Saturated Fat: No longer the villain? (Was it ever?)

I was glad to see this post from Dr. Steve Parker on our heart health blog: Are Saturated Fats Really That Bad?  Although the folks at the Weston Price Foundation have been arguing for years that saturated fats are good for you, I've always found their manifestos to be those of people who have already made up their minds and then gone looking for the evidence to support their point of view, ignoring or misrepresenting any evidence that seems to get in the way.  So, it was nice to see a more impartial review of this particular issue.

I was particularly interested because I've been getting a lot of questions about coconut oil--a vegetable source of saturated fat. It's alleged health benefits are being heavily promoted but there's not much solid evidence to back up the claims.

Are Saturated Fats from Vegetables Better?

I've found it hard to evaluate whether saturated fats from vegetables are better than saturated fats from animals--in part because I think much of the conventional wisdom about saturated fats and heart disease was were on shaky ground in the first place.  False assumptions lead to poor study design.

Maybe the truth is that the vegetable saturated fats aren't better than animal saturated fats but that the animal fats weren't that bad in the first place?

No wonder so many people complain that the medical/nutritional world is constantly pulling the rug out from under their feet. We're constantly reversing our recommendations and turning yesterday's "wisdom" into today's outdated myth.

How can people who try so hard to get it right get it wrong so often?

Why is it so hard for us to get it right? As Marion Nestle's argues in the introduction to her recent book, What to Eat, part of the problem is embedded in the very nature of scientific research. In an effort to reduce the variables, nutritional research focuses too much on the details and not enough on the big picture.

"The range of healthful nutrient intake is broad, and foods from the earth, tree, or animal can be combined in a seemingly infinite number of ways to create diets that meet health goals," she writes. "The attention paid to single nutrients, to individual foods, and to particular diseases distracts from the basic principles of diet and health...But you are better off paying attention to your overall dietary pattern than worrying about whether any one single food is better for you than another."

I suspect that the kind of reductionist thinking that Nestle is deploring is exactly what got us into this mess about saturated fat.  We were looking for a culprit for heart disease. We found one in saturated fat...but I suspect we overlooked the critical importance of the context in which that saturated fat was being consumed.

Your thoughts?

So, CRP doesn't cause heart disease. I never thought it did.

Much has been made this week about some new studies showing that C-reactive protein, a compound that signals systemic inflammation, does not cause heart disease. See this description of the research from CNN (Study suggests C-reactive protein doesn't cause heart disease) and this reaction from the LA TImes: If C-Reactive protein isn't a cause of heart disease, what is?

Frankly, I'm not sure what the fuss is all about.  The media is acting as if the link between inflammation and heart disease has been thrown into question. It hasn't.

C-reactive protein is one of several markers for systemic inflammation. Elevated CRP levels indicate an increased risk for heart disease--and many other diseases as well.  While I guess it was important to make sure one way or the other, I, for one, never thought that CRP itself caused heart disease or arterial damage. It simply signals that inflammation is present.

A Declaration of Independence?

Many have questioned whether CRP is an independent risk factor. In other words, does measuring CRP levels really tell us anything that we don't already know from other screening tests?

I think it does. The other gold standard for assessing heart disease risk (cholesterol) is notoriously flawed.  Measuring both CRP and cholesterol gives a more complete and nuanced picture.  Monitoring CRP can also be a valuable way to monitor the effectiveness of treatment, especially lifestyle and diet interventions.

CRP screening is relatively inexpensive (around $60) and no more invasive than a standard cholesterol test. Plus, as this recent study points out, elevated CRP levels can help identify who is at highest risk for fatal (as opposed to non-fatal) heart attacks and might help us pinpoint those who would benefit from more aggressive treatment regimens.

Tell me something I don't know

For me the big unanswered question about CRP and disease risk is not whether the protein itself causes damage (which it apparently does not). What I'm waiting with bated breath to see is whether lowering elevated CRP with diet and lifestyle (as opposed to pharmaceuticals such as statin drugs) lowers the risk of disease.

Are BMI guidelines for the birds?

Q. I recently read that the standard BMI calculation and guidelines aren't accurate for African-Americans and other ethniticies. Can you explain why and do you have recommendations for ethnic specific guidelines?

A. Your BMI, or body mass index, is nothing more than a way of expressing your weight in relation to your height.  When we say that a BMI of between 19 and 25 is considered ideal, we're really just saying that for every height, there is a suggested healthy weight range. I'm 5'9" for example.  The suggested healthy weight range for me is 128 to 169.  (Click here to look up your BMI)

I think you're probably referring to a recent article in the British Journal of Nutrition  (reported in the Washington Post), which points out that the BMI guidelines are based on statistics gathered in a predominantly Caucasian population.  

Because of differences in average bone density, lean muscle mass, and so on, the BMI guidelines may be misleading for non-Caucasians. For example, it might underestimate healthy weight range for some people of African descent and overestimate the range for some of Asian descent.  Even for Caucasians, though, the BMI is a fairly crude gauge of body composition. For example, it's not a good guide for athletes, who have more muscle mass, or for the elderly, who have lost muscle and bone mass.

The BMI guidelines are supposed is to help identify people who may have too much (or too little) body fat.  Other ways to gauge whether you are carrying around an unhealthy amount of fat include:

Have a fitness trainer measure your body fat percentage.  The recommended percentage depends on your age and gender but as a very general guideline, women should try to keep body fat under 30% and men under 25%.  There are several methods of measuring body fat. The most accurate is also the least convenient: It involves being submerged in a tank of water.  A fitness trainer can get a pretty good estimate using body fat calipers--but good training and technique are essential.  Those scales and hand-held devices that calculate body fat by measuring electrical impedance are notoriously inaccurate.

Measure your waist size. A waist measurement of more than 35" for women or 40" for men increases your risk of heart disease and other diseases.

Calculate your waist-to-height ratio by dividing your waist measurement by your height.   If you are 5'5" and your waist measures 32", your ratio would be 32/65 or 0.49.  A ratio of less than 0.50 is considered healthy.

Calculate your waist-to-hip ratio by dividing your waist measurement by your hip measurement.  If your waist measures 32" and your hips measure 38", your ratio would be 32/38 or 0.84.   As a general rule, women are shooting for a ratio of less than 0.8 and guys for a ratio of 0.95 or less.

Ask your physician for individual guidance.  Your physician sees the whole you, not just a single measurement or statistic. If you're not sure whether your weight is healthy or not, ask your health care provider for input.

Regular versus instant oatmeal

Q. I have been eating instant oatmeal almost daily for a couple of years now. A friend recently told me I have been wasting my time if I thought I was eating it for nutritional reasons. Is instant oatmeal less effective than the regular stuff?

A. Actually, the nutritional differences between regular and instant or quick-cooking oatmeal are so insignificant that the Nutrient Data Laboratory for the USDA has just one analysis which applies to all three kinds of oatmeal.  All three contain the same amount of fiber and the same amount of cholesterol-lowering compounds.

The biggest difference is in taste and texture.  Regular oatmeal contains larger pieces of rolled oat grains and is a little chewier than the instant and quick-cooking varieties. (Ironically, it really doesn't take much longer to cook regular oatmeal than it does to make instant.)

Of course, I'm only talking about plain oatmeal. If the instant oatmeal that you're eating is flavored, then you're also getting a big helping of sugar with your oats. While that doesn't take anything away from the oatmeal, it may add undesirable (empty) calories. Also the little packets of instant oatmeal usually contain a slightly smaller serving than the standard serving of regular oatmeal--so you're getting a slightly smaller helping of fiber.

But rest assured that a serving of plain instant oatmeal is just as nutritious as the same amount of plain regular oatmeal.

Understanding the difference between dietary cholesterol and blood cholesterol

Q. Here in Baja, squid is abundant and we like to eat alot of it. Your site says it is high in cholesterol. Is that bad cholesterol or the good stuff? Can you break it down for me?

 

A. Dietary cholesterol (the cholesterol found in foods such as eggs and seafood) is neither "good" nor "bad."   Those terms are often used to describe different types of cholesterol-containing compounds in your blood.  In your body, cholesterol is bonded to various types of proteins to form packages called lipoproteins. LDL and HDL are two types of cholesterol-containing lipoproteins.

 

LDL is often characterized as "bad" because elevated levels are one risk factor for heart disease. HDL cholesterol is often described as "good" because high levels of this type of cholesterol lower your risk of heart disease.

 

The most recent research indicates that cholesterol from your food has very little effect on how much cholesterol is in your body.  If you're trying to reduce your LDL cholesterol, it's more effective to reduce your intake of saturated fat.

 

In other words, enjoy the squid!

 

 

Omega-6 fats: Have they gotten a bad rap?

I don't know how much of this has percolated through to the mainstream media, but lately I've noticed quite a few articles and editorials directed at medical and nutrition professionals arguing that omega-6 fats have been unfairly maligned.

Out of balance

The idea that has taken hold in the popular consciousness is that we need to eat more omega-3 fats and less omega-6.  It's often pointed out that our ancestral (hunter/gatherer) diet provided roughly equal amounts of these two essential fatty acids and that the modern (post-agriculture) diet provides ten to twenty times as much omega-6 as omega-3.  This imbalance is thought to promote low-level systemic inflammation and hasten aging and disease.

We can address the imbalance by eating more omega-3 (found in fish, flax, hemp) and/or by consuming less omega-6 (found in vegetable oils and processed foods made with them).

But eating less of something is never as popular as eating more of something--or better yet, simply popping a pill that lets you continue eating whatever you want.  So, who wins here? Primarily, people who sell fish oil and other omega-3 supplements.  (See also this recent post on fish oil supplements and their impact on the environment.)

Defending Omega-6 fats

But someone (perhaps vegetable oil manufacturers?) seems to think that people are being needlessly alarmed about omega-6 fats. Thus, the rash of recent articles arguing that omega-6 fats are not the problem--in fact, they promote good health.

What's the evidence for this? Well, for example, it's been pointed out that people who eat more omega-6 fats have lower incidence of heart disease than those who eat less, and that increasing the omega-6 intake can have a favorable effect on cholesterol levels.

But let's take a closer look. It turns out that:

• Omega-6 fats improved the total-to-HDL cholesterol ratio when they are consumed instead of carbohydrates.

• Omega-6 fats reduced LDL cholesterol  and heart disease risk when they are consumed instead of saturated fat.

So, what's actually at work here? Are these folks healthier because they ate more omega-6 or because they reduced their intake of carbohydrates and saturated fat?  Frankly, I think the most that can be concluded here is that omega-6 fats might be less damaging to your heart than carbohydrates and/or saturated fat. But I certainly wouldn't go looking for ways to increase my omega-6 intake based on this research.

My recommendations--pending further data

I am still convinced that improving the ratio of omega-3 to omega-6 fats is a good idea. For the vast majority of us, this means increasing our intake of omega-3s and/or decreasing omega-6.   Note: A small amount of omega-6 is essential for health but you'd have to be eating close to a fat-free diet to be at risk of omega-6 deficiency.

Reducing refined carbohydrates or saturated fat may also improve your health. But I'd suggest you replace those calories with monounsaturated fats (such as those in olive oil) rather than vegetable oils. Unlike omega-6, which has only been shown to be LESS HARMFUL, monounsaturated fats have actually been shown to be BENEFICIAL.

Your thoughts?

Ask Monica: If I'm restricting carbs, do I need to restrict fruits and vegetables?

Q. I've read that you need to restrict carbs and calories in any diet attempt. However, I've also read that one should consume lots of fruits and veggies, both of which are primarily carbs. What do I do?

A. First, let me point out that although restricting carbohydrates is a popular (and effective) approach to weight loss, it is not the only way to lose weight.  The only thing needed for a successful weight loss program is to consume fewer calories than you use.  You can cut calories by restricting carbs or fats--or simply by eating a little less of everything.

But, back to the root of your question:  are the carbs in fruits and vegetables unhealthy? No!  You're absolutely correct that fruits and vegetables are close to 100% carbohydrates. However, the amount of carbohydrate per serving is quite small--particularly for vegetables (other than potatoes and corn).

Carb-restricted diets

When most people talk about restricting "carbs," they're really talking about refined carbohydrates. This includes breads, pasta, pastry, sodas, and anything else made with flour and/or sugar. These foods are generally low in nutrients and often provide a lot of empty calories, so cutting down on them makes good sense if you're trying to lose weight. Too many refined carbohydrates can also increase your risk of Type 2 diabetes and heart disease, so cutting back is also a good way to make your diet healthier, even if you don't need to lose weight.

The more extreme forms of carbohydrate restriction also restrict whole grains like brown rice and oatmeal and starchy vegetables like corn and potatoes. While I personally don't think you need to eliminate all grains and starchy vegetables in order to be healthy, I also don't think these foods are necessary from a nutritional point of view.  (Although you do have to be somewhat thoughtful about what you replace them with!)

Eat as many vegetables as you like

Most fruit contains a lot of natural sugars (along with plenty of nutrition). Although the amount of sugar and carbs in whole fruit is low compared with refined carbohydrates, it might be a good idea to limit your intake of fruit to 2 to 4 servings a day. Dried fruit and fruit juices are very concentrated sources of sugar and calories and I often advise people to avoid them when dieting. 

But any diet theory that instructs you to restrict vegetables because they contain carbohydrates is highly suspect.  With the exception of corn and potatoes, vegetables are extremely low in calories and carbohydrates and packed with fiber and nutrients. As far as I'm concerned, eat as much of these as you like!

Cardio fitness DOES still matter!

Have you noticed a bit of a backlash against cardiovascular exercise lately? The Cardio Free Diet, by Jim Karas, is a good example. The author argues that toiling away on a treadmill or stationary bike is the least efficient way to lose weight.

I agree. In terms of burning fat and calories, you get more bang from your buck by spending that time on moderate- to high-intensity strength training.

However, cardiovascular fitness is still important. 

Although it may not be the shortest path to a sleek and toned physique, maintaining a moderate to high level of cardiovascular fitness slashes your risk of heart disease and increases your life expectancy, as reiterated by this latest report.

The authors of this review pooled data from a number of large studies and found that people with maximum aerobic capacity of 7.8 METs or more had a substantially lower rates of heart disease and death from any cause.

Want to see how fit you are?

All you need is  a track or other accurately measured one-mile route and a stopwatch. Time how fast you can walk (not run!) a mile and take your pulse as soon as you finish. Then, plug your numbers into this calculator to estimate your aerobic fitness in both VO2max and METs.  (See the calculator for more complete instructions.)

If you find that your cardiovascular fitness is low, it's time to add a little cardio back into the exercise routine.  But you don't need to log countless hours or miles on the stairmaster.  Our fitness guru Steve Cabral explains the basics of interval training, which is the best (and fastest) way to increase your aerobic fitness level.

Eggs for breakfast for easier weight loss

Do you remember those photos they used to put on cereal boxes, showing the cereal "as part of a complete breakfast." Invariably, they would include a bowl of cereal, topped with a few photogenic banana slices, a glass of milk, a glass of orange juice, and (inexplicably) a slice of toast with a pat of butter or margarine perched on top.

In the current era of carb-consciousness, few would think of this as a healthy breakfast today. Instead, eggs are back in favor, having been rehabilitated from their undeserved bad rap as artery-clogging cholesterol bombs.

The latest research indicates that eggs and other high-protein foods are an ideal choice for breakfast.  Eating eggs is not associated with elevated cholesterol or increased risk of heart disease. Plus, protein foods will get you a lot farther than the same number of calories from high carbohydrate foods like cereal and toast. People feel less hungry throughout the day when they eat a higher protein breakfast, tend to eat fewer calories and lose more weight.

A suite of new studies presented recently at the 2009 Experimental Biology meeting reinforces that eggs can be a great addition to both heart-healthy and weight-loss diet plans. For added nutrition, choose omega-3 fortified eggs, which are also lower in saturated fat.

And if you do eat cereal or toast for breakfast, be sure to choose high-fiber, low sugar options. And rather than doubling up on the carbs, pair one or the other with a high protein food such as eggs or low-fat cheese or yogurt.

Nuts and fish both improve blood fats, but differently

My recent post on the effects of low-carb and low-fat diets touched off a heated debate among ND readers on which heart risk factors are most significant.  Various commenters argued that triglycerides were more important than cholesterol, or that HDL was more significant than LDL, or that various ratios were the key to assessing heart health risk. 

Well, there's something for everyone in this latest study, which found that eating both walnuts and fish reduces a variety of heart health risk factors.  Eating four ounces of salmon twice a week lowered triglycerides about 12% and increased HDL levels by about 3%. Eating an ounce an a half of walnuts every day, on the other hand, lowered total cholesterol about 5% and LDL cholesterol by about 9%, thereby improving the ratio of total to HDL cholesterol.

Interestingly, there was very little overlap in the benefits of these two foods.  Walnuts had no effect on triglycerides, for example, while salmon did not change LDL cholesterol.  So, it appears that a heart healthy diet should include both. And the amounts used in the study are perfectly reasonable: A small handful of walnuts per day and a small portion of fish twice a week. 

Update (5/1/09): For a heart healthy spring meal that features both salmon and walnuts, see Megan Steintrager's post on our sister site Epicurious.com