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Appetite For Construction
Mar 29 2002

By Dr. John M Berardi, Ph.D.
First published at www.t-mag.com.

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Enzymes: Gold or Fool's Gold?

Q: What do you think of digestive enzymes? There some very smart people on both sides of the argument regarding their value.

A: Before I answer this one, I'm not ashamed to admit that digestive physiology is not my forte. Simply put, spending my days in the lab, elbow-deep in nitrogenous fecal matter embedded with undigested kernels of corn, ammonia and urea-filled liquid yellow waste, and gastro esophageal intubation devices designed to swim in rank digestive juices is not my idea of a glamorous career. However, I've learned a thing or two about digestion over the years and here's my take on trying to coax a bit more nutrition out of your food intake.

Before I get into this discussion however, let me share with you a story that may impress upon you the potential importance of proper digestion. Late one night at the SWIS conference in Toronto, I was sitting in the lobby of our hotel talking nutrition with one big-mutha of a bodybuilder. The guy was probably 5'6" or 5'7" and well over 230 lbs, his weight consisting mostly of lean mass (I'd say he wasn't much over 10% body fat). Well anyway, we were talking about training, competing, drugs, nutrition, etc. when it became painfully obvious to me that this guy knew how to eat "well" (by conventional standards) but wasn't well versed in the art of "high-performance" nutrition.

Before "popping the question," I asked first about drugs. He assured me that he had used steroids in the past but it had been well over a year since he used anything. In addition, the doses he had used in the past were relatively mild by most bodybuilding standards. With this out of the way, I went ahead and asked the dreaded question that I always hate discussing with guys like this; the "How many calories do you eat per day?" question.

The reason I hate to ask this question is that I need well over 4,000 and sometimes upwards of 5,000 calories per day simply to maintain my weight (190-200 lbs). Therefore when these big dudes tell me how few they eat, I wanna plant my size 10 and 1/2 right in their heavily muscled gluteal region. Reservations aside, I asked the question anyway. And I got the answer that I feared. He told me that on a good day he "might get 2,500 calories," but some days it's far less. Arghhh! That man had size that I'll never - ever - see on my wiry-by-comparison physique and he spends half the time and half the money that I do in the grocery store.

So that got me thinking. Maybe it's true. Perhaps some people simply need fewer calories because their body digests and assimilates everything that it's given while others, like myself, waste (in more ways than one) a lot of food just trying to give our cells the fuel they need. With that said, let's look at how this difference may manifest and how those of us with "frequent shopper miles" can catch up to our full-walleted and heavily muscled friends.

There are three main factors that determine how much of our food gets into the body to provide fuel. They are digestion, absorption and transit time. You see, most food is absorbed in the small intestine. And if food isn't completely digested by the time it gets there, then the small intestine simply can't absorb it and it'll pass right out into the feces during normal transit times. Also, if there's a whole lot of digested glucose, fatty acids, amino acids and peptides in the small intestine, their transporters may become saturated and full absorption can't take place. Finally, if the small intestine transit time is too fast, then even complete digestion and the availability of receptors can't stop your nutrients from just being swept out of the body.

So with three potentially limiting factors, determining which is most important to assimilation is difficult but very important to your question, especially if you're eating loads of food. With respect to protein intake, several studies have shown that only about 75-90% of moderate doses (25-48g) of intact proteins are assimilated while 90-95% of very large doses (up to 100g) of partially digested/hydrolyzed proteins are assimilated. This indicates that digestion is the big limiting factor for protein intake. If you could get more protein to the small intestine in a more digested state, more will ultimately be absorbed.

In addition to protein digestion, a diet high in fiber - while very, very essential for good health - may also slightly impair digestion. Fiber tends to hold water and create thick, viscous solutions in the gastrointestinal tract (much like how casein clots in the stomach). This leads to slowed emptying of food from the stomach, which is a good thing as it keeps you full for longer and prevents large and rapid rises in blood sugar and insulin. Some types of fiber (soluble: gums, pectins, hemicellulose, mucilages) also decrease small intestine emptying time while others (insoluble: cellulose, lignin) increase small intestine emptying time. So different types of fiber may affect small intestine transit differently (the longer the food is in the small intestine, the more "time-released" it will be).

While soluble fiber may appear better as it slows digestion down, the thick solutions formed when fiber binds all this water may actually provide a physical barrier that impairs the ability of digestive enzymes to access all of the nutrients in the food. In addition to this physical barrier, fiber may actually decrease the effectiveness of some of the digestive enzymes for protein and lipid digestion by neutralizing them. Finally, this fibrous "sludge" may actually prevent nutrients from diffusing to their absorptive sites. But don't let this dissuade you from getting at least 20-40 g of fiber per day. This stuff is very beneficial in terms of dieting, disease prevention and management, and GI health. So how do we find a balance?

In individuals who suffer from pancreatitis (these people don't secrete enough natural digestive enzymes), digestive enzyme supplementation is very helpful in getting the most nutrition from their food. But it also appears, as evidenced above, that even healthy people with high-fiber and protein intakes may benefit from some added digestive power.

The problem however, is that regular ol' health store digestive enzymes are easily broken down in the stomach before they ever get to the small intestine. Since we want them to act in the small intestine (that's where many of the natural ones work), this isn't a good scenario. But there may be an answer. Some digestive enzymes on the market are enteric coated. Pancreatic enzymes delivered in this manner have proven to be most effective since they are protected from stomach acidity (pH of about 2) but dissolve well in the small intestine (pH of about 6). Other non-coated enzymes probably aren't very effective.

In addition to digestion itself, I mentioned that transit time is another important factor in nutrient assimilation. This one is easier to manipulate than digestion. Transit time is slowed down by specific foods like casein and fibrous (soluble) carbohydrates (as mentioned above). But again, be careful. Although fiber may slow transit time, it may actually decrease nutrient absorption. This is where eating these foods with additional enzyme support may make a difference. In addition, protein and fat intake also slow transit time. This slowed transit time (especially in the small intestine) gives the body more time for the protein to be digested and absorbed before it is swept away. The herb passion flower may slow down intestinal transit time without decreasing absorption.

So, what do I think of digestive enzymes? Well, unless you can find a good enteric coated digestive enzyme complex (good luck), you probably won't get enough benefit from regular digestive enzymes to justify the cost. If you can, however, you may be able to get away with a smaller grocery bill next month. Unfortunately you'll be making up the costs in enzyme pills.

And in regard to transit time, combine high-protein meals with some essential fatty acids. This will definitely slow transit time. And if you want to try a supplemental approach, 4-8 g of passion flower with your higher protein meals may also help.

Oil and heat

Q: What's the skinny on cooking oils and heat? Does heat negatively affect certain oils? Is there one oil I should use, or am I being too anal?

A: Since there are several good books that discuss the impact of different fats on health and body composition and since I've discussed fats often before, I'll avoid a detailed discussion of fats in general and focus simply on giving you a quick overview of what heating does to fats and my answer to the age-old question: To cook or not to cook?

Heating, under both normal high-temperature household conditions (pan frying) as well as more extreme conditions (repeated deep frying and extreme laboratory conditions), affects both the characteristics and composition of dietary fat. Heating changes the chemical structure of the fat and leads to oxidation as well as the loss of some nutrients like antioxidants and essential fatty acids. These changes are relatively universal and only vary in degree (pun intended) and duration of heating.

All oils will oxidize in a big way if repeatedly heated to high temperatures for long periods of time. But even normal household frying temperatures and durations can cause partial oxidation. Some fats, however, do better than others. Saturated fats like butter and tropical fats like coconut and palm oil are the most resistant to oxidation since they're more heat stable. Olive oil (due to it's phenolic content and monounsaturated structure) is next in terms of resistance to oxidation and heat stability. Olive oil can be made more stable by the addition of antioxidants to the oil (for example, Vitamin E). And polyunsaturated fats bring up the rear as the most easily oxidized fats and the least stable.

Therefore we now have an order of "cooking safety, showing that the saturated fats were the best while olive oil and polyunsaturated fats are the worst. This means that the physio-chemical properties of the good, "healthful" oils are the worst with cooking. Therefore the picture emerging is that the "good fats" need to be unprocessed and heated in order to stay "good."

Although I hate to do this to you, there's more bad news for us to contend with. While there are big increases in lipid oxidation products with heated oils like olive and safflower, there are also measurable physiological effects as a result. Cooking with these oils also leads to increases in plasma triglycerides and LDL cholesterol (the bad kind) and decreases in HDL cholesterol (the good kind) when compared to non-heated oils (which actually do the opposite). So not only does heating affect the fat, but it affects how the body handles the fat. Strike two!

Finally, I'll give you the last piece of bad news. It's well known that pan-frying/grilling meat will typically produce mutagenic (cancer-causing) agents. However, newer data are showing that cooking with most oil actually increases the heat transfer from the pan to the meat, increasing the mutagenic activity of the food. Strike three!

So, with all of this bad news, what's a health conscious weight lifter to do? Well, I'm about to make some recommendations. Keep in mind that some of them may go against conventional thought and/or practice. But I'm not here to appease the masses. The following recommendations will optimize your use of fats for both health and physique enhancement.

Never use additional fats when pan-frying/grilling meat! If pan-frying/grilling meat, use a non-stick surface or coat the pan with a minimal amount of some sort of cooking spray. This will prevent large increases in the amount of mutagenic chemicals formed.

Never use mono- or poly-unsaturated fats when pan-frying! When pan-frying non-meat dishes, use a non-stick surface or coat the pan with a minimal amount of cooking spray. If some sort of oil must be used for this type of cooking, use a saturated fat source like butter since these types of fats are most stable. Just be careful with how often you do this since excess saturated fat intake presents a whole other host of health problems.

When baking, use saturated fats and/or olive oil only! These are best to use for oil stability reasons (but see above for saturated fat warning).
Never heat flax oil or fish oil! Oil supplements like flax oil and fish oil need to be consumed without any further processing or else their EFA content will be destroyed. Exposure to heat and light should be prevented. In addition, olive oil is best when the extra virgin type is consumed and it's consumed unheated.

Never, ever deep fry foods!

Never, ever cook with polyunsaturated fats! Corn, canola, safflower, flax, etc. oils are the least heat stable of the oils, will become highly oxidized, and will lose their EFA content with cooking.

Fiber and fat loss

Q: A few nutrition experts out there have stated that fiber is really important when dieting for fat loss. Why exactly? And how much are we talking about here?

A: With the current "carbohydrate phobia" that's running rampant as well as the crazy notion that powders and shakes can actually replace food (they can't!), it's no wonder that nutrition experts have to actually tell their clients to eat fiber. To be sure, there's no doubt that some of the low-carbohydrate diets that are storming the weight loss market have, in some ways, revolutionized the health industry and the examination of them has given us valuable insight into nutrient biochemistry, the function of specific metabolic pathways, and alternative modes of weight loss.

In addition, the introduction of liquid nutrition has made it easier to meet calorie demands, especially for athletes. But as usual, the general public, like toboggans hanging precariously atop the most slippery of slopes, fails to put new information in it's proper context, gliding down whichever slope the most marginal of winds blows them toward, heading downward, faster and faster toward disaster. If eating fewer carbohydrates is good, swish, eating no carbohydrate must be better. If liquid nutrition is easy, swish, diets consisting of nothing but shakes would sure be convenient. And so on.

But rather than continue my tirade any further, I'll get focused and discuss the merits of eating a good amount of dietary fiber (which comes from carbohdrate sources) when dieting for fat loss. Among the nutrients classified as "dietary fiber," there are a wide range of structural and chemical differences. These lead to different physiological responses in the body, just like what we see with dietary carbohydrates, proteins, or fats. So, you knew it was coming; a fiber isn't even a fiber.

Fiber is basically an indigestible nutrient and the two main types of fiber are soluble and insoluble fiber. Below is a little chart showing the differences between the two:

Soluble

Hemicellulose
Pectin
Gum
Mucilages
Dissolve in hot water? Yes
Gastric transit? Yes
Intestinal transit? Slower
Nutrient Absorption? Decreased

Insoluble

Lignin
Cellulose
Hemicellulose
Dissolve in hot water? No
Gastric transit? Slower
Intestinal transit? Faster
Nutrient Absorption? No change

The solubility issue is important as soluble fiber has a great ability to bind liquid (think of a sponge soaking up digestive juices and water as it moves through the GI tract) while insoluble fiber doesn't. The soluble kind of fiber is most important to our discussion today.

When ingested, the soluble sponge I mentioned above ends up as a thick, viscous solution in the stomach, especially when the fibrous foods are relatively unprocessed and large in size (unprocessed oats and grains). This solution tends to slow down transit through the stomach and the small intestine. In addition, the fibrous component of the solution can bind nutrients and these will ultimately pass through the stomach and small intestine, traveling along with the fiber.

For the dieter this situation offers both benefits and drawbacks. First, the benefits:

• You'll be satiated for a longer period of time after a meal, thus potentially staving off the hunger pangs that you'll undoubtedly feel when dieting.
• This will prevent the rapid introduction of nutrients into the blood stream and large spikes in blood glucose, fatty acids, and insulin. This will thus control both nutrient delivery and the hormonal response to meals. This will also help prevent fat gain by controlling insulin.
• This will prevent the absorption of excess lipids and cholesterol, thereby decreasing the amount of utilizable calories in your food.
• The movement of this fibrous undigested sludge into the small and large intestine can lead to the activation of microflora that are capable of causing fermentation of the fiber. Upon fermentation, fiber can actually be degraded to short chain fatty acids (fats). These fatty acids lead to increased water and sodium absorption in the colon, increased mucosal cell (GI cell) turnover, the provision of lipid energy, and a whole host of other functions that may be protective against cancer.
• Proliferation of microbes in the colon. This detoxifies the colon by helping to bind and excrete toxins. In addition some microbes inhibit tumor cell formation.
• Microbial formation can increase fecal bulk and lead to more frequent defecation (no more white-knuckle trips to the toilet).
  However these benefits come at a price. This viscous solution may end up also doing the following:
• Providing a physical barrier that reduces the mixing of food with digestive enzymes, thus preventing some digestion from occurring.
  o Interfering with enzymatic breakdown of proteins or lipids via interference with the enzymes themselves.
• Decreasing the nutrient diffusion rate to the GI wall, thereby creating a situation where it takes longer for the nutrients to get to their absorption sites. Thank goodness that this is the case as this fiber allows for more time in the stomach and small intestine and this may help to cancel out this increased diffusion rate.

With the weight of the information that we now know, it appears that fiber is well designed for diet phases since it basically slows movement of food through the GI tract and also prevents the digestion and absorption of some of your food. I know this latter portion sounds negative, but if you're exercising and providing the body with a balanced nutritional plan, this may actually be an advantage.

In addition to these benefits, we shouldn't overlook that it may make the diet easier by curbing appetite and making your trips to the bathroom a little less "binding." Finally, a diet high in soluble fiber is excellent for controlling high blood lipids (cholesterol and triglycerides), type two diabetes (insulin resistance), obesity, gallstones, irritable bowel syndrome, constipation, and colon cancer.

So the next questions to ask are where should this fiber come from and how much is enough? Well, I shoot for about 40-50g of mixed fiber per day when dieting, but no more (the absolute lower limit is 20g per day). Rather than trying to use supplemental sources, it is my opinion that your main fiber sources should be (in order of importance): vegetables, beans, nuts, fruit, and grains (like oatmeal). If you simply eat 1 oz of mixed nuts, 1 apple, 2 cups of kidney beans, and 2 cups of mixed vegetables each day, you'll be getting 41 g of fiber. There are no excuses about not being able to get enough fiber from food.

But, since some of you will be whining about not liking beans or vegetables or whatever, or some of you will be using too much protein powder when dieting, I'll make this concession for you. If you simply can't get your 40-50 g from food, then a small amount of supplemental fiber is okay. In this case you should choose to sample from a few different sources of fiber including soluble fiber like psyllium, guar gum, and apple pectin and insoluble fiber like flaxseed. One source alone won't cut it. Nature provides several fiber sources in every food for a reason. Always add this varied fiber blend to your protein shakes and if necessary, add it to your other meals. When in doubt, remember this fiber rhyme:

Fiber - fiber, it's good for gettin' lean;
It helps help to keep your colon clean;
Eat fiber with food or fiber with shakes;
So eat your fiber for goodness sakes.