Top 5 Nutrition Myths: Busted

By Cassandra Forsythe, PhD, RD

Despite years of research and top-quality science, the world of nutrition is still riddled with flawed thinking. Most people feel that because they eat, they must be experts in nutrition. However, it’s not really their fault if their reasoning is wrong.

Most people get their nutrition beliefs from the news and it seems that reporters change their minds almost as often as people change their socks—which is mostly true.

One day you read that eggs give you heart disease, the next day you hear that they’re actually good for you. What’s a person to believe? The best thing to do is to think like your great-grandparents when it comes to food. What do I mean by that? Well, if your great-grandparents wouldn’t recognize the food or nutrition advice, then it’s probably not good for you.

Another way to decipher truth from myth is that if you didn’t actually witness a food or animal produce being grown or raised, there’s most likely something unhealthy about it—whether it is pesticides, hormones, or antibiotics unnecessarily added. You just can’t be too sure these days.

In this article, I’m going to help you weed through and differentiate some popular nutrition facts from fiction. I’ll comb through the top 5 myths and explain why they deserve busting.

1. Saturated fat causes heart disease.

butter-350x375Over the past 40 years, butter has become the poster child for saturated fat and has gained reputation as a deadly food. Mainstream media has effectively scared many of us for years into thinking butter is terrible for our health. But, is it?

Vilified and condemned to an unhealthy fate, butter not only will cause your heart to stop beating spontaneously, but it’ll increase the size of your love handles faster than a bag of Twizzlers (these delicious, twisty red sticks of joy are fat-free, so, they must be better for you, right? So goes the reasoning). However, a meta-analysis of 21 unique studies, including almost 350,000 people, published in the American Journal of Clinical Nutrition concluded that there is no relationship between intake of saturated fat and the incidence of heart disease or stroke.1

Yes, you read that right: NONE.

This study was published by some of the top lipid (fats) researchers in this country, whom at one time themselves also thought saturated fat was to blame for our high heart disease rates. In this meta-analysis, 11,000 of the 350,000 of the people studied developed cardiovascular disease (CVD), over a time period of 14 years. By combining these different studies into one investigation, the authors were able to see if there was really any association between saturated fat intake and risk of heart attacks and stroke, which in fact, there was not any. They found that there was a weak association only in studies involving smaller number of cases, but not larger ones.

If this publication, and others since it was published shows that saturated fat isn’t a key player in heart disease, how did saturated fat get its bad reputation? Let’s take quick trip back in time.

It all started in the 1950's when a physiologist named Ancel Keys, Ph.D. compared fat intake and heart disease deaths in six countries, including the U.S., and found that saturated fat was connected to heart disease. In hindsight, the truth was that the countries he used to prove this statistic were cherry-picked to show this result because that’s what he believed. While Dr. Keys used data from six countries, he actually had statistics from 22 countries available. And when scientists analyzed those statistics, the apparent link between eating saturated fat and heart disease disappeared. Yet, the public was never made fully aware of these findings.

In this new investigation, the authors wrote the following:

"Our results suggested publication bias, such that studies with significant associations tended to be received more favorably for publication. If unpublished studies with null associations were included in the current analysis, the pooled relative risk estimate for CVD could be even closer to null."

So, what’s the bottom line? Butter is not the heart killer that we once thought. In fact, your grandparents would probably tell you to eat butter, and not margarine, because it’s healthier. But we’ve been led to believe a different line of thinking, and because of it we ended up consuming tubs of hydrogenated margarine, which, due to their high trans fat content, increases our risk of heart disease more than butter possibly could have ever achieved. Even the non-hydrogenated margarines are not playing out to be the heart saviors we thought they would be. Thus, go ahead and enjoy butter when you need it—it’s a natural food not tampered with by modern man.

2. Diet soda is healthier than regular soda.

Many people dislike the taste of plain water, so they turn to carbonated beverages and other sweetened drinks to satisfy their fluid needs.

soda-450x340Since 1950, our consumption of carbonated beverages has climbed from 10 gallons per person per year, to more than 50. Of this, diet soda makes up 30 percent of the total volume – that’s a lot of pop (for our Canadian and Mid-west readers)!

The reason for the increased popularity of diet beverages, including soda and juice drinks, is the association of sugar with the development of obesity, diabetes and many other chronic conditions, which is true. But, our obsession with sweet drinks has not led us down the right path by replacing sugar with artificial sweeteners. Instead of reducing our sugar intake, we replaced it with something even sweeter, but with no caloric value: artificial sweeteners.

In recent years, scientists have found that the artificially-sweetened beverages we drink to lose weight and reduce our risk of diabetes are actually associated with weight gain and an increased incidence of diabetes and insulin-resistance.

But how is this possible? Weren’t these sweeteners supposed to be better for us? Apparently not. Several large epidemiological studies in humans have indicated a direct correlation between frequent diet beverage consumption to double the risk of diabetes, obesity, and metabolic syndrome.

Other human data indicate that substitution of sugar with artificial sweeteners doesn’t actually reduce appetite, but stimulates it even more!2,3 Artificial sweeteners act almost exactly the same in the body as sugar despite their minimal caloric value. They activate sweet receptors in the brain and endocrine cells in the gut making you think you had sugar, but because there are no calories associated with them, the brain realizes something isn’t right.

Tricking the body in this way disrupts our normal energy regulation such that we end up seeking out more food to replace the nutrients we should have received from the non-nutritive sweet foods (namely, carbohydrates and more sugar).

So, what’s a person to do? Should you just eat regularly sweetened foods? Or continue to use artificially-sweetened substitutions? In a perfect world we’d do neither.

The American food supply has become sickly sweet and because of this, we’re one of the more obese nations in the world, and your great-grandparents would agree. The only way to reduce our intake of all these sweet items is to read food labels carefully and watch out for unnecessarily added sugars.

As far as artificial sweeteners go, the best bet is to reduce them as much as possible, if not to cut them out completely. This includes Saccharine, Sucralose/Splenda, Acesulfame-K, Cyclamate and Aspartame. Even Stevia and Agave sweeteners don’t seem to have any benefit.

To be clear, occasional intake of most items in the context of a healthy diet and regular exercise has no known negative effects, but sweetener is a sweetener, regardless of the type. Over time your palate will learn to appreciate unsweetened tea or coffee, and will recognize a good, unsweetened slice of bread (such as sprouted grain bread) compared to the overly sweet breads commonly found on grocery shelves.

As Henry Feilding once said, “Love and scandal are the best sweeteners of tea.” His words could not be any closer to the truth. Your grandparents would raise their cup to that.

3. Coffee is bad for your health.

Whenever a person begins a “cleansing” diet, one of the first things they’re supposed to eliminate is coffee. Sure, perhaps giving your body a break from stimulants is a good idea, but is coffee actually a toxic and unhealthy substance? Well, let’s look at the facts.

Now, more than ever, studies are popping up actually touting the hefty list of health benefits from your favorite brew. From cancer risk to liver disease to type 2 diabetes coffee has been shown to have favorable effects. One of the reasons for coffee’s ability to improve risks of disease is its high content of antioxidants, namely polyphenols. These compounds protect body cells from free radical ions and reactive atoms that can disrupt normal function and lead to diseases like cancer and diabetes.

In several human investigations, individuals who consumed 2 or more cups of coffee a day had half the risk and rate of liver disease and cancer as those who consumed no coffee at all.4,5 In a January 2010 publication, Harvard epidemiologists found that consumption of 5 or more cups of coffee or tea daily compared to no consumption was associated with a decreased risk of glioma (brain cancer).6

For reduction of diabetes, Australian researchers combined data from 18 studies including over 457 000 participants and found that for every additional cup of coffee consumed each day, there was a seven percent reduction in risk in this widespread disease.7 Similar inverse associations were found for decaffeinated coffee and tea and risk of incident diabetes indicating that the effects are likely due to the polyphenol content of these beverages and perhaps not caffeine itself.

Now that you know coffee can actually benefit your health, here's an important factor to consider:

Coffee loaded with artificial whiteners or excess sweeteners (sugar or artificial), may negate the benefits of this healthy drink.

As pointed out above, excess sweetness and artificial anything is most likely a bad health move. Instead, learn to enjoy your coffee black, or with a small amount of cream (or milk) and sugar-in-the-raw.

Just be careful to enjoy your hot coffee slowly so you don’t burn your tongue!

4. High protein diets are “bad to the bone.”

One of the knocks against high protein diets is their suspected negative effect on bone health.

beef-cooked-450x340Part of the reason for this supposed detrimental outcome is that protein decreases your body’s natural pH balance, resulting in an acid overload that must be buffered by the bone. This was thought to release calcium from the skeleton, which would weaken bone strength. However, protein also has beneficial effects on bone by increasing bone growth factors, enhancing calcium absorption (in addition to often supplying calcium), and increasing muscle mass and strength.

In a recent meta-analysis of 61 studies from late 2009, researchers found little to no evidence that dietary protein had a negative effect on bone health—whether it be from animal or vegetable sources.In fact, there was a slight positive effect of increased protein intakes on bone strength which accounted for one to two percent of total bone mineral density. Despite slight decreases in body pH levels from increased protein intake, there is apparently no detrimental effect on bone strength and density.

Other benefits of high protein diets include improved satiety during weight loss regimes, and retention of lean body mass (muscle). There also does not appear to be any detrimental effect of increased protein intake on kidney or heart health. In fact, because additional protein can help you attain a more optimal body composition, there are only good reasons to include it in your diet today.

What’s the bottom line here?

Well, great-grandpa and grandma also enjoyed protein as part of their healthy daily diets. However, the protein they chose came from local farms, and weren’t covered in breading, high sugar sauces or preserved with carcinogenic chemicals. The same should apply to you—be smart when choosing protein: know where it comes from, ensure it wasn’t injected with unnecessary hormones or antibiotics, and try to eat it in its most natural state possible paired with healthy side dishes.

5. Low-carb diets are neither practical nor healthy.

Dr. Atkins’ name is often synonymous with low-carb living. Yet, there are plenty of low-carb diet plans out there today that have similar characteristics. The common theme behind all these nutritional designs is a significant reduction in carbohydrates from the typical American fare with a corresponding increase in protein and dietary fat.

Foods usually consumed include leafy greens, berries, meats, fish and poultry, eggs, dairy, oils, nuts and seeds. None of these foods need to be low in fat (like dairy), and for some people, that’s a source of contention. As we’ve learned above, high saturated fat in the diet, which is often the case with low-carb living, is not a precursor to heart disease. However most people still do not feel comfortable with all this fat in their diet. I mean, how good can it be to replace your toast at breakfast with an extra egg? Well, in fact, for some people, it is a very good thing.

Also, there’s often increased protein intake on a low-carb diet, that for some people causes concern. But, as we learned above, all this protein is not detrimental for bone health or kidney function. In fact, the higher protein content of these low-carb plans enhances their success for weight loss because protein has the ability to improve satiety and promote fullness faster than many high-carb foods.

In 2009, at the University of Connecticut, Jeff Volek, PhD and I conducted one of the first controlled feeding studies of a low-carbohydrate diet. In this investigation, we studied eight men and fed them everything they needed for two six-week periods. Our aim was to compare a high saturated fat, low-carbohydrate diet with a high unsaturated fat, low-carbohydrate diet in the absence of weight loss on markers for heart disease and inflammation, and body composition.

This study was a follow-up to a larger study we conducted in which we found that despite a three-fold greater intake of saturated fat on a low-carb weight loss diet, the saturated fat content of the blood decreased significantly compared to a low-fat diet. What we found in this feeding study was that both the high saturated fat and a low-saturated fat low-carb plan reduced systemic inflammation, decreased or did not elevate the saturated fat content of the blood, and did not have any negative effects on markers of oxidative stress measured in the urine.

Also, despite a lack of weight loss, a few of the participants actually lost body fat while retaining or gaining muscle mass just due to removing carbohydrates from their normal intake. For many people, a low-carb nutrition plan has many positive benefits: it helps reduce cravings for sugar and sugary foods, it increases consumption of foods rich in calcium, heme iron, vitamin B12, and essential fats, and it promotes greater intake of low-carb green-leafy vegetables which are known to reduce cancer risk.

As far as practicality, some people worry that they will miss out on healthy whole grains, higher carb fruits and several healthy convenience foods. However, the health benefits of a low-carb diet are still seen in the absence of these items. Despite the potential lack of dietary fiber on a low-carb plan, many people still see an improvement in gut health (oftentimes people will discover their intolerance to gluten or addiction to flour products once they make this switch).

Despite being a former low-carb researcher who sees the benefits of this diet, I will clarify this: A low-carb lifestyle is not for everyone.

But, it can be a very good option for many people, especially those who lead fairly sedentary lifestyles and have no need for excess carbohydrate foods in their diets. Even for those who are more active, a reduction in carbs from the normal 65 percent recommended for exercisers can help reduce body fat, improve cardiovascular health and calm inflammation in ways never experienced before.

Wise words from great-grandpa and grandma on this topic: continue to choose fresh, minimally processed foods as often as possible. Just because you’re following a low-carb diet, doesn’t mean you need to over-consume processed meats, hydrogenated margarines or “sugar-free” substitutes for real food. You can find nitrate-free organic bacon more easily than ever before, grass-fed meats, free-range chicken and eggs, and organic berries and olive oils.

Choose wisely as your great-grandparents would have and a low-carb diet can be one of your greatest health allies if you so choose to follow it.

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About the author:  Cassandra Forsythe, PhD, RD

Cassandra Forsythe, PhD, RD, CSCS, CISSN is an Assistant Professor at Central Connecticut State University (CCSU). She is a mother, entrepreneur, health and fitness enthusiast, and the author of The Modern Woman’s Guide To Good Nutrition. Cass is also on the advisory boards for Women’s Health magazine, and You can learn more about Cass on her website.


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