I guess it goes with any profession or field of study, there are simply times when people just get it wrong. There are also times when an answer is not quite framed properly, or lacks adequate context and comparison, ultimately confusing the public or leaving them in the dark. The following are a few examples of nutrition messages that keep getting tossed around that nobody is being called on….
Make Vitamin D with Winter Sunshine
I recently watched an interview where the expert was telling the interviewer how she had done a great thing for her health by going out for a 15 minute walk in the sunshine thereby getting her daily dose of vitamin D. Sounds good but for the point that it was the end of December in Canada and vitamin D production via sunlight ended around the beginning of October, some 2 1/2 a half months prior! Right out of the gate, the ‘expert’ got it wrong which set the tone for the rest of the segment, sadly, the unsuspecting audience was given an erroneous message. Even if there was adequate UVB, 15 minutes on the face wouldn’t produce much and it would only produce some in those with fair complexions.
For the record: in Canada, appreciable vitamin D production via UVB radiation, is only possible from about the end of March/mid April to the end of September [the amount of vitamin D that can be produced depends on complexion, time of day, and amount of body exposed to said UVBs!]
Omega-3 fats, They’re All The Same
Omega-3 fats come in two forms, alpha-linolenic acid (ALA) from plants and, primarily EPA & DHA from animals (fish & seafood, yes there is some DHA in seaweeds but we’re typically talking about fish). People will, more often than not, interchange them in discussions about health. Often you’ll hear people refer to omega-3 (EPA/DHA) research and then talk about it in the context of a flax or chia seed discussion – yikes! They say something like ‘flax has omega-3 fats and omega-3 fats are needed for brain development and are therefore essential for prenatal health or infant brain development’. Despite being in the same family (omega-3) ALA and EPA/DHA are not identical, are structurally different and have different physiological effects. DHA, for example, is a structural fat of the brain and is the key omega-3 fat for brain development, not ALA. Fish, not flax, is brain food.
For the record: ALA and EPA/DHA are omega-3 fats but are very different and cannot be interchanged. The ‘buzz’ around omega-3 fats can almost entirely be attributed to EPA/DHA, the omega-3 fats that people are not getting enough of, whereas the average North American diet provides enough ALA. Be sure to ask yourself, ‘are they referring to ALA or EPA/DHA?’, whenever you hear someone talking, or if you are reading about, omega-3 fats.
Saute or Stir Fry with Olive oil and You’ll Freakin’ Die
I can’t tell you how many times I’ve heard people sound the alarm, ‘you shouldn’t use olive oil to stir fry/saute with because the heat will break it down to toxic products’. The smoke point of any fat or oil is the temperature at which it starts to break down [the technical stuff where the fatty acids separate from the glycerol]. Different fats have different smoke points. For example extra virgin oil’s is 191 C or 375 F, butter’s is 135 C or 275 F, and grape seed oil’s is 216 C or 420 F. At first glance, grape seed oil seems like a better oil because it has a higher smoke point but the fact is, it has more double bonds that are more susceptible to damage from heat than something with fewer double bonds like olive oil. So while the oil is still intact, it can be damaged as well.
Enough to drive you crazy right?
The reality is, all fats, once extracted from any source, are susceptible to, and, get damaged. They are easily damage from light, oxygen, and heat. Fats inside whole foods like nuts, seeds and tissue like meats, fish or eggs, are better protected but even during cooking, some damage occurs – That’s life. You have to eat and the health benefits from eating nutritious whole foods that contain fat far outweigh any theoretical risk from ‘oxidation’ etc. The real concern would be the amount of highly heated oils, and more importantly, deep-fried foods, one is eating than the over simplified statement of ‘cook with olive oil and perish’. No one has ever demonstrated that fats used in cooking [save lots of deep-fried foods] are a health problem but I would welcome any research that suggests otherwise.
For the record: High temperature cooking will destroy any fat to some degree and make it less healthful [the resultant products are polycyclic aromatic hydrocarbons - nasty!] but to suggest it’s detrimental or health or will increase chronic disease is hyperbole. For medium-low and medium heat sauteing/frying, pretty much any oil is fine from that perspective. Because most are consuming too many omega-6 fats, I recommend coconut oil, ghee, olive or avocado oil for sauteing; the amount of oil used with this method of food prep tends to be minimal compared to the amount you’d get from anything deep-fried [now that's a different story!]