High-carb diet ... delicious but deadly?
Put that sandwich down, now. As if the link between carbohydrates and the muffin-top spilling over your waistband wasn't bad enough, new research indicates that a high-carbohydrate diet may also influence your cancer risk and the growth of tumours.
Scientists at Canada's British Columbia Cancer Research Centre found that mice fed on a high-protein, low-carbohydrate diet had slower tumour cell growth than those fed a typical Western diet high in carbohydrates. While the experiments were conducted with mice, the findings appear to be strong enough to be applied to humans.
"On the Western diet, half of the mice had tumours by middle age. On the low-carb diet, none of the mice had the tumours," said Dr Gerry Krystal, who authored the study along with colleague Dr Vincent Ho.
The mice used were predisposed to breast cancer, and had a life expectancy of two years.
Published in the July issue of Cancer Research, the study found about 70 per cent of the mice on the Western diet developed cancer by the time they died, compared with 30 per cent of those on the low-carb diet.
"Only one of the mice on the Western diet reached a normal lifespan, and half of the other mice reached or exceeded the expected lifespan."
Cancer cells depend on glucose more than normal cells do, and carbohydrates in the bloodstream convert quickly to glucose. "It's possible that by simply changing our diet to a low-carb, low-fat, high protein diet, we can starve the cancer by eliminating the glucose the tumours need to grow," said Krystal.
The "Western diet" consisted of 55 per cent carbs, 23 per cent protein, and 22 per cent fat, while the other mice ate 15 per cent carbs, 25 per cent fat and 60 per cent protein. Krystal also noted that while the two diets contained the same number of calories, mice on the high-carb diet "gained a lot of weight."
"Taken together, our findings offer a compelling preclinical illustration of the ability of a low CHO [low carbohydrate] diet in not only restricting weight gain but also cancer development and progression," the study concluded.
"I would like to see people go up to 35 per cent protein," said Krystal, who suggested that any dietary changes to lower carbohydrates would have health benefits, although he warned that diabetes sufferers should consult a doctor before altering their diet. However, a study published last year indicated that an animal-based low-carb diet was linked to an increased risk of death, while a plant-based low-carb diet was linked to decreased risk.