You Ask, I Answer: Monoglycerides & Diglycerides

What are monoglycerides and diglycerides?

I've seen them on food labels but don't know what they are or why they are in some foods.

-- Lisa (last name withheld)
Brooklyn, NY

Ah, yes. Nothing makes you want to reach for a dictionary more than reading a food label.

Monoglycerides and diglycerides are related to triglycerides (three fatty acid molecules bound to a glycerol molecule) -- the basic unit of all dietary fats.

They consist of either one or two fatty acid molecules bound to a glycerol molecule and are mainly used as emulsifiers, thickeners, and binders in a variety of different foods.

Although they can be obtained from triglycerides, they are very easy to create synthetically.

"Non-natural" peanut butters, for instance, contain mono and/or diglycerides in order to prevent the oil from separating from the more paste-like crushed peanuts.

You will also often see them present in margarines and low-fat butter replacements.

They pose no health risks -- or benefits.

You Ask, I Answer: Saturated Fat

You mentioned that saturated fat is the "bad" fat and this definitely is the common understanding these days.

Have you read any conflicting evidence about this?

After reading the first half of Gary Taubes' Good Calories, Bad Calories I came to the conclusion that saturated fat really isn't a big deal unless you're in the extreme heart disease risk category, which, at 27 and with normal cholesterol levels, I don't think I am.

And, while I don't agree with Taubes' anti-carb approach, I found his evidence about regarding the fat-cholesterol link (and how research was so highly influenced by politics, guesswork, and some key personalities) very interesting, and moderately convincing.

It seems that cholesterol levels are only veeery minimally affected by saturated fat in one's diet.

I'm wondering how you feel about this aspect of his argument, or if you've seen other people calling the evilness of saturated fat into question recently.

I thought I had it all figured out, but this is the one thing I'm still not sure about.

Thanks so much.

-- Meredith (last name unknown)
Via the blog

Gary Taubes is certainly not the first -- or only -- person to question the saturated fat/heart disease connection.

Although some studies date as far back as the 1950s, Mr. Robert C. Atkins brought the research out of the scientific community and into the mainstream.

He -- along with his proteges -- claimed that eating endless amounts of steaks, butter, and bacon actually led to healthier lipid profiles than low-fat, high-carb diets.

And so we come back to the issue of flawed logic. Let me explain.

Like Atkins, Taubes and his ilk approach this scenario from a very narrow "black or white" perspective.

Firstly, they are quick to judge detractors as low-fat advocates.

This is grossly inaccurate. For instance, I strongly disagree with Taubes, but a quick browse through this blog makes it clear I do not advocate low-fat diets.

Instead, I believe that an adequate amount of the right fats is crucial for our health.

I fail to understand why Taubes and his supporters practically worship saturated fat but completely fail to mention the health benefits of monounsaturated fats and omega-3 fatty acids.

They aren't saying "fat is healthy; make sure to include almonds, olive oil, and wild salmon in your diet!" Instead, they pretty much push red meat and bacon.

Mind you, current guidelines do not call for a complete elimination of saturated fat from the diet; they simply suggest no more than 20 grams a day (assuming a daily intake of 2,000 calories).

Many dietitians -- myself included -- recommend a low intake of saturated fat, but simultaneously urge people to seek out the healthy fats found primarily in salmon, olive oil, walnuts, flaxseed, and avocados.

Although there are some professionals who advocate very low-fat diets -- Dean Ornish comes to mind -- many of the dietitians I know do not support skimping on healthy fats.

Now, when you compare a high-fat (in this case, saturated fat) low-carb diet to a high-carb (conveniently, high in refined carbohydrate), low-fat diet, the high-fat diet will lead to a better lipid profile (triglycerides, for instance, are related to refined carbohydrate intake, not dietary fat).

This, however, is misleading.

It's akin to only comparing bronze (diet high in refined carbohydrates and low in fat) and silver (diet high in fat, albeit saturated, but low in refined carbohydrates) and claiming silver to be the most expensive metal.

Yes, the most expensive of the two.

But, bring in platinum (a diet low in saturated fat but high in mono unsaturated fats and whole grains) and suddenly silver doesn't look quite as amazing.

I would like Gary Taubes to compare two high-fat diets (one high in saturated fats, one high in mono and polyunsaturated fats) and conclude, with a straight face, that the saturated fat-rich one is the healthiest.

There are literally hundreds of human clinical research studies showing a correlation between saturated fat intake and heightened coronary heart disease risk.

One interesting one was published in the July 2005 edition of the British Medical Journal.

Turns out that, in 1991, the Polish government stopped subsidising foods high in saturated fat.

Eleven years later, "deaths from coronary heart disease had dropped by over a third in the 45-64 age group - a 38 per cent drop for men and 42% for women."

During this time, saturated fat consumption fell by 7 percent, and -- more importantly -- polyunsaturated fat consumption increased by 57 percent!

We again come back to the notion that the key is not in reducing total fat intake, but in replacing saturated fats with healthier varieties.

Taubes happily bashes anyone recommending a low-fat diet, but what are his arguments against replacing saturated fats with Omega-3 fatty acids (a type of polyunsaturated fat) for improved lipid profiles?

Moving on to red meat, there is also a good deal of research showing that colon cancer risk is indeed affected by red meat consumption (this 2006 meta-analysis from the Pakistan Journal of Nutrition summarizes some major findings well).

A great Italian study by Talvani et al in 2000 also looked at red meat intake and cancer risk.

I recall Mr. Taubes scoffing and referring to all this evidence as "questionable" when he was on Charlie Rose several years ago.

How he came to that conclusion I do not know.

In my mind, sanctifying saturated fat and telling people to eat it liberally is irresponsible.

By the way, this idea that advice to eat less red meat is some sort of conspiracy relating to politics is rather laughable since, as Marion Nestle brilliantly explains in Food Politics, the national beef association threw a major hissy fit when Dietary Guidelines originally urged the public to simply "consume less red meat".

They were quickly changed to "choose lean cuts of meat," so as to not offend the powerful beef lobby.

We come back, as always, to the issue of moderation.

Have a slice of Swiss cheese here and there or pour a splash of whole milk into your morning coffee if it makes you happy; just don't make saturated fats the main players of your diet.

Numbers Game: Answer

A 2007 Internet survey of 20,000 adults in the United States by the National Lipid Association found that three percent were able to identify the desired values for total cholesterol, HDL ("good") cholesterol and triglycerides.

A shockingly low figure.

I'm willing to bet that the remaining ninety-seven percent not only do not know what ideal values they should have, but are also unaware how nutrition affects those numbers!

As far as figures go, when it comes to total cholesterol, you want to be at less than 200 mg/dL.

A number between 200 and 239 is considered a moderate risk (this risk is lowered if the number is a result of low 'bad' cholesterol -- LDL -- and very high 'good' cholesterol -- HDL), and anything over 240 significantly increases your risk of developing coronary heart disease.

Moving on to HDL ('good cholesterol', which sucks up cholesterol in the body and transports it to the liver for processing), a value of at least 60 mg/dL is required for it to serve as a protective force against heart disease.

Anything below 40 men and 50 for women is considered low and another risk factor for coronary heart disease.

Although triglycerides are a lipid, high values are linked with excessive intake of refined carbohydrates (processed flours, sugar, etc.)

Anything below 150 mg/dL is great, while a number between 150 and 199 should raise the "Caution!" flag.

Triglyceride levels are considered high at anywhere between 200 and 499 mg/dL, and anything above 500 is cause for serious concern.

Numbers Game: Ignorance is Not Always Bliss

An 2007 Internet survey of 20,000 adults in the United States by the National Lipid Association found that ______ percent were able to identify the desired values for total cholesterol, HDL ("good") cholesterol and triglycerides.

a) 10
b) 3
c) 5
d) 7.5

Leave your guess in the "comments" section and come back on Saturday for the answer -- and the correct values!

You Ask, I Answer: Sugar

How does sugar affect weight gain and fat storage?

-- Anonymous

Sugar -- in all its forms -- amounts to 4 calories per gram. In other words, whether you are having sugar in the raw, honey, or plain white table sugar, the calories you are taking in per gram are the same.

If you look at a food label and see that a product contains 30 grams of sugar, a simple math calculation would let you know that 120 of its calories (30 grams x 4 calories per gram) are coming from sugar.

The issue of weight gain and fat storage has more to do with high fructose corn syrup.

Unlike sugar, which stimulates the pancreas to create insulin and lower blood sugar levels, high fructose corn syrup goes straight to our liver.

Our liver is not used to such visits, so it goes into freak-out mode, hitting the panic button to release its troops. Our pancreas are used to sugar dropping by, so it has insulin ready to balance its effects.

However, all the liver can offer is a series of enzymes that tell the body not only to store fat, but also to raise triglyceride levels. The most alarming thing is that these enzymes don't help tell our brains that we are full.

Thus, it appears to be easier to overeat foods with high fructose corn syrup rather than those with real sugar.

Sugar in and of itself is not fattening. It just so happens that sugary snacks are also high in fat (which clocks in at 9 calories per gram) and, thus, pack quite a caloric punch.

All-Star of the Day: Peanuts

Although almonds often take the “super nut” title, the peanut also needs to be recognized for its tremendous health benefits.

Peanuts are an excellent source of heart-healthy monounsaturated fats, the same ones that make olive oil and salmon such powerfoods. Remember, diet high in monounsaturated fats and low in saturated fats has been proven to reduce the risk of cardiovascular disease by as much as 20 percent. “Low-fat” is not the answer; “smart fat” is!

An ounce of peanuts contains 164 calories, 7 grams of protein, 10 percent of our daily folate recommendation, 29 percent of our managenese needs, and 19 percent of our suggested niacin (vitamin B-3) intake.

Although those figures themselves might not be groundbreaking, peanuts’ antioxidant level is extremely high, rivaling that of many fruits.

In fact, resveratrol (the antioxidant found in grapes -- and, thus, red wine -- that boasts tremendous heart-healthy properties) is found in significant quantities in peanuts!

A plant compound known as beta-sitosterol also exists naturally in peanuts, and recent research links it to reductions in rates of breast and prostate cancer.

A 10-year study in Taiwan involving over 20,000 subjects (published in the January 2006 issue of the World Journal of Gastroenterology) found that the average participant who ate an ounce of peanuts twice a week lowered their risk of colon cancer by 34 percent!

Additionally, studies at Pennsylvania State University’s nutrition department found that regular consumption of foods high in monounsaturated fats -- such as peanuts -- lowered triglycerides while keeping heart-healty HDL cholesterol stable, whereas a low-fat diet LOWERED HDL levels.

Yes, peanuts are high in fat (one ounce provides 14 grams of fat), but this has proven to be a positive attribute.

Studies at Harvard, Penn State, and even countries like Israel and Papua New Guinea all came to the same conclusion. When subjects were allowed to eat an ounce of peanuts as a snack twice a day, they reported feeling fuller and therefore eating less total calories a day!

So, yes, you can most certainly enjoy peanut butter as a grown adult. However, be sure to buy “natural” peanut butter (Smuckers is my favorite). The ingredients? Just two – peanuts and salt.

Most conventional peanut butter adds “partially hydrogenated oils” (the always evil trans-fats) and added sugars, which turn this all-star into a fallen celestial body.

All-Star of the Day: Kiwi

This little fuzzy guy from the Far East (kiwis are native to China) is quite the nutrition master.

Kiwi is, hands down, one of the best sources of Vitamin C. One cup of the egg-shaped citrus fruit packs 5 grams of fiber, 273% of our vitamin C needs, 13% of our daily vitamin E recommended intake, and 16% of the hypertension-preventing potassium we should get each day into just 108 calories!

The high antioxidant activity in kiwi has also shown a lot of promise.

A 2004 study at Norway’s University of Oslo published in the August 2004 issue of peer-reviewed journal Platelets concluded that after eating two to three kiwi fruits a day, test subjects lowered their risk of forming blood clots by approximately 20 percent. How? Certain phytonutrients (plant chemicals) in kiwi make blood platelets less sticky, therefore making it harder for them to lump together in the walls of our arteries. Sweet!

This same study also found that these same subjects reduced their triglycerides (a type of blood fat associated with an increase in heart disease risk) level by 15 percent.

It gets better! A study at Great Britain’s Rowett Research Institute demonstrated that just eating one kiwi a day helped damaged DNA – which has the potential to increase our risk of developing many cancers – repair itself! This is huge. Many foods are able to help decrease the risk of DNA damage, but certain antioxidants in kiwi are able to undo the damage to some extent.

A word of warning – be cautious when feeding kiwi to infants and young children. A study at England’s Southampton University’s Allergy and Inflammation Services unit published in the July 2004 edition of Clinical and Experimental Allergy found that kiwi resulted in a higher percentage of allergy symptoms in young children than other fruits.

The study isn’t considered complete since researchers have yet to find out what properties in this fruit result in its apparent higher allergen position, but it’s worth keeping in mind for now.

Next time you're making a fruit salad, be sure to include your new furry friend!