It's Just One Meal. How Bad Could it Be?
Rich foods packed with oils, animal products, white flour, and sugar may look tempting to you at a holiday gathering. Maybe tempting enough for you to say to yourself “It’s just for today, just this one meal. I’ll go back to my healthful Nutritarian diet tomorrow — one unhealthful meal can’t possibly harm me.” Is that true?
Aside from the fact that a single low-nutrient meal may awaken old addictive drives that could then lead to many more low-nutrient meals, a single meal is enough to cause damage to your cardiovascular system. There are more cardiac deaths on December 25, 26, and January 1 than any other days of the year.1 This sobering observation suggests that overindulging at a holiday meal can be extremely hazardous to your heart.
First, I’d like to define the phrase “endothelial function,” which will be used frequently in this article: The endothelium is a specialized layer of cells that forms the inner lining of all blood vessels. Endothelial cells produce nitric oxide and other substances that regulate blood pressure, maintain balance between pro-thrombotic (blood clotting) and anti-thrombotic mechanisms, and act as a selective barrier between the blood and surrounding tissues. The functions of the endothelium are crucial; endothelial dysfunction is an early event in atherosclerotic plaque development and cardiovascular disease.2
Now let’s take a look at the traditional components of a holiday meal, and how they affect our cardiovascular system...
Meat, cheese, and oils. Over fifteen years ago, a study reported that eating a meal in high saturated fat, and animal product impaired endothelial function for four hours following the meal, and this effect has been confirmed in the literature over and over.3,4 For example, a study presented earlier this year reported the detrimental effects of a sausage, egg and cheese breakfast sandwich on endothelial function.5 In addition to impaired endothelial function, single low-nutrient, high fat meals have been reported to induce insulin resistance, increase circulating adhesion molecules (which allows excess LDL and inflammatory cells to enter the vessel wall — a contributor to atherosclerosis), induce oxidative stress, and deplete the body’s circulating antioxidants. 6-8 The detrimental effects of a high saturated fat meal on endothelial function are believed to occur via oxidative stress and activation of pro-inflammatory pathways.4,9 Although most of the studies have focused on high saturated fat meals, there is also evidence that animal protein and excess oils (high in omega-6 fatty acids) may also negatively affect the endothelium and induce oxidative stress.10,11
Bread, pasta, and sugary desserts. Refined carbohydrate is just as harmful to endothelial function as saturated fat. Refined carbohydrates cause dangerous spikes in blood glucose — repeated spikes over time promote diabetes and other chronic diseases, but what about a single high glycemic meal? Acute hyperglycemia (short term elevated blood glucose after a single refined carbohydrate-rich meal) has been shown to impair endothelial function, promote blood clotting (which increases heart attack risk), induce oxidative stress and deplete circulating antioxidants, increase blood pressure, increase circulating adhesion molecules, impair the body’s ability to fight infection, and decrease blood flow to the heart.7,12-17
Salty snacks, beer, and wine. A single, high salt meal impairs endothelial function, just like high saturated fat or high sugar meals, and alcohol magnifies the increase in blood glucose from a refined carbohydrate-rich meal.18,19
The point: A SINGLE unhealthful holiday meal inflicts damage on the cardiovascular system, contributes to atherosclerotic plaque development, and in susceptible individuals may even provoke a cardiac event. Also important, is that the most eating enjoyment at special occasions comes from gourmet Nutritarian food that pleasures your taste buds, your heart and your intelligence.
1. Kloner RA. The "Merry Christmas Coronary" and "Happy New Year Heart Attack" phenomenon. Circulation 2004;110:3744-3745.
2. Higashi Y, Noma K, Yoshizumi M, et al. Endothelial function and oxidative stress in cardiovascular diseases. Circ J 2009;73:411-418.
3. Vogel RA, Corretti MC, Plotnick GD. Effect of a single high-fat meal on endothelial function in healthy subjects. Am J Cardiol 1997;79:350-354.
4. Hall WL. Dietary saturated and unsaturated fats as determinants of blood pressure and vascular function. Nutr Res Rev 2009;22:18-38.
5. Lacroix S, Des Rosiers C, Gayda M, et al: Abstract 752: Baseline Triglyceridemia Influences Postprandial Endothelial Response to a Single Mixed Mediterranean-type Meal Compared to a High-saturated fat meal. In Canadian Cardiovascular Congress. Toronto, Canada; 2012.
6. Ramirez-Velez R. [Postprandial lipemia induces endothelial dysfunction and higher insulin resistance in healthy subjects]. Endocrinol Nutr 2011;58:529-535.
7. Ceriello A, Quagliaro L, Piconi L, et al. Effect of postprandial hypertriglyceridemia and hyperglycemia on circulating adhesion molecules and oxidative stress generation and the possible role of simvastatin treatment. Diabetes 2004;53:701-710.
8. Tsai WC, Li YH, Lin CC, et al. Effects of oxidative stress on endothelial function after a high-fat meal. Clin Sci (Lond) 2004;106:315-319.
9. Lacroix S, Rosiers CD, Tardif JC, et al. The role of oxidative stress in postprandial endothelial dysfunction. Nutr Res Rev 2012;25:288-301.
10. Mohanty P, Ghanim H, Hamouda W, et al. Both lipid and protein intakes stimulate increased generation of reactive oxygen species by polymorphonuclear leukocytes and mononuclear cells. Am J Clin Nutr 2002;75:767-772.
11. Hennig B, Toborek M, McClain CJ. High-energy diets, fatty acids and endothelial cell function: implications for atherosclerosis. J Am Coll Nutr 2001;20:97-105.
12. Lemkes BA, Hermanides J, Devries JH, et al. Hyperglycemia: a prothrombotic factor? J Thromb Haemost 2010;8:1663-1669.
13. Mohanty P, Hamouda W, Garg R, et al. Glucose challenge stimulates reactive oxygen species (ROS) generation by leucocytes. J Clin Endocrinol Metab 2000;85:2970-2973.
14. Turina M, Fry DE, Polk HC, Jr. Acute hyperglycemia and the innate immune system: clinical, cellular, and molecular aspects. Crit Care Med 2005;33:1624-1633.
15. Fujimoto K, Hozumi T, Watanabe H, et al. Acute hyperglycemia induced by oral glucose loading suppresses coronary microcirculation on transthoracic Doppler echocardiography in healthy young adults. Echocardiography 2006;23:829-834.
16. Rammos G, Peppes V, Zakopoulos N. Transient insulin resistance in normal subjects: acute hyperglycemia inhibits endothelial-dependent vasodilatation in normal subjects. Metab Syndr Relat Disord 2008;6:159-170.
17. Lee IK, Kim HS, Bae JH. Endothelial dysfunction: its relationship with acute hyperglycaemia and hyperlipidemia. Int J Clin Pract Suppl 2002:59-64.
18. Hatonen KA, Virtamo J, Eriksson JG, et al. Modifying effects of alcohol on the postprandial glucose and insulin responses in healthy subjects. Am J Clin Nutr 2012;96:44-49.
19. Dickinson KM, Clifton PM, Keogh JB. Endothelial function is impaired after a high-salt meal in healthy subjects. The American journal of clinical nutrition 2011.