Potatoes are a high-carb, high-glycemic food, which has blood sugar and insulin disruptive effects. (Photos.com)
On the other side, we also know that excesses of certain carbohydrates (those that are disruptive to blood sugar and insulin) in the diet have some capacity to induce many ills, including weight gain, type 2 diabetes, and cardiovascular disease.
There is some evidence that encouraging us to turn away from fat and toward carbohydrate is one major factor that is fueling the burgeoning rates of chronic diseases that we have seen over the last three decades.
I was interested to read about a recent study that shows the potential hazards of applying the low-fat and high-carb paradigm. In this study, post-menopausal women were asked to increase their carbohydrate intake over a four-week period. As a result, they ended up eating more starch over the course of the study.
The glycemic index of the diet was increased as well, which means the new diet was more disruptive to sugar and insulin levels. There was also evidence of increased fruit and vegetable consumption during the study.
First the good news: Subjects lost weight, and antioxidant capacity of the blood was enhanced.
Now, the bad news: Subjects saw significant increases in the level of “unhealthy” blood fats, called triglycerides, as well as significant decreases in the level of “healthy” HDL cholesterol. The authors of the study conclude, “In postmenopausal women, following the U.K. dietary guidelines resulted in changes in the lipid profile that were more likely to favor an increased risk of CHD [coronary heart disease]. …”
While the authors suggest that this may be balanced by the reduced BMI (body mass index—a measure of body fat) and increased antioxidant status in the body, I suggest that these benefits are also available to those adopting a lower-carb diet. Those adopting a lower-carb diet have the capacity to maintain a high antioxidant status by keeping up a good intake of low-carb vegetables, including green leafy ones.
If a reduction in BMI is what’s required, then it’s perhaps useful to reflect that low-carb diets consistently outperform low-fat ones for weight loss.
This study demonstrates at least some of the potential hazards that come with taking conventional dietary advice. It should serve to remind us of the fact that some carbohydrate sources are not the cozy, wholesome, healthy foods some maintain they are.
References:
Arefhosseini SR, et al. Effect of advice to increase carbohydrate and reduce fat intake on dietary profile and plasma lipid concentrations in healthy postmenopausal women. Annals of Nutrition and Metabolism 2009;54(2):138–44.
Dr. John Briffa is a London-based physician and health writer with an interest in nutrition and natural medicine. His Web site is drbriffa.com
