Tuesday 15 June 2021

Meat-free marvels: does a vegetarian diet reduce your risk of disease?

Is it me, or are there times when contemporary diet trends appear to verge on pseudoscientific crankery? While I briefly mentioned potentially dangerous items such as raw water and unpasteurised milk a few years' ago, it's surprising how many fad diets in developed nations bear a suspicious resemblance to the traditional ingredients of non-Western societies. 

Super foods are a particularly overhyped element of this faddish arena; the marketing suggests they can help achieve perfect 'balance' and 'wellness' in the body. Some assertions go much further, with consumption of the likes of kombucha claimed as something of a miracle cure. While the pseudocereal quinoa is sold in the West as the 'grain of the gods', it is unlikely to give the partaker any super powers. It certainly didn't save the Inca and Anasazi - who cultivated it in pre-Columbian America - from the rapid collapse of their civilisations and apparently suffered from disease and famine as much any other society.

There is a scientific basis for recommending certain non-meat items, from the antioxidants in tea and coffee to the vitamin D in mushrooms, while various plants and vegetable oils contain Omega-3 fatty acids. But a recent report has concluded that a vegetarian diet may have a marked positive effect on overall health compared to one with regular meat consumption. The research was conducted by the University of Glasgow, with the data showing substantial reductions in disease biomarkers for non-meat eaters. However, it was unable to provide an underlying reason for the positive results, once risk factors such as age, alcohol and nicotine intake had been accounted for. Cholesterol and products linked to increased risk of cancers, cardiovascular disease, and liver and kidney problems were all lower in vegetarians.

Apart from suggesting that vegetarians eat more fibre, fruit, vegetables and nuts - some of which have known health benefits - the report's conclusion also noted that rather than the positive effect of these items, avoiding processed meat products and red meat may have also contributed to the results. As someone who hasn't eaten meat in over thirty years, I find the research extremely interesting, although I think there are many other factors that should be considered, with the report forming just part of the debate. 

For example, the data was drawn from c.420,000 people living in just the UK, rather than from a variety of nations and environments. In the past century, the diet and lifestyle of most people in the West has changed enormously, with the emphasis on quick-to-prepare meat dishes including the likes of burgers and sausages, remaining at the forefront despite the replacement of physically demanding lives with predominantly sedentary ones. In other words, the diet hasn't changed to match the alteration in lifestyle. It's little wonder that obesity has outranked malnourishment in some nations.

In addition, it is thought that several billion people, predominantly in less developed regions, consume insect protein on a regular if not daily basis. This is a profoundly different diet to those of Western meat eaters with the latter's concentration on domesticated species such as cattle and horse, sheep/goat, poultry, etc. Although game, bush meat and exotic species such as crocodile are eaten in many regions, these are a much smaller element of the human diet. 

In contrast, vegetarians in many regions can eat an enormous variety of plants and fungi. The geographic and seasonal availability of many fruit and vegetables is expanding too: until a few years ago I hadn't heard of jackfruit, but it is now available as the tinned unripe variety from many stores here in New Zealand. So in both time and in space, there's no such thing as a typical vegetarian diet! This also doesn't include the differences between lacto-vegetarians and vegans; it would definitely be rather more time-consuming to plan a diet with an adequate mix of proteins in the absence of eggs and dairy products. It would therefore be interesting to conduct research to find out the health differences between these two groups.

Although some of the blame for poor health and obesity has been placed on processed and refined foods, there is an ever-increasing array of prepared vegetarian products, often marketed as meat substitutes for meatatarians wanting to cut down on their consumption of animal flesh. My daughters (regular meat eaters) and I have a penchant for fake bacon made of wheat, pea and soy and I also eat a variety of meat-free sausages and burgers as well as Quorn products. 

Many companies are now getting on the bandwagon, with products that aim to replicate the taste and texture of the real thing. Some brands such as Beyond Meat and Impossible Foods have seen a rapid rise to international success, while the UK bakery chain Greggs has benefitted from its tasty (if high-fat) Quorn-based vegan sausage roll becoming one of their top five selling products. Therefore the range of processed foods suitable for vegetarians has grown out of all proportion to those available several decades ago. Could it be that these may have detrimental health effects compared to the less refined ingredients traditionally eaten by Western vegetarians (and still eaten in developing nations)?

Just as there are shed loads of books claiming that epigenetics will allow you to self-improve your DNA through your lifestyle, diet gurus play upon similar fears (and gullibility) to encourage people to eat all sorts of weird stuff that at best maintains equilibrium and at worst can lead to serious health issues. I personally think that a wider amount of research, undertaken in all sorts of regions and societies, needs to be done before a vegetarian diet can be claimed to be distinctly superior to a meat-based one. Of course, a reduction in ruminant farming is good for the planet in general - both for saving water and reducing methane - but as far as a diet equates to health I still think that moderation and a sensible attitude can be key factors in this regard. Nevertheless the Glasgow study certainly is...wait for it...food for thought!