Recent studies confirmed the theory that low glycemic food has certain health benefits as opposed to high glycemic food, but these insights are not yet generally accepted by health authorities. Low GI foods are less likely to cause large increases in blood sugar levels, and an effect on obesity and diabetes is widely recognized. Recently reported health benefits relate to acne and the risk of lung cancer. But more important is to ensure a well-balanced healthy diet, and some high glycemic food do offer a lot of nutrition.
What is the glycemic index
The glycemic index is the indexing of the glycemic response of a ﬁxed amount of available carbohydrate from a test food to the same amount of available carbohydrate from a standard food consumed by the same subject (Jenkins, 2002). Some studies suggest that it is the glycemic load that promotes higher insulin levels, not a high glycemic index. Glycemic Load (GL) is a measure of both the quality (the GI value) and quantity (grams per serve) of a carbohydrate in a meal. (Website Glycemic Index Foundation).
Health benefits of low GI food
Food with a high glycemic index causes increased insulin levels which makes the body stop burning fat as a fuel and store excess food-energy (calories) as fat. The most commonly accepted health risks of high glycemic food is an increased risk of developing diabetes and obesity.
Researchers from MD Anderson Cancer Center went quite far in their research on health effects of GI, and found that eating food with a high glycemic index increases the risk of lung cancer. (Melkonian, 2016) When investigating never smokers in the study, the researchers found that those in the highest GI group were more than twice as likely to develop lung cancer as those in the lowest group. The relatively mild effects of a risk factor such as GI are more evident in the absence of the dominant risk factor smoking.
Interestingly, GL had no significant associations with lung cancer risk. This suggests that it is the average quality, instead of quantity, of carbohydrates consumed that may modulate lung cancer risk. (Melkonian, 2016) Also an analysis of studies by Barclay et all (2011) on glycemic index, glycemic load, and chronic diseases also concluded that, overall, it is the GI that has a more powerful effect than the GL, which suggests that, irrespective of the level of carbohydrate intake, the GI of contributing carbohydrate foods is important.
Another recent study examined the effect of high glycemic food on the prevalence of acne vulgaris in young, non-obese adults. The researchers found that, compared with controls, patients with acne had significantly higher dietary glycemic index and glycemic load levels (Asli Aksu Çerman, M.D., 2016). Higher dietary GI was also found to be associated with increasing odds of incident depression. (Gangwisch J.E. et al. August 2015.)
Opinions of health authorities
The Dutch National Diabetes Fund recognizes the health benefits of low glycemic food for patients with diabetes, and publishes a table with GI and GL of foods on its website.
However, several other independent institutions that provide information on nutrition are more critical. Although new research has found positive health effects of the glycemic index of food, both the American Diabetes Organisation and the Dutch Nutrition Centre are hesitant in giving clear nutritional advice on their websites concerning low glycemic index food.
They do acknowledge that the effect of low GI food on human health has been confirmed through research, but what exactly is attributable to the glycemic index is still unclear. Also high glycemic food like whole-wheat bread has proven health benefits, including reduced risk of cardiovascular disease. In addition, the use of the glycemic index of a food is complex, since more factors other than the GI of a food product ultimately determine the glycemic load of a meal. When eating a high GI food, you can combine it with other low GI foods to balance out the effect on blood glucose levels.