First exercise, now cardiologists are against fruits and vegetables?Published 3.2.2017 Updated 3.3.2017
What the hell is up with cardiologists lately? Aseem Malhotra (British cardiologist) goes around arguing against exercise and now a cardiologist is saying vegetables are bad for your heart? WTF? An attempt to ensure perpetual employment for cardiologists? Truly, we are living in a Trumpian age.
Salim Yusuf is a Canadian Cardiologist who recently gave a presentation that was briefly available on Youtube. Malcom Kendrick noted the presentation in Part 26 of his apparently never going to end series on what causes cardiovascular disease (CVD). I intend to comment on Kendrick's series, but thought I'd wait to see what his final conclusion is. I'm beginning to think there will be no conclusion.
In any event, the video was only available to people with the link, it had not been indexed so that it would show up in a search. The video became something of a cause célèbre in low carb circles online, and thus got far greater distribution than the creators intended. That, plus the fact that the video presented unpublished and preliminary results is likely the reason that it was either pulled from Youtube, or its settings were set to private. Or it may have been pulled due to criticisms from another cardiologist, Joel Kahn.
Dr Kahn was part of the vegan diabetes summit I watched recently, and from which I am still writing up the rest of my notes. Kahn's primary criticisms of the talk were Yusuf's offhand slandering of Ancel Keys at the end of the talk, his misrepresentation of Keys seven country study, as well as his touting lobbyist Nina Teicholz's work. My thoughts about Teicholz and her lobbying have been noted previously. David Katz also critiqued Yusuf's presentation (as always, the standard provisos about Katz apply).
I saw the video before it was removed, and I also took screenshots of the results presented. However, because the data is unpublished, I don't think that it would be right to publish those shots. I will however, refer to the results presented in them in the rest of this discussion. The MedPage link (above) provides a decent a recitation of what was presented in the talk, though it omitted mention of the Keys slander.
Yusuf slammed the use of surrogate endpoints— which is another way to say biomarkers. Biomakers are the easiest way to measure effects, however. It's not like low carb high fat (LCHF) proponents don't point to biomarker improvement to demonstrate the effectiveness of their diet. Health results from myriad factors, many of which can’t be controlled. However, if you insist that the hard end points (heart disease and death) matter, to this observer, the vegans still have the advantage.
Then after saying surrogate end points shouldn’t be the target, Yusuf suggested a new surrogate end point to consider, the ratio of ApoB/ApoA, which he said was better. Make up your mind, doctor. His points about the cost of fruits and vegetables can be pushed back on as well. Legumes are vegetables, and legumes are inexpensive.
It’s a straw man to say what kind of vegetables should be eaten. Any and all vegetables should be eaten, local indigenous plants will likely be cheaper for populations to eat. Beans, legumes, pulses (whatever you call them) are inexpensive and can be the answer— particularly since legumes, along with fruit (a point missed by most low carbers crowing about the presentation) were unambiguously positive with respect to heart health in his results. Eat your beans!
When comparing the effects of macronutrient ratios, a diet of 55% carbs was still fine. That. Is. Not. Low. Carb. If protein is assumed to be 15% of the diet, then the fat level is 30% not 60-85% (which is the level to be considered LCHF). Yusuf's complaint is that the World Health Organization (WHO) says that up to 75% carbs in a diet is safe. Excuse me doctor… the very low fat Asian diets on which some of the longest lived people thrive can be that high in carbs. Does your data included that evidence? He does admit that too much fat is bad for you and points to a Finnish study where fat intake was extreme (LCHF?).
If you eat animal products… it’s tough to get below 30% fat intake. No need to shove sticks of butter and wads of coconut oil down your gob every day. Yusuf claims dairy is protective, which is fine, however, there is no reason to consume dairy unless you enjoy it. There is nothing in dairy that can’t be had from alternate natural foods. And yes, I acknowledge my lactose intolerance colors my view of dairy.
Sodium intake recommendations were another segment of the talk. His analysis indicates that up to 5 g of sodium (note: that is not actually salt) is fine unless you have hypertension (high blood pressure) But even then, salt levels don’t have to be super low. Salt intake recommendations are a topic of current controversy in cardiology and nutrition, but my assumption is that it's because most people eat tons of processed foods, and processed foods have tons of sodium. I wrote about this not too long ago, I'm not going to repeat myself here. Avoid processed foods, and most people can forget about sodium intake is my view.
Because this was an oral presentation of unpublished results, it's not possible to say with certainty where this data was drawn from. As is always the case in meta-analyses that mine older studies for new results with statistics, how the results were compiled in the first place and how the studies chosen differed in methodology is important in determining whether the meta-analysis has any validity at all. I know that meta-analysis are supposedly at the top of the research hierarchy in terms of the weight that is supposed to be given to them, but frankly, I don't know that I agree. Especially if the "data" of a study relies on the recall of its subjects, as so many nutritional studies do.
If I've learned nothing since beginning to read nutrition/diet/health research/articles/blogs, it's that people lie about what and how much they eat. Not all the lying is conscious, it's incredibly difficult to remember what was eaten in the past, unless you eat very little variety. However, misremembered food diary data are no more useful than fraudulent ones. In addition, humans are awful at gauging how much they ate.
Now it's one thing when a low carb or vegan blogger lies about what he eats to protect his/her brand or livelihood, it's another when subjects in a nutrition study lie (or misremember, to use the politer terminology) what they ate. An enormous amount of nutritional research and results are based on self-reported intake. Garbage in garbage out (GIGO), to use the engineering terminology. It doesn't matter how fancy your statistical massage of your data is if that data was garbage in the first place.
Bottom line: If a cardiologist tells your to avoid eating fruits, vegetables or legumes, run, don't walk, out of his office.
Added 3.3.2017: Here is yet another set of reactions to Yusuf's presentation, which includes a new link to the presentation, though I don't know if the link will remain live.
Disclaimer Please remember that I am not any sort of medical professional. Nothing written on this site should be consider or construed to be medical or nutritional advice.
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