The impact of salt on health has been reviewed on a number of occasions over the years with mixed results. The latest meta-review of the evidence was commissioned by the German Ministry of Health just last year and concluded that population-wide salt reduction was not justified from a public health point of view. The controversial nature of the evidence will have great significance for international trade if salt reduction policies are ever enacted. This month's Food Technology Magazine features an OpEd I wrote on this issue.

When the World Trade Organization (WTO) was established in 1995, an international agreement on sanitary and phytosanitary measures (SPS) to reduce risks arising from additives, contaminants, toxins, or pathogens in foods took effect. Intimately linked to the SPS is an additional agreement on Technical Barriers to Trade (TBT), signed in the same year and designed to restrict the use of unjustified measures for the purpose of trade protection.

The aim of the SPS and TBT Agreements is to ensure that regulatory actions are not misused for protectionist purposes and don't result in unnecessary barriers to international trade. The intent is to reduce arbitrary decisions by requiring all health protection measures to be based upon an objective analysis of the preponderance of scientific evidence.

Import regulations that fall under the provisions of TBT or SPS Agreements are typically complex and frequently employ standards that create a high hurdle for imports. Exporters, whose own governments do not implement similar standards, find it difficult to understand the logic or need behind the regulations, so an objective evaluation of the science supporting them goes a long way in resolving disputes.

The core strategy of the recent Institute of Medicine (IOM) Committee report on "Strategies to Reduce Sodium Intake in the United States" is the FDA removal of GRAS (generally recognized as safe) status from salt and the regulation of the amount to be added to each food category. Removing the GRAS status of salt and regulating what is an essential nutrient and arguably the oldest and most ubiquitous food additive in the world will be a monumental task and will undoubtedly have enormous consequences for food and food trade around the world.

Several European countries are major exporters of traditional food products to the U.S. Breads, olives, ham, sausages and cheeses--produced through processes standardized centuries ago--are typical examples. These products and processes are so well established that many are protected with geographic origin designations. Not only are products such as Parmesan and Gorgonzola cheeses, olives, anchovies, prosciutto, and pepperoni consumed directly, but they are also key ingredients in many other products such as pizza and pasta dishes.

These traditional products were developed long before refrigeration. Many employ high salt levels for debittering (olives), curing (hard cheeses), mold culturing (blue-veined cheeses), water activity control (black forest and prosciutto hams, corned beef, salamis, etc.), and storage (anchovies, capers, fish roe, salt fish). The intent of the IOM report makes it unlikely that these traditional products will be permitted. While it is impossible to say whether low-salt variations of these products will achieve market success or whether salt replacement additives will themselves come under regulatory analysis for potential health issues, one thing can be predicted with a fair degree of certainty. Regulation of the salt content of foods will be carefully scrutinized regarding its impact as a non-tariff trade barrier.

For exporters of traditional French, Greek, and Italian foods, the health benefits of the high salt content Mediterranean Diet have been acknowledged for centuries. Despite Americans' stable consumption of salt for the past three decades, ischemic heart disease death rates in the U.S. have fallen precipitously. All of the above are rational reasons to invoke the SPS and TBT Agreements to challenge whether the regulation of salt in foods is an arbitrary measure and an unjustified barrier to trade or one supported by the preponderance of scientific evidence.

Supertasters are people who experience taste with far greater intensity over the average. It is estimated that about 25% of the population are supertasters and women are more likely to be supertasters than men as are Asians and Africans. The cause of this heightened response is thought to be due to an increased number of fungiform papillae or taste buds. Although one would think that the taste sensation would be an advantage if it is more sensitive, this is not always the case. An increased response to bitterness may severely limit the range of foods that are palatable. Vegetables have important phytochemicals that are protective of heart disease and cancer risk but their natural bitterness may turn supertasters off.

A potential unintended consequence of population-wide salt reduction has been highlighted in a paper by John Hayes and colleagues from Pennsylvania State University, published in the latest edition of Physiology and Behavior .

Hayes and colleagues examined the response of supertasters to varying amounts of salt in a wide range of foods. As indicated previously, these supertasters make up about 25% of the population and are genetically hypersensitive to bitter tastes, leading them to naturally avoid some vegetables and other foods that taste naturally bitter.

The researchers measured the liking and intake of foods with varying amount of saltiness among 87 healthy adults (45 men).

Supertasters reported greater saltiness in chips and pretzels and soup broth at levels comparable to regular-sodium products. They also found greater sensory enjoyment to growing salt concentration in cheeses (where sodium ions mask bitterness).

Despite adding less salt, supertasters consumed more sodium through food, as salt was more important to preference, both for its salty taste and masking of bitterness. This suggested to the researchers that supertasters appreciate increased salt in food formulations to mask naturally bitter foods particularly vegetables and other foods that may be deemed to be healthy.

The Dietary Guidelines Advisory Committee (DGAC) of the U.S. Department of Health and Human Services and the U.S. Department of Agriculture may increase health risks, including obesity, by ignoring sound science as they announce recommendations to reduce sodium consumption to 1,500 mg per day. It is reckless for the government to risk the health of Americans by relying on substandard levels of evidence and refusing to consider new evidence.

The rationale behind the recommendation is purportedly blood pressure reduction. While no one doubts that a small percentage of our population may experience modest blood pressure declines from salt reduction, it has not been scientifically established that a population-wide reduction will benefit overall health. Research indicates health risks for some on low salt diets, including higher risk of heart attacks. And new research shows that not a single modern society consumes such a low level of salt as that recommended (less than 4 grams of salt per day). This recommendation is essentially an unauthorized massive clinical trial using 300 million Americans as guinea pigs.

Recent research (Can Dietary Sodium Intake be Modified by Public Policy? David A. McCarron, Joel C. Geerling, Alexandra G. Kazaks, Judith S. Stern) involving data collected from more than 19,000 individuals in 33 countries has demonstrated that healthy humans, all around the world, consume sodium within a relatively narrow range (2700 mg- 4900 mg sodium) – a range controlled by a number of physiological mechanisms. The DGAC recommended level of 1500 mg is drastically lower and will result in unintended health consequences if Americans strive to reach the recommended target.

Most nutritionists agree that reduced sodium in food preparations will very likely increase the obesity crisis because individuals will consume more calories just to satisfy their innate sodium appetite and their search for eating satisfaction.

Perhaps the greatest failure of the Dietary Guidelines is their priority focus on single nutrients rather than the whole diet. Concerns over blood pressure would be better addressed if Americans would eat more salads, vegetables and fruits. Italians consume more salt than Americans yet they have better cardiovascular health because they eat a well balanced diet. They use salt to make healthy foods more delicious...without adding calories.

The public comment period on the Dietary Guidelines is June 15 to July 15.