There are many different "belief systems" in nutrition.
Each one has their own set of myths and misconceptions.
Here are the 10 biggest myths in alternative nutrition.
Added sugar is a disaster when consumed in excess.
There is no doubt about it, the evidence of its harmful effects is overwhelming.
However, even though people are well aware of this, avoiding sugar can be extremely difficult.
Not just because it's everywhere, but also because people get overpowering cravings for foods that are high in sugar.
This has led many experts to believe that sugar (and the junk foods that contain it) can be downright addictive for a lot of people.
There is actually a lot of evidence that supports this, in both animals and humans. Sugar can "light up" the same areas in the brain as drugs of abuse, and cause many of the same behavioral symptoms (, ).
Unfortunately, some people need to take things to the extreme and claim that sugar is 8 times more addictive than cocaine.
This myth is actually highly prevalent in certain health circles.
It is based on a study in rats, showing that they preferred water sweetened with sugar or saccharin (a very intense zero calorie sweetener) over intravenous cocaine ().
It was a striking result, but hardly proof of anything in humans.
Sugar is very unhealthy, and potentially very addictive. But saying that it is more addictive than cocaine, one of the most addictive narcotics in existence, is just ridiculous.
As a recovering drug addict and food addict, I can tell you that the two substances are NOT comparable.
Bottom Line: Sugar can be addictive for many people. However, saying that it is 8 times more addictive than cocaine is completely wrong and not supported by the evidence.
Some people think that calories are all that matters for weight loss.
Others think that they are completely irrelevant.
They say that you can lose weight no matter how many calories you eat, as long as you choose the right foods.
As with so many things in nutrition, the truth is somewhere in between.
Eating certain foods can help support weight loss by boosting metabolism (increasing calories out) and reducing appetite (reducing calories in).
In many cases, people can lose tons of weight without ever counting a single calorie.
However, if they are losing weight, it means that more calories are leaving their bodies than entering them. That is an indisputable scientific fact.
Of course, this does NOT mean that you need to count calories to lose weight.
Changing your diet so that it happens on "autopilot" can work just as well, if not better.
Bottom Line: Some people believe that calories are completely irrelevant for weight loss/gain. Even though calorie counting isn't always necessary, calories still count.
Extra virgin olive oil is the healthiest fat on the planet.
However, many people believe that it should not be used for cooking.
It is claimed that the fats and antioxidants are sensitive to heat, and may even turn into harmful compounds.
It is actually true that oils can be sensitive to heat, but this primarily applies to oils high in polyunsaturated fatty acids, such as soybean and corn oils (12).
The polyunsaturated fat content of olive oil is only 10-11%, which is low compared to most other plant oils ().
There have actually been many studies on olive oil and cooking, showing that the oil maintains its healthful properties despite being exposed to high heat.
The only bad thing that happens to olive oil when heated, is that the flavor may change slightly.
I personally use extra virgin olive oil for almost all of my cooking. It is incredibly healthy and delicious.
Bottom Line: It is a myth that olive oil damages when exposed to heat. Numerous studies show that the fats and antioxidants in olive oil can withstand cooking temperatures, even for long periods of time.
Heating your food in a microwave oven is fast and highly convenient.
However, there are people who believe that this convenience comes at a cost.They claim that microwaves produce harmful radiation and cause damage to healthy nutrients in foods, and that there are studies showing microwaved food to be downright harmful to health.
But when you go through the literature to look for these studies, they are nowhere to be found.
Microwave ovens are actually designed in a way that doesn't allow the radiation to escape.
Studies also show that they are even better at preserving nutrients than cooking methods like boiling and frying (, , ).
Some people don't want to use microwaves, and that's fine. But there is no evidence that they cause harm, and no scientifically valid argument to avoid them.
Bottom Line: There are no published studies showing microwave ovens to be harmful. Many studies show that they are effective at preserving nutrients compared to other cooking methods.
The old myths about saturated fat and dietary cholesterol have been debunked.
Both have little effect on blood cholesterol in most people.
If anything, they raise HDL (the "good") cholesterol and change the LDL particles from small to large, which are benign (, ).
However, some people misunderstand this and think that blood cholesterol levels, the stuff your doctor measures, is meaningless as well.
It is true that the conventional numbers, Total and LDL cholesterol, don't always give an accurate picture of true heart disease risk.
But the LDL lipoproteins, the carriers that move cholesterol around in the bloodstream, are very important (26).
With a few exceptions, having very high LDL "cholesterol" is bad, because it usually means that you have a high number of LDL particles (LDL-p), which is strongly linked to heart disease and death ().
Although LDL "cholesterol" is not the enemy, the "cholesterol carrying LDL lipoproteins" are important.
Bottom Line: Dietary cholesterol and saturated fat are harmless. However, the lipoproteins that carry cholesterol in the bloodstream are very important for heart disease risk.
Mycotoxins are toxins produced by molds ().
They are found in all sorts of commonly consumed foods.
There is an ongoing myth that coffee is generally contaminated with harmful levels of mycotoxins.
However, it is highly unlikely that this would happen, because mycotoxin levels in foods are tightly regulated. Crops that exceed the safety limit are discarded ().
Molds are actually ubiquitous in the environment, and mycotoxins are everywhere. Almost every single human has detectable levels of mycotoxins in the blood ().
There really is no need to fear regular coffee due to mycotoxins.
Bottom Line: It is completely false that regular coffee contains high levels of mycotoxins. Mycotoxins are everywhere, but the amount found in coffee is far below the safety limit.
The alkaline diet is very popular.
Proponents of this diet claim that foods are either acidic or alkaline to our bodies.
They say that acidic foods lower the pH value of the blood (make it more acidic), and that cancer cells can only grow in an acidic environment."Acidic" foods include meat, dairy and grains, while "alkaline" foods are mostly plant-based foods like vegetables and fruit.
The truth is, the pH value of the blood is tightly regulated by the body. It simply does not change, unless in serious poisoning or disease conditions.
Cancer is also perfectly capable of growing in an alkaline environment, and our blood is slightly alkaline by default ().
The alkaline diet may be healthy, but that's because it is based on healthy, whole foods. It has absolutely nothing to do with these foods being acidic or alkaline.
Bottom Line: It is not true that foods can change the pH value (acidity) of our bodies, and there is no convincing evidence behind the alkaline diet.
The myth that dairy causes osteoporosis is an extension of the alkaline diet myth.
It is claimed that dairy protein makes the blood acidic, so that the body takes calcium out of bones in order to neutralize the acid.
However, dairy products have several properties that make them, quite literally, the perfect food for bone health.
Last but not least, they are high in quality animal protein, which has actually been shown to be beneficial for bone health in numerous studies (, ).
The studies show that dairy products lead to improved bone health in all age groups, increasing bone density and lowering the risk of fractures (, , , ).
Many of these studies are controlled trials in humans, the gold standard of science.
Although dairy isn't needed for bone health, the evidence shows that it can be highly beneficial.
Bottom Line: Despite some people claiming the opposite, most of the studies show that dairy products are highly beneficial for bone health.
Low-carb diets have numerous benefits.Studies show that they cause fast weight loss and major improvements in health markers (43, 44, 45).
The effects on metabolic syndrome and type 2 diabetes are particularly striking (46, ).
Many people believe that because lowering carbs helps treat these problems, that it must be the carbs that caused them in the first place.
It is true that refined carbs, including added sugars and refined grains, can contribute to weight gain and metabolic disease (, 49, ).
But the same is NOT true for whole, single ingredient carbohydrate sources.
There have been numerous populations around the world that were in excellent health eating a high-carbohydrate diet based on real foods.
When metabolic problems like obesity and type 2 diabetes have already taken place, low-carb diets work. There is no doubt about it.
But that doesn't mean that carbs themselves caused these health problems.
Even though these foods are off limits on a very low-carb diet, many people can remain in excellent health eating plenty of unprocessed high-carbohydrate foods.
As with most things in nutrition, this depends entirely on the individual. A low carb diet is great for some people, but a high carb diet works just fine for others.
Bottom Line: Low-carb diets are effective. However, this does not mean that whole food carbohydrates are inherently fattening or harmful.
Unhealthy foods are the biggest reason the world is sicker and fatter than ever before.
As we know, the main reason for the harmful effects of added sugars is their high fructose content.Fructose can only be metabolized by the liver in significant amounts. When the liver gets overloaded, it starts turning the fructose into fat (, 52).
This can lead to a host of metabolic problems, and is believed to be among the leading drivers of many common diseases ().
But here's where it gets interesting. Agave nectar is actually much higher in fructose than both regular sugar and high fructose corn syrup.
Whereas sugar is 50% glucose, 50% fructose, agave nectar is 85% fructose (54)! If anything, agave nectar is the single unhealthiest sweetener in the world.
It makes regular sugar look healthy in comparison, and that is saying something.