by Danièle Todorov and Delphine Van Roosebeke
Ever wish the question of what to eat could be, well, simple? In an interview with cardiologist Dr. Jacques Genest, we discuss themes in “common sense nutrition:” the research behind it, the barriers to adherence, and its evolving definition.
New trends in popular nutrition seem to pop up every day. This fervor for novelty has distracted us from what Dr. Jacques Genest simply calls “common sense nutrition.” Dr. Genest is a clinician in cardiovascular disease at The Research Institute of the McGill University Health Centre and a former researcher at the HNRCA. We had the pleasure of speaking with him last November during the 5th International Symposium on Chylomicrons in Disease. (For brevity and clarity, the questions from our original interview have been paraphrased.)
Q: Supplements are immensely popular and it looks like they are here to stay. Is this frustrating to you as a practitioner?
I’m old enough to have given up. What I tell my patients is that I have no trouble with vitamin supplements, but nutrition will be far more imperative. I tell my patients to purchase [fish oils] in the original container. In other words: Eat fish. And to have a good diet as recommended by a food guide—fruits, vegetables, and no added salt. They are simple recommendations people love to forget.
Q: Such as?
Take a 46 year-old, blue-collar working male. He comes home and he will tell you that a nice piece of meat with a potato, brown gravy, and salt is like the elixir of the gods. If you put in front of him a regular salad with endives, he will not like that. So how do you change a mindset in which the palatability of food gives so much pleasure?
Q: As we have seen in the course Macronutrients [NUTR 370], there is a link between the carbohydrate intake and lipogenesis [the metabolic formation of fat]; however, there are still many people who put emphasis on minimizing dietary fat. Do you agree?
From a public health perspective, I think maybe it’s not as relevant as caloric intake. I have some patients that come back from France and they apologize because they’ve been eating some Camembert and some foie gras. I say, look, your lipids have never looked better. I think its portion size far more than anything else. Compare a steak that you would get in Europe—you’d get about a 3 oz. steak. Here, you’d get basically a quarter of a brontosaurus. Now, I’m a huge believer in no saturated fat. I tell my patients, if you want to eat meat, eat meat that flies and that swims.
About thirty years ago, we went from a fat-diet to recommending a switch to carbohydrates. My personal impression is that this has been a huge mistake. The insulinemia you get with a high-carb diet is probably deleterious. Whereas a protein-rich, fat-rich diet is much more slowly absorbed, doesn’t produce hyperinsulinemia, and probably gives a better sense of satiety. I think we’ll look back and say that this might have been one of the biggest nutrition errors in the late 20th century.
We had forgotten about the covariates that come with a low-fat diet. Move to Japan where there is a relatively low-fat diet but you also have an incredibly good lifestyle. If you turn to more northern populations where you need the fat for some reason, you don’t necessarily correlate fat intake with cardiovascular disease. You don’t correlate caloric intake with cardiovascular disease.
Q: When you see patients, would you first talk about diet rather than prescribing medication?
My primary prevention patient—the 46-year-old man—I will often give up to two years to fix his bad habits. [If there is no lifestyle change in that time], then he is middle-aged, has high blood pressure, high cholesterol, and high blood glucose. He’ll need two pills for blood pressure, two pills for diabetes, a pill for cholesterol… Five pills when he’s 46; imagine how many pills he’s going to have when he’s really sick. And my success rate is probably less than 10%. The biggest threat [to long term health] is the insulin needle. It’s not having a heart attack, it’s going on the needle.
Q: What is the biggest gap in our knowledge that’s impairing how patients are treated?
You’re again a 46-year-old man. You have a bit of hypertension and your cholesterol is high. I put you on a statin and a blood pressure lower. At your next visit, your blood pressure is extremely normal and your cholesterol is extremely low. Why should you stay on an exercise program and a diet? The perverse effect of our outstanding medication may be that we’re not making the lifestyle effort to treat ourselves naturally.
Authors’ note: We can’t quite explain how we got onto this tangent about low-density lipoprotein (LDL), but it has been fascinating to think about and it would be a shame to exclude it.
What was your diet [50,000 years ago]? Tuberous vegetables, berries, and very little meat. Then something happens to you—you started domesticating animals. You got something you never had in your diet before, two things you rarely found in nature—cholesterol and saturated fats. It takes about a million years to change your genes through evolution. In 50,000 years, we haven’t had time to adapt to a huge influx of saturated fat and cholesterol.
How many animals do you think have LDL? Zero. Maybe the hamster if you feed it an extreme Western-style diet. But animals do not make LDL. In times of starvation, we developed the VLDL [very low-density lipoprotein] system. In my view, VLDL is unidirectional. [After removal of triglycerides by lipases], the particle should be completely taken up by the liver with no cholesterol on it. Where does the cholesterol go? It should go to HDL [high-density lipoprotein], which is the main source of cholesterol for most cells, rather than making or incorporating it. It might not be such a bad thing to say that we’re not meant to have LDL and that any technique to prevent it will be good, especially lifestyle nutrition.
Surprisingly, there is a lot standing in the way of ‘common sense nutrition’. Adding a supplement or a medication is relatively easy compared to changing deep-rooted eating behaviors like food preferences and portion size. Recommendations around fat intake have changed dramatically and are still being hotly debated. The inclusion of animal products in these recommendations is even questionable from an evolutionary point of view. Dietitians and clinicians certainly have their work cut out for them.
A big thank you to Dr. Genest for taking the time to speak with us! It was a fascinating conversation and hopefully an equally enjoyable read.
Danièle Todorov is a first-year student in Nutritional Epidemiology with a focus on maternal nutrition and a minor obsession with lipid metabolism, a holdover from her biochemistry days.
Delphine Van Roosebeke is a master’s graduate in the Biochemical and Molecular Nutrition program with a background in biochemical engineering. Delphine has a crush on nutrients and the magic they perform in our body, and loves to share her knowledge with anyone who wants to hear it in a fun and approachable way!