Today we have a great guest post about the wide array of “superfoods” currently available on the market. Victoria Lim is a young blogger with a B.Sc. in nutrition. Her fields of expertise include fitness, nutrition, debunking diet myths and walking a dog for miles and miles.
With the growing interest in health and nutrition during the past few decades, certain foods have been labeled by the media as “superfoods” and are getting all the attention. On top of that, it seems that there is a new type of food every year or so that’s been “discovered” and seems to be getting wildly promoted, making people somewhat suspicious whether it’s all just marketing and whether the claims hold any value or not. In search of the truth about the validity of labeling some foods this way, we’ll go over some relevant facts and scientific findings. Let’s see what’s real, what’s just marketing hype, and what is somewhere in between.
What are superfoods, actually?
Superfood, a word that has found its way into the mainstream English language, is defined by the Oxford English dictionary as “a nutrient-rich food considered to be especially beneficial for health and well-being”. Some typical examples of foods that carry this label would be kale, spinach, blueberries, acai berries, quinoa, almonds, avocados, etc. There is no official definition, and you can notice how Oxford, while acknowledging that these foods are rich in nutrients, prefers not to take a stand on whether they are better than other nutritious food or not. Keep in mind that this is actually a marketing term used to refer to foods whose nutrient content provides more health benefits than that of other foods… supposedly. The term is not a scientific one and it is avoided by dietitians and nutrition scientists, the reason being that things are not so black and white – and now you’ll see exactly why.
There is no dispute that the so-called superfoods are nutritious and healthy, as numerous studies have shown. The issue comes when applying the results of these studies to real life diets and drawing conclusions from experiments conducted in laboratory conditions. These conditions simply can’t be translated to the way we actually eat. Most of these studies are conducted on animal models (typically rats), or on isolated batches of human cells (so-called “in vitro” experiments). While these types of studies definitely provide us with the information about the chemical components and properties of the examined food, there is no guarantee that the effects would be similar when the same food is consumed in a normal diet.
A big part in that also plays the fact that the foods are mostly studied in isolation, which is significantly different from real human consumption since we combine different foods in our diets. This especially reflects on the absorption of nutrients in varying degrees. For example, research shows that beta-carotene in carrots and spinach is better absorbed when eaten with a full-fat salad dressing. The conclusion is drawn from a study conducted on 7 people, with blood samples being taken hourly for 12 hours, which is a disparate approach from in vitro experiments.
How should studies be conducted?
On top of that, some studies suggest that the physiological effects of consuming some of these foods are usually just short-term, meaning that you would need to consume them continuously in order to get any benefits. The point is that studying the impact of certain foods on human health is extremely complex because various parameters need to be taken into consideration – our genes, lifestyle, and dieting habits. And so, it’s not really scientifically correct to bring in the fanfare after observing positive effects of a certain nutrient on isolated human cells. When trying to investigate the effects on humans, ideally, two methods need to be combined to get accurate results:
- Intervention studies: researchers manipulate the test subject’s diet for a longer period of time to determine the effect of a certain food or nutrient
- Observation studies: researchers observe the effects of natural differences in various test subjects’ diets
With this in mind, it’s no wonder that some of the trusted information we have on certain foods is based on conclusions drawn by nutritionists over a long period of observation.
The superfoods that are super, and those that are not…
So let’s approach the idea with caution and look into what is just media hype and what actually holds value.
Extensive research has proven the benefits of nuts, and almonds are at the absolute top for many reasons, one of them being that they are one of the richest sources of vitamin E, which is difficult to obtain naturally. They are an excellent source of protein and because of that, they’ve become a favorite among vegans, so those who are allergic to nuts usually opt for vegan protein shakes in order to avoid replacing almonds with something much heavier. Another superfood that holds true to its label is avocado, whose nutritional profile really is impressive. Also, kale has proven to be very densely packed with nutrients, containing 134% of daily vitamin C requirements, 200% of vitamin A, and 700% of vitamin K in just 100 grams and 33 calories. When eaten with fat such as olive oil or avocado, the vitamin K of kale, necessary for bone health and regulating blood clotting, is much better absorbed.
Acai berries, for example, were mentioned by Dr. Oz back in the 2000’s and the craze has been going on ever since. It’s claimed to have amazing benefits, such as helping preventing cancer and promoting anti-aging, but although not harmful, acai berries have completely unremarkable nutritional value, according to dietician Jennifer Sygo in her book “Unmasking Superfoods”. Sygo suggests that acai berries, which have been studied mainly in industry-sponsored research, simply don’t live up to the hype and you would get better antioxidant value with a glass of wine. The exact same goes for the much-hyped goji berries, which is claimed to have 140% of our daily vitamin A requirements in 28g of serving, but you can get the same value, and with fewer calories in carrots and oranges.
In conclusion, it’s important to be suspicious of the food industry and remember that there’s a lot of industry-sponsored research out there. Even if some of them are wrongly proclaimed as superfoods, none of the foods are in any way bad for you – some of them are just meaningless at best and can be easily replaced with accessible, common foods, such as carrots, apples, and onions. Everything points to the fact that it is important to eat a very wide variety of nutritious foods for a balanced nutrient intake, rather than narrowing down the range in hopes that the food we’re eating is miraculous.