Is pomegranate really nature’s Viagra? Is HFCS really the same as sugar? Do you need extra vitamin D? All these answers and much more here.
Pomegranate: the Hard Data
Q: Recently, pomegranate has been called a "natural Viagra." What's up with that?
A: What's "up" with that – pun intended – is that rats fed pomegranate extract in a research environment start showing spontaneous randy behavior. The researchers believe that the high antioxidant content of pomegranate juice may help protect against the physical damage that can cause erectile dysfunction.
A human study by Christopher Forest, a researcher at the University of California in Los Angeles, showed that men who drank just one eight-ounce glass per day for a month were able to get erections easier, perhaps because it leads to a boost in blood supply to the male genitals. It does this by raising levels of nitric oxide, which relaxes blood vessel walls.
So, yeah, go ahead and drink up!
Q: It looks like high-fructose corn syrup is getting a PR boost. Is HFCS really the "sweet surprise" that the site claims, or is it as bad as we thought?
A: The Corn Refiners Association, representing the makers of high-fructose corn syrup, is indeed fighting back after years of bad publicity. The commercials are everywhere. Here's the first one. The second, in which a hot chick offers a doofus guy an ice pop and he stutters, "But, duh, this has, like, high-fructose corn syrup," doesn't appear to be available online anymore. Which is a shame.
I especially love it when she patiently explains to him in her best "talking to a slow adult" tone that high-fructose corn syrup is natural 'cause it's made from, gosh, corn! And it's perfectly fine "in moderation." Silly boy. (If you put "high-fructose corn syrup" into the search engine on YouTube, you'll find some wicked parodies of the ads.)
Well, if that foxy lady offered me a poisoned mushroom I'd probably fall for it, but the facts don't change, and high-fructose corn syrup is the same dreadful crap it's always been. But, since it is the subject of massive confusion, I'll try to clear things up. Several issues are in play here, and they overlap.
First things first: In the beginning there was plain old table sugar, also known by its scientific name, sucrose. Sucrose is a disaccharide, meaning it's a blend of two simple saccharides, or sugars, in this case glucose and fructose.
Take a molecule of glucose and a molecule of fructose, link them with a chemical bond, and you've got yourself a molecule of sucrose. Put a bunch of those molecules together in a bowl, place the bowl on the table at the IHOP with a little spoon, and you're in business.
Now, it's pretty much a given that a high intake of sugar is bad for you, and a list of all the reasons why would fill this whole column. So let's save that for another day. What's interesting for our purposes today is that a fair amount of research has been done investigating exactly which of the two components of table sugar is worse for you. And fructose is the hands-down "winner."
Don't misunderstand me: The fructose found naturally in an apple is absolutely fine. But the difference between fructose in an apple and fructose in a soda is the difference between a beautiful fur coat on a wild fox and that same fur on the back of a fat lady at the opera. It's gorgeous on its original owner. On the lady, not so much.
In its original setting, fructose is surrounded with healthy nutrients, phytochemicals, and fiber. When it's extracted and made into a liquid sweetener, it's a nightmare.
Interestingly, fructose doesn't raise blood sugar very much, leading to the absolutely boneheaded idea – popular for a while – that it's a "good" sugar for diabetics. Fructose has now been shown in studies to lead to insulin resistance. It's also the sugar that most raises triglycerides, a serious risk factor for heart disease. In short, it's bad news.
Something else to consider: Table sugar used to be expensive. The average Joe could afford it, of course, but for food manufacturers wanting to sweeten products it was a high-ticket item. So its prohibitive cost was one reason you didn't find sucrose in every single food item we bought. Even Cokes and Pepsis only came in eight- or 12-ounce sizes.
Then, because of situations that involved all sorts of political wheeling and dealing and resulted in both sugar tariffs and corn subsidies, manufacturers were highly motivated to find a solution to the problem of expensive sugar. Enter high-fructose corn syrup.
Take a subsidized crop like corn, perform a bunch of chemical operations on it, and voilà, you had something that was even sweeter than sucrose at a fraction of the cost. It could be added to virtually everything on the table, making those items tastier and, of course, more profitable.
Now here's where it gets tricky. Chemically speaking, high-fructose corn syrup really isn't that different from table sugar. In case you didn't take your gingko this morning and have already forgotten the first paragraph of this story, sucrose is 50 percent fructose and 50 percent glucose. High-fructose corn syrup, at least the most common kind found in soft drinks, is 55 percent fructose and 45 percent glucose.
It's not a huge difference, but the problem is that it's everywhere, including foods that were never sweetened before. It's the major sweetener found in soft drinks (it's been used in Coca-Cola since 1985, for example), which constitute a double-digit percentage of the calories we consume as a nation. One form of it, which is used in baked goods, has an even higher percentage of fructose.
Thus, we're now consuming more fructose than ever. Even though HFCS is only slightly higher in fructose than table sugar, people who drink a lot of soda can easily consume 20 to 30 grams of additional liquid fructose each day.
The Corn Refiners Association's pro-HFCS ads make two arguments:
- It's no worse than sugar. Okay, maybe, but that's like saying Salems are no worse than Marlboros.
- It's natural because it's made from corn. Maybe so, but so is ethanol, and I'm not drinking that either.
OD on Vitamin D
Q: The info about vitamin D in your first Testosterone interview was fascinating. So, what's the prescription here? Do we need to supplement more with vitamin D in the winter? And how much sun is safe in the summer?
A: If you're a model hanging out all day at the pool at the Delano Hotel in South Beach in August, you can probably skip the supplements that day. But for the rest of us, I think vitamin D supplements are a good idea, even in the summer.
Studies clearly show that 2,000 IUs a day is completely safe, and even the very conservative Institute of Medicine considers 2,000 IUs a "safe upper limit." Off the record, most nutritionists think the safe upper limit is way higher. After all, the body can easily make 10,000 to 20,000 IUs a day in the sun without toxicity. But for legal and political reasons, they aren't going to buck the system by recommending more than what the IOM considers completely safe.
So let's be conservative and go with 2,000 IUs. The possible benefits here are just so high, and the potential risks so low (and nearly all theoretical anyway), that I can't see any reason not to keep popping those little Tic Tac-size pills in the summer, unless you're exposed to a ton of sun on a daily basis.
As far as how much sun is "safe," it depends on whom you ask. On one side of the argument you have mainstream medicine warning you to slather SPF 45 on your body every time you venture out for a Starbucks, unless you want to die of skin cancer. On the other side you have some mavericks and pioneers who think we're being way too sun-phobic. I happen to agree with the latter group.
But make up your own mind. Read The UV Advantage by Michael Holick, Ph.D., M.D., a professor of medicine and dermatology who was fired from his post at Boston University after publishing his book.
Or read Your Best Health Under the Sun, by Al Sears, M.D.
Neither of these guys advocates going back to the days of lying out all day unprotected with tin foil around your face, but they do think we've gone just a tad overboard with our fear of sun exposure.
Best Nut for Health Nuts
Q: Is there a best nut to eat? I've heard that peanuts are the worst because of allergens. Are walnuts, almonds, or macadamias the best?
A: Peanuts aren't actually nuts; they're legumes. And they're perfectly good for you ... unless you have an allergy. If you have a really serious allergy, they can kill you. Other than that, they're fine. They have some potassium, a couple of grams of fiber, some iron, and even some resveratrol, the anti-aging compound most abundant in red wine and the skin of grapes (not to mention some highly concentrated supplements).
Walnuts, almonds, macadamias, pistachios, cashews, hazelnuts, and pecans are all real nuts, and all of them are great for you, unless you're one of the many people with nut allergies. All of them have excellent nutritional profiles, even though the nutrients are different from one to the next.
Walnuts are a significant source of omega-3 fats. Most of the fat in the other nuts, as well as in peanuts, is monounsaturated, the same kind found in abundance in the Mediterranean diet.
Hazelnuts contain beta-sitosterol, a plant sterol that lessens the symptoms of benign prostrate hyperplasia. Cashews are loaded with minerals and have a respectable five grams of protein per ounce. Pecans also have a ton of minerals, along with about three grams of fiber per serving. Pistachios have one of the highest phytosterol concentrations of any snack food, and also perk up the immune system for good measure. Finally, Brazil nuts are one of the best sources of selenium on the planet. Selenium is a superstar mineral and powerful antioxidant that's been associated with lower rates of cancer.
So the bottom line on nuts is this: They're all good. Several of the most important long-term research projects, including the Iowa Women's Health Study and the Nurses Health Study, show a consistent 30 to 50 percent lower risk of heart disease associated with eating nuts a few times a week.
Mix and match to taste. Just remember that they're loaded with calories, so it's important to watch your portions!
The Other Way to Juice
Q: Over the years I've tried juicing several times (veggies, not 'roids) but in the end I always quit because I just don't like the taste. What do you think of juicing? And do you have any favorite recipes?
A: I think it's a quick and painless way to get a ton of vitamins, minerals, enzymes, phytochemicals, and other assorted good things you might not consume without juicing.
If you're clever, you can disguise some of the tastes you dislike. Use some apple or pear as a base, for example, and you can easily hide the flavor of a stalk or two of nutrient-rich broccoli.
The only thing you lose when you juice is the fiber in the vegetables and fruit. That's a big loss, but you can make up for it with diet and supplements. It's a fair trade-off for a lot of people because of the incredible nutrient concentration in a glass of fresh juice. (Make sure it's really fresh; the nutritional components deteriorate quickly, so you want to drink it almost immediately after making it.)
Another concern: If you're diabetic or insulin-resistant, you have to know that juices heavy on fruit or carrots can raise your blood sugar a lot.
Finally, remember that many fruits and vegetables contain carotenoids and other valuable phytochemicals, which are best absorbed with a little fat. So take some fish oil caps with your veggie and fruit juice, or throw in a squirt of Barlean's Organic Flax Oil. You'll never notice the taste, and you'll absorb the nutrition better.
Favorite combinations for me include:
Pear, celery, cucumber, ginger
Apple, spinach, carrot, ginger
Red pepper, apple, radishes, tomato, frozen cranberries
Mix, match, and experiment.
The Magical Fruit ...
Q: I've always avoided beans because of their carb count. But in your book, The 150 Healthiest Foods on Earth, you mention that beans are the ultimate blood-sugar regulator. So are beans good or not? Is there a "best" bean?
A: Beans are great. Remember, it's not just about the carb content, but whether they're "fast-burning" or "slow-burning" carbs. Beans burn so slowly that if you eat them on Monday morning your blood sugar doesn't go up until Tuesday night. Okay, I'm kidding, but they do digest a lot slower than most other carbs. Part of that is due to the fiber – anywhere from 11 grams to 17 grams in one serving– which you can deduct from your total carb content.
There are all kinds of compounds in beans that appear to inhibit cancer cells from multiplying, or protect the cells from certain kinds of genetic damage that can lead to cancer. One study showed that men who consumed the most beans had a 38 percent lower risk of prostate cancer. In the Nurses Health Study, women who consumed the most beans or lentils had a significantly reduced frequency of breast cancer. And it only took two or more servings a week to get that benefit.
I consider different types of beans pretty much interchangeable from a nutrition point of view, although some, like adzuki beans, have more fiber than others. All of them are good, but if you're buying the canned kind, make sure to read the label and check for sodium content and added sugar. Some brands are loaded with both.
One dissenting opinion on beans in general that's worth mentioning comes from my respected colleague Loren Cordain, Ph.D., of The Paleo Diet and The Paleo Diet for Athletes fame. He's concerned about substances in beans called lectins. Lectins are a mixture of protein and carbohydrate that aren't digested and broken down and can bind with any tissue in the body, creating problems in susceptible people. So all beans and legumes are on Cordain's "avoid" list, along with grains.
I think Cordain is really smart, but I'm not sure I agree with all of his recommendations. Obviously, some people might have a problem with beans, but if you're not one of them, I think they're fine. (For what it's worth, eggs are also on Cordain's "avoid" list.)
Final thought: Eating beans is one of the nutritional habits shared by people in three of the four "blue zones" – the parts of the world where people live the longest. That's from the book by Dan Buettner, who looked at the common diet and lifestyle practices of the people who live in those regions and enjoy the longest, healthiest lives on the planet.
- Khan, MS, PhD, Alam, Safdar, MS, Mahpara, Ali Khan, MS, PhD, Mohammad Muzaffar, Khattak, MS, Khan Nawaz, and Anderson, PhD, Richard A. "Cinnamon Improves Glucose and Lipids of People With Type 2 Diabetes." Diabetes Care 26(2003): 3215-3218.