Nutrition & Health – Archive

Nutrition & Health – All Posts

Amazing results challenge guidelines in new study (22/May/17) - American Heart Association: "Replace saturated fat with PUFA and MUFA"; Recent study: "No. This advice needs revising" Continue reading
Know your fats (infographic) (20/May/17) - A helpful little graphic reference for the different fatty acid groups: MUFAs, PUFAs and Sat Fats. Continue reading
Gluten Update April 2017 (28/Apr/17) - Gluten disrupts microbiome; Relatives of coeliacs often gluten sensitive; NCGS persists after 8 years on gluten-free diet + more Continue reading
Salt and cardio-vascular disease: Policy and Science clash (19/Mar/17) - Salt recommendations - way out of step with the science Continue reading
Salt vs sodium measurements (12/Mar/17) - Confusing sodium and salt measurements - it happens to the best of us. Continue reading
Cardiologist attacks diet dogma at 2017 Symposium (3/Mar/17) - MUST WATCH - Cardiologist Dr Salim Yusuf presents findings from the PURE study which challenge fat, carb, meat, salt and 5-a-day dogma Continue reading
Gluten – what we learned in 2016 (part 2) – the Great Imitator (7/Feb/17) - In part 2 of our gluten update we look at 20+ conditions that were linked to gluten in 2016. Essential reading for understanding this multifaceted toxin. Continue reading
Gluten – what we learned in 2016 (part 1) (22/Jan/17) - A summary of key developments in our understanding of grain related disorders. Continue reading
Heart disease trials: Low-fat diet fails. Nuts and olive oil succeed. (10/Dec/16) - Two of the largest intervention trials ever undertaken demonstrate that nuts and olive oil beat low fat diets when it comes to heart disease prevention. Continue reading
5 everyday ancestral foods with proven health benefits (25/Oct/16) - Our ancestors developed complex methods for turning inedible seeds, leaves and fruit into nutritional powerhouses. Five of them made it into modern life. Continue reading
Male fertility ~ a fishy business (14/Sep/16) - The 20th century saw a huge decline in male fertility, and a huge increase in omega 6 oil consumption. Are the two connected? We fish out the latest research on seafood for semen. Continue reading
The Microbiome on BBC Radio 4 (2/Jul/16) - Listen again to these two excellent radio broadcasts from BBC Food Programme on the micobiome. HIGHLY RECOMMENDED Continue reading
Vegetable oils losing their halo (14/Apr/16) - Just published: A US research group has recovered raw data from a large scale study from the 1970's and finds no evidence for benefits from switching butter for vegetable oils. Continue reading
“The sugar conspiracy” – recommended read (7/Apr/16) - A rollicking read about how for decades nutritional science ignored the dangers of sugar whilst needlessly demonising saturated fat. Continue reading
Behind a healthy eating quiz – Australia’s nutritional mafia (6/Mar/16) - Why was a healthy lifestyle quiz in the Independent quietly linked to an Australian government funded researcher? We dig into the murky world of nutrition politics. Continue reading
Processed food, obesity and flagella (15/Feb/16) - Food additives and obesity, flagellated bacteria and TLR5... Where will the amazing human microbiome take us next? Continue reading
UK vegetarians DON’T live longer than meat eaters study finds (18/Jan/16) - The Oxford EPIC study finds that vegans and meat eaters have similar all cause mortality. No evidence that red meat causes bowel cancer. Continue reading
Coffee – its light and dark side (20/Dec/15) - How much coffee is good for you? Regular coffee consumption is associated with a longer, healthier life, but there are a couple of important caveats. Continue reading
Omega-6 and Omega-3 PUFAs: Five recent research papers (11/Nov/15) - Are you getting enough omega 3 PUFAs? or are you blowing out on omega 6's? We discuss five of the latest papers that show why it matters. Continue reading
Why no one should eat grains. Part 3: Ten more reasons to avoid wheat (30/Oct/15) - Beyond coeliac disease and NCGS – we look at the many ways that wheat can affect everyone. Includes new groundbreaking research. Continue reading
More Evidence William Davis Was Right: Wheat Does Increase Obesity According to New Study (12/Oct/15) - SCOOP: new trial demonstrates that gluten increases weight gain via suppression of thermogenesis Continue reading
“Scientists claim Paleo diet is nonsense” is nonsense (19/Sep/15) - Did our brains evolve on a high-carb diet of spuds? or are the newspapers turning our heads to mash? We respond to misleading headlines. Continue reading
Why no one should eat grains. Part 2 – The definitive guide to Non Coeliac Gluten Sensitivity (27/Aug/15) - A detailed examination of the current science on this recently recognised gluten pathology. Includes new videos from world class researchers. Continue reading
Seafood, Sex and Evolution (3 videos) (24/Jul/15) - Watch our recent public talk on the role of seafood in brain health, evolution and female sexiness. (Three videos) Continue reading
VIDEO: Harvard Scientist Supports U-Turn on Dietary Fats (26/Jun/15) - It looks like 40 years of advice to limit fat consumption to less than 30% of calories has been quietly retired! A Harvard scientist explains why it's a good move. Continue reading
Why no one should eat grains. Part 1 – The tip of the Iceberg (23/Jun/15) - Understand coeliac disease and you will know why eating gluten is playing Russian roulette with your health. Continue reading
The chemical warfare on your plate (7/Jun/15) - The fascinating story of how natural insecticides in plants can be good for us, but how wheat has evolved the ability to turn an insect's immune system against itself... oh, and us. Continue reading
Adventures in mushroomland (7/May/15) - A wide range of exotic mushrooms is now available in UK supermarkets, but which are the best? Continue reading
Sleep & Health: part 1 – Sleep’s central role (26/Apr/15) - Why sleep quality is one of the most significant health factors within your control. Continue reading
The Balanced Diet Argument – Just Another Straw Man (30/Mar/15) - Why paleo, primal and gluten-free diets are actually re-balancing British nutrition. Continue reading
Pannage pig in the New Forest Pork – tradition and nutrition (8/Feb/15) - Following her appearance on BBC4's Any Questions, Afifah looks at the nutritional value of pork. She reports on little-known health benefits, even for bacon. Continue reading
Why we pass on the semi-skimmed and low-fat dairy (26/Nov/14) - Recent study finds that full-fat dairy products are associated with reduced obesity. Continue reading
Animal products that protect you from UV damage (2/Nov/14) - Evidence that compounds in a range of animal products can protect the skin from UV damage and cancer. Continue reading
Gluten and Schizophrenia – does it all start in the womb? (12/Oct/14) - Research is now identifying how schizophrenia starts in the womb Maternal infections and dietary antigens such as gluten are implicated A key immune molecule C1q has been identified which links schizophrenia, gluten and neuronal development in the unborn child Evidence … Continue reading
Dr Malcolm Kendrick – Autumn Seminar – Tickets now available (7/Aug/14) - . For our 2014 Autumn Seminar we are very pleased to present Dr Malcolm Kendrick, author, speaker and blogger, who will expose the myths and misunderstanding around cholesterol and heart disease. This talk is not to be missed whether you simply wish to … Continue reading
Vitamin A from animal sources – more good news (27/Jun/14) - Studies show vitamin A may prevent obesity, diabetes, and protect the heart - but Beta-carotene may counteract vitamin A health benefits. Continue reading
Raw milk risks – putting them in perspective (15/Jun/14) - So straight up: there are risks of consuming raw milk. Lets not pretend otherwise. Raw milk may contain pathogens which can cause pretty unpleasant infections including Salmonella and Listeria. Milk is an excellent medium for growing bacteria, and consequently there are outbreaks … Continue reading
Milk & Alcohol – was the good Doctor on to something? (27/May/14) - Milk and alcohol - which featured in Dr Feelgood's 1978 hit of the same name - have opposing effects on gut health. Continue reading
Why were ancient teeth healthier than ours? (3/May/14) - Unpicking the complexities of how human oral health changed with the advent of agriculture. Continue reading
Is Low-Carb really Normo-Carb? (25/Feb/14) - Looking at the effects of high and low-carb diets on glucose, insulin and free fatty acids suggests low carb diets are normal. Continue reading
New Study Vindicates William Davis: Modern Wheat is more Toxic than Ancient Varieties (16/Feb/14) - Study shows modern wheat aggravates IBS more than ancient strains. Continue reading
Sugar on Trial on Trial (2/Feb/14) - When it comes to nutrition it seems once again that TV's mantra is "Never let facts get in the way of a good story" Continue reading
The Now Show – Sugar Lobby sketch (25/Jan/14) - Radio 4's The Now Show, poke fun at Big-Sugar's lobbying of Government food policy... Brilliant! Give it a listen! Continue reading
Ketogenic Diet and Cancer (24/Jan/14) - I came across this neat little report on the ketogenic diet in cancer about a year ago, but it has just cropped up again so I thought I would put it on my blog (as well as a couple of other videos … Continue reading
New study vindicates Weston A Price (20/Oct/13) - Scientists identify Price's 'Displacing Foods of Commerce' as ideal for inducing full-blown metabolic syndrome in rats. Continue reading
Calorie Counting vs Meal Timing (31/Aug/13) - Why a high protein breakfast might work better than calorie counting. Continue reading
Mistletoe in Cancer (20/Aug/13) - This legendary herb of the druids has been shown to have anti-cancer properties in multiple studies. Continue reading
Fifth Food & Health Group Meeting – Sugar (17/Apr/13) - 30th March, 2:30pm – 40 attendees The reason for covering the subject of sugar on this occasion was partly due to the recent visit of Professor Robert Lustig to England, and partly because it was Easter. Many countries have seen an exponential increase in sugar consumption over the … Continue reading
Cholesterol – Sunny Side Up (21/Feb/13) - The good side of the bad stuff. Cholesterol ain't what we were all led to believe. Continue reading
3:1 Keto Lunches (10/Feb/13) - If you are eating low-carb then these lunch suggestions are easy-peasy and can be modified any way that fits your diet preferences. However, if you need to eat a truly ketogenic diet then they may need modifying a bit. Anyone attempting … Continue reading
Eating well needn’t cost a fortune (22/Jan/13) - How a quality animal based diet can feed the family without breaking the bank. Continue reading
Third Food and Health Group Meeting – Grains (20/Jan/13) - Our third meeting was on the topic of cereal grains, such as wheat, rye, oats, rice, corn and barley. Unfortunately, due to a mix up with the room booking we ended up in the smaller upstairs room. To make matters even more … Continue reading
Kombucha Brew Success! (22/Dec/12) - Our first attempt at making this fermented beverage went well. Continue reading
Salt of the Earth (21/Dec/12) - Key article & video: Scant Evidence That Salt Raises BP, Review Finds During our second Food and Health Group meeting, Caroline was demonstrating how to make lacto-fermented veggies. When she added a couple of tablespoons of salt to the mix … Continue reading
Second Food and Health Group Meeting – Fermented Foods (17/Dec/12) - Our second local food group meeting took place on 2nd December 2012, with 35 people attending.  The wrist bands worn by these tribal elders are in fact important tools – disk-shaped steel blades, used for flaying and butchering a goat … Continue reading
Listen to lard (4/Nov/12) - Today's Food Programme on Radio 4 was all about lard! Includes interviews with Stephanie Seneff and Gary Taubes. Continue reading
West Sussex local animal food producers list (2/Nov/12) - Below is a list of our local animal food producers. Local food is food you can trust, animals that you can see grazing, farmers you can talk to and quality you can often feel in your guts. This list is … Continue reading
First Food and Health Group Meeting (30/Oct/12) - The first of the Food and Health Group meetings was held on Sat 27th Oct and was a huge success. Thank you to all those who made it run so smoothly. Keir began the afternoon with a fascinating presentation about … Continue reading

Recent Posts

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 at 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

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