Updated 16 July 2023
Says the article by Wang et al. (2023):
"Multiple nutritional effectors of a healthy vegetarian diet modulate important metabolic, hormonal, and immune factors associated with the development of cardio- and cerebrovascular diseases".
Below are their recommendations, all in one picture: Health-promoting effects (i.e., potential of effects) of healthy vegetarian (i.e., including vegan) diets (with an "s") ...
Below are their recommendations, all in one picture: Health-promoting effects (i.e., potential of effects) of healthy vegetarian (i.e., including vegan) diets (with an "s") ...
Abbreviations in the picture:
- BCAA: branched-chain amino acid ... This means, the amino acids leucine, isoleucine, and valine. Some body builders take these as a supplement.
- FA: fatty acid
- GI: glycaemic index; it basically means, foods that kick up your blood sugar level
- HbA1c: haemoglobin A1c, the standard long-term blood glucose marker
- LDL-c: low-density lipoprotein cholesterol; aka the "bad cholesterol", but really ALL cholesterol is bad (and yes, we need it too) ... but high blood levels are bad
- SCFA: short-chain fatty acids: basically, eat a lot of fibre and the bacteria in your large intestine will produce a sour environment - which is thought to be a good thing
- VLDL-c: very-low-density lipoprotein: the other bad cholesterol
- T2: type 2, the most common type of diabetes
- TMAO: trimethylamine N-oxide .. the new and controversial kid on the block ... A higher intake of carnitine and/or choline will likely increase TMAO blood levels which *may* increase cardiovascular disease risk.
The plant-based foods the authors consider "bad" by Wang et al. are: refined grains, high-fructose corn syrup, saturated fatty acids (not the really short ones) and trans fatty acids, salt, and artificial sweeteners.
---
P.S.: As far as I can see there are several mistakes in the article by Wang et al. (2023):
1) Haemorrhagic (hemorrhagic) stroke
The articles states: "Accumulating evidence indicate[s] that some vegetarians, especially vegans who are consuming restrictive diets, are at greater risk of developing haemorrhagic stroke [...]". They don't cite a reference here that refers to the haemorrhagic stroke risk.
Further on in the article, they again write: "There is evidence to suggest that some vegetarians, particularly those who follow restrictive diets such as vegans, may be at greater risk of haemorrhagic stroke stroke and bone fractures if they do not
carefully plan their diets and consume fortified plant-based foods or
supplements." Again they don't cite a reference. Indeed, Tong et al. (2019) reported that in EPIC-Oxford "vegetarians had higher rates of haemorrhagic and total stroke", i.e., vegetarians as in lacto-ovo-vegetarians and vegans combined. However, supplementary table 3 by Tong et al. (2019) shows that vegans indeed had an almost statistically significant, but just looking at the numbers quite clearly increased risk of "total stroke" [hazard ratio (95% CI): 1.35 (0.95 to 1.92)] and especially "ischaemic stroke" [1.54 (0.95 to 2.48)] but not very clearly higher for haemorrhagic stroke [1.09 (0.53 to 2.26)], especially as lacto-ovo-vegetarians had a higher haemorrhagic stroke risk [1.48 (1.11 to 1.97)] - all these are compared to the omnivore group.
Therefore, the statement that "some vegetarians, especially vegans" have an increased risk of haemorrhagic stroke seems incorrect. Rather, vegans should be made aware that B12 supplementation and optimizing their intake of other key nutrients is important. Wang et al. (2023) even suggest that "[...] complete elimination of animal food is not required for lowering blood pressure and might even increase haemorrhagic stroke risk, possibly due to very low intake of saturated fat." It should be clearly stated that this is highly speculative, and it contradicts current advice (including that by Wang et al. - see their Figure 1) to drastically lower saturated fat intake.
Vegans should be aware that B12 deficiency will likely damage arteries and increase stroke risk. Also see this earlier post regarding the stroke issue. The more recent meta-analysis by Dybvik et al. (2023) should also be taken into account.
2) "100% plant-based"
Unimportantly but incorrectly Wang et al. state that vegan diets are "100% plant-based" which they are not. B12 is not plant-based, neither are mushrooms, salt, calcium carbonate, vitamin D (D2 or D3), yeast, ...
3) "American and Canadian Dietetic Associations"
The Academy of Nutrition and Dietetics and the Dietitians of Canada may not feel flattered.
4) Seventh-day adventists in the US
This is not really an actual mistake. ... Wang et al. write that "[...] subsequent [recent] studies suggest that the protective
effect against CHD of vegetarian diets seems to be almost exclusively
limited to the Seventh-day Adventists, who don’t smoke, don’t drink alcohol, do regular physical activity, and are very religious and socially
connected. Indeed, data from epidemiological studies of English and
German vegetarians show only a modest protective effect against cardiovascular and overall mortality. A German prospective study [an old study from the 1990s] of
1225 vegetarians and 679 health-conscious non-vegetarians has shown
that there is no difference in mortality among vegetarians and this control group of health-conscious individuals consuming meat three to four
times per month. Cigarette smoking, obesity, alcohol intake, and exercise patterns seem to explain most of the differences in cardiovascular mortality among these different groups. Another potential problem
is diet quality, which can vary greatly among both vegetarian and
non-vegetarians." However, the most obvious explanation seems to be that the vegetarians and especially the vegans in Europe were deficient in B12 and other micronutrients (such as iodine, vitamin D, and selenium). Whereas their US-American counterparts (in the Seventh-day adventist studies) live much closer to the equator (more sunshine), live in a place with more selenkium-rich soils, and - importantly - likely took more supplements, and likely had a higher intake of B12-fortified foods, and higher doses of B12 in both supplements and fortified foods.
5) Breast cancer
This seems to be a mistake ... Wang et al. write: "The risk of developing breast cancer is no different between vegetarian and non-vegetarian women in most studies, and some epidemiological data in Adventist and British women suggest vegans, but not lacto-ovo vegetarians, may have an increased risk." They cite (Wang et al.'s reference 98) Penniecook-Sawyers et al. (2016) who reported that, in the Adventist Health Study-2 in the US, "vegans showed consistently lower (but non-significant) point estimates [regarding breast cancer] when compared with non-vegetarians (all cases: HR 0·78; CI 0·58, 1·05; P=0·09)". So, the article by Wang et al. should say "decreased" rather than "increased".6) B12 production in "animals"
Wang et al. write: "Vitamin B12, for example, is an essential vitamin produced by specific strains of soil bacteria that animals ingest when grazing grass. During digestion, large amounts of vitamin B12 are formed and incorporated in the animal’s meat, milk, and eggs." Yes, maybe, but chickens who lay eggs don't graze. In the rumen of ruminants, B12 is produced by B12-producing microorganisms. All other animals (non-ruminants, including humans), I would assume, consume vitamin B12. Chickens and pigs and non-grazing ruminants are usually fed B12 in the form of B12-fortified feed and animal-source, the latter especially in the case of non-ruminants. And sometimes ruminants too - remember BSE? 🧠
7) B12 in duckweed
Wang et al. write: "[...] vitamin B12 in duckweed is bioavailable." Maybe, but this could be misunderstood as saying that duckweed can be a great source of B12 for vegans, which seems highly uncertain.See VeganHealth's post on this topic here.
See this earlier post about duckweed as a vegan B12 source here.
8) The risk in "ethical vegans"
Wang et al. write: "Dietary calcium deficiency especially when coupled with protein restriction and excessive sodium intake can increase the risk of bone fractures in ethical vegans who do not consume healthy diets rich in calcium- and protein-rich plant food." I don't see why this risk (and the influence of sodium may be overstated [?]) should only affect ethical vegans and not all vegans. The stereotype, of course, that some (especially in the US [?]) self-perceived plant-based experts may have is that health-motivated vegans have a healthy diet while vegans who are vegan because of animal suffering/animal rights are "junk food vegans". But this seems inaccurate. Going into details would fill a whole book chapter.
9) Figs
Wang et al. write: "Legumes, soy products (especially tofu made with calcium sulphate), and figs are also excellent sources of dietary calcium and protein." This seems to be a mistake. Most obviously, figs are not good sources of protein. Figs can be described as a relevant source of calcium but maybe not excellent sources. And legumes in general do not really seem to be great sources of calcium either. So, the two topics of calcium and protein seem to have been suboptimally combined in this sentence.
Reference:
- Tian Wang, Andrius Masedunskas, Walter C Willett, Luigi Fontana: Vegetarian and vegan diets: benefits and drawbacks. Eur Heart J, 2023 Jul 14;ehad436. doi: 10.1093/eurheartj/ehad436. Online ahead of print