A second look at antioxidants

One of the current fads in nutrition today is antioxidants -- vitamins like C and E that go after free radicals, molecules created by the breakdown of oxygen during metabolism.

"Each of us constantly creates free radicals simply by living and breathing, Tara Parker-Hope writes in The New York Times. "But these molecules are highly reactive and capricious, sometimes attacking other cells and damaging tissue. Wilding free radicals have been linked with a number of diseases and with aging."

Exercise, she writes, creates even more free radicals, and so athletes were encouraged to to lots of antioxidants. A few years ago, however, some researchers started fooling around with rats. One group got lots of antioxidants before exercise, the other got none. The antioxidant bunch showed no free radicals in their blood.

The leg muscles of the other exercised rats, though, teemed with free radicals. But at the same time, they buzzed with other, unexpected biochemical reactions. In their legs, genes were being expressed that activated growth factors that, in turn, increased levels of ‘‘important enzymes associated with cell defense’’ and ‘‘adaptation to exercise,’’ the researchers wrote. There was hardly any similar activity in the rats with low free-radical levels. Somehow, the researchers speculated, the free radicals had jump-started a process that over time would allow the rats’ muscles to adapt to exercise. Suppressing the production of free radicals had, they concluded, prevented the ‘‘activation of important signaling pathways’’ and altered the muscles’ ability to adapt to exercise. As a result, they wrote, ‘‘the practice of taking antioxidants’’ to ward off the presumed free-radical damage caused by exercise ‘‘may have to be re-evaluated.’’

Then another study last year, this time with humans.

A group of young men were enrolled in a month-long exercise program. Some swallowed moderately high doses of the antioxidant vitamins C and E. Others did not. At the end of the month, the men not taking the vitamins showed higher-than-average activity in their bodies’ innate antioxidant defense system. The men downing the vitamins did not, which makes sense; the antioxidant vitamins were mopping up the free radicals for them. But at the same time, the men not taking vitamins significantly increased their insulin sensitivity, a key measure of the health benefits of exercise, while those taking the antioxidants did not. Apparently, when the body’s natural antioxidant defense system went into high gear, so did its ability to handle insulin. Removing the necessity for the body to deal, on its own, with the free radicals also prevented other adaptations that make exercise healthy.

What does all of this mean?

‘‘The evidence suggests that antioxidants are not needed’’ by most athletes, even those training strenuously, said Li Li Ji, a professor of exercise physiology and nutritional science at the University of Wisconsin and one of the authors of the rat study. ‘‘The body adapts,’’ he said, a process that can, it seems, be altered by antioxidant supplements.


Another lesson: ‘‘Eat well,’’ he said. Although this is not yet proved, it seems likely, he continued, that antioxidants from foods, like blueberries, green tea and carrots, may work in tandem with the body’s natural antioxidant defenses better than those from supplements.

But the overriding lesson of the newest science about exercise and antioxidants may be as simple as: let the body be. ‘‘It is quite a smart machine,’’ Dr. Ji said. ‘‘It knows how to respond’’ to stresses like a hard run, without the need for antioxidant pills.

It's not clear how this affects people not consider "athletes," and that will be something to discover. But, in the Duh Department, it seems that if exercise is good for us, and we know it is, the body is wise in its own ways.

Try a little ginger

A new study shows that ginger may also be an effective pain reliever for sore muscles. The study, published in The Journal of Pain, showed a daily dose of two grams of ginger eased muscle pain caused by exercise-induced muscle injury. The results showed that raw and heat-treated ginger reduced muscle pain by 25% and 23%, respectively. Researchers say previous studies in animals have shown that ginger has anti-inflammatory properties, which might help explain its beneficial effects on muscle pain.

The National Center for Complementary and Alternative Medicine, part of the National Institutes of Health, says it is unclear whether ginger is effective in treating rheumatoid arthritis, osteoarthritis, or joint and muscle pain.

The center takes a conservative view on all supplements, and that's a good thing, because there's a lot of baseless information out there.

My yoga instructor, Zen Momma, swears by ginger and turmeric for muscle relief. The NCCAM says that preliminary findings from animal and laboratory studies suggest that a chemical found in turmeric—called curcumin—may have anti-inflammatory, anticancer, and antioxidant properties, but these findings have not been confirmed in people.

These guys just can't be fun at parties.

Why fish oil protects against diabetes

You've heard that fish oil is good for you for a lot of reasons, but nobody ever knew exactly why. Now some scientists have discovered that omega-3 fatty acids reduce inflammation that can lead to diabetes.

By studying fat tissue in the mice consuming fish oil, researchers found that omega-3 fatty acids seem to act on a particular receptor on cells, GPR120, which, when activated, blocks inflammatory processes.
Chronic inflammation can lead to insulin resistance, a precursor to diabetes.

"If we can fix the inflammation part, it's possible that we could prevent insulin resistance or even ameliorate diabetes," said study co-author Saswata Talukdar, a post-doctoral fellow at University of California, San Diego.

Here's more of the science.

Fat tissue contains macrophages, immune system cells that gobble up bacteria, clear out cellular debris and help rid the body of infection. But macrophages found in fat can also have a downside. When macrophages "go rogue," Talukdar said, they produce cytokines and other pro-inflammatory proteins.

A build up of cytokines can result in a "signaling cascade," that eventually leads to low-grade, chronic inflammation and insulin resistance, Talukdar said. In people with insulin resistance, cells are unable to properly utilize insulin, which regulates blood sugar levels. That can lead to type 2 diabetes, which is often linked to obesity.

While studying fat tissue, researchers found that omega-3 fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), acted on the specific receptor, GPR120 (for G protein-coupled receptor), found on the surface of macrophages.

The GPR120 receptor is found only on pro-inflammatory macrophages in mature fat cells, according to the study. Exposure to omega-3 fatty acids activates the receptor, which reduces the runaway pro-inflammatory cascade.

This study focused on diabetes, but omega-3 fatty acids may also help with other diseases in which inflammation plays a role, including cancer and cardiovascular disease, researchers said.


Being appropriately cautious, the researchers said it is not guaranteed that the same result would be found in humans.

The National Institutes of Health has a lot of information on omega-3s here, including dosing information.

For healthy adults with no history of heart disease, the American Heart Association recommends eating fish at least two times per week. In particular, fatty fish are recommended, such as anchovies, bluefish, carp, catfish, halibut, herring, lake trout, mackerel, pompano, salmon, striped sea bass, tuna (albacore), and whitefish. It is also recommended to consume plant-derived sources of α-linolenic acid, such as tofu/soybeans, walnuts, flaxseed oil, and canola oil. The World Health Organization and governmental health agencies of several countries recommend consuming 0.3-0.5 grams of daily EPA + DHA and 0.8-1.1 grams of daily α-linolenic acid. A doctor and pharmacist should be consulted for dosing for other conditions.

More on how to buy vitamins

Since my previous post, I've come across more information from the Dietary Supplement Quality Initiative, which seems to be independent. It offers this guidance:

Here are some strategies for learning about the quality of any dietary supplement.
1. If it carries the ConsumerLab.com quality seal or appears on the list of brands on their www.ConsumerLab.com website that passed their random independent testing program, you can be assured the supplement is high quality and should perform as expected.

2. If it carries the USP or NF seal, the producer is claiming that it meets the US Pharmacopoeia or National Formulary standards for that product. Among other things, these standards cover potency, minimum dosage, and purity from contamination.

3. If it carries the NNFA's "GMP" seal, the manufacturer has passed a comprehensive, independent inspection of its manufacturing process. (This gives solid assurance of a well made product, but says nothing about the manufacturer's choices of which ingredients and potency levels to use.)

4. If it carries the BioFIT trademark, the product has passed "biological assay" testing, which means that it displays biochemical activity that is consistent with having the corresponding effect in the human body.

5. SupplementWatch.com uses a subjective, 100-point system for rating brands. Up to twenty points are awarded for each of five categories: health claims, scientific theory, scientific research, safety and side effects, and value (relative cost).

6. Call the supplement's producer and ask for the head of their quality control or assurance program. (Be prepared to ask a few questions!) This will tell you if they actually have a quality control program. If they don't (they might be a reseller or rebrander), ask how they deal with quality control issues.

How to buy vitamins

You don't always get what you expect in vitamins and supplements, and you have to be careful. So how do you know which brand is best? I've been frustrated in trying to answer that question. I have found one answer at Consumer Reports. Here's what it has to say:

With all the choices, it's no wonder half of multivitamin users in a new, nationally representative Consumer Reports telephone survey expressed some doubt that they were taking the right product for their needs. Our survey, which included 2,002 adults and took place in April 2010, uncovered some other concerns, too: Fifty-six percent of respondents who took a multivitamin worried that it contained harmful ingredients, for example, and 47 percent expressed concern that their multivitamin didn't contain the levels of nutrients listed on the bottle. 

Here's one solution.

USP verified indicates that a product has been verified for purity, strength, safety, dissolvability, and manufacturing quality by the USP, an independent standards-setting authority for the drug and dietary supplement industries. USP claim indicates that the manufacturer claims the product was made to one or more of the USP's quality standards or specifications, but the claim is not vetted by the USP. The verification seal holds more weight than a USP claim on the label, which several of the other products we tested had. 

USP is, no, not the post office, but rather U.S. Pharmacopeia. Here's a database it recommends, and you can check their approved list here. Here's one of its symbols:

I've also read about ConsumerLab, which charges a fee to read its reports. I haven't tried it. And the FDA has information here. And the National Institutes of Health here.

By the way, Consumer Reports checked out 21 multivitamins. All but one of the products we tested met their label claims for key essential vitamins and minerals, and none contained worrisome levels of contaminants such as arsenic or heavy metals. Most of the pills we tested also passed the U.S. Pharmacopeia's dissolution test, which involves immersing them in a simulated stomach-acid solution to determine whether they'll dissolve properly in your body.

Their research shows that the best of the bunch can save you money: Kirkland, the Costco brand, topped the list of multivitamins.

Do you know what's in those supplements?

A dozen ingredients commonly found in dietary supplements should be avoided, according to a new study by Consumer Reports, because they are linked to cancer, coma, kidney and liver damage, heart problems, and death.

The magazine singles out 12  ingredients it termed the ''dirty dozen." "The dozen we call out in this report are by no means the only dangerous ingredients," Nancy Metcalf, senior program editor at Consumer Reports, told WebMD. "They are the ones we chose to highlight."

Here's the list:

• Aconite, used for joint pain, wounds, gout, and inflammation, but linked with nausea, vomiting, heart rhythm disorders, respiratory system paralysis, and death.
• Bitter orange, used for weight loss, allergies, and nasal congestion, but linked with fainting, heart rhythm disorder, heart attack, stroke, and death.
• Chaparral, used for weight loss, colds, infections, inflammation, cancer, and detoxification, but linked to kidney and liver problems.
• Colloidal silver, used for fungal and other infections, Lyme disease, rosacea, psoriasis, food poisoning, chronic fatigue syndrome, and HIV/AIDS, but linked to bluish skin color, mucous membrane discoloration, neurological problems, and kidney damage.
• Coltsfoot, used for cough, sore throat, laryngitis, bronchitis, and asthma, but linked to cancer and liver damage.
• Comfrey, used for cough, heavy menstrual periods, chest pain, and cancer, but linked to liver damage and cancer.
• Country mallow, used for allergies, asthma, weight loss, bronchitis, and nasal congestion, but linked to heart attack and arrhythmia, stroke, and death.
• Germanium, used for pain, infections, glaucoma, liver problems, arthritis, osteoporosis, heart disease, HIV/AIDS, and cancer, but linked to kidney damage and death.
• Greater celandine, used for upset stomach, irritable bowel syndrome, liver disorders, detoxification, and cancer, but linked to liver damage.
• Kava, used for anxiety (and is possibly effective, according to Consumer Reports), but linked to liver damage.
• Lobelia, used for coughs, bronchitis, asthma, smoking cessation, but linked to toxicity, with overdose linked with fast heartbeat, very low blood pressure, coma, and possible death.
• Yohimbe, used as an aphrodisiac, for chest pain or diabetic complications, depression, and erectile dysfunction (and possibly effective, according to Consumer Reports), but linked to high blood pressure and rapid heart rate at usual doses and at high doses linked to severe low blood pressure, heart problems, and death.

Some things you can do, according the Metcalf:

• beware of products that have been linked with the most problems -- those for weight loss, sexual enhancement, and body building.
• buy products that have a "USP Verified" mark, which means the manufacturer has asked the U.S. Pharmacopeia, a nonprofit standards-setting authority, to verify the quality, purity, and potency of its raw ingredients or the finished product.
• check out alerts and advisories regarding dietary supplements on the web sites of the National Institutes of Health Office of Dietary Supplements and the FDA.