What the Pro Vegan Film 'What The Health' gets Wrong
This film has scared a lot of people about animal products. The film maker does a great job in almost making a horror film, by showing venerable pregnant women and needles, dim lighting when interviewing doctors and showing animals in bad lighting with flies all around them.
It made 37 health claims and used professional people making it believable and trustworthy. They said processed meat causes cancer, eating an egg is like smoking 5 cigarettes and dairy makes you ill and isn’t good for bones. But they have exaggerated weak data which cannot prove causality to promote a vegan diet. These studies involve using food frequency questionnaires asking people what they had eaten in the last 6 months which can be over or under reported.
The documentary said eggs are full of cholesterol which is outdated data. In most cases cholesterol doesn’t influence blood cholesterol levels as much as the type and amount of fat eaten. Studies looking at dietary causes of heart disease have found no link with regular egg consumption.
Small studies
Some studies include 1 or 2 people so cannot be generalized to the whole population. In studies a risk ratio less than 2 means a small association and 96% of studies they used had this. Eg the film said woman who have had breast cancer had one serving of whole dairy a day which increased their chance of dying from diseases by 49%. This was an observational study as well.
They used 19 epidemiological studies which are based on observations eg a study linking dairy at a young age and type 1 diabetes. This observational study showed that kids who had cows milk instead of being breast fed were more likely to get diabetes. But this is seriously confounded. Eg There is a link between not breast feeding with families of lower socio ecomonic status and health difficulties.
Some studies had really small sample sizes like one that said heart disease was stopped and reverse when following a plant based diet. This study had 41 people and they told them to exercise, meditate and supplement so multifactorial. They have tried to replicate study since but no one has achieved same result.
You even have clinical trials which don’t even support what the filming is claiming. There isn’t one single Randomized control trial.
They used one metaanylse which is good to support that when you go on a plant based diet you can reduce cholesterol within a few days. Results showed this but it also reduced good cholesterol which gives you a higher risk of CVD
They also used a lot of biased blog posts and websites from vegan diet doctors which aren’t peer reviewed so you have a lot of commercial and intellectural conflicts of interests. Plus they down play a lot of research linking sugar and diabetes probably because the sugar industry funded this research. There are plenty of studies that link sugar and diabetes.
All in all once you dig deeper you realize it is not even worth listening to when yo hear about the quality and bias. My advice is to try to eat a lot of fruit and veg, fish and limit processed meat and red meat to once a week