Written by: Tom Nikkola – Director of Nutrition & Weight Management
In this and upcoming articles, we’ll take a look at some of the myths surrounding the macronutrients in the diet – carbohydrates, protein and fat. Today, we’ll take a look at some common myths about carbohydrates.
Adding whole grains makes a difference
Dietary guidelines often reference the suggestion to increase the intake of whole grains. You’ve probably noticed a growing number of food products labeled with “contains whole grains” and similar claims. The truth is, replacing processed carbohydrates in the diet with whole grain foods has been shown to have health benefits, not adding more whole grains to a diet. Substituting whole grain carbohydrate for refined grains has been suggested to help reduce visceral fat,[i] improve diet quality and nutrient intake,[ii] reduce total cholesterol and LDL cholesterol levels[iii] and decrease blood pressure.[iv]
Researchers in the WHOLEheart study found when they controlled for all other dietary factors, increasing the amount of whole grains versus refined grains did not provide any benefit. They were left concluding “The lack of impact from increasing whole grain consumption on CVD (cardiovascular disease) risk markers implies that public health messages may need to be clarified to consider the source of whole grain and/or other diet and lifestyle factors linked to the benefits of whole-grain consumption in observational studies.”[v]
As you make changes to your nutrition plan, keep in mind “whole grains” are unprocessed grains, not processed foods like cereal with added whole grains to make the label look better.
High-fructose corn syrup is just sugar
Whether it’s called high-fructose corn syrup (HFCS) or “corn sugar,” HFCS has become more of a health concern than regular sugar. The sugar industry claims the two are chemically the same. Calorie for calorie, HFCS and table sugar might seem indistinguishable, but the ways our bodies respond to each are significantly different.
Princeton University conducted a study on rats that builds a pretty strong case on this point. Rats were fed diets of the same total calories, protein, fat and carbohydrates. The only difference between the two groups was that one was fed sucrose and the other HFCS. The HFCS rats gained considerably more weight.[vi]
The Childhood Obesity Research Center found many soda manufacturers use a HFCS version with 10-20% more fructose than previously assumed. Regular consumption can substantially increase a child’s risk for developing Type 2 diabetes and other metabolic disorders. With fructose as big a health concern as it is, unknowingly consuming more can only lead to additional health issues.[vii]
You must eat carbs to feed your brain
There’s no doubt our brains are energy gluttons. They burn about 22% of a body's total calorie consumption each day — that’s a lot of fuel. The Institute of Medicine (IOM) has recommended people consume 130 grams of carbohydrate each day to ensure the brain’s glucose requirements can be met from food.[viii] According to investigation by Gary Taubes in his book Good Calories, Bad Calories, the IOM arrived at this level by looking at what the average person needed to consume each day to avoid the body creating its own glucose. They found the average person needed 100 grams each day, and then added another 30 grams as a buffer.
But while carbohydrates are part of a healthy nutrition plan, they are not essential nutrients like some amino and fatty acids. The truth is, the body can create its own glucose from fat and protein and, if glucose production cannot keep up with requirements, another energy source called ketone bodies can be safely used.
Another way this myth is contradicted is by looking at brain-related degenerative diseases. Alzheimer’s disease is a growing health concern, and there’s growing evidence to suggest that it is a “Type 3 Diabetes.” Excessive carbohydrate intake, especially fructose, seems to increase the development of advanced glycation end-products (AGEs), modified proteins that influence physiological aging and neurodegenerateive diseases, like Alzheimer's disease.[ix]
Carbohydrates can be a healthy part of a nutrition plan, although research shows they’re not as necessary as we may have once thought. Avoiding refined grains is a wise choice and though whole grains are likely a better choice compared to refined grains, they still should not be eaten in excess.
See also: Comparing Low-Fat and Low-Carb
Do some other carbohydrate myths come to mind? Share thoughts or add comments below.
This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.
[i] McKeown NM, Troy LM, Jacques PF, Hoffmann U, O’Donnell CJ, Fox CS. Whole- and refined-grain intakes are differentially associated with abdominal visceral and subcutaneous adiposity in healthy adults: the Framingham Heart Study. Am J Clin Nutr. 2010;92(5):1165-1171
[ii] O’Neil CE. Whole-Grain Consumption Is Associated with Diet Quality and Nutrient Intake in Adults: The National Health and Nutrition Examination Survey, 1999-2004. J Amer Diet Assoc. 2010;110(10):1461-1468
[iii] Giacco R, Clemente G, Cipriano D, Luongo D, et al. Effects of the regular consumption of wholemeal wheat foods on cardiovascular risk fa ctors in healthy people. Nut, Metab, Car Dis. 2010;20(3):186-194
[iv] Tighe P, Duthie G, Vaughan N, Brittenden J, et al. Effects of increased consumption of whole-grain foods on blood pressure and other cardiovascular risk markers in healthy middle-aged persons: a randomized controlled trial. Am J Clin Nutr. 2010;92(4):733-740
[v] Brownlee IA, Moore C, Chatfield M, Richardson DP, et al. Markers of cardiovascular risk are not changed by increased whole-grain intake: the WHOLEheart study, a randomized, controlled dietary intervention. Br J Nutr. 2010;104(1):125-34
[vi] Parker H. Princeton University. A sweet problem: Princeton researchers find that high-fructose corn syrup prompts considerably more weight gain. News at Princeton March 22, 2010. http://www.princeton.edu/main/news/archive/S26/91/22K07/index.xml?section
[vii] Ventura EE, Davis JN, Goran MI. Sugar Content of Popular Sweetened Beverages Based on Objective Laboratory Analysis: Focus on Fructose Content. Obesity. doi:10.1038/oby.2010.255
[viii] Food and Nutrition Board. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids. Institute of Medicine of the National Academies Consensus Report. September 5, 2002.
[ix] Seneff S, et al. Nutrition and Alzheimer’s disease: The detrimental role of a high carbohydrate diet. Eur J Intern Med. 2011;doi:10.1016/j.ejim.2010.12.017