Lead is nasty. Since the body has a tough time eliminating it, exposure to very small amounts can cause poisoning over the long term. Diagnosis of lead poisoning is challenging because of the variety of symptoms it can produce. Vomiting, constipation, abdominal pains, headaches, mood disorders, high blood pressure, tingling sensations and fatigue can all be the result of lead poisoning, but of course these symptoms can also have other causes. Then there are the truly worrisome issues like developmental problems, learning difficulties and eventual loss of mental faculties. Lead poisoning is most worrisome in children under the age of six when the nervous system is still forming.
Exposure to lead-based paint in old buildings is a big problem, and lead paint still crops up in some imported toys that kids may put in their mouths. There is also the problem of lead in water in areas where old lead pipes are still in use. Since our body has no requirement for lead, every effort should be made to avoid ingesting lead compounds, but total avoidance is impossible since lead occurs naturally in the soil and gets incorporated into anything that grows in the soil. And that includes cacao trees and therefore chocolate. Yes there is lead in chocolate and that has raised the ire of some activist groups who claim this represents a risk especially to children. And what better time to get publicity for a warning about chocolate than Valentine’s Day. So a California watchdog group called “As You Sow” has trotted out its annual chocolate scare.
So, how much should we worry about eating chocolate? Let’s play with numbers a little. Total avoidance of lead is impossible, but the World Health Organization has determined that a tolerable daily intake for children is 3.6 micrograms per kg per day. This means that even if this amount is consumed every day, no problems are foreseen. A 20 kg child can therefore consume 72 micrograms of lead a day. Dark chocolate has the most lead with 0.07 micrograms per gram. That means 50 grams, a pretty good chunk of chocolate, will contain 3.5 micrograms of lead. Milk chocolate has less, but cocoa powder has more, at 0.25 micrograms per gram, but a serving of cocoa would only be about 7 grams which yields 1.75 micrograms of lead. Far from the daily tolerable limit of 72!
Of course lead is found in other foods as well. Berries contain as much as chocolate, and one normally eats a greater weight of berries than of chocolate. A glass of canned apple juice would have more lead than a serving of chocolate. Liver contains thousands of times more, but warnings about liver do not make the headlines. Even when the lead in all food consumed is totaled, it is unlikely that a child would exceed the 72 micrograms. Nevertheless, lead intake should be minimized as much as possible. And with chocolate, improved processing can reduce levels because studies have shown that the lead content of the finished product is greater than that found to occur naturally in the beans. The lead likely comes from machinery and air drying in places like Nigeria where leaded gasoline is still used. The bottom line here is that if you are eating enough chocolate to have to worry about lead, you are eating way too much chocolate. Happy Valentine’s Day.
Not exactly what you expect to hear when you are peacefully walking in San Francisco’s Chinatown. But the boisterous elderly Chinese gentleman seemed charismatic enough, and the establishment didn’t look like an opium den. Indeed it wasn’t. It was a tea house. But not your ordinary tea house.
We quickly found ourselves plunked down at a long counter along with a number of other tourists who had been dragged in from the street.
“It’s not for taste, it’s for health,” began “Uncle Gee,” who I was to learn was a local institution.
“Eighty-four years old,” he boasted, and “in perfect health!”
“Drink eight cups of tea a day; never coffee!”
“Tea full of antioxidants against cancer!”
Not only were we treated to a lecture on the “science” and history of tea, we were also ordered to try about half a dozen varieties.
“Never use boiling water, the tea will scream,” and so did he. “Don’t even dream about adding milk or sugar.”
“Steep for only twenty seconds!”
We sipped rosebud tea from Iran to ward off insomnia, and “puerh” for weight loss and heart problems. Next came Blue People Ginseng Oolong. I don’t know why the “blue.” I looked around and none of the people drinking it were turning blue. Everyone enjoyed that one. It was a truly different taste, with a hint of licorice, “a party-in-your-mouth tea,” we were told.
As our taste buds were partying, I glanced around at the dozens and dozens of jars, all with intriguing names.
“Monkey-picked green tea” for “cleansing the body” caught my attention. It wasn’t clear if this was to be applied to the outside or the inside of the body, or how the monkeys had been trained to pick tea. I wanted to ask if this was just monkey business, but didn’t dare. I did muster up enough courage to ask Uncle Gee about his favourite tea, the one that kept him young and so full of whatever. He quickly pointed to “Angel Green tea.”
“Good for high blood pressure, cholesterol, diabetes and detox.”
At $160 a pound, I suspect good for profits too, although there was no “hard sell.” The tea bash ended with Uncle Gee telling us that while we were strangers when we came in, we were now part of the family. How could I resist buying some Angel Green and Blue People?
We’ve been enjoying both teas ever since, but other than frolicking taste buds, I can’t vouch for any benefits. But tea leaves do contain more than 700 compounds, many with potential biological activity. It is the “polyphenols,” the “catechins” in particular, that have aroused researchers’ interest enough to generate a truckload of studies.
When rats are fed green-tea leaves, their blood cholesterol and triglycerides go down. Levels of such enzymes as superoxide dismutase, catalase and glutathione-S-transferase, all involved in removing foreign chemicals from the body, go up. The rats are also less prone to weight gain, apparently because of an increase in metabolism.
But in these studies, the rats consume far more tea on a weight basis than people ever can. As far as human-population studies go, some show a decrease in colon, breast, stomach and prostate cancer; but others don’t. The studies are neither consistent nor convincing, which is not surprising given that there are numerous varieties of tea, their chemical profiles depending on the type of tea, where it is grown and how it is harvested, stored and processed. Most of the epidemiological studies that have shown health benefits have focused on Asian populations, where tea consumption is much greater than in North America, and lifestyles are very different.
Laboratory studies have also been carried out with various tea components. For example, heterocyclic aromatic amines, compounds produced when meat is cooked at a high temperature, are less likely to trigger cancer in the presence of the polyphenols theaflavine gallate and epigallocatechin gallate. Such findings, along with the suggestion of increased rates of metabolism, have led to the sale of various dietary supplements based on tea extracts. Why go to the trouble of drinking tea when you can just pop a “cancer-fighting, fat-burning” pill?
But here we run into a problem. Such dietary supplements are poorly regulated; and the amount of catechins they contain can be far greater than that available from drinking tea. The high doses may indeed help to increase metabolism and result in weight loss, but the cost can be high. Just ask the teenager who walked into the emergency room at Texas Children’s Hospital with his chest, face and eyes bright yellow due to severe liver damage, after using a concentrated green-tea extract he bought at a “nutrition” store as a “fat-burning” supplement.
There was concern that he might need a liver transplant but luckily his liver, an organ that has regenerative properties, managed to recover. He did have to give up sporting activities, and will require regular liver function checkups.
Unfortunately this is not an isolated case, and such cases are not limited to green-tea extracts. Recently aegeline, a compound found in the leaves of the Asian bael tree, showed up in supplements marketed as an aid in losing weight and building muscle — despite a lack of any credible evidence. But aegeline may not be without some effect. More than 50 people suffered liver damage, two had to have liver transplants and one died after consuming a supplement containing aegeline.
The multi-hospital-based Drug Induced Liver Injury Network in the U.S. has found that liver problems due to herbal and other dietary supplements have increased three-fold in the last 10 years. Conventional medications still cause far more cases of liver injury, but they also have evidence of efficacy, which is not the case for many herbals.
I suspect that Uncle Gee would have a few devilish words to say about people who might think that they can encapsulate the benefits of Angel tea in a pill. He would likely argue that supplements cannot replicate the same rejuvenating effects he experiences from his daily tea regimen.
I must admit he did look robust and way younger than 84.
But when pushed, he did tell me that he runs six miles three times a week, and can bench press 110 pounds.
So maybe it’s not only the tea that’s keeping him young.
I think we are safe in saying that green tea doesn’t make taste buds frolic. So why do people drink it? The same reason for which the Chinese have been consuming it for millennia. Its supposed health benefits. Green tea doesn’t contain the flavourful compounds that form when tea leaves are allowed to ferment. During fermentation enzymes are released that convert the naturally occurring polyphenols in the leaves to a host of tasty compounds. Instead of being fermented, green tea is made by steaming or drying fresh tea leaves in order to prevent oxidation of the polyphenols. It is these polyphenols that in laboratory and animal studies show anti-cancer effects as well as increased rates of metabolism.
But how can on benefit from tea’s polyphenols without having to put up with green tea’s unappealing flavor? Supplement manufacturers have found a way. Just extract the catechins, the main class of polyphenols in tea, and plunk them in a pill. Then promote the pill as a cancer-fighting or fat burning supplement. But here we run into a problem. Such dietary supplements are poorly regulated and the amount of catechins they contain can be far greater than that available from drinking tea. The high doses may indeed help to increase metabolism and result in weight loss but possibly at a high cost. Just ask the teenager who walked into the emergency room at Texas Children’s Hospital with his chest, face and eyes bright yellow due to severe liver damage after using a concentrated green tea extract he bought at a nutrition store as a “fat burning” supplement. Doctors feared he may need a liver transplant but luckily his liver, an organ that has regenerative properties, managed to recover. He did, however, have to give up sporting activities and will require regular checkups of his liver function.
Unfortunately this is not an isolated case and such cases are not limited to green tea extracts. Various herbal supplements have been linked with liver damage, some because of undeclared ingredients, such as steroids. These are promoted as bodybuilding supplements and may actually have an effect because of the hidden steroids. People generally assume that herbal products that are sold are tested for safety and efficacy but this is not the case. Until regulations are tightened the incidence of liver damage from dietary supplements is going to continue to increase.
Since 1999 we have increased spending on science, as we should have, and we have seen an increase in suicides. But one has nothing to do with the other. The population has increased and suicides are proportional to population.
Consider bisphenol A, the chemical used to formulate polycarbonate plastics and epoxy resins that line food cans. It has been accused of causing everything from obesity and cancer to heart disease and developmental problems. There is indeed an association between blood levels of BPA and heart disease but that may well be because people with heart disease have consumed more canned foods with high salt and fat content. They would have higher blood levels of BPA leached from cans, but the culprit is the sugar and fat content. In fact the Canadian Food Inspection Agency carried out a survey of BPA in canned foods and concluded that an adult would need to consume approximately 14 kg of canned vegetables each day (approximately 50 servings) to reach an exposure to BPA that may pose a safety concern.
On the other hand, there are some associations that may eventually prove to be causative. FDA in the U.S. recently learned of a cluster of acute liver failure cases in Hawaii. It turned out that the cases were associated with having used a dietary supplement called OxyElitePro advertised as an aid to losing weight and building muscles. The product contained aegeline, an alkaloid extract from leaves of the Asian bael tree. Researchers believe this may be the culprit, although genetics likely play a role because most of the victims were of Pacific island ancestry. Although the case is not iron clad, the supplement has been taken off the market.
Another association that has recently been publicized is that between the murderous rage of the California mass killer Elliot Rogers and his addiction to creatine which he was taking for body building to make himself more attractive to girls. There is virtually no evidence that creatine can lead to rage like steroids can, but nevertheless the association has been widely publicized. It likely has no greater connection to causation that than that between per capita margarine consumption and the divorce rate in Maine, another spurious association discovered by the clever Harvard statistician.
The French are always worried about their liver. Maybe it’s because of all the red wine they drink. But they also love their “petit pain au chocolat” for breakfast. That’s puff pastry with a delicious piece of dark chocolate in the middle. If we are to go by a recent study presented at the International Liver Congress, that piece of chocolate may actually reduce the liver concerns.
Dark chocolate is good for you! We’ve heard that before. But it has always been in connection with its antioxidant content. Flavonoids in particular. Antioxidants, the “good stuff” found in many fruits in vegetables, neutralize the damaging effects of free radicals. Free radicals are highly reactive substances generated by our natural breathing process, but also by external sources such as cigarette smoke. Due to their high reactivity, free radicals can kill bacteria, but they can also cause cellular damage and DNA disruption. This type of long term damage means higher risk of disease, including cancer. (more…)