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Low-carb Paleo and ketogenic diets improve endurance, prevent colon cancer

Runners and triathletes go low-carb Paleo for endurance training success.
Photo by Ezra Shaw/Getty Images

While runners and endurance athletes have long followed high-carb, low-fat diets, an increasing number are embracing the low-carb, high-fat Paleo and ketogenic diets to enhance performance.

Fitness experts say the Paleo diet's emphasis on whole foods and healthy fats and its avoidance of refined sugars and processed foods make it ideal for athletes.

Ultrarunner Timothy Olson told Runner's World he experienced improved recovery after adopting the Paleo diet. Olson set a new course record at the Western States 100-mile endurance run in 2012, a few months after going Paleo.

"My legs are less swollen after really long runs," said Timothy. "I can go hard again sooner than I did before I went Paleo."

Olson's results are similar to what former Ironman triathlete Mark Sisson experienced. Sisson said he improved his athletic performance, his body composition, and his energy levels after switching to a low-carb, high-fat (LCHF) Paleo diet.

Sisson used to carb-load during his years as an endurance athlete, but said he actually got healthier while doing less exercise after going Paleo.

“I fell into the paradigm of eating complex carbs for fuel,” Sisson told Palm Springs Life. “I got fit, but my health declined. I was one of the top runners in the country but had many health ailments.”

Mark said by reducing carb intake and increasing the amount of healthy fats, your body learns to burn fat (instead of glucose) for fuel. "Over time, you become good at burning off your own body fat for energy rather than depending on carbohydrates throughout the day," he said.

Fitness coach and author Robb Wolf agrees. "The Paleo diet is the healthiest way you can eat because it is the only nutritional approach that works with your genetics to help you stay lean, strong and energetic," said Wolf, author of "The Paleo Solution: The Original Human Diet."

Joe Friel, a U.S. Olympic triathlon coach, said the Paleo diet works for endurance athletes because it helps with recovery. “[Paleo offers] better long-term recovery due to greater micronutrient content, allowing the athlete to train with a greater stress load,” said Friel.

Ironman Triathletes Followed Ketogenic Diet

Fitness expert Ben Greenfield trained for the 2013 Ironman Triathlon World Championships in Kona, Hawaii by following a high-fat, low-carb ketogenic diet and completed the epic endurance race in a blistering 9:59:26. Ben, author of the bestseller "Beyond Training," detailed his ketogenic diet experiment on his blog.

The Ironman triathlon consists of a 2.4-mile swim followed by a 112-mile bike ride and then a 26.2-mile marathon, done in that order without a break. Greenfield's breakfast the morning of the Ironman was a half-stick of butter, two shots of MCT oil, and a cup of coffee — a stark contrast to the vats of pasta most endurance athletes inhale before a race.

Similarly, Dr. Jay Lehr, a 78-year-old triathlete, recently revealed he has followed a low-carb, high-fat ketogenic-style diet his entire life and credits it for his excellent health.

Jay has thrived on a diet of red meat, saturated fat, dairy, eggs, butter, and lard and has never felt better. “I’ve never been inside a regular doctor’s office,” said Lehr. “I have lived my entire life on high fat — dairy, eggs, butter and lard.”

Jay recently completed his 13th Ironman triathlon.

New Study Says Low-Carb Diets Prevent Colon Cancer

Meanwhile, scientists at the University of Toronto say low-carb diets like the Paleo and ketogenic diets prevent cancer and can reduce the risk of colon cancer by up to 75 percent.

Martin and his team conducted studies on mice and identified a gut bacteria that fuels cancer growth by converting carbs into cancer-spurring metabolites. Following a low-carb diet dramatically reduced the spread of cancer, said Martin, who published his findings in the medical journal Cell.

The latest study from UT confirms other findings by cancer scientist Dr. Thomas Seyfried of Boston College. Seyfried’s decades of research indicates cancer is a metabolic disease that can best be treated with the low-carb, high-fat ketogenic diet.

Dr. Seyfried, widely considered the godfather of the nutritional treatment of cancer, joins a growing number of researchers who say the ketogenic diet can treat most forms of cancer.

This is because nearly all the healthy cells in our body have the metabolic flexibility to use fat, glucose and ketones to survive, but cancer cells lack this metabolic flexibility and require large amounts of glucose and cannot survive on ketones. So by limiting carbohydrates (as the keto diet does) we can reduce glucose and insulin, and thus restrict the primary fuel for cancer cell growth.

So far, there are numerous anecdotal success stories. One is Joe Mancaruso, a 56-year-old Texas man, who has been battling terminal lung cancer without chemotherapy using the ketogenic diet. “I am convinced I would not be here today if I had continued with chemo,” said Mancaruso.