January 2011: Jeff Volek, PHD (Part 2)by John Meadows on January 24, 2011
JOHN: One of my favorite oils is red palm oil for it’s Vitamin A, E (all tocotrienols), and blend of saturation and monounsaturation. Any thoughts on that oil or any other oils you like? I put it on top of eggs mainly.
VOLEK: I have not tried red palm oil, but it is a good source of nutrients as you mention and there is increasing interest in health effects of tocotrienols. Taking a step back for perspective it is important to realize that if you are consuming 60-75% of your total energy as fat, picking the right types of fat containing foods becomes important. This is especially true when you are consuming maintenance levels calories because the absolute amount of fat will be quite high. Many oils are rich in PUFA containing n-6, and these are not very palatable at high intakes. Yes they are essential in the diet, but the amount needed to meet requirements is just a few grams. These oils will also drive up n-6 levels increasing the ratio of n6 to n3 which is probably not a good thing. This is true of soybean, corn, and safflower oils so these are ones you should avoid on a low carb diet. That’s easier said than done because we put soybean oil everywhere. It can be a challenge to find mayonnaise not made with soybean oil. The oils to use are those with less PUFA like olive oil which is almost 80% MUFA. Canola oil is also rich in MUFA. Butter is a good fat source a little higher in SFA but still contains a good portion of mix MUFA and is low in PUFA. Its worth pointing out that SFA and MUFA are neutral in the sense they do not contribute to the n6 and n3 balance…that is something specific to the types of PUFA consumed. So in summary, butter, olive oil, canola oil, and foods generally rich in SFA and MUFA should be staples on a low carb diet. Coconut and palm oil also contain a fair amount of SFA and lower PUFA content so they make for a nice change of pace on a low carb diet.
JOHN: If we could, would like to touch on the role of fruits and veggies in one’s diet. It would seem that for health purposes and intake of fiber, that these two also be a cornerstone. How do you work fruit into a low carb plan, being that some fruits contain a decent amount of carbohydrates? I typically blend high antioxidant fruits like blueberries and raspberries in my post workout protein drinks, and have apples on occasion throughout the day.
VOLEK: First of all, we need to stop grouping fruits and vegetables together as if they were the same. They are much more different than alike both botanically and functionally. The benefits of high fiber intake are mainly if you consume a lot of carbs, but nevertheless fiber intake is moderate on a low carb diet if you are regularly consuming vegetables, nuts and seeds. On a low carbohydrate diet, berries can be eaten but if you are trying to induce nutritional ketosis best to view them as a garnish rather than a staple. Non-starchy vegetables do not spike glucose or insulin levels and therefore are highly encouraged.
JOHN: Would also like to touch on digestion. It doesn’t really matter what you eat, if you can’t absorb it well. Can you give our readers some tips on promoting good digestion, and preventing issues such as Leaky Gut that can lead to severe problems down the road? I realize this is a huge topic, but just looking for some general tips her, such as increasing intestinal flora, protecting gut lining, etc.
VOLEK: Gut health is an emerging area talked about in the media and being studied by researchers. There are over a trillion microorganisms in our GI tract, that’s more than 10x the number of cells we have in our body. These bacteria synthesize vitamins and amino acids, degrade dietary plant polysaccharides, and metabolize orally administered therapeutics. The metabolic capacity of this ecosystem far exceeds that of the liver, yet we have very little understanding of how these bacteria (called the microbiome) affect health. Recent studies that have characterized the microbiome have shown associations with obesity, diabetes, inflammation, insulin resistance and other chronic diseases. How the microbiome changes with nutritional input however remains relatively unknown. I do think there will be major discoveries in the next decade in gut health and ways to promote better digestion and absorption of nutrients to improve metabolic efficiency. Right know what we know is pretty crude.
JOHN: Can you tell us about any interesting studies or cutting edge type stuff you are involved with right now?
VOLEK: We have several projects planned or underway. I’ll just mention three lines of research that might be of interest to your readership. We have studies planned to delineate individual responses to carbohydrate intake. The primary aim is to demonstrate that plasma saturated fat levels are a function of dietary carbohydrate intake rather than one’s saturated fat intake, with an emphasis on identifying unique ‘carbohydrate tolerance’ signatures. This seems counter-intuitive, but the truth is saturated fat intake has little to do with how much saturated fat is in your body. We expect to find a “metabolic tipping point” in a person where increased dietary carbohydrate begins to be converted to fat and show atherogenic tendencies. We are also 3 years into a very large project designed to compare the effects of whey protein to soy protein and carbohydrate supplementation on physiologic adaptations to resistance training. All subjects are training for nine months and using one of the three respective supplements. It will be the largest and longest study on whey protein supplementation combined with resistance training that I’m aware of and we have a broad spectrum of outcome markers. Another exciting area of research has been investigation of a novel extract derived from whey protein that has been shown to promote increased nitric oxide in vitro. We have been studying it’s effects after oral intake in young and older adults and shown that it indeed promotes vasodilation perhaps through a nitric oxide-mediated mechanism.
JOHN: Finally, would like your opinion on the following supplements. Can you share with us how well you think these items work or don’t work?
Beta Alanine (for high volume resistance training)
VOLEK: In my research as well as others in the early 1990s, we proved high intensity performance was significantly improved by taking creatine supplementation. Over a decade later, a similar story may be playing out with beta-alanine. The body of work is nowhere near that of the creatine literature base, but early works looks promising. Beta-alanine works through a different mechanism most likely by buffering acid in muscle during high intensity exercise and improving force/power output. The one downside or concern I have with beta-alanine is that if you take more than 750-800 mg at a time, you’ll be at the threshold of noticing a tingling, pricking or numbness sensation on the skin – a condition called paresthesia. It’s not dangerous, just noticeable and I suspect will deter some people from using it. Bottom line, I think its an exciting supplement with potential ergogenic effects for high intensity exercise.
NAC (as an antioxidant)
VOLEK: There is evidence that N-acetyl-cysteine (NAC) can have antioxidant effects for athletes. Studies show supplementation with NAC significantly elevates plasma total antioxidant status and reduces protein carbonylation and lipid peroxidation. Cysteine is a rate limiting amino acid for glutathione synthesis, a primary intracellular buffer, and studies have shown NAC supplementation can improve glutathione antioxidant status. How this all translates into better recovery and performance athletes is all very tricky, but in conditions of excess free radical generation, such as high volume training, promoting a more robust anti-oxidant defense system seems to make sense.
Essential Aminos (as a pre-workout precursor for protein synthesis)
VOLEK: This makes a lot of sense. Research indicates the rate limiting step for muscle protein synthesis is availability of essential amino acids. Taking them before a workout increases the chances they will be delivered to the active muscles due to increased blood flow to those areas.
Leucine (as a precursor for protein synthesis taken pre and post workout
VOLEK: Again, makes sense. Of all the essential amino acids the availability of leucine is most highly correlated with protein synthesis. We now know it actives mTOR triggering protein synthesis, so it actually acts as a regulator of the process in addition to being a substrate (building block) for proteins. There is probably a limit though and recent evidence indicates that there is a temporal disconnect between plasma levels of leucine and protein synthesis. So there are some details yet to be worked out in terms of how to best supplement with leucine to keep protein synthesis engaged after exercise. I think right now my best guess is pulsatile increases work best.
NO type products
VOLEK: There are a number of nutraceuticals including several antioxidants, arginine and certain extracts that have been shown to promote dilation, probably though nitric oxide. Most of this work has been done using a technique that measures dilation of the brachial artery in response to a hypoxic stimulus using ultrasound. It is called flow mediated dilation, and generally is thought to reflect vascular function and nitric oxide bioavailability. We do these tests in my laboratory. Vascular dysfunction is a risk factor for heart disease. Thus, I see these supplements as potentially being effective to help promote improved vascular function and decrease a risk factor for chronic disease. How they play out as ergogenic aides promoting more anabolism or better recovery remains to be shown.
JOHN: Awesome insight Jeff. Thank you so much for your time, and for helping the readers and myself acquire more knowledge!
VOLEK: You are welcome, it’s been a pleasure!