Dr Rosemary Stanton OAM
Many dietitians feel affronted when people with little expertise in human nutrition promote theories that are not backed by evidence. That’s totally understandable but knowing when and how to oppose requires finesse. I believe this is the case with Paleo diets.
It’s not an easy area because there is no single Paleo diet and often no obvious reason for what various paleo enthusiasts include or exclude. The exclusions, however, usually include all grains, legumes, dairy products and sugar.
Paleo diets usually favour meat, usually processed as well as fresh. Some recommend lean meat; others endorse meat fat. Bacon seems particularly popular. Even though most Paleo diets shun dairy products, many make an exception for butter. There are sea salt lovers and those who eschew its use. Others use soy sauce freely, ignoring both its salt content and the fact that it is made from (forbidden) legumes. Coffee, tea and alcoholic drinks may be in or out. These differences mean that what we may criticise about one version may not apply to another. So what should we do?
I’d start by noting the points where Paleo diets agree with, and add to the Dietary Guidelines. These include promotion of vegetables and nuts and the condemnation of junk foods and drinks. I’m also happy to recommend ‘bone broth’ as an excellent base for soups and sauces and a great substitute for salty soups, although I can’t resist pointing out that many of us have been making this for years, but have always called it ‘stock’.
The topic of bone broth also provides a useful way to note the hazardous nature of some Paleo recommendations. Stock (alias ‘bone broth’) is great for adding flavour to soups and sauces, but it has no magic properties and is certainly not a suitable substitute for breast milk or infant formula. The dangerous claims made by the authors (Pete Evans, Helen Padarin and Charlotte Carr) of the Paleo book Bubba Yum Yum mobilised action. Fortunately, some of us had known of the claims being made because we were asked about them by journalists whose long-lead time meant their magazines had been given pre-publication material. But the real momentum occurred when DAA, the Public Health Association and others, backed by an analysis of the formula from FSANZ and the federal Department of Health, contacted the publisher. This not only led to some worthwhile media discussions but some other ‘celebrity’ cooks publically distanced themselves from extreme diet ideas.
Despite the variety of Paleo diets available, they all condemn all grains, legumes, milk, yoghurt and cheese (or appropriate alternatives made from legumes). To refute these claims, we need evidence at our fingertips. Fortunately, the Dietary Guidelines are a valuable starting point with very stringent NHMRC levels of evidence showing specific benefits for these core foods. All evidence statements in the Dietary Guideline are based on at least five high quality studies, appropriately graded according to the strength of the evidence. And this is freely available online at www.eatforhealth.gov.au.
Of course, the evidence doesn’t stop with the 2013 Guidelines, so it’s also important to keep collecting the results of appropriate studies.
It’s also important to check what some Paleo enthusiasts use as ‘evidence’. I did this recently when a Nut-Net discussion participant listed 22 studies that supposedly were ‘evidence’ favouring Paleo diets. I found the same 22 references (including spelling mistakes) on an Italian blog site. Here’s a run-down on what I found:
·     11 were small and/or short term (several with less than 10 people, some for 10 -14 days);
·     3 were duplicate reports from the same studies;
·     1 was on pigs;
·     1 was a review (which found the evidence too poor to draw any conclusion);
·     1 described a protocol for a forthcoming study;
·     1 was an abstract for a conference paper;
·     1 was a case control study supposedly comparing results for colorectal adenomas from subjects or controls who had followed a Paleo or Mediterranean diet in 1991-94 (which precedes the Paleo craze);
·     1 looked at the feasibility of frozen and prepared Paleo meals (funded by a commercial company);
·     1 found significantly deleterious blood lipid levels in 44 subjects after 10 weeks on the diet;
·     1 two-year study found no benefits of paleo diet among 49 people who completed the study.
It’s also helpful to take an anthropological look at the topic. A number of noted anthropologists have spoken out on the errors in claims made by Paleo enthusiasts. Some references to these can be found at:
http://www.newscientist.com/article/mg21729090.400-should-we-aim-to-live-like-cavemen.html http://www.scientificamerican.com/article.cfm?id=why-paleo-diet-half-baked-how-hunter-gatherer-really-eat.
http://tedxtalks.ted.com/video/Debunking-the-Paleo-Diet-Christ.
http://ajcn.nutrition.org/content/71/3/665.full
http://ajcn.nutrition.org/content/72/6/1590.full
Commercial food interests are now coming to the Paleo party with paleo chips, paleo chocolate, paleo protein bars, paleo muesli, caveman cookies, paleo protein bars, paleo pancake batter and even a paleo pizza crust base (http://paleosnacks.com.au/shop/). I think it’s fair enough to point out the absurdity of this commercialisation.
Conclusion: With so many restrictions on what can be consumed, followers would be expected to lose weight. But is this a healthy way to do it bearing in mind that there is little evidence to support paleo diets and no long-term studies to judge health outcomes.