Sugar has many aliases and, according to Prevention magazine, precisely 57 different names. Nowadays, sugar is ubiquitous and permeates much of our food supply, even in places you might least expect, like ketchup and barbecue sauce.

So where did sugar originate? Sugar cane was initially grown about 10,000 years ago on the island of New Guinea where people picked and ate it raw. By AD 500, sugar was powdered in India and used as a treatment for various ailments, but sugar refinement was a covert process that eventually spread to Persia. The Arabs were the first to turn sugar production into an industry after Arab armies conquered Persia and marched away with sugar’s potent secrets.

By the time cane sugar reached the West (roughly 600 years ago), it was classified as a spice and purchased by European royalty, the only ones with the means to pay the exorbitant prices. Two hundred years later, slave labor on sugar cane plantations made it possible for the working class to buy sugar. The Industrial Revolution made sugar accessible to everyone and manufacturers now refine raw sugar into the white crystals available in our grocery stores.

How much sugar do we really consume? Below are some astounding statistics and, just to provide some context, one 12-ounce can of Coke has 10 teaspoons of sugar:

• In 1822, Americans consumed approximately 1.8 teaspoons per day
• By 2012, each American consumed 30.6 teaspoons per day, which equates to almost 3 ½ cans of soda
• As of 2012, the average American child consumed a whopping 32 teaspoons per day, or almost 3/4 of a cup

Why do we want sugar? Essentially, sugar in the bloodstream “stimulates the same pleasure centers of the brain that respond to heroin and cocaine… In this sense, it is literally an addictive drug.” (National Geographic)

Several prominent scientists suspected that sugar might cause diabetes as early as the 1920s, but it wasn’t until 1972 that John Yudkin, a British physiologist and nutritionist, proclaimed the evils of sugar in a book entitled Pure, White and Deadly, which was written to send the message that overconsumption of sugar was leading to many diseases, including heart disease, liver disease, and some cancers. The book was based on a series of studies during the 1960s showing that high amounts of dietary sugar resulted in increased amounts of fat and insulin in blood, raising the risk for heart disease and diabetes. However, Yudkin’s message was overshadowed by Ancel Keys (click here to read the recent saturated fat blog for more on Keys) and other scientists who preached the theory that saturated fats caused heart disease and obesity.

Richard Johnson, MD, a nephrologist the University of Colorado in Denver, says that “every time I study an illness and trace a path to the first cause, I find my way back to sugar.” Dr. Robert Lustig, a pediatrician and endocrinologist at the University of California at San Francisco, has proclaimed that the “food industry has contaminated the food supply with added sugar” that has become a poison.

– Holly Hough, PhD

References: Prevention; Forbes; Mind Body Nutrition; National Geographic; The New York Times (February, 2014); The New York Times (April, 2011); Mother Jones; The Huffington Post

Image by Uwe Hermann, via CC

Click to read Holly’s post, Saturated Fats: Friend or Foe?

For decades, we have been advised to steer clear of saturated fats. Several research papers published in the early 1950s implicated dietary fat as a key player in the development of heart disease. By 1961, the American Heart Association (AHA) published dietary guidelines that included reduction of saturated fats and in 1982, the Nutrition Committee of the AHA recommended no more than 10% of daily calories from fat.

So what are saturated fats? They are usually solid at room temperature and found in the foods we tend to like the most, that is, meat, cheese, ice cream, butter, and other dairy products. A few plant-based oils, such as coconut and palm oils, also contain saturated fats.

Scientists have recently revisited the role of saturated fats in cardiovascular disease and, as it turns out, the early studies may have been wrong. Authors of one paper published in 2010 and another in early 2014 analyzed data from a number of previous studies. The authors indicate that there is no relationship between dietary saturated fat and heart disease risk and, furthermore, the evidence does not support our current dietary guidelines that encourage “low consumption of saturated fats.” In fact, authors of a separate study found that a “low-carbohydrate diet was more effective for weight loss and cardiovascular risk reduction than a low-fat diet.”

Nina Teicholz, an investigative journalist, recently authored a book entitled The Big Fat Surprise (released in March of 2014) that corroborates the recent findings regarding saturated fats. Ms. Teicholz spent eight years sifting through previous research on the connection between heart disease and saturated fats. According to her, the research that was the basis for our current dietary guidelines was severely flawed.

The primary author, Ancel Keys, was a physiologist at the University of Minnesota in the 1950s. The story goes that Keys became interested in heart disease when he observed that American businessmen were experiencing high rates of heart attacks, Europeans had lower death rates from coronary heart disease when food supplies were low following World War II, and then-President Eisenhower himself had a heart attack, bringing cardiovascular disease to the medical forefront. Following a series of smaller studies, Keys developed his theory that fat, particularly saturated fat, caused heart disease, which came to be known as the diet-heart hypothesis.

In 1953, Keys published a very influential paper where he purported a “remarkable relationship” between fat and heart disease.  He presented data from the United States, Canada, Australia, England and Wales, Italy, and Japan supporting his hypothesis that consumption of fat causes heart disease.  Several years later, Jacob Yerushalmy, a biostatistician at the University of California at Berkeley, noted in a separate paper that, although the countries Keys selected supported the diet-heart hypothesis, data were available for 22 countries.  As it turned out, when data from all countries were analyzed, the causal relationship between dietary fat and heart disease disappeared.

Keys launched what came to be known as the ‘Seven Countries’ study in 1958.  He collected data on dietary habits and heart attack rates in the United States, the Netherlands, Finland, Yugoslavia, Italy, Greece, and Japan.  As a result, Keys reported that greater consumption of animal fat led to a higher rate of heart attacks. There were a few problems with his data, however.  Keys visited Greece during Lent when people abstain from eating meat, which would have skewed his data.  Additionally, the correlation between animal fat and heart attacks was not observed in Finland, Greece, and Yugoslavia.  Keys also intentionally left out countries such as Holland and Norway where residents eat a lot of fat but experience little heart disease.

In spite of the flaws, Keys’ research received a great deal of media attention and he ultimately persuaded both the AHA and the U.S. government that saturated fats were the bad boys that caused not only heart disease but played a major role in the development of obesity and cancer as well. What followed are the national dietary guidelines that are still accepted today.

Dariush Mozaffarian, MD, at the Harvard School of Public Health, is one of many researchers who now believe that our current dietary guidelines need to be revisited. He says that “we can’t judge the healthfulness of a food [only] by how many grams of saturated fat it has.” Other experts aren’t buying the new findings. Walter Willett, MD, Chair of Nutrition and Mozaffarian’s colleague at the Harvard School of Public Health, says the conclusions of recent studies should be disregarded.

What does all of this mean for us? It is unknown when or if the current dietary guidelines will change and it will take more research and discussion to alter a long-held belief. If you have questions regarding these new findings and wish to revisit your own nutritional habits, please to talk to your doctor and/or a dietitian.

– Holly Hough, PhD

Please consult with your doctor before making any dietary changes.

References: American Heart Association; The Journal of Nutrition; Annals of Internal Medicine; American Journal of Clinical Nutrition; British Columbia Medical Journal; WebMD; Dr. Frank Lipman: Interview with Nina Teicholz; NBC News

Images by Flicker users Yamashita Yohel and Anne Hornyak, via CC

Click to read Holly’s post, A Spoonful of Sugar…Not So Nice After All

Are eggs making a comeback? For decades, we have been advised to limit egg consumption to reduce our risk of developing heart disease in spite of the fact that eggs contain beneficial substances like protein, Vitamins A and D, calcium, and choline (important for brain function). Eggs have gotten a bad rap, probably because just one yolk contains 187 mg of cholesterol, which is 62% of the recommended daily intake. While it is true that eggs are high in cholesterol, there is now solid research that shows no connection between eating eggs and heart disease.

For example, participants in the Multiple Risk Factor Intervention Trial that had a blood cholesterol level lower than 200 mg/dL ate more eggs than those whose cholesterol was greater than 220. In a separate study, individuals who ate two eggs per day for six weeks experienced no change in total or LDL cholesterol, or ‘bad cholesterol’.

The truth is, cholesterol is in every cell of the human body and is used to make hormones like testosterone and estrogen. The liver actually produces cholesterol and makes all the cholesterol your body naturally needs. There is no dietary requirement for more; however, when we eat foods high in cholesterol, the liver produces less of this natural cholesterol. So what foods are high in cholesterol?  Usually those foods that are also high in saturated fat, like animal products.  Since the American diet typically includes a lot of animal products, we consume quite a bit of cholesterol as a result.

Alice Lichtenstein, a professor of nutrition science at Tufts University, says that the major determinant of LDL (‘bad cholesterol’) levels is saturated fat and lowering saturated fat in the diet subsequently lowers LDL cholesterol.  While eggs are indeed high in cholesterol, they are low in saturated fat, which for many years has been accepted as the primary culprit in raising the risk for heart disease.  New evidence is surfacing, however, that shows no relationship between saturated fat and heart disease risk, a revelation contrary to long-held beliefs.

So…based on what what we do know, how many eggs can you eat? Most experts agree that one egg per day is fine. The American Heart Association (AHA) no longer limits the number of eggs you can eat, but instead recommends limiting cholesterol intake to 300mg daily. People with diabetes who eat eggs may be at increased risk for heart disease, so if you have diabetes or very high levels of total and LDL cholesterol due to a genetic disorder, experts say it is best to limit your egg consumption to three yolks per week.

Perhaps it’s time to reevaluate eggs – they may be an egg-cellent choice after all!

– Holly Hough, PhD

Please consult with your doctor if you have concerns about your cholesterol or before making any dietary changes.

References: Journal of the American Medical Association; American Journal of Clinical Nutrition; The Boston Globe; Harvard School of Public Health: The Nutrition Source; Annals of Internal Medicine

Image by Flickr user Bryan Jones, via CC