huge increase in weight and diameter of health professionals attending health conferences. They have GI and skin disorders likely caused by suboptimal diet.

E Siguel, MD, PhD

Siguel, E. Deficiencies and Abnormalities of Essential Fats in Gastrointestinal and Coronary Artery Disease. Journal of Clinical Ligand Assay 2000; 23:104–11.
Siguel, E. Clinical Impact of Methodological Issues in the Diagnosis of Deficiencies and Abnormalities of Essential Fats. Journal of Clinical Ligand Assay 2000; 23:112–21.

Competing interests: No competing interests

03 December 2014
Eduardo N Siguel
Physician, researcher
PO Box 10187, Gaithersburg, MD 20898, USA