Marc Joseph Nutrition - Blog

In a review study published in the journal Thrombosis and Hemostasis, researchers note that vitamin K deficiency may be much more common than previously thought.

A primary action of vitamin K in the body is to help in a chemical reaction called carboxylation. Potential vitamin K deficiencies can be identified by measuring in the body the level of under-carboxylated compounds, such as osteocalcin and matrix Gla protein (MGP), both of which are involved in the maintenance of bone structure.

The scientists note that there is a substantial amount of incompletely metabolized osteocalcin and MGP in many otherwise apparently healthy individuals, which suggests that the majority of these people may be subclinically deficient in vitamin K.

Results Not Surprising

The findings aren’t too surprising, given that the primary dietary sources of vitamin K are:

• Green, leafy vegetables - spinach, kale, chard, lettuce
• Broccoli
• Parsley

These aren’t foods that most people eat regularly in adequate amounts (e.g., a cup per day). And, the biological half-life of vitamin K is relatively short — a few days. That means if you’re not regularly consuming vitamin K, you may become deficient.

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A review article published in the peer-reviewed journal Alternative Therapies in Health and Medicine summarizes the impact of heavy metals mercury and cadmium on the vascular system.

The overall vascular effects of mercury include oxidative stress, inflammation, thrombosis, vascular smooth muscle dysfunction, endothelial dysfunction, dyslipidemia [high LDL cholesterol, low HDL, high triglycerides], immune dysfunction, and mitochondrial dysfunction. The clinical consequences of mercury toxicity include hypertension, CHD [coronary heart disease], MI [myocardial infarction], increased carotid IMT and obstruction, CVA, generalized atherosclerosis, and renal dysfunction with proteinuria …

… Cadmium concentrates in the kidney, particularly inducing proteinuria and renal dysfunction; it is associated with hypertension, but less so with CHD. Renal cadmium reduces CYP4A11 and PPARs, which may be related to hypertension, sodium retention, glucose intolerance, dyslipidemia, and zinc deficiency.

More on Mechanisms

There are several primary ways in which heavy metal exposure may increase the risk for vascular disease:

Increased Oxidative Stress - Mercury and cadmium have high affinity for molecules that contain sulfhydryl groups (-SH), including several sulfur-containing antioxidants, such as N-acetyl cysteine (NAC), alpha-lipoic acid, and glutathione. As a result, when the body is exposed to these heavy metals, antioxidant function is compromised and oxidative stress increases.

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Chronic inflammation is an important factor in many conditions, including heart disease, diabetes, cancer, neurodegenerative diseases (Alzheimer’s, Parkinson’s), arthritis, digestive disorders, and more.

In a recent study published in the top journal Science, researchers at the University of Chicago identified what seems to be a key link between the immune system and high blood lipid (cholesterol and triglyceride) levels.

Specifically, the scientists found that when tumor necrosis factor cytokines (immune system messengers) were over-expressed on T cells (white blood cells that regulate immune response and attack virus-infected, foreign, and cancer cells) in mice, that blood lipid levels rose.

Since the liver and intestines are believed to be primarily responsible for regulating blood lipid levels, the researchers also looked at the livers of the mice. The liver secretes an enzyme called hepatic lipase, which breaks down lipids (e.g., VLDL, triglycerides). The scientists observed that the livers of mice that had T cells expressing greater inflammatory cytokines produced less hepatic lipase, and thus had higher blood lipid levels.

As one of the study’s co-authors notes, the implications of this finding could be far-reaching:

“Those with inflammatory problems such as lupus, rheumatoid arthritis and inflammatory bowel syndrome have a higher incidence of cardiovascular disease, often associated with elevated lipid levels,” added co-author Godfrey Getz, MD, PhD, professor of pathology, biochemistry and molecular biology at the University of Chicago. “This study may explain why.”

Causes of Increased Inflammation

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In a recent study published in the American Journal of Clinical Nutrition, researchers have found that the current Adequate Intake (AI)* for choline may not be sufficient to prevent fatty liver and muscle damage.

*An AI is a suggested intake in place of a Recommended Daily Allowance (RDA) in cases where there is insufficient scientific information to make a definitive intake recommendation.

Specifically, the scientists gave the study participants 550 mg choline per day (the AI for men) for every 70 kg in body weight for 10 days, followed by a diet of < 50 mg choline (plus 400 mcg of folic acid in some participants).

When given the choline deprived diet, 77% of the men and 80% of the post-menopausal women developed fatty liver or muscle damage, whereas only 44% of pre-menopausal women developed such signs. Estrogen increases the body’s production of phosphatidylcholine (see below) and may account for this observed difference.

Notably, nearly 1/4 of the men in the study developed signs of fatty liver and muscle damage while consuming the current AI level of choline.

Choline - What is It and Why Should You Care?

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In a study published in the journal Diabetes, researchers found that increased belly fat led to the production by fat cells of higher levels of inflammatory molecules that may directly promote systemic (whole body) inflammation. This increase in systemic inflammation may, in turn, raise the risk for several diseases, such as heart disease, diabetes, cancer, and cognitive decline.

There are two types of abdominal fat:

1. Subcutaneous fat - found just beneath the surface of the skin (the fat you can “pinch”)
2. Visceral fat - found in the spaces between internal organs

(Image: LA Times)

Visceral fat appears to be the primary source of the problem:

[T]he research team says visceral fat likely contributes to increases in systemic inflammation and insulin resistance. They sampled blood from the portal vein [which routes blood to the liver from the gastrointestinal tract] in obese patients undergoing gastric bypass surgery and found that visceral fat in the abdomen was secreting high levels of an important inflammatory molecule called interleukin-6 (IL-6) into portal vein blood.

“The portal vein is filled with blood that drains visceral fat,” says first author Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis and an investigator at the Istituto Superiore di Sanita, Rome, Italy. “Portal vein blood had levels of IL-6 that were 50 percent higher than blood from the periphery.”

Increased IL-6 levels in the portal vein correlated with concentrations of an inflammatory substance called C-reactive protein (CRP) in the body. High CRP levels are related to inflammation, and chronic inflammation is associated with insulin resistance, hypertension, type 2 diabetes and atherosclerosis, among other things …

… “Many years ago, atherosclerosis was thought to be related to lipids and to the excessive deposit of cholesterol in the arteries,” Fontana says. “Nowadays, it’s clear that atherosclerosis is an inflammatory disease. There also is evidence that inflammation plays a role in cancer, and there is even evidence that it plays a role in aging. Someday we may learn that visceral fat is involved in those things, too.”

Evidence Building

This latest study is one of many to highlight the influence of excess fat on systemic inflammation and disease risk. Here are links to a few other studies:

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Garlic is a plant with many potential medicinal benefits, including:

• Cardiovascular effects
• • Reduction of mildly elevated cholesterol and triglyceride levels
  • Decreased oxidation of LDL cholesterol (antioxidant)
  • Improved arterial elasticity
  • Reduced platelet stickiness & increased fibrinolytic (anti-clotting) activity
• Anti-microbial actions
• • Anti-bacterial/yeast/viral
• Anti-cancer effects
• • Reduced risk for developing several types of cancer, including colon, stomach, & esophageal

However, as this recent paper notes, for best results it’s important to:

1. Crush the garlic and allow it to sit for a few minutes before adding it to a cooked dish. With crushing, alliin, the sulfur-containing amino acid in garlic, comes in contact with the enzyme alliinase, which converts alliin to allicin. Allicin and related sulfur compounds (thiosulfinates) are believed to be the primary compounds responsible for garlic’s healthy effects.
2. Only cook the garlic for a brief period of time at moderate heat or lower once it’s added to the dish. The paper’s authors noted that garlic’s anti-platelet strength was preserved in both crushed and uncrushed garlic samples when they were cooked at under 400 degrees F for less than 3 minutes. Whereas cooking for 6 minutes reduced the anti-platelet effect in the crushed garlic and completely suppressed it in the uncrushed sample. Cooking for 10 minutes completely inhibited the anti-platelet effect in both samples.

Garlic prepared and eaten as above is preferred. Garlic supplements with standardized allicin content are an ok second choice. However, since a garlicky taste* can sometimes even be noticed with deodorized supplements, and supplements likely can’t replicate all of the potentially beneficial compounds found in raw garlic, this is a case where I’d definitely go with the food.

* Parsley eaten with or after a meal can help to blunt garlic odor.

Regular and moderate garlic intake (e.g., 1 to 2 cloves per day) may be a useful part of an overall program for maintaining a healthy heart.

Note: Because of garlic’s anti-clotting effects, people taking anticoagulant (blood-thinning) drugs, such as Coumadin or aspirin, should work with their physician or nutritionist to determine if garlic use is safe and appropriate.

In a recent study published in Nutrition and Metabolism, researchers found that interesterified (IE) fat, which is being pushed as a replacement for trans fats, may actually have more negative health effects than trans fats themselves.

The negative health effects of trans fats have been widely known for some time:

• increase bad cholesterol (LDL)
• decrease good cholesterol (HDL)
• impair endothelial cell (e.g., arterial) function
• associated with greater risk for heart disease and diabetes

Beginning in 2006, the Food & Drug Administration (FDA) began requiring all food manufacturers to list trans fats separately on the Nutrition Facts labels on packaged foods:

That move certainly has helped make it easier to select healthier products at the grocery store.

And, late last year, in a move that may start a trend, New York City banned trans fat use in restaurants.

Questions remain, though. What will replace trans fat products? Many products have been developed for both frying and baking. Will the replacements be any healthier?

Interesterified (IE) fats have been developed as one alternative. These fats are made by combining liquid oils (e.g., canola oil) with solid fats (e.g., palm oil) and mixing them with acids or enzymes to form a fat of desired consistency. The process is called interesterification.

The study mentioned above put study participants in three groups using the following test fats (~30% overall fat, >70% test fat):

• palm oil (a saturated fat) - PO
• partially hydrogenated soybean oil (containing 3.2% trans fat and 6.5% palm oil) - PHSO
• and an interesterified fat (with 12.5% stearic acid, a saturated fat) - IE

Researchers found that after four weeks:

• Blood glucose levels were 40% higher after meals in individuals using the IE diet versus those using the PO or PHSO diet.
• Fasting insulin levels were 10% lower in those using the PHSO diet and 22% lower in those using the IE diet.
• HDL (or good cholesterol) fell by 8 percent for the PHSO diet and 7 percent for the IE diet.

Not so good. Although the results of this study need to be replicated (this study was funded and staffed by the Malaysian Palm Oil Board), it seems like IE fats may be ones that you’ll want to avoid.

Your best bet is including in your diet unaltered fats in healthy combinations. For example, try using olive oil (high in monounsaturated fats) as your primary dietary oil, and layering on essential fats (Omega-3 fats as found in fish oil and small amounts of Omega-6 fats as found in vegetable oils).

With many baby boomers about to retire, maintaining independence and the ability to live an active, engaged retirement are top of mind. A recent study published in the Archives of Internal Medicine found that deficiencies in several micronutrients may increase the risk for having difficulty performing daily tasks as people age.

Specifically, the study looked at women over the age of 65 and found that deficiencies in selenium, vitamin B6, and vitamin B12 were all associated with significantly greater risk of experiencing disability, which was defined as self-reported difficulty in performing two or more activities such as bathing, dressing, toileting, transferring and eating.

Selenium is an essential trace mineral that is used by the body in important antioxidant-related enzymes. Selenium also plays an important role in immune function and may help to prevent the onset of certain cancers, such as prostate cancer.

Vitamin B6 and B12 are involved in important enzyme reactions, nervous system function, and help to maintain low homocysteine levels. High homocysteine levels are associated with oxidative stress, endothelial dysfunction, vascular diseases (heart disease, stroke), and, in particular, with decline of cognitive function.

Nutritionally, your best bet for avoiding the potential problems highlighted by this study are to follow a good diet, including mostly whole foods, lots of fresh vegetables & fruits, healthy fats, and lean protein sources.

Also, supplementation with a broad-based multi-vitamin/mineral containing at least 200 mcg selenium and the B vitamin equivalent of a B-50 complex, may help to ensure that you get adequate amounts of these essential nutrients on a regular basis and to prevent/delay the onset of disability. It’s important to select supplements containing both adequate and well-absorbed forms of the different nutrients.

A somewhat sad commentary on the slow adoption in the U.S. of a simple, inexpensive, and effective way to help prevent and treat heart disease using fish oil:

Every patient in the cardiac care unit at the San Filippo Neri Hospital [Rome, Italy] who survives a heart attack goes home with a prescription for purified fish oil, or omega-3 fatty acids.

“It is clearly recommended in international guidelines,” said Dr. Massimo Santini, the hospital’s chief of cardiology, who added that it would be considered tantamount to malpractice in Italy to omit the drug.

In a large number of studies, prescription fish oil has been shown to improve survival after heart attacks and to reduce fatal heart rhythms. The American College of Cardiology recently strengthened its position on the medical benefit of fish oil, although some critics say that studies have not defined the magnitude of the effect.

But in the United States, heart attack victims are not generally given omega-3 fatty acids, even as they are routinely offered more expensive and invasive treatments, like pills to lower cholesterol or implantable defibrillators. Prescription fish oil, sold under the brand name Omacor, is not even approved by the Food and Drug Administration for use in heart patients.

“Most cardiologists here are not giving omega-3’s even though the data supports it — there’s a real disconnect,” said Dr. Terry Jacobson, a preventive cardiologist at Emory University in Atlanta. “They have been very slow to incorporate the therapy.”

The article goes on to note that since the prescription fish oil is not licensed in the U.S. to prevent heart disease (only to treat high triglycerides), community doctors don’t learn of its potential preventive use and insurance companies don’t provide reimbursement.

Amazing, isn’t it?

The majority of Americans, not just heart attack patients, don’t get adequate intake of omega-3 fatty acids. Fish is by far the best food source of these healthy fats, but there are clearly toxicity risks. Supplements are a much safer route and help to ensure that you get a regular supply.

The prescription fish oil capsules are fine. They’re concentrated to have about three times more omega-3 fatty acids than most non-prescription products. But they’re also a lot more expensive and require a prescription.

Non-prescription products, as long as they’re tested for contaminants, are just as good. And some manufacturers even make concentrated formulas to reduce the number of necessary pills.

Most brands of fish oil are tested for contaminants. You can check many brands here.

Given the many benefits of omega-3 fatty acids in helping to prevent and treat disease, hopefully we’ll their use increase in medicine going forward — and not just in Europe.

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.