Gary Taubes on American Heart Association confirmation bias

In our recent post ‘Amazing results challenge guidelines in new study‘, we looked at research that came to exactly the opposite conclusion to that of The American Heart Association who currently recommend replacing saturated fat with MUFAs and omega-6 PUFAs. The researchers concluded:

recommendations of supplementation with these fatty acids in the general diet should be revised.

The public at large are confused by what they see as flip-flopping over dietary issues: butter is bad one week, but ‘back’ the next. Many people find it hard to believe that such an authoritative body as the American Heart Association could be wrong. How can a few small researcher groups and flag-waving bloggers (like us!) possibly be right? Surely august bodies like the AHA sort through the data and discard the poor quality studies? Surely they can be trusted to do due diligence on our behalf?

These are reasonable thoughts for people to have and they are not wrong to think like this, but such convictions rely on our public agencies not slipping into the kinds of confirmation bias that science is supposed to protect us from.

In a recent Op-Ed Gary Taubes (science journalist and author of the best selling book Good Calories Bad Calories) tackles this topic head on. Continue reading

Giant Puff Ball with Garlic and Rosemary


…served here with scrambled eggs and smoked salmon.

✓Gluten-free ✓Grain-free ✓Sugar free ✓Low-carb ✓Dairy-free option

Here’s one for the hunter-gatherers amongst you: If you are lucky enough to come across this excellent wild-mushroom, it’s easy to cook, mild flavoured, melt in the mouth and looks pretty on the plate…

First catch your puffball…

When you first stumble upon the fruiting body of the giant puffball fungus (Calvatia gigantea) it can be a little unsettling. These are one of the largest edible fungi in the UK and are found most often in rough grass or pasture.

We thought ours was some rubbish left in the countryside and went to pick it up – only realising what we were dealing with after dislodging it from its tiny umbilical earth-stalk. We found three others close by, but just took the one we had detached, which was the size of a small football.

Despite a little slug damage, the puffball was in good condition – firm, white – at its peak for eating. At their best the flesh is a consistent texture all the way through and squeaks a little as it is cut. Once they start to go over they lose their solidity, and become yellow or brown – not so good. Really old ones are like a dried up brown bag and puff spores like some gothic talc dispenser at the slightest touch, which is what they are really all about as a fungal reproductive organ.

Cooking Giant Puffball

Once home, the puffball needs only a quick wipe over to remove dirt. It can be stored in the fridge until you are ready to use it.

Collect the other ingredients: Fresh garlic and rosemary (ours came straight from the garden), olive oil, salt and pepper and your favourite oil for frying (I used goat’s ghee which burns less readily than with olive oil).

Crush the peeled garlic cloves with a little salt to make a paste. Add a little olive oil.

Cut the puffball into half inch (1cm) thick slices. Each slice may need cutting in half to fit in your pan, but they do shrink a little during cooking.

Spread the crushed garlic paste on both sides of the puffball slices. Add chopped fresh rosemary. Small sprig tips can be pushed into the flesh.

Heat a large pan with plenty of butter, ghee or other fat of your choice. Fry for a few minutes on medium heat.

Turn and fry on the other side for another minute or two. They should develop a nice colour. Don’t overdo it or you will burn the garlic.

That’s it! They are ready to serve.

I made scrambled egg to go with them, along with some smoked salmon. We had it for Sunday brunch for two. Delicious.

The remaining 3/4 of the puffball went in the fridge and was cooked in a similar way over the next few days with our evening meals: once as a side dish interleaved with sliced fried aubergine (egg plant), and today with roast duck and salad.

Tomorrow I’m going to try the last of my giant puff ball with fried halloumi. I think they will go together really nicely.

After that. Who knows how long I’ll have to wait to come across another Jiggly-puff ball. But I’ll be ready to catch it when I do…

 

 

Low fat (but not full fat) dairy associated with increased risk of Parkinson’s disease

Read time: 4.5 minutes (850 words)

Intro

MedPage Today [full article here] drew my attention to a recent Harvard study published in the journal Neurology [abstract herewhich took a closer look at previously identified associations between dairy products and Parkinsons Disease. Their analyses were based on data from two large prospective cohort studies, the Nurses’ Health Study (n = 80,736) and the Health Professionals Follow-up Study (n = 48,610), with a total of 26 and 24 years of follow-up, respectively. An previous study (see below) found an increased risk of Parkinson’s with higher levels of dairy protein consumption.

The latest study looked more carefully at the different types of dairy product. They found that among those who ate 3 or more portions of low fat dairy per day (skimmed milk, low fat cheese and yogurt etc) 4 in 1000 went on to develop Parkinson’s disease, whereas among those who ate no portions of low fat dairy only 3 in 1000 developed the disease.

Comparing the two groups that equates to a roughly 33% increased relative risk. Of course that is only a rather piffling 0.1% absolute risk increase – hardly anything to worry about in the grand scheme of things. What makes this study interesting, however, is that the association did not exist for full fat dairy products only low fat ones.

Uric acid and Parkinson’s disease

The study’s authors speculate that the increased risk seen in the low fat milk group may be due to the ability of milk protein (casein and lactalbumin) to reduce uric acid levels. Parkinson’s disease and uric acid? I wasn’t aware of this link, so started digging into the research…

A particularly helpful review in Practical Neurology [Uric Acid’s Relationship with Stroke and Parkinson’s Disease: A Review] filled me in on the background.

It turns out that there is a growing body of evidence demonstrating an association between low uric acid levels and incidence of Parkinson’s disease. Not only do Parkinson’s sufferers tend to have have low levels of uric acid, but those with higher levels have slower and less aggressive progression of the disease. Importantly, some studies have identified that low uric acid levels four years prior to the onset of Parkinson’s symptoms has a stronger association than levels at onset of symptoms, suggesting that uric acid is linked to the  pathogenesis of Parkinson’s.

Uric acid BTW is an intriguing endogenous antioxidant which although primarily synthesised by the body is also influenced by diet. Excess levels can lead to the formation of crystals which is the basis of the painful condition gout, but can also contribute to kidney stones and kidney damage. Foods containing purines, such as shellfish, offal, meat and beer, can raise uric acid levels, as can alcohol and fructose, so should be avoided if you suffer from gout or kidney stones. The idea that such foods may be protective against Parkinson’s is interesting (although clearly one would not want to go as far as to cause gout!) On the other hand, dairy, cherries and vitamin C are associated with lower risk of gout and are classed as hypouricemic foods as they reduce uric acid levels.

It is believed that uric acid may exert a neuro-protective effect through it’s antioxidant action:

It has been hypothesized that uric acid reduces oxidative stress on neurons. This may have a significant bearing on therapeutic management of disease, as many neurological disorders are believed to result from oxidative stress. As a potentially modifiable risk factor, the prospect for uric acid and its derivatives to play a role in disease modification or prevention has great potential. – Pello et al, 2009

Studies looking at dietary associations with Parkinson’s disease have identified that uric acid lowering foods (e.g. dairy) are always associated with an increased risk of Parkinson’s, except for one. Vitamin C is the only uric acid lowering nutrient associated with reduced Parkinson’s risk: possibly because it is a powerful anti-oxidant itself.

Results from an earlier analysis of the Health Professionals Follow-up Study found clear trends indicating reduced incidence of Parkinson’s disease with increasing consumption of fructose and alcohol (uric acid raising foods) and an increased risk with higher levels of dairy protein consumption (a uric acid lowering food) Adapted from Xiang Gao et al, 2008

Full fat dairy

In the new study the increased risk for Parkinson’s disease was only associated with low fat dairy, not full fat. Why wasn’t full fat dairy associated with an increased risk of Parkinson’s?

For now there is no clear answer, but according to MedPage Today the authors of the study say “The lack of association with full-fat dairy products could be due to a countervailing effect of saturated fats. I think more research is needed to better understand the mechanisms involved in this association,”

The benefits of dairy fats have come up time and again, yet I still know many people who avoid full fat milk, cream, cheese and butter. See our posts:

Bottom Line

The size of the increased absolute risk of Parkinson’s disease associated with consuming low fat dairy products (0.1%) is too small to make it a reason in and of itself to avoid low fat dairy – unless of course, you have a family history of the disease in which case every bit of risk reduction helps.

For all of us, however, this study adds to the evidence of the benefits of full fat over low-fat dairy.

References

  • Intake of dairy foods and risk of Parkinson diseaseKatherine C. Hughes et al, Neurology, June 2017 [Abstract]
  • Low-Fat Dairy Linked to Small Increased Risk for PDKate Kneisel, Contributing Writer, MedPage Today, June 2017 [Full article]
  • Uric Acid’s Relationship with Stroke and Parkinson’s Disease: A Review Scott Pello et al, Practical neurology, Jul/Aug 2009 [Full article]
  • Diet, Urate, and Parkinson’s Disease Risk in Men, Xiang Gao et al, American journal of epidemiology, 2008 [PMC full text]

In the News

  • Why you’re better off eating FULL fat dairy: Consuming three or more portions of the low fat variety of yoghurt, milk or cheese raises the risk of Parkinson’s disease, Daily Mail [Online Article]
  • Low-fat milk linked to Parkinson’s risk, The Times [Online Article]

May News Round-Up

In_the_News_May · Cancers and sugar
· Nuts reduce colon cancer
· Bone broth keeps skin young
· Cinnamon reduces belly fat
· Ketogenic diet controls diabetes
· Cheese is (un)surprisingly healthy
· More protein for elderly
· Tick born diseases on the rise

Some cancers are more dependant on sugar

Very low carb diets have shown some efficacy in cancer treatment as many cancers have a high dependence on glucose and low metabolic flexibility, making ketogenic diets a potential treatment adjunct. A new study has found that some cancers have higher reliance on glucose than others. (News Medical May 26th) . Lead author Dr. Jung-whan, said:

“As a culture, we are very addicted to sugar. Excessive sugar consumption is not only a problem that can lead to complications like diabetes, but also, based on our studies and others, the evidence is mounting that some cancers are also highly dependent on sugar. We’d like to know from a scientific standpoint whether we might be able to affect cancer progression with dietary changes.”

It still amazes me that such authors say ‘sugar’ when they mean ‘glucose’. The above quotation would lead most people to think that added sugar was the issue, whereas all carbohydrate – especially grains and potatoes – raise blood glucose and should be avoided if such diets are to be helpful.

Tree nuts, but not peanuts, linked to lower colon cancer recurrence

A study tracking patients with stage 3 colon cancer found that those eating more tree nuts had half the incidence of recurrence and half the chance of death, than those that ate few tree nuts (Business Insider UK, 17th May)  The effect was not observed for peanuts which are not a true nut, but a legume.

Bone broth & collagen

The Huff Post (9th May) has a nice article about bone broth, collagen and skin ageing. The recipe they give at the end is more chicken soup compared to my own bone broth, and it omits vinegar – a crucial ingredient if you want to extract the maximum mineral content from the bones.

Cinnamon improved antioxidant status and reduced belly fat in mouse study

The Mail Online (8th May) reports on a study that feeding mice cinnamon along with an obesogenic diet reduced inflammation, weight gain and accumulation of abdominal fat. The cinnamon also reduced stomach temperature by 2°C which aids digestion and “This in turn avoids damage to the stomach’s lining, reducing inflammation and many diseases of the guts, said experts at RMIT University’s School of Engineering in Melbourne.” Well I never!

Pasta sales down as Italians avoid ‘for health reasons’

The Express (May 25th) explains that pasta sales in Italy have fallen as many Italians now avoid carbs and gluten. I am not surprised as Italy is at the epicentre of gluten research with many of the worlds leading studies being carried out by their researchers  (See our post Why No One Should Eat Grains Part 2: the definitive guide to Non Coeliac Gluten Sensitivity)

Ketogenic diet ‘naturally controls diabetes’ (you don’t say!)

The Express (May 16th) has a surprising little article explaining that a high fat, low carb (ketogenic diet) can reverse diabetes. Yes. I have implemented it successfully with my patients and it works.

Cheese – a rising health star

A nice article in the Mail Online (May 23rd) explaining the research around cheese. A similar article is also available in The Times (May 26th – subscription)

Vitamin D round up

Tick born infections set to explode

The US is predicting a bad year for tick born infections. Such infections, including Lyme disease, is on the rise in the UK too. News Medical (May 27th) explains how to check for ticks after being outdoors. “Everyone who spends time outdoors, even just playing in the backyard, should perform a daily check.”

Study finds fennel is effective in reducing postmenopausal symptoms

Science Daily (May 17th) reports on this placebo controlled triple blind study, along with a subtitle that is a rare admission:

Herbal medicine grows in popularity because of its effectiveness without serious side effects

Despite being a well run study, the authors fail to say which part of the fennel plant they are using. Duh! The seeds, leaves, roots, flowers, bark… that’s herbal medicine 101. All parts are not equal! In the case of fennel all parts are at least non toxic (but with something like rhubarb, think again, roots, stems and leaves all have very different compounds and effects).

RDA of protein for older people is too low

There is a growing body of evidence that points to reduced mortality in the elderly when daily protein intake is increased – primarily because it reduces muscle loss which otherwise contributes to falls. Stuart Phillips of McMaster University in Canada argues for improved guidelines. ‘He argues that there should be a stronger focus on leucine; an indispensable amino acid and building block for proteins. The elderly have a higher need for leucine to build muscle proteins, and milk-based proteins (e.g. milk and whey) are a good source for this.’  News Medical (May 24th) Interestingly, Dr Phillips discusses his own diet:

“I enjoy a variety of foods, and the only thing I specifically focus on is limiting my intake of sugar and refined carbohydrates. But of course, given the benefits of proteins, they are a big part of what I think about when planning my meals.”

Cauliflowers are tasty and nutritious (plus recipes)

Hardly news, but thank you to The Telegraph (May 4th) for reminding us that it improves brain health, reduces cancer risk, unclogs arteries and helps with weight loss. The best bit is they provide some great recipes at the end!

Recipe of the month

Here’s a recipe that makes good use of a couple of the ideas in this month’s post. Bon appetite! –

Amazing results challenge guidelines in new study

  • A new study challenges the dietary guidelines for heart health
  • MUFAs and omega 6 PUFAs not effective at reducing atherosclerosis risk
  • Omega 3 fish oils reverse triglycerides and weight gain in an animal model of insulin resistance, despite increased calories

Read time: 9 minutes (1400 words)

Guidlines for prevention of heart disease have shifted in recent years away from a simplistic ‘reduce total fat’ message towards a more nuanced emphasis on the type of fat. The current American Heart Association (AHA) recommendation is to ‘replace saturated fats with monounsaturated (MUFA) and polyunsaturated (PUFA) fats.’

For the purpose of this post, I am going to put aside my objection to the demonising of saturated fats and instead focus on the MUFA / PUFA alternatives recommended by the AHA. Similarly, I am not going to challenge the cholesterol hypothesis nor debate the merits or otherwise of lowering LDL cholesterol here. Instead I am going to look at a recent paper that studied the effects of MUFAs and PUFAs on atherosclerosis risk.

Note the terms n-3, n6- and n-9 in the title of this paper; these are just shorthand for omega-3 polyunsaturated fatty acids (ω3 PUFAs), omega-6 polyunsaturated fatty acids (ω6 PUFAs) and omega-9 monounsaturated fatty acids (ω9 MUFAs). I’ve made a quick reference guide for these below, showing typical foods high in each kind of fat:

The role of triglycerides in cardiovascular disease

Cardiovascular disease is often preceded by insulin resistance during which changes to the cholesterol delivery system increase the risk of atheroma formation in the artery wall. One of the hallmarks of insulin resistance is an increased production in very low density lipoproteins (VLDL) which are high in triglycerides.

The following is a quick explanation about triglycerides which you can skip if it’s a bit too much or you are already familiar with the subject…

The relevance of triglyceride-rich VLDL

VLDL is a carrier protein, produced by the liver, which transports triglycerides from the liver to the adipose (fat) tissue. It is important to note that these triglycerides are primarily endogenous i.e. manufactured by the body, rather than coming directly from dietary sources.

VLDL and triglycerides are raised principally by (1) Excess caloric intake from any source and (2) Carbohydrates (and especially fructose). In the former case the formation of VLDL can be seen as the body packing away and storing excess calories which are transported to the adipose tissue where they can be stored for a rainy day as fat.

In the case of carbohydrates, triglyceride rich VLDL is manufactured as a response to overwhelming surges in blood glucose that cannot be dealt with sufficiently by insulin induced uptake by the organs, especially muscle and liver glycogen stores. Indeed some have said that raised blood triglycerides are a reliable marker of carbohydrate consumption.

If cells become insulin resistant they stop taking up glucose effectively, increases the need for diversion of calories into the endogenous VLDL pathway. Hence insulin resistance is characterised by raised triglycerides.

Fructose has some unique metabolic problems as it does not trigger insulin, so cannot be taken up by cells as quickly as glucose. Instead it has to be processed by the liver, which can easily be overwhelmed, turning the excess into triglyceride rich VLDL.

It should not be surprising then, that the rats used in the study I am reviewing here, were made insulin resistant by feeding with sugar water (30% sucrose water) for 12 weeks. Sucrose is equal parts glucose and fructose, so their water contained 15% of each of these sugars.

So the aim of this study was to see how different dietary fats affect the dislipidemia associated with insulin resistance, especially the triglycerides. To do this the rats in this study were split into 5 groups: A control group on standard diet, whilst the other four were all made insulin resistant by feeding 30% sucrose water for 12 weeks. Of the four insulin resistant groups one was supplemented with n3 PUFAs, one with n6 PUFAs and one with n9 MUFAs.

It’s a pretty obvious experiment to undertake, and at this point you might rightly be asking why? Hasn’t this has all been done before? Surely the science on such a basic question is settled? With 60 years of American Heart Association advice you would think they had the science to back up their assertions and advice, wouldn’t you?

Well, shockingly, you would be wrong. As the authors note:

To our knowledge no studies have addressed the impact of dietary n-3, n-6 and n-9 fatty acids on VLDL composition and size in the [insulin resistant rodent] model.

There are several reasons why this basic question has not been answered before:

  1. Many previous studies looking at the effects of PUFAs on insulin resistance have applied n6 and n3 together, with only a few addressing n6 alone
  2. Previous studies evaluating n3 fish oils have used cod liver oil, which contains high levels of vitamin A, D and cholesterol, which could affect the findings.
  3. Assessment of MUFAs (n9) have usually used olive oil, which contains a broad range of phytochemicals which may be responsible for the beneficial heart effects observed in those studies, rather than the actual monounsaturated fats it contains.

To get round these problems ithe researchers used the following oils:

  • n3: fish oils from pressing whole fish, hence low in vitamin A and D.
  • n6: linoleic acid rich sunflower oil, low in phytonutrients
  • n9: high oleic sunflower oil

Rodent diets contained 15% w/w of each oil, which represents about 35% by calories i.e. similar to a standard western diet.

Results

What they found was striking and deserves some careful reflection.

To make the findings a little easier to appreciate I have made a graph of some of the key results, but tables with all the study data are provided at the end of the post.

Data is expressed as mean percentage differences compared to the standard rodent chow diet (Reference). All four insulin resistant diets (IR) were sucrose rich; the three intervention diets consisted of supplementing with 15% w/w with n-3: deepwater fish oil; n-6: sunflower oil; n-9: high oleic sunflower oil.

Triglycerides ()  and Liver fat ()

The effects of the high sucrose feeding, as expected was a jump in triglycerides, which can be seen between the Reference and IR results above. Dramatically, supplementation with n3 fish oils almost completely reversed this dyslipidemia, returning VLDL particles to normal. Whilst remarkable, this is in line with previous epidemiological, human and animal studies that have shown n-3 PUFA have positive physiological effects on IR and lipid metabolism.

n6 and n9 oils, however, only weakly attenuated these harmful changes, failing to reverse the atherogenic state of the VLDL particles. This casts doubt on the validity of the American Heart Association recommendations.

In the case of the MUFA (n9), previous studies using olive oil have shown greater improvements in insulin resistance parameters, but as already noted, olive oil contains a broad range of bioactive phytochemicals (e.g. sterols and polyphenols). By using high oleic sunflower oil this study has been able to show that MUFAs do not of themselves produce these beneficial effects.

In relation to MUFAs this is particularly important as many processed food uses high MUFA oils that are low in phytonutrients as these can impart undesirable flavours.

Accumulated liver fat follows a similar pattern to plasma triglycerides. Again, n3 oils produce the best reductions in damage caused by insulin resistance.

Weight gain () and Calorie intake ()

Some of the most surprising results were seen in relation to caloric intake and weight gain. All groups of rats could eat ad libitum, yet in the n3 fish oils and n9 MUFA groups caloric intake was considerably raised. Extraordinarily, despite this those fed the n3 fish oils had no weight gain during this trial, whilst those fed the n9 high oleic oil had the most weight gain.

Rats fed the n6 sunflower oil supplemented diet had lower caloric intake than the n3 and n9 groups, but still gained more weight than the n3 group.

Conclusion

The authors of this study conclude:

In insulin resistance, while n-3 PUFA showed expected favorable effects, supplementation with n-6 PUFA and n-9 MUFA did not prevent atherogenic alterations of VLDL. Thus, the recommendations of supplementation with these fatty acids in general diet should be revised.

The authors seem somewhat nonchalant about the n3 fish oils, but it is worth reflecting for a moment just what those fish oils did: the rats were drinking insane quantities of sugar, eating a hyper caloric diet, yet avoided most of the effects of insulin resistance and weight gain. That’s a pretty impressive feat as far as I can see!

Implications for diet

This study looked at the effects of fat choice in the context of insulin resistant animal models. The results support and extend previous research in humans and epidemiological studies. Taken together these point to certain food choices: fish, seafood and olive oil are good choices based on these results; Omega 6 vegetable oils such as sunflower, safflower, corn and soya oils are best avoided, as are low-polyphenol MUFAs like high oleic oil and possibly filtered rapeseed (Canola) oil. A high quality fish oil supplement seems prudent too.

Based on the ideas suggested by this study cold pressed rapeseed oil is potentially interesting as like extra-virgin olive oil, it contains high levels of phytonutrients, but unlike olive oil it has significant levels of alpha linolenic acid (ALA), a short chain n3 fatty acid. Based on the results above I would expect it to have beneficial metabolic effects possibly similar to or slightly better than Olive oil. Well that’s my prediction. So lets see…

I searched Pubmed for “rapeseed cardiovascular”. Sure enough, in one of the first studies I found [Baxheinrich et al, 2012] patients with metabolic syndrome (which is just one step down from full blown insulin resistance), were placed on a low calorie diet enriched either with olive oil (high n9 MUFA, low n3 ALA) or cold pressed rapeseed oil (high n9 MUFA high n3 ALA) for six months. Although both groups improved similarly on many metabolic measures (body weight, systolic blood pressure, cholesterol, and insulin levels), the cold pressed rapeseed group had significantly lower triglycerides. That said rapeseed oil is probably less suitable than olive oil for high temperature cooking as the ALA it contains is very heat sensitive. Still, its a good choice for salad dressings and mayonnaise!

Additional data

For those of you who like to dig into the data here are some key tables from the study:

(1) Composition of diets; (2) Intakes and body weight; (3) Effects on adipose tissue/liver and serum parameters

References

Gluten-free diet MAY be unhealthy and MAY increase risk of heart attack (or not)

OK, so I made up the quote above, but it captures a certain zeitgeist that’s in the air right now. The media is all too keen to uncritically give gluten-free and clean diets a kicking at the moment, wagging fingers at all those ‘silly people’ who fell for the anti-gluten message even though they don’t have coeliac disease – what fools!

Except, as we have explained in multiple articles on this site, gluten has a far greater reach than that 1% who have classic coeliac disease. Non coeliac gluten sensitivity (NCGS) is a recognised and studied condition, with an estimated prevalence of up to 6% of the population.

And even a cursory look behind these dismissive headlines shows that the studies they are based on add almost nothing to our understanding of gluten pathology, and indeed contradict themselves. Continue reading

Paleo veggies (video and infographic)

MODERN WILD FOOD GATHERING. When you know what to look for there are plenty of edible wild plants out there. How do they fit into a paleo diet?

There have recently been a number of articles making pronouncements on the original paleo diet, as eaten by our paleolithic ancestors. At the end of last year, December 2016, we had…

  • Ancient leftovers show the real Paleo diet was a veggie feast (New Scientist)
  • Secrets of the paleo diet: Discovery reveals plant-based menu of prehistoric man (Eureka Alert)

Then in March this year…

The more recent articles appeared following a paper by Laura Weyrich et al. published in Nature, March 2017, titled Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus. Afifah has written a post about the herbal medicines these Neanderthals were using, and we are going to publish a guest post addressing the vegetarian claim shortly.

The December articles on paleo veggies were prompted by an Israeli study (Melamed et al. PNAS) which identified the remains of a wide variety of plant food remains in a cave in the Levant (modern Israel). The 780,000 years old remains are unusual as plant materials are rarely preserved at such sites, so this paper provides some insight into the plants resources used by our ancient ancestor homo erectus.

The remnants include no fewer than 55  different species including roots, seeds, nuts, fruit and leaves. Many of these resources were seasonal and some required simple processing and cooking. Here is the New Scientist Video that accompanied their article, which, I think you will agree, has a touch of the Blue Peter about it:

You would think from the headlines that evidence that our ancestors ate a wide variety of plant foods is new or somehow overturns Paleo Diet thinking. The media portrays the Paleo Diet as consisting largely of red meat, but that is wrong. Since its inception, proponents of the modern Paleo Diet such as Professor Lauren Cordain have argued that we should be eating more like hunter-gatherers. That has always meant both the gathering part (eating plant foods) as well as the hunting bit (eating animal products).

What is strange about the recent media pronouncements is that the research that stimulated them is perfectly in accordance with Paleo Diet principles. It seems as if the media are spinning these stories for the sake of headlines, which makes them, in the lingo of the day, fake news does it not?

Paleo Veggies

A careful reflection on the details of the foods identified in the Melamed study suggest a number of subtle paleo principles we might all like to take on board:

1. Increase the range of plant foods eaten

Few of us eat as wide a variety of plant foods as these ancient hominids. Modern hunter gatherers also tend to eat a far wider range of plant foods than typical modern humans. Not only does eating a range of plant foods increase the range of phytonutrients ingested, but it also reduces the exposure to the anti-nutrients found in any one plant source.

2. Eat seasonal food

This is really part of eating a wider range of plant foods and means we give our body a rest from any anti-nutrients when that food is out of season. Another plus is that seasonal foods can be higher in nutrients than those that are grown out of season under artificial light: that’s why winter tomatoes and early season strawberries often taste so insipid (taste being evidence of nutrients. Read ‘The Dorito Effect’ for more info on this amazing area of science).

3. Grow your own

Our ancient ancestors couldn’t preserve foods by canning and freezing. The freshest foods you can eat are those that you have just picked from your own garden, minutes before eating them. Here at Rosemary Cottage we grow a lot of our own fruit, berries, and veg (in fact we have a blog just about this here). They are packed with flavour and much higher in nutrients than supermarket varieties which are often picked under-ripe and have sat around for a couple of days on the shelves or have been flown half way round the world in a low oxygen ‘protective atmosphere’. If you haven’t got a garden or allotment you can buy living salads, mustard and cress, or growing herbs which provide the same fresh-food benefits.

4. Eat wonky, small, damaged  and organic veggies

Studies have shown that fruit and veg that have been exposed to harsh environmental conditions often have higher levels of nutrients as these compounds are primarily plant defence compounds. The perfect, class 1 fruit and veg we are offered in the supermarket have been overly pampered, sacrificing nutrients for looks. Many of the phytonutrients in veggies are concentrated in the colourful skins. Cherry tomatoes therefore pack more nutrients per kilo than their larger cousins as they have a larger surface are to volume ratio. Another benefit is that buying wonky veg increases farm profits and reduces food waste.

Organic fruit and veg tends to be less perfect, more blemished, usually class 2. Possibly for this reason they often have higher levels of nutrients (European Journal of Clinical Nutrition)

5. Include close-to-wild foods

It is a fact that many modern fruit and veg have been bred to increase water, sugars and starches and to be less bitter or sour – all of which has diluted the phytonutrients. Consequently, some of the most nutrient dense plant foods are those that have had the least selective breeding such as the following.

  • Leaves: Water cress, rocket, parsley, purslane, coriander leaf, miners lettuce, samphire, seaweed, tea
  • Fruit: Blueberries, red and white currents, blackberries, raspberries, alpine strawberries, olives, capers, sour cherries
  • Seeds: All nuts and seeds, coffee
  • Roots: Salsify, scorzonera, oca, pink-fir apple potatoes, water chestnuts, tiger nuts
  • Shoots: Sprouted seeds, mustard and cress, bamboo shoots, asparagus, sprouting broccoli
  • Flowers: Artichokes, borage, nasturtium, calendula

Many of the above need only be eaten in relatively small quantities as it is often the toxins in these plants that stimulate our immune system, so you don’t want to over do them. (See our post: The chemical warfare on your plate). For example, health benefits of tea and coffee seem to peak at 4 to 5 cups per day and the benefits of tree nuts levels off at 30g per day. In some cases over doing it can actually lead to harm: for example spinach, which if consumed every day can lead to kidney stones due to its high oxalic acid content. Daily juicing of spinach is therefore unwise, despite ‘green smoothie’ proponents waxing lyrical about it. (Read here about some of the problems with oxalates)

I’ve made a nice info-graphic of some wild-like foods you might want to try. Although they are not always easy to come by I have seen all of these in supermarkets or farmers markets over the last year or so. I have several of them in my current garden, and have eaten all of them at one time or another. How many have you tried?

Final thoughts

A little thought about the paleo veg principles above makes it clear why paleo veganism must have been a rare or intermittent occurrence. Few paleo veggies contain sufficient calories to sustain life, and due to their anti nutrients eating them in large quantities or for prolonged periods could easily lead to problems. Furthermore, the wild foods that are sufficiently high in calories (nuts, seeds and some tubers) would need to be available in quantity, year round, or starvation would be a very real risk. Changing availability and seasonality mean it is unlikely our ancestors were vegans for extended periods, although there would no doubt have been times when animal food sources were limited and they would have been forced to get by on plants alone. In short – humans are and have always been highly adaptable omnivores.