WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Consuming what has been called "safe" levels of chemicals in combination at low doses has concerned scientists for decades. While many chemicals are thought to be safe at very low doses tested in isolation, what happens when you ingest a little bit of a lot of different chemicals over time?
When regulators consider consumer risk, they evaluate a compound's safety using laboratory animals and exposing them to an individual chemical in progressively smaller amounts until the chemical no longer demonstrates the ability to trigger negative health effects, including cancers. They use this amount to determine some small fraction they "believe" is potentially safe for people.
However, the assumption that toxicity is dose-dependent is not always true, especially for chemicals that mimic hormones.1 And, regulators are not required to test mixtures of these chemicals to determine what the outcome would be under real-world conditions.
Over your lifetime, you may be exposed to nearly 80,000 man-made chemicals present in your food, water, air and personal care products.2 It only makes health sense to evaluate the effect this chemical soup, ingested or absorbed nearly every day, has on your health. A recent study has found that when even small amounts of chemicals from food, pharmaceuticals and personal care products are combined in your body, you may experience liver damage.3
So-Called 'Safe' Levels of Chemical Mixtures Demonstrate Liver Damage
Outside of a laboratory you are never subjected to just a single stressor or single chemical.4 Recent research has demonstrated low levels of chemicals, considered safe by regulators, are actually toxic when present in the body in mixture. The experiment was designed to evaluate real life situations in a general population exposed to combinations at low doses from environmental sources, food, pharmaceuticals and personal care products.5
Using four groups of Sprague-Dawley rats, the researchers administered a mix of chemicals in their drinking water for a period of six months. The control group received water, which was free from additional chemicals. Of the three treatment groups, the low-dose group received 25 percent of the European Union (EU) acceptable daily intake, the medium dose received exactly the acceptable daily intake defined by the EU, while the high-dose group received five times the acceptable daily intake.6
After six months, the researchers evaluated body weight and biochemistry markers, finding the animal's weight increased above 10 percent in all male groups relative to the controls.7 Modest increases were found in the females who received medium and high doses of the chemicals. Additionally, the researchers found adverse effects in liver testing, especially at the low-dose level and primarily in males.
Overall, the results suggest exposure to low doses may induce liver damage as a result of the combination of different toxic mechanisms. The results of this study support previous research demonstrating the effects of chemical cocktails, even at low levels,8 on the liver,9 and their potential for triggering cancer.10
Do You Consume These Chemicals?
The chemicals tested by the researchers included some that may not sound familiar. As you read through the list, it will become clear it is very difficult, if not impossible to avoid consuming these chemicals. Others included in the study were glyphosate, a commonly used herbicide on genetically modified crops, BPA found in plastic products, the artificial sweetener aspartame, and ethylparaben and butylparaben, which are preservatives used by food, pharmaceutical and personal care manufacturers.
Carbaryl
This is a manmade pesticide commonly used to control aphids, fire ants, fleas, ticks and spiders. It is sold under the brand name Sevin by Bayer and brief exposure may result in weakness, dizziness and sweating. Pinpoint pupils, lack of coordination, muscle twitching and slurred speech have also been reported.11 |
Dimethoate
An insecticide used to kill mites and insects systemically and on contact, it is used on aphids, thrips and whiteflies on crops such as apples, corn, grapefruit, lemons, pears, pecans and tomatoes, as well as other vegetables.12 |
Methomyl
Used as a pesticide since 1968 on field crops such as lettuce, and on oranges, it is extremely toxic when ingested and has been restricted by the Environmental Protection Agency (EPA). It may only be used under direct supervision of trained and certified applicators.13 |
Methyl parathion
A restricted-use organophosphate pesticide, it is used to control insects by contact or by respiratory action. It is readily absorbed through the skin, and accidental skin contact or inhalation have caused human fatalities.14 |
Triadimefon
This is a fungicide for agricultural use and seed treatment for barley, corn, cotton, oats, rye, sorghum and wheat. Trade names include Amiral, Bay MEB 6447 and Bayleton.15 |
Sodium benzoate
This is a preservative commonly found in foods, pharmaceuticals and cosmetics.16 |
Folate May Help Mitigate Pesticide Damage
While it is challenging to eliminate exposure to a chemical mix, there are steps you may consider to help protect your liver and support function. One of those steps is increasing your intake of folate. In one study involving 83 patients with nonalcoholic steatohepatitis (NASH), researchers found levels of folate and vitamin B12 were inversely related to the development of fibrosis or the formation of scar tissue. According to the researchers:17
"Our study demonstrated a statistically significant correlation between low levels of folate and vitamin B12 with the histological severity of NASH. These findings could have diagnostic and therapeutic implications for patient management and follow up."
Past research has identified an association between low levels of vitamins and chronic liver disease, but this is the first to find an association between folate and vitamin B12 level to NASH severity. Recognized as the most prevalent liver disease worldwide, the condition places a dramatic burden on society. The researchers believe low levels of folate and vitamin B12 may be used as an independent predictor and could have practical implications for assessment and prognosis.18
Another study based in China suggests a folate-deficient diet may increase your risk of liver cancer.19 Lead authors from the U.S. National Cancer Institute and National Institutes of Health found evidence folate deficiency is associated with liver damage and liver cancer.20
The researchers recruited 412 patients who tested positive for Hepatitis B and were at higher risk for liver damage. Folate levels were measured in the participants at the start of the study. Participants were then followed for four years. During the study period, 20 cases of liver cancer were diagnosed.
When data was compared, higher red blood cell folate levels were associated with a 67 percent lower risk of liver cancer.21 The researchers stated more research is required to support the observations, but they concluded the study suggested increased folate in humans could be inversely associated with the development of liver damage and hepatocarcinoma. The researchers found folate appeared to offer the liver some degree of protection against damage.
Folate Is Not Folic Acid
If you're not sure what the difference between folate and folic acid is, you're likely in good company. Many professionals and health practitioners frequently mix up the two as the terms are often used interchangeably. Although some argue they are essentially the same, important distinctions between the two compounds are obvious in the way your body metabolizes and utilizes the vitamin.22
Both of these nutrients are a variety of vitamin B9, but they are not the same chemical structure. Prenatal vitamins and many processed foods are fortified with folic acid to help prevent birth defects associated with a deficiency during fetal development. Deficiency in folate during the first trimester is a major risk factor for neural tube defects such as spina bifida, anencephaly and exencephaly. However, folate and folic acid are not interchangeable.
Your body stores approximately 10 to 30 milligrams of folate at a time, nearly 50 percent of which is in the liver. The other half is stored in blood and tissue. However, while most associate deficiency with pregnancy, other health problems may occur with a folate deficiency, including elevated blood concentrations of homocysteine, cancer and depression.23
Folate is the natural form of vitamin B9 found in foods and once referred to as folacin. The word was derived from the Latin "folium," meaning leaf. Green leafy vegetables are abundant sources of folate.
Folic acid, on the other hand, is a manufactured vitamin and is the form added to some supplements and foods. While folic acid is readily absorbed, this synthetic form is not converted in the intestines as is folate. Instead, it is converted in the liver. This means folic acid can reach saturation more quickly, which may result in overexposure if you're taking supplements. The best way to get enough vitamin B9 is to eat foods rich in folate, such as asparagus, avocados, Brussels sprouts, broccoli and spinach.24
Milk Thistle Helps Prevent Liver Damage
The milk thistle herb has been used for thousands of years to support liver, kidney and gallbladder health. It contains the flavonoid silymarin, thought to be responsible for the beneficial effects attributed to milk thistle, including liver protection and antioxidant, antiviral and anti-inflammatory properties. The herb is native to the Mediterranean and is regarded as a weed in some areas of the world. When the leaves are crushed, they release a milky sap, which is where the herb gets its characteristic name.
Silymarin is actually a group of compounds working together to provide multiple health benefits, protecting the liver as an antifibrotic by preventing tissue scarring. The compounds are also believed to act as a toxin blockade agent by inhibiting the binding of toxins to liver cell membrane receptors. It has been used to treat alcoholic liver disease, acute and chronic viral hepatitis, and toxin-induced liver diseases.
The herb suppresses cellular inflammation through the expression of genes associated with cellular stress, specifically endoplasmic reticulum stress. The anti-inflammatory effects may be accomplished in part using a two-phase process similar to those used by other beneficial natural compounds, like curcumin (found in turmeric) and EGCG (epigallocatechin gallate, a component of green tea).25
A study26 revealed the first-phase cellular response to silymarin in cells is a rapid increase in expression of genes associated with cellular stress, specifically endoplasmic reticulum stress. In severe cases, such stress may lead to cell death, which can be beneficial in some cases (such as cancer). The second phase involves a longer suppression of gene expression associated with inflammation. Along with inhibiting inflammatory signaling pathways, silymarin also:27
• Activated AMP-activated protein kinase (AMPK): AMPK is an enzyme inside your body's cells. It's sometimes called a "metabolic master switch" because it plays an important role in regulating metabolism.28 According to the Natural Medicine Journal:29
"AMPK induces a cascade of events within cells that are all involved in maintaining energy homeostasis. . . . AMPK regulates an array of biological activities that normalize lipid, glucose, and energy imbalances.
Metabolic syndrome occurs when these AMPK-regulated pathways are turned off, triggering a syndrome that includes hyperglycemia, diabetes, lipid abnormalities, and energy imbalances … In other words, activating AMPK can produce the same benefits as exercise, dieting, and weight loss — the lifestyle modifications considered beneficial for a range of maladies."
• Inhibited mammalian target of rapamycin (mTOR): When the mTOR pathway is overactivated it may increase your risk of cancer.30 The power of this pathway has only relatively recently been appreciated and is critical to cell growth, proliferation and survival.31 Many new cancer drugs are being targeted to use this pathway.
N-acetylcysteine Supplement Supports Your Liver Health
N-acetylcysteine (NAC) is a precursor needed for glutathione biosynthesis. This incredibly useful supplement has many benefits relating to its ability to boost production of glutathione, an antioxidant used to reduce free radical damage and which plays a role in the detoxification of heavy metals and other harmful substances.
The most common use of NAC is for liver support. In one study, the researchers suggest NAC may be a better alternative for supporting the liver in those with hepatitis C and for those with other chronic liver diseases than the antioxidant resveratrol.32 According to the authors,33 "Taking all these data together, abundant evidence suggests that antioxidants can effectively attenuate the oxidative and nitrosative stress in liver injury, ultimately improving inflammation and fibrosis progression."
Alcohol and acetaminophen are two common compounds metabolized through the liver and associated with liver damage. NAC supplementation has been effective in minimizing damage associated with alcohol consumption when taken prior to alcohol ingestion.34 Increasing glutathione reduces acetaldehyde toxicity triggering many hangover symptoms. NAC is also used as an antidote for acetaminophen toxicity, which also causes liver damage by depleting glutathione.35
Nonalcoholic fatty liver disease is a common liver problem triggered by oxidative stress. In a study published in Hepatitis Monthly,36 researchers evaluated 30 patients with nonalcoholic fatty liver steatosis, giving half of the group NAC and the other half vitamin C. Liver function and other measurements were taken initially and at one, two and three months. The researchers found NAC improved liver function in the patients in their study.
Seek Out Whole, Organically Grown Foods and Safe Personal Care Products
The sad fact is most of the foods and personal care products found on grocery store shelves are loaded with chemicals known to cause liver damage and other health conditions. The best way you have to prevent damage is to — as much as possible — avoid the chemicals in the first place. The first tangible step you can consider to overhaul your diet and lifestyle is to go organic.
Organic products are available in close to 20,000 natural food stores and nearly 75 percent of traditional grocery stores in the U.S. Polling data37 shows the No. 1 reason people purchase organic products is to avoid pesticides, and it is a primary reason why eating organic foods and using organic products is so important for your health and the environment. To read more about how to eat organic and what it means for your health, see my previous article "Go Organic."
According to the Environmental Working Group (EWG), the average American woman uses 12 personal care products and/or cosmetics in a day,38 containing 168 different chemicals. Although men use fewer products, on average they are still exposed to nearly 85 chemicals daily from their personal hygiene routine. Clearly, this vast chemical exposure is not insignificant, especially as you consider it occurs virtually daily over your lifetime.
You may evaluate the products you're currently using, or find EWG's safe list of products by checking the EWG Skin Deep Cosmetic Database.39 Additionally, I suggest reading my previous article, "7 Domestic Factors That Can Make or Break Your Health," to discover areas where you can reduce your chemical exposure and healthier options you can use at home, including making your own effective and easy to use cleaning products with ingredients you likely already have in your kitchen.