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The large majority of the available evidence is in favor of a protective association between fruit and vegetable consumption and the risk of stroke. The worst foods appear to be meat and soda. Eating, like, a burger for lunch and a pork chop for dinner, two breakfast sausage links, and a typical 20-ounce bottle of soda may increase stroke risk by 60%. Reviewers suggest the meat effect may be the saturated fat or cholesterol, the iron-mediated oxidized fat or the salt, but it could also be the TMAO. The carnitine in meat and the choline in dairy, seafood, and especially eggs is converted by our gut bacteria into trimethylamine, which is oxidized by our liver to TMAO, which may then contribute to heart attacks, stroke, and death.
And indeed, in a 2019 study published in the Journal of the American Medical Association following tens of thousands of Americans for a median of about 17 years, up to a maximum of 31 years, found that “higher consumption of dietary cholesterol or eggs was significantly associated with higher risk of incident cardiovascular disease and all-cause mortality, in a dose-response manner.” Meaning those who ate more eggs or consumed more cholesterol in general appeared to live significantly shorter lives, on average, and the more the eggs, the worse it was––and this includes egg consumption and stroke. But that’s not what a meta-analysis funded by the egg industry found.
It turns out such meta-analyses have evidently been flawed by major methodological drawbacks; so, to eat or not to eat? It would seem moderation of egg consumption is called for, along with other sources of dietary cholesterol, given the new study data, which had the advantage of a “longer follow-up than the majority of the previous studies and may [therefore] have provided more power to detect associations.”
Similarly, with meta-analyses of dairy, no apparent link emerged, but evidence of publication bias was found––meaning there appeared to be missing studies, potentially shelved by industry-funded researchers for not showing funder-friendly effects. Researchers studying the relationship between funding sources and conclusions in studies of sugary drinks and milk found that studies funded by the likes of Coca-Cola or the Dairy Council had over seven times the likelihood of coming to funder-friendly conclusions than independent research––which is twice as bad as drug companies. Big Pharma only seems to be able to get away with a three-fold bias. Of particular interest, not a single one of the interventional studies looking at soda or milk ended up with an unfavorable conclusion.
The bottom line is that yes, dairy fat may be better than other animal fats, such as those found in meat, but something like whole grains would be better still––though swapping dairy out for refined grains or added sugar wouldn’t be doing you many favors. When it comes to stroke risk, vegetable fat is better than dairy fat, meat fat is the worst, whole grains are better, and fish fat, added sugars, or refined grains are statistically about the same.
In terms of dietary patterns and stroke, most of the studies on plant-based dietary patterns have found a protective effect against stroke, whereas those looking at Westernized patterns, those based more on animal foods and added sugars and fats, found a detrimental effect of the adherence to Westernized patterns. African-Americans are five times as likely to die from a stroke in middle age, a black/white disparity largely driven by the fact that they’re just having so many more strokes. In this population, a Southern-style diet, characterized by a lot of fried foods and meat, may be playing a role in increasing the risk of stroke, whereas adherence to more plant-based diets may reduce stroke risk.
Yes, wrote the director of the Stroke Prevention & Atherosclerosis Research Centre, “learning to make vegetarian meals every other day is a tall order for most North Americans, but is feasible given tasty recipes and a positive attitude.”
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