Marc Joseph Nutrition - Blog

An announcement that didn’t make the major newspaper headlines, but is nevertheless big news. Researchers at the Linus Pauling Institute at Oregon State University (OSU) have discovered a new technique that allows them to observe and accurately measure the level of a key oxidant (superoxide) in animal cells.

Prior to this, there was no direct and accurate way to measure superoxide or its origin from the two places that produce it, the cell’s cytosol or mitochondria. Now there is.

With the new system developed at OSU, researchers can use a fluorescent microscope, a fairly standard laboratory tool, to actually see levels of superoxide and observe changes as experiments are performed with living cells.

Oxidation is a process that occurs naturally in the body — for example, in cell energy production and some immune reactions. As a result of the process, unstable atoms and molecules (e.g., free radicals such as superoxide) can be formed.

The body produces substances (e.g., glutathione, superoxide dismutase, catalase) that help to stabilize these atoms and molecules and prevent excessive damage and inflammation. We also take in anti-oxidants through our diet, in the form of different nutrients such as vitamins C and E, that help to neutralize these free radicals.

When these free radicals accumulate, cell structures can be damaged. This damage is believed to play an important role in many degenerative diseases, including ALS, Parkinson’s, Alzheimer’s, heart disease, hypertension, diabetes, and more.

The discovery of this technique will help researchers better understand what’s really happening in cells, as well as the effects of different potential treatments, and should help to speed research in many diseases. It’s definitely good news.

Why does the flu usually only appear during the winter months and disappear during the summer? A group of researchers just published a review study that suggests vitamin D deficiency may be responsible.

You can read the abstract of the study here, and an excellent summary article (well-worth reading) discussing the study’s primary findings here.

The researchers note that vitamin D has many important effects on the immune system, including:

• Acting as an immune system modulator — preventing excess inflammation and increasing the ‘oxidative burst’ potential of macrophages, a type of immune system cell
• Stimulating the expression of anti-microbial proteins in immune system cells and in cells lining the respiratory tract

When vitamin D is deficient, as it often is during the winter months, the hypothesis is that the body is less able to develop an appropriate immune response and defend against respiratory infections.

In the summary article linked above, one of the study author’s describes how in the hospital in which he worked a flu epidemic developed in Spring 2005. However, all of the patients in his ward had been taking 2,000 IU vitamin D daily for months, and not one of them developed the flu.

Of course, those observations are not definitive proof. More research is necessary to determine cause and effect.

Yet, the authors make a good case in the paper for how vitamin D may explain observations, such as:

1. Why the flu predictably occurs in the months following the winter solstice, when vitamin D levels are at their lowest,
2. Why it disappears in the months following the summer solstice,
3. Why influenza is more common in the tropics during the rainy season,
4. Why children exposed to sunlight are less likely to get colds,
5. Why cod liver oil (which contains vitamin D) reduces the incidence of viral respiratory infections,
6. Why the elderly who live in countries with high vitamin D consumption, like Norway, are less likely to die in the winter,
7. Why the elderly are so much more likely to die from heart attacks in the winter rather than in the summer,
8. Why African Americans, with their low vitamin D blood levels, are more likely to die from influenza and pneumonia than Whites are.

Bottom-line, it’s important to maintain vitamin D at summer-time levels year-round. For people living in higher latitudes where the intensity of the sun’s UV rays are not strong enough to generate vitamin D during the winter, the only way to do that is with sun lamp exposure or supplementation. If using supplementation, it’s also important to monitor your vitamin D levels to ensure that you don’t get too much.

The short answer: No. Shellfish is fine in moderation. The original research that estimated shellfish cholesterol levels used less sophisticated testing methods that weren’t able to distinguish between cholesterol and other sterols. As a result, cholesterol levels looked higher than they actually were.

Summary here.

Longer explanation here.

Here’s a table with the cholesterol content of various foods.

Among shellfish, shrimp, crab, and lobster tend to have the highest cholesterol levels.

Putting Things in Perspective

It’s important to note (and not well-known) that the average person’s body generates about 1000 mg of cholesterol per day from both external sources (diet) and internal sources (created by the body’s cells).

The average daily dietary cholesterol intake is ~600 mg, of which only about one-half is absorbed, or ~300 mg.

So, the typical diet only supplies less than one-third of your daily cholesterol. The rest is produced by cells in your body — about 20% by cells in your liver and the other 80% by other cells in the body. Statins work by inhibiting an enzyme that is involved in producing cholesterol in the liver.

Note that, using the table in the link above, you’d have to eat more than 3/4 lb. of shrimp or crab to take in 600 mg of cholesterol. I wouldn’t recommend eating that much regularly, but it helps to put things into perspective.

Bigger Concerns

I would be more concerned with potential toxins (heavy metals, PCBs) in seafood, as well as with antibiotics used in farm-raised species (e.g., shrimp). These levels, of course, vary depending on the type of seafood and from where it was sourced.

I would also be more concerned with overall intake of saturated fat and trans fat, both of which are positively correlated with greater risk of cardiovascular disease.

There are actually several different types of saturated fat. Some may promote higher bad cholesterol levels, while others may be neutral in their effect. Moderation is key.

Trans fats, on the other hand, are bad all around.

Cholesterol is an important chemical compound in the body. It’s used for hormones, bile salts, and even vitamin D. But there are several types (LDL, HDL, etc.), and ratios between the different types may be just as important as overall levels for predicting heart disease risk.

Cholesterol is often not the biggest problem in heart disease. Inflammation is. More on that here.

A new review study to be published in an upcoming issue of The Lancet notes that there are over 200 industrial chemicals that may damage the human brain, yet most are neither examined for potential effects on the developing brain nor tightly regulated. With one out of every six children now affected by a developmental disorder, the stakes are high.

As one of the study’s authors notes: “We must make protection of the young brain a paramount goal of public health protection. You have only one chance to develop a brain.”

This article does a good job of summarizing the study’s important points:

Few chemicals are assessed for neurotoxicity in the developing brain:

The authors then examined the published literature on the only five substances on the list–lead, methylmercury, arsenic, PCBs and toluene–that had sufficient documentation of toxicity to the developing human brain in order to analyze how that toxicity had been first recognized and how it led to control of exposure…the number of chemicals that can cause neurotoxicity in laboratory animal tests exceeds 1,000

The toxicity issue is most critical for children:

A developing brain is much more susceptible to the toxic effects of chemicals than an adult brain. During development, the brain undergoes a highly complex series of processes at different stages. An interference–for example, from toxic substances–that disrupts those processes, can have permanent consequences. That vulnerability lasts from fetal development through infancy and childhood to adolescence. Research has shown that environmental toxicants, such as lead or mercury, at low levels of exposure can have subclinical effects–not clinically visible, but still important adverse effects, such as decreases in intelligence or changes in behavior.

The impact is significant, both in terms of people and dollars:

[Researchers] conclude that industrial chemicals are responsible for what they call a silent pandemic that has caused impaired brain development in millions of children worldwide. It is silent because the subclinical effects of individual toxic chemicals are not apparent in available health statistics. To point out the subclinical risk to large populations, the authors note that virtually all children born in industrialized countries between 1960 and 1980 were exposed to lead from petrol, which may have reduced IQ scores above 130 (considered superior intelligence) by more than half and increased the number of scores less than 70. Today, it’s estimated that the economic costs of lead poisoning in U.S. children are $43 billion annually; for methylmercury toxicity, $8.7 billion each year.

What can be done?

The study’s authors have four recommendations:

1. Document chemicals that have caused toxic effects on the nervous system in humans to facilitate targeted preventive action against releases of these chemicals;
2. Document human exposures to neurotoxic chemicals and identification of subgroups at risk due to residence, occupation, diet, and other factors;
3. Research the consequences of developmental exposures to neurotoxic chemicals to expand our understanding of the long-term consequences of such exposures; and
4. Screen for neurotoxicity of commonly used chemicals to identify those that may present a hazard to brain development.

But they mention that these actions are expensive and will likely not be taken soon.

In the meantime, there are steps that individuals can take to protect themselves and their own children, including:

• Drinking filtered water
• Avoiding produce that is high in pesticides
• Reducing the use of harmful cleaning products in the home
• Selecting safer personal care products
• Having your residence tested for lead if it was built prior to 1978, and having lead paint professionally sealed and/or replaced
• Avoiding mercury in fish, amalgams, and vaccines

And for people who suspect toxin exposure may be an issue for either themselves, their own children, or future planned children, there are also other actions that can be taken.

Interesting article in the San Francisco Chronicle discussing the disillusionment with dieting:

Eighty percent of the people who responded to a recent survey by Mintel International, a marketing research firm that specializes in food, said they are making up their own diet plans by trying to eat less fat and cut calories. Only 6 percent said they are on commercial diets such as Jenny Craig, Weight Watchers and NutriSystem. Nearly 70 percent said they aren’t interested in the diets of celebrities…

…nutritionists and doctors are finding that many dieters prefer to go it alone. People are fed up with taking off the weight only to regain it, others are frustrated by the strictures of popular plans on the market, and then there are those who are just plain confused by the sheer volume of food do’s and don’ts.

Given both the proliferation of diet hype and the tripling of the obesity rate in recent years, it’s no wonder many people have said, “Enough!”

Steven Blair, a professor at the Arnold School of Public Health at the University of South Carolina, is on the right track:

“People need to stop obsessing on the weight and start focusing on health…We’re not all going to look like models and movie stars. Get over it and get a life.”

That’s not to say people shouldn’t target a healthy body weight for their height and build, but the focus really does need to be on health and not just weight. There are many things that one can do to benefit health without obsessing about every calorie, including:

• Selecting healthier food choices when available, e.g.:
  • Whole grains instead of refined grains
  • Foods and drinks without added sugars
  • Lots of vegetables, organic if possible
  • Freshly prepared foods, rather than processed foods
  • Foods low in saturated animal fats and without trans fats
• Moderating portion sizes
• Eating smaller meals, each with some protein, spaced throughout the day to control blood sugar and appetite swings
• Getting adequate fiber and filtered water in the diet to help ensure the excretion of waste and toxins
• Getting regular, moderate exercise
• Supplementing with a core set of essential nutrients to ensure that your body’s cells have the raw materials to function well

Nutrition can seem complex and confusing, but it doesn’t have to be. Taken incrementally, simple changes like those above can make a difference and help you to be healthier and feel better.

These were a few of the headlines after the recent release of two studies examining the health benefits and risks of eating fish:

Seafood benefits found to outweigh risks (Boston Globe)

Eat more fish, study urges, despite toxin risk (Reuters)

Seafood not your health foe, studies say (SJ Mercury News)

The first study, a meta-review* completed by researchers at the Harvard School of Public Health and published in the Journal of the American Medical Association, boldly suggested that regular fish consumption could reduce the risk of heart attack death by 36 percent and the overall risk of death by 17 percent.

(* A meta-review is a review of the existing body of research. Perhaps the Harvard meta-review excluded studies like this one, “Mercury in fish poses heart risk for middle-aged men“?)

The second study, a report completed by the Institute of Medicine (IOM), was more balanced in its review of the research. It concluded only that the regular consumption of fatty fish may reduce the risk of heart disease, while “contaminants that may be present in seafood may pose a risk to some especially susceptible groups of people.”

A More Balanced View

Just reading the headlines, one could easily draw the conclusion that concerns about toxins in seafood are overblown and that there’s really nothing to be concerned about unless you’re a pregnant woman, a prospective mother, or a small child. Fortunately, the NY Times presented a much more balanced perspective in their coverage:

The Harvard study, to be published in the Journal of the American Medical Association today, said the benefits of eating fish high in omega-3’s strongly outweighs risks from contaminants like PCB’s and dioxin found in high concentrations in fish like farmed salmon. Calling those risks “greatly exaggerated,” Dr. Darius Mozaffarian, one of the two authors, said, “Seafood is likely the single most important food one can consume for good health.”

Dr. Marion Nestle, a professor of nutrition, food studies, and public health at New York University, who described the “very sunny Harvard study” as “astonishing,” remains unconvinced. “The report’s conclusion that the risk of death can be reduced by 36 percent is just stunning,” she said. “It would indeed make eating fish the single most important decision you can make for your health. But those of us who have been in nutrition for a long time have seen miracle foods come and go: vitamin E for heart disease, beta carotene to prevent cancer; now it’s fish.”…

…The report from the Institute of Medicine tells the government that much more research is needed. Dr. Malden C. Nesheim, chairman of the institute’s committee and a provost emeritus at Cornell, said, “We are quite cautious because the studies we looked at are not controlled for all the variables, and we can’t distinguish between the effects from omega-3’s or replacement of other foods in the diet.”

The NY Times reporter then exposed some of the behind-the-scenes political maneuvering:

The National Oceanic & Atmospheric Administration [NOAA] had requested the institute’s report because it said consumers were confused about how much and what kind of fish they should eat. The two studies, which conflict in important aspects, seem unlikely to provide much clarity. “The high degree of certainty in one report and the extreme caution in the other,” said Rebecca Goldberg, a senior scientist with Environmental Defense, an advocacy group, “will make people more confused than ever.”

To the surprise of Institute of Medicine officials, NOAA sponsored the hastily called press conference at which the Harvard report was released, even though that study conflicted with the one prepared by the institute. “We’re just trying to make consumers feel good*,” said William T. Hogarth, assistant administrator for fisheries of the National Marine Fisheries Service*, part of NOAA.

[* emphasis added]

Major environmental and groups noticed the inconsistencies as well:

Both reports have come under criticism from environmental groups and from the Consumers Union. “In addition to being concerned about the failure of the JAMA and I.O.M. reports to address the risks of mercury in tuna,” said the consumer organization, “we are also concerned that both reports dismiss concerns about PCB’s in most fish.”

“These reports are urging Americans to eat more seafood as if it were a crisis,” Dr. Goldberg said. “According to NOAA’s own statistics, per capita consumption of seafood has risen from 14.8 pounds in 2001 to 16.6 pounds in 2004.”

Jane Houlihan, the research director of the Environmental Working Group, another advocacy group, said, “The Harvard study reads like an advertisement for the seafood industry.”…

…“Once again pregnant women are being told it’s O.K. to eat tuna,” Ms. Houlihan said. “The reality is, 90 percent of women would exceed government’s level for a safe dose of mercury if they ate six ounces of albacore tuna every week as the F.D.A., E.P.A and now I.O.M. recommend.”

What to Do

Omega-3 fats found in fish clearly are beneficial for heart, brain, and immune system health. There’s a great overview of those benefits discussed in this article, “Omega-3 Fatty Acids: Vital to a longer, healthier life.” And the truth is that the majority of people do not take in adequate amounts of these healthy fats.

Unfortunately, though, many fish are contaminated with toxins such as mercury. Do yourself and your family a favor. Use a simple online calculator like this one to help plan safe seafood consumption.

(While you’re there, ask yourself why government agencies responsible for advising consumers on safe fish consumption haven’t put together such easy-to-use tools? The IOM, in fact, recommended the creation of such tools in their report.)

Better yet, to ensure adequate Omega-3 fat intake, include regular consumption of fish oils that have been tested to be free of contaminants such as heavy metals, PCBs, etc. There’s a good list of safe products here.

A couple of weeks ago, I talked about the importance of adequate vitamin K intake in helping to prevent the calcification (hardening) of blood vessels often seen in heart disease and cerebrovascular diseases, such as stroke and Alzheimer’s Disease.

Just as vitamin K is critical for preventing the calcification of blood vessels, it is also essential for calcifying bones and keeping them healthy and strong.

In a recent study, researchers with the University of Michigan School of Nursing found that the current government recommended intake of vitamin K may not be high enough for peri-menopausal women in order to avoid a decline in bone mass density (BMD).

The protein osteocalcin, which helps to bind calcium to bone, requires vitamin K in order to work properly. Researchers found a higher percentage of inactive (or undercarboxylated) osteocalcin in early post-menopausal women 40-52 years old, indicating that they may have inadequate vitamin K levels in order to prevent bone loss.

The researchers also noted that a decline in estrogen levels may impair vitamin K function in bones even before bone loss can be measured.

Given that:

• Vitamin K is found in significant amounts in only a few foods (e.g., leafy greens)
• These foods are not eaten regularly and in large amounts by most people
• And the results of this study and others like it indicate the importance of vitamin K for maintaining healthy bones

It makes sense if you are a peri-menopausal woman to regularly supplement with this nutrient, preferably with a supplement that contains both primary forms of the vitamin — K1 and K2.

Two Important Notes:

Vitamin K is fat-soluble. It needs to be eaten with a meal containing fat for proper absorption.

Vitamin K also affects blood clotting. People taking blood thinning drugs need to talk with their physicians before supplementing, as increasing vitamin K intake may change the necessary prescription.

Earlier this year, researchers took a look at air pollution levels in the Northern California Bay Area and the potential association with autism spectrum disorders (ASD).

The study, published in the respected journal, Environmental Health Perspectives, found that the risk of ASD was 50% greater in babies born in areas with chlorinated compound and heavy metal air pollution levels in the top quartile. Compounds that had the greatest individual risk of association were mercury, cadmium, nickel, trichloroethylene, and vinyl chloride.

The researchers examined other potential variables that may have affected the results (including maternal age, race, education, and parity; paternal race and age; low birth weight, preterm delivery, and child race), but found them to not have significantly altered the chemical group findings. The results, of course, could not take into account potential individual exposures to the various chemical compounds.

Not Just the Bay Area

The results mirror those in another 2006 study that examined data for each county in Texas and found that autism rates increased by 61% and special education rates increased by 43% for every 1,000 pound increase in mercury emissions. Fossil-fuel burning power plants were the primary heavy metal source.

Few areas of the country are really immune from these potential air pollution effects, as evidenced by these stories discussing the effects of mercury in cement plant emissions in both Michigan and the NY Hudson Valley areas.

Clearly, more attention needs to be paid to air pollution levels of these compounds. As mentioned in the NY Hudson Valley article, efforts to regulate lower emissions haven’t been enacted quickly:

In 2000, a federal judge ordered the EPA to draw up rules for limiting mercury, hydrochloric acid and hydrocarbons at the nation’s cement plants. The decision was prompted by a lawsuit by EarthJustice and the Sierra Club, and the judge agreed the new rules were required by the Clean Air Act.

After the EPA took no action, the environmental groups joined with others in a coalition and again sued successfully, in 2004, to force action.

Last fall, the EPA proposed new rules, and determined new and existing plants would face limits on hydrochloric acid and hydrocarbons, but that cost and technological barriers prevented regulation of mercury. The environmental coalition has protested. A final decision is expected in December.

“It’s just ridiculous,” said Jim Pew, an attorney for EarthJustice. “These guys are big emitters and for whatever reason, EPA has decided to blow it off.”

For those who are affected by these air pollutants, especially heavy metals, waiting for government action isn’t really a good option. There are steps that can be taken to reduce the impact of these toxins.

(Following is a guest post written by health enthusiast and local food advocate, Carla Borelli. Carla Borelli is the author and publisher of Local Forage, a blog devoted to the sourcing of traditional whole foods in the San Francisco bay area.)

There is much talk and campaigning lately about eating locally produced foods. When you plan to “eat local”, you have to define for yourself what is local. Is it food from your own country? From your state? From farms within 150 miles of your house? Nutritionist Joan Gussow suggests trying to buy food produced “within a day’s leisurely drive of our homes,” a goal “designed to maintain a living countryside.” Jessica Prentice’s SF Locavores group pledged to eat only foods grown or harvested within a 100 mile radius of San Francisco.

How To Incorporate Local Foods Into Your Diet

Whatever you define as local, here are some ideas for how to begin to incorporate local foods into your diet .

• Learn what foods are in season in your area and try to build your diet around them. Local chef and food educator, Jessica Prentice has a very helpful food wheel which identifies what foods are grown in the San Francisco Bay Area, and what is in season at various times of the year.
• Shop at a local farmers market and/or subscribe to a CSA (Community Supported Agriculture) service like Mariquita Farms , Eatwell or Full Belly Farm. Click here for an article in the SF Chronicle on CSAs.
• Ask the manager or chef of your favorite restaurant how much of the food on the menu is locally grown, and then encourage him or her to source food locally. Urge that the share be increased. Do the same at the local supermarket or school cafeteria.
• Take a trip to a local farm to learn what it produces.
• Buy extra quantities of your favorite fruit or vegetable when it is in season and experiment with drying, canning, jamming, or otherwise preserving it for a later date.
• Plant a garden and grow as much of your own food as possible.

Why Local Foods Are Important

Aside from the obvious benefits of freshness and good flavor, for me eating local is a matter of integrity. It represents a vote (with my dollars) in favor of farmers who care deeply about their customers and the ecology, and a vote against industrial food producers who subjugate almost all human values to the earning of high profits. When I buy from local purveyors, I get a transparency that is otherwise lacking in conventional store-bought foods; I know specifically how the food was produced, where it came from and who produced it. I get food I can trust.

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Curcumin, the yellow pigment found in tumeric, a common ingredient in curry, may help to protect against cognitive decline and slow the development of Alzheimer’s disease (AD).

There’s been quite a bit of research done the past few years regarding the potential connection. Two recent studies reinforce that link.

The first study looked cognitive performance and curry consumption in older, non-demented Asian individuals (aged 60-93 years). Researchers found that those who ate curry occasionally or frequently scored significantly better on a standardized mental health test. Those people who consumed curry often or very frequently had a 49% reduced risk of cognitive impairment, while those consuming it occasionally had a 38% decreased risk.

The study was observational, so cause and effect could not be determined (there may have been other factors playing a role — e.g., vegetable and fat intake), but the results are consistent with earlier experimental evidence on curry.

The second recent study found that immune system cells (macrophages) in blood drawn from AD patients were able to break down beta-amyloid plaques (found in the brains of AD patients) significantly better when treated with curcumin.

This study was a lab study (i.e., the test were done on the blood samples in petri dishes), but nevertheless the results were consistent with earlier research examining the effects of curcumin on immune system function.

Finally, this review study provides a good overview of curcumin’s suspected biochemical benefits in diseases such as AD, as well as for other conditions, such as cancer, heart disease, inflammatory digestive disorders, arthritis, and osteoporosis. In short, curcumin seems to have an excellent ability to regulate proteins, enzymes, and other factors that manage immune system response.

Curcumin certainly seems like a safe and important substance to potentially help prevent and treat many chronic conditions.

(Note: If you’re considering increasing tumeric intake by eating restaurant prepared curries, it’s important to consider the type and and amounts of fats used in their preparation. Restaurant-prepared curries can often be high in fats, especially saturated fats (like ghee, or clarified butter, and vegetable oil). In high amounts, these fats may counteract some of the curry’s beneficial effects by promoting elevated cholesterol and/or inflammation. Try to identify restaurants that use moderate amounts of these fats and/or other more healthy alternatives, such as olive oil.)