Dr. DePetrillo's Greatest Hits

Dr. DePetrillo, our scientific director is known to his friends as a walking encyclopedia of useful medical information - sometimes almost too much of it!  

More than once, we've asked him a simple question and had him whip out a napkin and start drawing diagrams of molecules.  What we've done here is compile some of his "greatest hits" - particularly useful nuggets of info boiled down to "what you need to know."

We'll include some links if you want to see the research behind his ideas - but no diagrams of molecules!

A Diet where you can cheat every day!

Well, kinda!  I know this sounds like one of those claims made on TV, but give us a minute and read on.

If you've ever struggled to maintain a healthy weight (raises hand) you should forgive yourself, because pretty much all of the diets which have been developed over the last 50 years aren't really designed with an understanding of how human metabolism works.

And there's the other little problem - yeah, you can go on some sort of weird starvation diet, or a grapefruit diet, or paleo, or (shudder) a pasta diet, and let's say you lose a pile weight... what do you do after?  Since most of these diets are far too strange to stay on for more than a few months without losing your mind, what usually happens is you go back to your old ways and regain most or all of the weight you lost.  This is really discouraging, to say the least.

What's clearly needed is a way of eating that you can stick with.  Here it is.

We need a little background on metabolism first (we'll keep it short!)

Your body can burn three fuels, carbohydrates, fats and proteins. Protein is usually not burned for energy unless you are on a prolonged fast, lasting weeks.  So that leaves carbohydrates and fats. When you go without food for a few hours (as we all do every day when asleep) your body burns fat.

When you eat a nice breakfast such as fruit, yogurt, orange juice and coffee, the carbohydrates signal your pancreas to release insulin.   Any small amount of carbohydrate will tell your pancreas to release insulin. Even coffee with a spoon of sugar stirred in will do it.

As soon as your liver senses the insulin, it slams on the brakes with burning fat.  But it's even worse that that - instead of burning fat, it starts making fat from the glucose in your system.  Even if you don’t eat anything else that day, it takes your liver a good part of the day to stop making fat and go back into fat burning mode.  This simple fact explains why many diets fail you in trying to reach your objectives.  And we'll repeat - you don't fail, your diet fails.

Another bad result of frequently releasing insulin is that your body starts becoming tolerant to its effects: it takes more and more insulin to get your cells to absorb glucose. Of course, that's because your body wants to take that glucose and turn it into fat.  And insulin, in addition to its effects on glucose metabolism, is also a potent growth factor. Cancer cells love insulin and glucose!

If this makes it sounds like your metabolism is fiendishly designed to make and store as much fat as possible, well, actually it is.  Up until the invention of corn chips and beer, our biggest challenge was to store up enough fat to get through the Winter (and any other period when food was scarce).  People who weren't good at converting carbs to fat tended not to survive.  And we're all still stuck with that DNA.  Some more than others. 

OK, that's all you need to know about metabolism.

First, a big tip of the hat to Mark Mattson, who has done pioneering work on intermittent fasting or "time-restricted feeding" (TRF).  

As you can see from the explanation above, one thing that would work to keep your liver out of fat-making mode would be to eat absolutely nothing for long periods every day. This does work, and it's a great way to lose weight.  For example, you can eat absolutely nothing but dinner.  And at dinner, you can eat whatever you want.

But even though this is a great way of losing weight and improving your health, it's kind of a difficult lifestyle to pursue for any length of time.  First, depending on your own individual biochemistry and your level of physical activity, some of you are going to be hungry. Plus you have to explain to everyone why you aren't eating breakfast or lunch with them and they'll think you're a total weirdo.

 So here's another idea that gives you 99% of the benefits with much less pain: TRCF - Time-Restricted Carbohydrate Feeding.

Remember, our goal here is to stop the pancreas from releasing insulin and telling the liver "time to store fat!"  You can do that by not eating anything at all, but you can also do it by not eating any carbohydrates.

The basic idea is to keep carbs completely off your breakfast, lunch and snack menu and then eat whatever the heck you want for dinner.  This requires some online research and it means you have to pay very careful attention to what you eat in the morning and afternoon (because remember, even one spoon of sugar in your coffee sends you into fat-storing mode).

So here's the downside - you have to be completely unreasonable about what you eat during the day, because even one "healthy" whole grain cracker at lunch blows your diet for the entire day.  But all those people who would think you're a complete weirdo if you skipped lunch will now think that you're only sort of a weirdo because you're eating hard-boiled eggs with some cheese and nuts with a few carrots and celery thrown in.

But the upside (aside from losing weight) is that yes, you can have mac and cheese for dinner.

  - and you can even cheat on that a bit by eating foods which have carbohydrates that are not easily digested.  For example, most nuts have carbohydrates in them, but in the form of completely indigestible fiber. This is good to keep your intestinal bacteria happy! 


Vitamin D

As a hormone, Vitamin D influences many aspects of health. For the most complete exposition of the benefits of Vitamin D, which is actually not technically a 'vitamin' but a hormone, see John J Cannell, MD's site here: https://www.vitamindcouncil.org/health-conditions/   Yes, there are 45 health related effects of Vitamin D that are supported by thousands of good peer reviewed scientific papers!

Dr. DePetrillo wrote a peer reviewed paper which suggested, but did not prove, that high levels of Vitamin D during the Winter in a New England town reduced the risk of viral upper respiratory infections by 50%.  This was published in 2010, and since that time, prospective studies have determined that indeed, this is the case.  You can find a free copy of that paper here: http://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0011088&type=printable

Most Americans do not get enough Vitamin D.  Hence, getting enough Vitamin D is one of the easiest and most effective ways of helping you avoid illness. It is a major public health issue, but for reasons that are too long to delve into here, it is an underappreciated fact in a good portion of the medical community.

One can blame our current lifestyle which is at odds with millions of years of evolution. To get enough Vitamin D you need to have a fairly good amount of sun exposure, and the darker your skin, the more sun exposure you require.  Who gets naked and receives full sun exposure throughout the year? Not very many people!  In addition, if you live in an urban area with many cars and traffic, the nitrogen oxides in the atmosphere block the spectrum of sunlight required by your skin to make Vitamin D.  Another major issue is that the further north or south you live from the equator, the less Vitmain D you can make in the Winter months. Some people theorize that this is the reason viral infections are more common at that time.  The amount of Vitamin D you get from food, even fortified milk, is trivial to the amount that you need!  One other emerging fact is that if you are overweight, you will need a lot more intake of Vitamin D to maintain a healthy blood level.

What to do?  The next time you see your doctor, ask the to test your Vitamin D level.  If you are already taking it, be sure not to take any for at least 24 hours before your blood test, or the result will be highly biased.  Also, ask your doctor to order something called parathyroid hormone level or "PTH."

What should your level be?  You should aim for at least 60-80 ng/mL concentration in your blood. What is a reasonable amount to take per day?  A recent study suggested at least 4000 IU per day for adults, but some people may need as much as 10000 IU per day to achieve a good blood level.  If you are taking enough Vitamin D, your PTH level will be low normal, and that is exactly what you want because PTH is the hormone that takes calcium out of your bones!  If you PTH level is not low normal, and your Vitamin D level is in a good range, you may have a rare genetic condition which will need to be addressed by your doctor.  Getting enough Vitamin D will decrease your risk of developing brittle bones, also known as osteoporosis, as you get older.  I do not believe there is enough data to support  giving calcium supplements to people on a normal diet who have enough Vitamin D in their system, because it may raise the risk of arterial calcification, however, this is still a controversial topic.

If you have a history of kidney stones, you should discuss taking Vitamin D with your doctor, since Vitamin D helps you absorb calcium, and it may raise the risk of kidney stones.  However, for 99% of individuals, this is not an issue.