Foodborne Illness: How Safe is Your Food?

By Casey Adams, Ph.D.

Panic seems to grip our nation periodically with foodborne illness outbreaks. The past year witnessed a number of big recalls, and in recent years a variety of foods and beverages were pulled from shelves after reports of sicknesses from foodborne bacteria.

The peanut butter contamination early this year was the largest food recall in U.S. history. After Salmonella was found in some batches, billions of dollars of foods with even trace amounts of peanut butter were tossed out. Last summer some salsa products were found to contain Salmonella, forcing a huge recall that dearly cost the tomato farming industry. (It was later found that peppers from Mexico were responsible.) In 2007, a Listeria outbreak was blamed on milk products coming from a Massachusetts farm. In 2006, an outbreak of E. coli poisoning was blamed on spinach supplied by a California spinach grower. In 1999, Salmonella was found in unpastuerized orange juice from Mexico. In one of the more sensational E. coli outbreaks, Odwalla apple juice sickened sixty children with one death.

These are but a few of the many recalls and outbreaks of foodborne bacteria over recent years in the U.S. By far, most outbreaks are meat-related, but these are no longer sensational news. It is more sensational when a healthy food causes a foodborne outbreak.

What is going on here? Should we shudder when we buy and eat commercially prepared foods? Should we trust the pasteurization and sterilization processes supposedly supervised by the FDA and state health departments? In other words, can we trust our foods, and if so, which ones?

As a naturopath with a Ph.D. in natural health sciences, I am asked these sorts of questions quite often. My background in the natural food and beverage industry has also given me a perspective into the realities of commercial food preparation. Thus, my ability to answer these questions is unique. And so are some of my answers.

WHAT CAUSES FOOD-BORNE ILLNESS?

Food contamination can come from many sources. The harvesting and plant environment, the cleanliness of workers, food washing techniques and water quality can all infect food. An unsanitary facility can give rise to many bacteria, and these can get into the food during preparation. This was the case with the peanut outbreak, as the walls and ceiling tiles of the peanut factory were found moldy and bacteria-ridden. Bacteria can also reside within filling systems and packaging equipment.

A number of viruses and bacteria can reside within our foods. Clostrium botulinum can grow in food or juice containers, especially cans, to produce a sometimes-deadly disease called botulism. Campylobacter species is one of the most common foodborne bacteria, often prevalent in meat. This causes diarrhea, fever and cramping, but rarely death. The E. coli O157:H7 bacteria can sometimes be lethal (verocytosis) in immune-suppressed people. Mostly E. coli infection results in nausea and diarrhea. Salmonella is prevalent in the intestines of many wildlife, including birds, reptiles and other animals (including humans) and can sicken humans. Giardia, Shigella, Staphyloccus aureus, Mycobacterium tuberculosis, Yersinia enterocolitica, Campylobacter jejuni, Cryptosporidia and Listeria monocytogenes can also infect food, especially if they are prepared from infected water sources or from infected food handlers’ hands. Some viruses can also infect food. Calcivirus or Norwalk-like virus infections have been documented, mostly from fish and oysters, but can also be through hand contact. Trichinosis, quite common in pork, can also seriously sicken. Testing has also shown that 1 out of 20,000 commercial eggs are contaminated by Salmonella enteritidis.

While warm, moist environments are favored, bacteria can survive extreme environments. They can survive in the fridge, the freezer and even in low-oxygen vacuum containers. In colder temps, bacteria can incubate. A little warm moisture will revive them. Many food-borne bacteria colonize via the release of spores, which can survive even the most harsh conditions—including pasteurization. A single spore can quickly grow into an entire colony of bacteria.

WHAT IS PASTEURIZATION?

French chemist Louis Pasteur developed pasteurization in the 1860s to disprove the notion of spontaneous generation—a theory that some put forth to explain how life arose from chemicals. Pasteurization is by far the process that commercial food manufacturers use the most to reduce bacteria in foods and beverages. Studies have shown that about 99.99% of bacteria colonies are removed with this process.

Today pasteurization is used for practically every commercially packaged food that has significant water or moisture content. This includes practically every shelf-stable canned food, sauce and mix in jars. Today even produce, nuts, fruit, pre-packaged dinners, entrees, and refrigerated juices are also commonly pasteurized.

Pasteurization is the heating of a food to a point where a large percentage of the bacteria are killed. There are five basic types of pasteurization: Holder or steam pasteurization, high temp or flash pasteurization, ultra high pasteurization, irradiation pasteurization, and gas pasteurization.

Holder, vat, tunnel or steam pasteurization requires bringing the food or liquid to 140-145 degrees Fahrenheit for a period of about thirty minutes. For many foods, this takes place by heating the product after being packaged. Cans, for example, will be stored away into an airtight jacketed chamber. This might even follow kettle cooking and “hot-filling.”

Steam or tunnel pasteurization is used for many sauces and juices, especially those packaged in glass. Before this process, the product may still be heated and hot-packed. Following filling, the jar or container is sealed and placed on a conveyor belt, which carries it through a heated tunnel. The tunnel bakes the product while super-hot water is sprayed onto the package. This creates a blanket of hot steam in the tunnel. This combination heats the package and its contents to the desired temperature. Following the hot steam, a cooling section of the tunnel sprays colder water on it to cool the product down.

Flash or high pasteurization (also called HTST for “high temperature, short time”) is done primarily on liquids or slurry products. HTST will take the food or liquid to 160-165 degrees for 15 seconds. For some liquids, the temperature and time is different. Regular milk (non-UHT), for example, is typically pasteurized by heating to 120 degrees for about 20 seconds. HTST is typically done by running the product through a series of pipes and heat exchanger plates that boost its temperature quickly. Following this, the product is filled into the container. Some processors will run it through another heating tunnel after packing just to be on the safe side. Note that the expression “flash pasteurized” has been used in marketing to imply a system somehow less damaging than high temp pasteurization.

Ultra pasteurization (UP) will heat the liquid higher, sometimes over 200 degrees F, for a few seconds. Time and temperature can range, depending upon the product and the desired outcome. The intense heat of ultra pasteurization typically doubles the shelf life compared to regular pasteurization.

Then there is ultra high temperature pasteurization, or UHT. UHT will usually heat the food or liquid to about 280 degrees F, but only for a range from a half-second to two or three seconds. This is done mostly for liquids, which are run through a number of extreme heat exchanging chambers before being packaged, usually in an ‘aseptic’ vacuum package. UHT will typically allow a product to be put on the dry shelf for an extended period. This process is also sometimes referred to as sterilization.

Irradiation pasteurization is a growing method of reducing microorganisms from produce and other products. Because it does not raise the temperature of the product as high, it is also sometimes marketed as “cold pasteurization.” Imported produce is now commonly irradiated as shipments arrive. Increasingly, large U.S. food producers irradiate their ‘fresh’ products because the appearance and flavor of the product is often preserved. The most common method uses cobalt-60 radioactivity. X-rays and gamma rays are also used. Irradiation is not allowed in organic produce. There is also some concern regarding worker health in irradiation plants.

Gas pasteurization is used for a limited number of foods. Almonds and other nuts, for example are sometimes pasteurized by either gassing them with propylene oxide or hot steam. Organic nut production, of course, does not allow propylene oxide.

For milk and other liquids, UHT and HTST also accompany homogenization. Homogenization blends and mixes the product significantly, which can alter molecular polarity and structure.

Commercial foods that have higher acidity (usually with a pH of less than 4.6) and/or intense sugar content may be able to skip pasteurization. Commercial manufacturers usually have to pass a state pH test before they can package a liquid product without pasteurization. A few foods that are commercially unpasteurized include some balsamic vinegars, kombucha tea, hummus, honey, maple syrup, and a variety of fermented foods. Most juices like orange, apple, carrot and berry used to be commercially available fresh. After the Odwalla outbreak in the 90s, many regulators began requiring HTST for mass-distributed refrigerated fruit juices. Raw milk has been readily available commercially for thousands of years until recently. The FDA and state regulators have increasingly clamped down on commercial distribution of raw packaged foods due to the political sensationalism created by the 24-hour cycle of the news media.

IS PASTEURIZED FOOD HEALTHY?

This is an important question. Most nutrients are heat-sensitive. Vitamin C, fat-soluble vitamins A, E and B vitamins and even certain amino acids are depleted during pasteurization. Important plant nutrients such as anthocyanins and polyphenols are also reduced during pasteurization, along with various enzymes. Proteins are denatured or broken down when heated for long. While this can aid in amino acid absorption, it can also form unrecognized peptide combinations. In milk, for example, nutritious whey protein, or lactabumin, will denature into various peptide combinations, some of which are not readily absorbed.

A 2008 study on strawberry puree from the University of Applied Sciences in Switzerland showed a 37% reduction in vitamin C and a significant loss in antioxidant potency after pasteurization. A 1998 study from Brazil’s Universidade Estadual de Maringa determined that Barbados cherries lost about 14% of their vitamin C content after pasteurization. During heat treatment, vitamin C will also convert to dehydroascorbic acid, with a loss of bioflavonoids.

A 2008 study at Spain’s Cardenal Herrera University determined that glutathione peroxidase—an important antioxidant in milk—was significantly reduced by pasteurization. In 2006, this university also released a study showing that lysine content was also significantly decreased by milk pasteurization. A 2005 study at the Universidade Federal do Rio Grande determined that pasteurizing milk reduced vitamin A (retinol) content from an average of 55 micrograms to an average of 36.6 micrograms. A study at North Carolina State University in 2003 determined that HTST pasteurization significantly reduced conjugated linoleic acid (CLA) content—an important fatty acid in milk shown to reduce cancer and encourage good fat metabolism.

A 2006 study on bayberries at the Southern Yangtze University determined that plant antioxidants anthocyanins and polyphenolics were reduced from 12-32% following UHT pasteurization. Polyphenols are the primary nutrients in fruits and vegetables that render anticarcinogenic and antioxidant effects.

Probably the most important loss from pasteurization is enzyme content. Plant foods contain a variety of enzymes that aid in the assimilation or catalyzing of nutrients and antioxidants. These include xanthines, lysozymes, lipases, oxidases, amylases, lactoferrins and many others. Food enzymes also deter the formation of certain microbes, and help keep product from spoiling. The body uses food enzymes in various ways. Some enzymes, such as papain from papaya and bromelain from pineapples, dissolve artery plaque and reduce inflammation. While the body makes many of its own enzymes, it also absorbs some food enzymes or uses their components to make new ones.

Pasteurization also typically leaves the food or beverage with a residual caramelized flavor due to the conversation of many flavinoids and sugars to other compounds. In milk, for example, there is a substantial increase in lactulose from lactose after UHT pasteurization. Lactulose can cause intestinal cramping, nausea and vomiting.

As for irradiation, there is little research on nutrient content, but there is some evidence that irradiation may denature protein and nutrient molecules.

SHOULD WE AVOID ALL PASTEURIZED PRODUCTS?

Not necessarily. By all means, processed shelf-stable foods should be HSTS, holder or tunnel pasteurized—basically the same as being cooked. Any time a natural food is converted into a processed food—in other words, crushed, extracted, or ingredient isolated—it becomes disconnected from the full matrix of protective elements that nature provides to preserve food. Once processing takes place, the food becomes open to mass colonization by microorganisms, which can make us sick.

Whole foods in nature’s packages are significantly different from processed foods, however. Fresh whole foods produced by plants contain various antioxidants and enzymes that reduce the ability of microorganisms to grow. The Creator also provided whole foods with peels and shells that protect nutrients and keep most microorganisms out. Microorganisms may invade the outer shell or peel somewhat, but peel’s pH, dryness and density; and the pH of the inner fruit work together as a barrier to most microorganisms. For this reason, most fruits and nuts can be easily stored for days and weeks without having significant microbiological risk. Once the peel or shell is removed, the inner fruit, juice or nut must be eaten quickly to prevent contamination.

As for milk and milk products, raw milk contains a number of natural probiotics that effectively balance most of the bacteria in milk. Just as they balance our body’s microbiotic content, the probiotics in milk will typically prevent microorganism overgrowth and infection. Even so, raw milk should be purchased—if available—with caution. Raw milk should only be purchased from certified organic dairies that thoroughly test for certain bacteria such as tuberculosis. The dairy should also be primarily grass-fed rather than grain-fed. An organic grass-fed cow is less prone to many diseases because fresh grass helps prevent disease—just as fresh, raw foods help prevent disease in humans.

DO WE HAVE BACTERIA PARANOIA?

Yes. Our bacteria paranoia began in the 1860s with Louis Pasteur’s insistence upon the germ theory—a proposal that all disease was caused by microorganisms. To prove his point, he cruelly infected various animals with bacteria and studied their demise against uninfected controls. Yes, he proved that bacteria can cause certain diseases, assuming inoculation beyond the point of immunity.

However, he missed a central component of the equation. The fact is, our entire planet is covered with infectious bacteria in numbers beyond calculation. Each human body contains trillions of bacteria. So if the outside and inside world is covered with bacteria, why are we not all sick and infected all the time? How could some of us be healthy with so many bacteria around?

Microbiologists Antoine Bechamp and Claude Bernard, peers of Pasteur, took issue with Pasteur’s germ theory. They proposed the important issue in disease is not the bacteria, but the field, or environment within the organism. In other words, a healthy organism with strong immunity and probiotic populations can counter infective bacteria. Those who get sick, they proposed, were those with weakened, compromised immune systems.

We can confirm the field theory simply, because food-borne outbreaks result in the sickness and death of only a few people—while hundreds of thousands actually consumed the contaminated products.

In fact, many of our foods typically contain E. coli, Salmonella and many other bacteria species, and do not make people sick.

Unfortunately, the germ theory prevailed, and this unleashed the genie of antibiotics and so many other pharmaceutical panaceas over the last century. While many of these medicines have helped millions recover from infection, the over-prescription of antibiotics has also destroyed internal probiotic populations while creating many superbugs more powerful than the previous bacteria. In other words, the germ theory solution has created more deadly germs!

By far the best way to counteract bacteria is to develop a strong immune system and probiotic colonies. Those with healthy immune systems and probiotic populations will not get sick from eating a limited amount of contaminated foods. In fact, most of our bodies contain E. coli and Salmonella! E. coli is a common bacterium residing in the intestinal tract. Why do we not get sick from it? Because our probiotic bacteria populations keep E. coli populations in check. Like the many other bacteria in our bodies, including Candida and Staphylococcus species, E. coli in controlled populations perform a number of tasks useful to the body.

You see, like animals in the forest, bacteria colonies tend to control each other’s populations. In a healthy body and natural environment, our bodies harbor enough probiotics with their own ‘smart’ antibacterial strategies to keep most bacteria from overgrowth. Our body’s probiotics make up about 70% of our immune system. Beyond that, the body produces a number of antibodies and lymphocytes that identify and break down other microbial and viral infections.

This does not mean that we should not be careful with our foods and surroundings. Nor should we not take antibiotics in the case of a life-threatening emergency. Our minds are also part of our immune system. We should carefully wash our hands and wash our fresh foods before eating. We should put fresh foods in the refrigerator to avoid spoilage. We should eat fresh, local, organic whole foods with a minimal of processing and a minimal of cooking to maximize our antioxidant, enzyme and nutrient consumption. Certainly, whole grains and beans should be cooked. Other fibrous plant-based foods can be steamed or low-flame stir-fried.

If raw milk cannot be found from a trusted source, then organic non-homogenized HTST pasteurized (not UHT or UP) milk is probably the best choice. (Homogenizing denatures the enzyme xanthine oxidase—an important oxidizing catalyst.) An even better choice is probiotic-fermented organic dairy such as yogurt, buttermilk and kefir.

Now relax and have that peanut butter sandwich with your yogurt.