Parasite Protection

We don’t often think about parasites. But vacationers headed to a tropical country are often cautioned not to drink the water to avoid the ravages of traveller’s diarrhea. The culprits behind this humiliating affliction are pathogenic intestinal parasites, mainly protozoa that specifically colonize the human intestinal tract.

Some parasites live off human hosts, while others colonize the digestive tracts of other mammals, including livestock and household pets. Parasites usually enter the food or water supply via fecal contamination. In tropical areas it never gets cold enough to kill parasites, so they can remain alive in moist soil or water for months. Therefore, human and animal waste used as fertilizer poses a risk for many vegetable and fruit crops.

Most pathogenic parasites remain confined to tropical countries that lack basic sanitation, but some are common worldwide -— they either can live in colder climates or are continually brought in via travel, immigration, and agricultural products.

Trouble in paradise

Parasites are endemic to populations of tropical developing countries in Africa, Asia, and Latin America. Many of the local people have parasite infections that are benign for natives but severely pathogenic for newcomers or vacationers. But in some developing countries, particularly in sub-Saharan Africa, multiple parasite infections cause debilitating chronic illness and hundreds of thousands of deaths a year.

Intestinal parasites can exist in an in-between state where they cause only occasional symptoms and general fatigue. Most people in parasite-endemic countries don’t have access to medication, yet they manage to keep parasites in check.

Over the centuries, herbs, spices, and medicinal plants have been protecting people from parasites. Natural control Essential oils of cinnamon, citrus peel, clove, lemon grass, oregano, thyme, and yarrow have been shown to inhibit the growth of pathogenic protozoa in cultures. There have been a few human studies, but poultry studies confirm that cinnamon and citrus are safe and effective for keeping parasites in check.

A special preparation of emulsified oregano oil was tested on a small group of people with diagnosed intestinal parasites. The study, reported in Phytotherapy Research (2000), found that after six weeks of taking 600 mg of oil of oregano emulsion (four tablets, three times daily) parasites were eliminated in 10 of 13 patients and parasite load was reduced in the other three. Seven patients reported that their gastrointestinal symptoms were improved.

The emulsion is designed to spread evenly throughout the bowel so that it comes in contact with as many parasites as possible and does not concentrate in one location that could cause irritation. Essential oil of oregano (both Mediterranean and Mexican) contains a high level of the phytochemical carvacrol, which is highly effective against protozoa, bacteria, and fungi but fairly nontoxic to mammals.

Overlooked cause

According to a 2007 review by Australian doctors, low-level parasite infections may be a cause of irritable bowel syndrome, which is characterized by intermittent periods of bowel dysfunction and abdominal pain that have no obvious cause.

Treatment with antiparasitic oregano oil; ginger, mint, or camomile tea to soothe abdominal cramping; and glutamine (5 to 10 g per day) to rebuild the cells lining the intestinal wall may provide better relief than medications can offer.

Recently, infectious strains of candida yeast have developed resistance to the azole group of antifungal drugs, the primary pharmaceutical therapy. A 2008 study by Brazilian microbiologists found that the growth of drug-resistant candida strains was strongly inhibited by relatively low concentrations of oregano oil.

Cancer connection

Chronic parasitic infections can relentlessly inflame the bowel for years, leading to permanent damage and increasing the risk for gastrointestinal cancer. A 2005 study of 1,199 patients from Uganda and Zimbabwe with parasitic gastrointestinal illness found an increased risk for stomach, colorectal, and esophageal cancer.

Similarly, a 1998 study of Egyptians with urinary schistosomiasis found an increased risk for bladder cancer. Such clear associations between parasitic infections and cancer haven’t been found in Western countries, but there’s agreement that chronic gastrointestinal inflammation is a serious risk factor for colorectal cancer.

If you’ve been travelling, eating raw foods, drinking from streams or ponds, or interacting with people who have recently visited a develo