By Gabe Mirkin, MD
A popular book, “Grain Brain,” by Dr. David Perlmutter, claims that carbohydrates are “destroying your brain.” He says that “even healthy ones like whole grains can cause dementia, ADHD, anxiety, chronic headaches, depression, and much more.”
A similar book, “Wheat Belly,” makes many of the same claims. Most of these authors’ arguments against eating carbohydrates are based on data about refined carbohydrates and excess calories.
Refined carbohydrates are different from whole grains and other healthful sources of carbohydrates: vegetables, fruits, beans and seeds. The authors would be correct if they warned you to avoid refined carbohydrates. They should not condemn the healthful carbohydrates, which protect your brain and prolong life by helping to prevent diabetes (Am J Clin Nutr, August 2002;76(2):390-398), heart attacks (Am J Clin Nutr, September 1999;70(3):412-419; Eur J Clin Nutr, 2006 Oct;60(10):1145-59), and premature death (J of Am College of Nutrition, 2000;19(3):326S-330S).
Pre-Diabetics Improve by Eating Whole Grains
Just 12 weeks on a whole-grain cereal-based diet lowered blood sugar, insulin and triglycerides in pre-diabetics (Nutr Metab Cardiovasc Dis, 2014 Aug;24(8):837-44). When blood sugar rises too high, the pancreas releases huge amounts of insulin. Insulin converts the extra sugar into triglycerides, so triglycerides are a measure of the harmful effects of high blood sugar levels. Feeding diabetics refined carbohydrates caused:
• blood sugar levels to rise very high to increase cell damage,
• blood insulin levels to rise very high, which increases risk for heart attacks, and
• triglycerides to rise very high, which makes people fat and worsens diabetes.
On the other hand, feeding unrefined whole grain cereals lowered blood sugar, insulin and triglycerides, which help to prevent and treat diabetes.
Carbohydrates are chains of sugar molecules. They are found in all plants and all foods made from plants. Carbohydrates can be a single sugar, or two, three or more sugars bound together. Thousands of sugars bound together are called starch, and millions of sugars bound together so tightly that you cannot break them down are called fiber.
Only single sugars can pass from your intestines into your bloodstream. When you eat, food that contains starch enters your intestines, where enzymes knock off each end sugar consecutively and each end sugar is absorbed immediately. All simple sugars and starches that are broken down rapidly enter the bloodstream rapidly, which causes blood sugar to rise.
Fiber and other resistant starches contain long chains of sugars that cannot release their end sugars, so they are not absorbed. They pass to the colon, where bacteria convert them into fatty acids that help prevent colon cancer and heart attacks. You want to eat carbohydrates that release their sugars slowly, and restrict carbohydrates that release sugars rapidly. The easier it is to break carbohydrates down into single sugars, the higher your blood sugar level rises and the more insulin you produce.
The Difference Between Whole Grains and Refined Carbohydrates
A whole grain is a seed that is covered with a thick fiber coating like a capsule. When you eat whole grains, this capsule prevents sugar from being released, and blood sugar levels do not rise very much. On the other hand, when whole grain is ground into a powder to make flour, it loses its protective capsule that keeps it from being broken down so quickly. You get a high rise in blood sugar that calls out large amounts of insulin. Eating a lot of foods made from flour increases your chances of gaining weight and becoming diabetic.
The most healthful carbohydrates are those left with fiber where nature puts them: in whole grains, beans, nuts and other seeds, vegetables and fruits. The most harmful carbohydrates are foods made from refined carbohydrates: flour, white rice or milled corn, fruit juices and all extracted sugars.
Flour is Like Sugar
If you think sugar-free cookies, cakes and pastries will help you lose weight or control diabetes, you’ve gotten the wrong message. Flour makes your blood sugar rise almost as much as table sugar. Most recipes for baked goods use about six cups of flour for every cup of sugar. Eliminating the sugar does virtually nothing to slow the rise in blood sugar that you get when you eat most bakery products. Rice flour, corn flour or corn meal, and other “gluten-free” flours are just as harmful as flours that contain gluten.
Slowly Digested Carbohydrates
Refined carbohydrates are absorbed in the upper intestinal tract to increase risk for obesity and diabetes. On the other hand, slowly digested or non-absorbable carbohydrates that are absorbed in the colon help to lower cholesterol and prevent diabetes, heart attacks and premature death (American Journal of Clinical Nutrition. 2000;72(6):1461-1468). If you are diabetic or trying to lose weight, you don’t need to avoid all carbohydrates. You need to avoid only carbohydrates that cause a high rise in blood sugar.
Who Needs to Avoid Gluten?
The only people who need to avoid gluten are those with a relatively uncommon condition called celiac disease. Your doctor can order a blood test called “celiac panel” to see if you make antibodies against a component of wheat called gluten. If that test is positive, you may benefit from avoiding wheat, rye and barley, which contain gluten, and oats because oats are stored in silos that are commonly used to store wheat also. Otherwise, most of the scientific community agrees that you should eat whole grains and restrict the refined carbohydrates that can make you fat and diabetic and cause heart attacks. People who are gluten-intolerant can still eat whole grains such as wild rice, brown rice, corn and quinoa.
A healthful diet for everyone includes plenty of vegetables, fruits, whole grains, beans and other seeds. If you are trying to lose weight or are diabetic, you should restrict all foods that cause a high rise in blood sugar:
• foods made from flour (bakery products and pastas),
• all drinks with sugar in them, including fruit juices, and
• all foods that contain added sugars.
Even if you are not trying to lose weight, I recommend limiting these foods to keep from gaining the 10 pounds or more that most people add with each passing decade.
Reprinted with permission from Dr. Gabe Mirkin’s Fitness and Health e-Zine. Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana, often doing 30-60 miles in an outing. His website is http://drmirkin.com/.
You can reach your peak fitness, no matter whether you’re in your 50s, 60s or older. That’s the main message in our newest eArticle, launched just last week, Cycling Past 50, 60 and Beyond: Peak Fitness.
But what does it mean to be fit?
According to author Coach John Hughes, being fit means being in good health and physical condition because of exercise, i.e., scoring high in terms of “athletic maturity” – which he coined in his Cycling Past 60 series. Being fit also means being able to complete specific athletic goals.
You reach your peak fitness through smart training, Hughes says. “Smart training means following a specific training program to reach a specific goal, whether the goal is riding a multi-day tour, increased general fitness and longevity, more power to climb better, faster speed to set a personal best or to smoke your buddies, or maximizing your aerobic capacity to race.”
The programs in his new eArticle are based on the individual programs that he uses with his clients. The specific week-by-week workouts are designed to make any rider a better, fitter cyclist. Each of the four programs is then divided into two 4-week blocks. By following one of the programs for just 4 weeks, you’ll see measurable progress in your baseline fitness. And by following the program for 8 weeks, you’ll progress even further.
Achieve your goals and feel the satisfaction that comes from reaching your peak fitness. Cycling Past 50, 60 and Beyond: Peak Fitness shows you how. The 39-page eArticle is packed with useful information that will benefit all riders in your 50s, 60s and beyond (and younger riders, too!).
The untimely death of actor Robin Williams last week brought out any number of tribute and remembrance articles, including a few based on his love of road cycling, and of road bikes.
I knew, as I’m sure many of you did, that he was an avid cyclist – just like us! – and rode every chance he got from his home north of San Francisco. What I learned after his death was that owned around 50 road bikes and had, according to his local bike shop, “everything.”
One of the best articles I saw about his bike obsession was this one, in the Wall Street Journal, focusing on his meeting with his favorite bike builder, Dario Pegoretti. I thought you might enjoy it, too.
If the results from last week’s poll question, Do You Ever Have “Comfort Issues” When You Ride? are an indication, then a bike fit may well be something to consider.
Here’s the good news: 23% of readers answered the question, “On occasion, but not often.” And 4% said “No. Not really.”
But it gets worse from there. Fully 69% of you answered in the affirmative, that you do, in fact, have comfort issues when you ride.
Your “afflicted areas” were distributed almost evenly, with 13% saying “Yes. Mostly in my sitting area.” Another 11% went with “Mostly in my neck and shoulders.” 10% said “Mostly in my hands or wrists.” And only 4% suffer from feet discomfort.
But, here’s the kicker: 31% said, “Yes. In a combination of some of these.”
Yikes! The vast majority of us seem to be uncomfortable in one or more areas when we ride. We all know there can be any number of reasons for that. But, good grief, that sounds like a lot of unnecessary suffering to me!
If you’re among the roadies who have had a professional bike fit, good for you. If not, you might consider one. And even if you have had one, our bodies change over time, which could affect our on-bike posture, comfort, etc. I’m a believer in getting a new fit every 4-5 years or so.