Are wholegrains good for the heart?

The conventional nutritional approach for ‘heart health’ is a low-fat (specifically, low saturated fat), high-carbohydrate diet. For many reasons, this is not the sort of diet I would generally recommend to ward off heart disease. For more about this, click here.

One particular form of carbohydrate that has been vigorously promoted for its heart-healthy properties are the ‘wholegrains’ such as wholemeal bread and brown rice. The pushing of wholegrains appears to be backed by studies which allegedly find that those who eat more wholegrains tend to have a reduced risk of heart disease. However, these studies are epidemiological in nature, and by virtue of this can only really tell us about the association wholegrains have with heart disease, but in no way indicate that wholegrains actually reduce heart disease risk.

One major issues of studies of this nature is that they are prone to ‘confounding’. Essentially, the benefits associated with wholegrain consumption might not be due to wholegrain at all, but other things to do with wholegrain eaters. Wholegrains have been vigorously promoted as ‘healthy’ for ages now, and as a result, those who eat them are likely to be more health-conscious than those who don’t.

So, wholegrain eaters might, for example, exercise more, be less likely to be obese and smoke less than those who eat more refined grains. And it might be these factor that account for the apparent benefits of wholegrain eating.

One way to find out for sure whether wholegrains really are good for the heart is to conduct so-called intervention studies. What this would mean, in essence, would be to take a group of individuals, and randomise them to eating either a diet rich in wholegrain or a control diet (not rich in wholegrains), and then see over time if the wholegrain eaters ended up being protected from heart disease. I don’t believe such a study has ever been done.

The next best thing, perhaps, would be to do the same thing, but instead of monitoring heart disease risk, monitor ‘surrogate markers’ of heart disease instead. Surrogate markers for heart disease include factors include things like body weight and fatness, waist circumference, blood chemistry (e.g. glucose and insulin levels), inflammation, endothelial function (a measure of the health of the inside of the body’s arteries) and blood clotting. A recent study did just this [1].

In this study, 316 individuals aged 18-65 were randomised to one of three diets:

1. A diet which included 60 g of wholegrain each day for 16 weeks

2. A diet which included 60 g of wholegrain each day for 8 weeks, followed by 120 g of wholegrain for a further 8 weeks

3. A control diet (no dietary change, in which wholegrain consumption was less than 30 g per day) for 16 weeks

At the end of the study, there was no significant difference in any of the surrogate markers for heart disease tested.

Now, of course there are several potential explanations for these ‘disappointing’ findings including, perhaps, the fact that the study did not go on for long enough. However, four months is usually long enough to see quite dramatic changes in surrogate markers for cardiovascular disease, as long as the approach taken is correct.

It is perhaps the case that wholegrains and healthier than their refined counterparts. But they are still grains, and can still have relatively high glycaemic index (and glycaemic load) if eaten in quantity. As I have reported before, diets of relatively high GI and/or GL are associated with enhanced risk of cardiovascular disease. See here for more about this.

So, what might be better than adding wholegrain to the diet for reducing cardiovascular disease risk? I suggest taking grains out (or at least eating them in generally limited quantities). There is evidence that low-carb diets, compared to low-fat ones, lead to improvements in many surrogate markers of disease including serum glucose, measures of insulin resistance, triglyceride levels and high-density lipoprotein cholesterol levels [2].

And the other thing about low-carb diets is that they can really make a difference to body fatness, especially ‘abdominal obesity’. I had an email today from a fellow who had read my latest book (Waist Disposal), employed its advice, and promptly lost four inches (10 cm) off his waist in 5 weeks. I didn’t quiz him about precisely what he’s been eating, though I wouldn’t be surprised if the benefits he’s seen have been achieved without the ‘aid’ of wholegrains.

References:

1. Brownlee IA, et al. Markers of cardiovascular risk are not changed by increased whole-grain intake: the WHOLEheart study, a randomised, controlled dietary intervention B J Nutr 2010;104(1):125-134

2. Samaha FF, et al. Low-carbohydrate diets, obesity, and metabolic risk factors for cardiovascular disease. Curr Atheroscler Rep 2007;9(6):441-71

30 Responses to Are wholegrains good for the heart?

  1. Nancy LC 5 July 2010 at 10:40 pm #

    It is always good to see the whole grains myth challenged!

  2. Vivian 6 July 2010 at 12:17 am #

    Has there ever been any kind of study that compares a diet containing a ‘normal’ amount of whole grains against a diet with no grains at all? One that specifically looks at that the health outcomes of that difference?

    i’ve tried to have the whole v no discussion and am always met with the ‘healthy whole grains’ retort and haven’t been able to offer anything in reply except for personal experience.

  3. Jamie 6 July 2010 at 2:41 am #

    A couple of other good references here which John may have used in the past;

    No effect of 14 day consumption of whole grain diet compared to refined grain diet on antioxidant measures in healthy, young subjects: a pilot study.

    http://www.nutritionj.com/content/9/1/12/abstract

    Wholegrain cereals for coronary heart disease: Cochrane Review

    Plain language summary

    Wholegrain foods encompass a range of products and examples are wholegrain wheat, rice, maize and oats. The term wholegrain also includes milled wholegrains such as oatmeal and wholemeal wheat. The evidence found by this review is limited to wholegrain oats, and to changes in lipids as an outcome. There is a lack of studies on other wholegrain foods or diets. There is some evidence from this review that oatmeal foods can beneficially lower lipid levels such as low density lipoproteins (LDL) cholesterol and total cholesterol in those previously diagnosed with risk factors for coronary heart disease (CHD) even with relatively short interventions. However, the results should be interpreted with caution because the trials found are small, of short duration and many were commercially funded. No studies were found that reported the effect of wholegrain foods or diets on deaths from, or occurrence of CHD.

    http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD005051/frame.html

  4. Chris 6 July 2010 at 7:20 pm #

    Whom should we believe?

    ‘Here is bread, which strengthens man’s heart, and therefore called the staff of life’
    (Mathew Henry: 1662”1714, Commentary on Psalm 104) .. ..

    ‘The whiter the bread, the faster your dead!’
    (Michael Pollan; Food Rules) .. .. or

    ‘Full of natural goodness’ (the typical marketing mantra for wholegrains)

    Vivian, the power of the marketing message does seem to endure in the minds of many, doesn’t it?
    There are 342 references in Lorain Cordains’ paper, Cereal Grains: Humanity’s Double-Edged Sword, which makes for interesting reading, and I wonder if amongst those is a lead to a grain inclusive vs grain exclusive study.

    ‘The low GI guide to metabolic syndrome and your heart’; Janette Brand-Miller, 2005, looks a promising work on GI/GL and heart health.

    Andrew Whitley, writing ‘Against the Grain’, for the Guardian raises issues with the modern industrial scale of bread baking (The Chorleywood Bread Process) and modern improvers. Industrial bread may be more carcinogenic than bread produced by more traditional process.

  5. Abe 6 July 2010 at 9:51 pm #

    I’m with Vivian on this one – I have yet to see a comparison of wholegrain vs. no grain. Sure – whole grains may be better than refined grains. But both pale in comparison to a grain-free diet. Does anyone know of such a study?

  6. Jamie 6 July 2010 at 11:12 pm #

    Dennis,

    Suggesting that wholegrains are more nutrient dense than meat is perhaps coming from someone who hasn’t done a head to head comparison of the two, particularly say between wheat and liver. If you have information that shows the opposite, I’d love to see it.

    And one has to keep in mind that just because a food is nutrient-rish when tested in the lab, does not mean those nutrients make it into the body. And then, if they do, are they enough to counter any anti-nutrients that are also absorbed from that food source?

  7. Dennis 7 July 2010 at 2:05 am #

    Many studies have shown that whole grains are beneficial whereas refined grains are detrimental to health. See for example http://www.ncbi.nlm.nih.gov/pubmed/20548009
    This is believed to be due to the high micronutrient content of wholegrains compared with refined grains. Arguably whole grains are more nutrient rich than meat and fats, though less nutrient rich than fruit or veg (see eg page 120 of chapter 6 of Eat to Live by Joel Fuhrman). Miconutrient deficiencies have cumultative long term effects and do not neccearilty show up in surrogate markers which are more likely to reflect macronutrient changes. Even so, in the study, the surrogate markers were no worse when wholegrains were substituted for alternative unspecified foods. So wholegrains have micronutrient benefits and are no worse than other foods. No reason to avoid whole grains. The truth is that almost any diet based on whole unprocessed foods (whether veg, fruit, nuts, seeds, meat, fish or whole grains) is much better than the typical western diet consisting of 90% refined and processed foods.

  8. Peter Silverman 7 July 2010 at 3:42 pm #

    A little bit of whole grains has no effect on my blood sugar. A large portion, on the other hand, has a huge effect. I think if you wonder how whole grains affect you, checking your blood sugar after a few meals is better than reading any study.

  9. dennis 7 July 2010 at 5:46 pm #

    Jamie,
    Liver, from naturally fed animals, is an excellent food but my point is that, as a generality, all natural wholefoods – including wholegrains – are much better than modern refined and processed foods which constitute 90 % of the modern western diet. Bacon, salami and sausages are highly processed and not to be recommended whereas seafish, wild game and naturally fed unprocessed animal food are excellent. Whole oats, brown rice and rye are fine but refined grains should be avoided. Oils and fats should come from wholefoods such as meat, fish, nuts, seeds, olives and avocadoes. Extracted and processed oils and fats are nutrient poor and should be avoided. Even virgin olive oil is not high in nutrients and like butter should only be consumed in moderation. One should not obsess on any particular whole food but it is well nigh impossible to obtain anough calories from meat, fish, nuts, seeds and vegetables and fruits without consuming some whole grains. In moderation, like all whole foods, whole grains are beneficial

  10. Jamie 7 July 2010 at 8:47 pm #

    Dennis wrote:
    “it is well nigh impossible to obtain enough calories from meat, fish, nuts, seeds and vegetables and fruits without consuming some whole grains.”

    Oh really? I had better tell that to all my patients who eat only meat, fish, fowl, fruits, vegetables, nuts, & seeds and who, like me, engage in relatively high-intensity exercise on most days, without the use of wholegrains. And we are all the healthiest and most energised we have been for a long time.

  11. dennis 8 July 2010 at 11:20 am #

    Jamie,
    I don’t understand where you get your calories from. Do you eat only wholefoods or do you eat some processed foods (including such nasties as bacon, sausages, added fats and oils, fruit juices etc) ?
    Wife and I have felt incredibly energised since we switched from processed foods to wholefoods (including lots of wholefoods of all the items you mention plus some of a variety of different wholegrains other than wheat (ie oats, rye, millet, quinoa) , wheat being so highly optimised for yield, gluten etc content that it does not qualify as a natural wholefood as far as I am concerned). Humans survived well on many different diets, historically based on natural wholefood, and there is no need to ut a exclude all grains – see for example Weston A Price’s famous book on Nutrition and Physical Degeneration – the isolated Swiss, for example, survived largely on rye bread and cheese, particularly in winter months. The issue for diet is not ‘eat anything but grains’ rather it is ‘eat anything but refined and processed foods’. Frankly any reasonable , non-obsessive, diet which avoids processed foods will make one healthy and energised.

  12. Menon 8 July 2010 at 8:02 pm #

    Hi Dr. Briffa,

    I purchased your book “waist disposal” about a week ago. I am strictly following your diet plan. I lost about 3kgs in 4 days. Is this weight loss too quick. Additionally, I woud like to know if I can add Oats and Chickpeas in my diet.

    I am on metformin 500mg tablet.

    Thanks a lot.

  13. Jamie 9 July 2010 at 9:45 am #

    Dennis,

    Easy – FAT.

    Jamie

  14. Dr John Briffa 9 July 2010 at 10:05 am #

    Jamie/Dennis

    I love this: on the one hand we have people telling us that we need to avoid fat on the basis that it’s ‘calorific’. And on the other, we have those telling us to fill up on carbs (especially kids) because we ‘need’ the calories.

    Doesn’t make such sense, does it.

    Dennis – here’s something to consider – go and buy a bag of nuts, look at the calorie content, and ponder honestly if you think it’s not possible to meet your caloric needs eating a primal/paleo diet devoid of grains.

  15. Fiona 9 July 2010 at 5:02 pm #

    Hi Dr Briffa,

    Just wondering what your view is on the current trend for branding certain cereals as containing wholgrains, the suggestion being that these are somehow healthier? I saw golden nuggets, surely the sweetest cereal known, with the wholegrain banner on the box – I wouldn’t dream of feeding it to my child, but surely it helps kids with the pester power to get sugary cereals when they are being advertised as having health benefits…

    Fiona

  16. Gabriella 9 July 2010 at 8:58 pm #

    Dear All -
    I think all of you would get a lot of incredible information if you took the time to access http://www.westonaprice.org and read some of their articles on fats, cholesterol, vitamins, diet, etc.
    In particular there is an article on the incredibly high incidence of acid relfux in the US, This article addresses, among other things, the recommended use of high-fiber foods and whole-wheat grains in one’s diet.
    Here is the link:
    http://www.westonaprice.org/modern-diseases/digestive-disorders/1956-acid-reflux-a-red-flag.html
    Happy reading, Gabriella

  17. Jamie 9 July 2010 at 11:25 pm #

    Dennis wrote:

    “Added fat is nutritionally poor – and consuming huge amounts of fat laden wholefood is quite hard work.”

    Dennis,

    I cannot for the life of me fathom your logic here? By virtue of the fact that YOU struggle to consume fats, the rest of us apparently have the same issue. Well I’m sorry to inform you that it is actually really quite easy. On most mornings I will consume free-range eggs and free-range, gluten-free, naturally cured bacon cooked in coconut oil followed by a bowl of freshly chopped pineapple coated with shredded coconut. You can see that it has been very easy for me to consume plenty of HEALTHY fats in just one meal, let alone the others that I eat.

    I also weight train (strength + modified Crossfit) twice per week, teach spin classes 1-2 times per week, cycle 2-3 times per week at high intensity, and walk to work everyday. So I consider myself very active. Consuming a diet in which you claim it is very difficult to get enough calories, I have increased my lean body mass and decreased body fat levels, increased HDL cholesterol, decreased triglyceride levels, and decreased my blood pressure. I have also shaken some long standing sinus and skin issues that only return when I consume wholegrains. And without changing anything in the way I train, I have increased my performance on the bike.

    I have achieved all of this without having to eat constantly as I have had to do in the past on a wholefood WHOLEGRAIN diet. I couldn’t last anymore than 2-3 hours without having to eat.

    You are very much blinklered by a calories in vs. calories out model. Perhaps consider that if you increased your intake of quality fats (which may force you to do your homework on the nutritional adequacy of fat) whilst dropping some of the problematic foods that you still consume, you might actually be better off.

    As a suggestion, start by looking at the different health properties of the fatty acid subfractions that fall under the umbrella term – fat. Maybe start with looking up oleic acid (which makes up 10-15% of olive oil, but 40-60% of animal fat).

  18. dennis 10 July 2010 at 12:31 am #

    Added fat is nutritionally poor – and consuming huge amounts of fat laden wholefood is quite hard work. It’s very difficult to eat large amounts of nuts and seeds at one session which is why I add some oats – otherwise I lose too much weight. Similarly it’s very difficult to each large amounts of liver or fatty meats which is why I eat plenty of vegetables and legumes with them. I agree there is evidence against wheat in all forms, as well as all refined grains – indeed all refined and processed foods. There are a huge variety of different whole grains (with and without gluten) and legumes with different nutritional content (dozens – I won’t list them here) but only one milk in common use (cow’s) which I assume you recommend and from which you get some fat. There is just as much evidence against cow’s milk and cow’s milk products as there is against grains with the exception of modern wheat which is very suspect. However milk is less primal than most grains and why you should reject all grains but not reject cow’s milk is beyond me. The diet should be diverse – and a blanket restriction on all grains, which can hugely add to this diversity does not make any sense. Also you ignore individuals different biochemistry – Jack Sprat could eat no fat but his wife could eat no lean. Lots of different types of wholefood diets are very healthy – however one should probably minimise wheat and dairy as these have become ‘industrial’ products rather than ‘natural’ – spelt and goat’s milk (with A2 casein rather tha A1 casein) would be better.

  19. Jill H 10 July 2010 at 12:41 am #

    It has never made sense to me that ‘whole grains’ should be good for the heart or that ‘saturated fat’ should be bad. A balance of animal protein of good quality (animals that have been pastured and not confined and fed unnatural foodstuffs) veggies and fruits (local, organic, in season) along with indigenous whole grains (not modern wheat), nuts, legumes and other ‘questionable’ foods have been eaten by different cultures for many generations and proved healthful to them. The amounts available on a given day would have been dictated by eating locally what was in season. This kind of diet has nothing taken away, nor nothing added by the food processing industry with a mind to their profits not our health. By adhering to the ‘quality’ of the food there surely is a synergy and nutritional value that could never be achieved by eating processed foods. Variety is surely important – logic seems to suggest that constantly eating one type of food over the other does not make for a healthy diet. I do not understand that ‘high carb’ should mean ‘low fat’ or ‘high fat’ should equal ‘low carb’. I do believe though that the most dramatic change in our diet of the past 2 million years is due to the introduction of diets high in sugar and refined carbohydrates which have created profound disturbances in blood sugar and insulin production and this surely must have implications for heart disease.

  20. dennis 10 July 2010 at 12:18 pm #

    Jill H
    Well said !

  21. Mia Avery 10 July 2010 at 11:02 pm #

    Dear Dr. Briffa:
    I was surfing the ‘net’ for information on Colitis and other diseases of the stomach and colon and found that one of the symptoms for Celiac disease was ” an itchy condition which affected the “Buttocks”. Well I had that condition in spades, which I blamed on soaps and fabrics, etc. I have stopped eating whole wheat products and the itch has gone away. I had a test for Celiac Disease but it did not show positive results. My next step will be to reintroduce whole wheat and other gluten prducts to see if the itch returns.
    Have you had other complaints along this line? If so what would you suggest.
    Thank You.
    M.

  22. dennis 10 July 2010 at 11:56 pm #

    Jamie,
    I have no doubt that, you , personally, can manage a high fat diet and it may suit your metabolism but I do not want to get into a personal debate (please don’t tell me what to do and I won’t tell you what to do) The point is that yours / Dr Briffa’ is not the ONLY healthy diet. I recommend you read Joel Fuhrmann’s ‘Eat to Live’ and ‘Eat for Life’ for an equally healthy alternative. Also read Paul Clayton’s Health Defence (chapter 16) for a description of how fat affects insulin sensitivity. A diet high in fat reduces the activity of the enzyme LPL which controls triglycerides. Junk food (high fat , low in nutrients) makes one more prone to insulin resistance and more sensitive to excessive carbohydrate intake. If one has plenty of micronutrients including flavonoids and avoids too much fat, one can tolerate larger amounts of carbs. Also read ‘The reverse diabetes diet’ by Neal Barnard who cures diabetes by keeping fat to a minimum. I repeat – there are lots of different good diets. The problem is that the modern western diet is nutrient poor , having got progressively worse since the 17th century when milling was introduced and acceleratingly worse in the 20th century with food processing and now GM in the 21st century. Hundreds of books on diet have been written (I have read more than 200 and yes I have read Barry Groves and Gary Taubes). There are many ways to skin a cat, but the common feature (perhaps the only common feature) of all the respectable diets is the avoidance of refined and processed foods. Any reasonable natural wholefood diet is much more healthy than the modern western diet and there is absolutely no need to avoid all grains.

  23. Chris 12 July 2010 at 11:20 am #

    Fixed link

    Cereal Grains: Humanity’s Double-Edged Sword

  24. Jill H 13 July 2010 at 1:26 am #

    Thanks Chris – gosh, sobering reading and I cannot pretend to understand the half of it. I do notice the author Loren Cordain is a paleo researcher and has written a book on the Paleo Diet – Lose Weight and Get Healthy – in 2002. I am afraid there is no way I have half the knowledge to ‘Vet the Vet’ but what did jump out at me was he concludes by saying “Cereal grains obviously can be included in moderate amounts in the diets of most people without any noticeable, deleterious health effects and herein lies their strength ………….The downside of cereal grain consumption is their ability to disrupt health and well being in virtually all people when consumed in excessive quantity”. I would absolutely go along with that and why are people consuming excessive quantities? The irony being that they have been told to by ‘experts’ in probably the case of wholegrains and bombarded by advertising on television and supermarkets for refined processed grains often masquerading as whole grains by having a bit of bran added back in with a few vitamins and probably charging a premium for doing so. Marion Nestle has said ‘The problem with nutrient-by-nutrient nutrition science is that it takes the nutrient out of the context of the food, the food out of the context of the diet and the diet out of the context of the lifestyle”, which is why I love the work of Weston Price because what he did was use his eyes and powers of observation. I work with veterinarians and the most powerful tool they have is their powers of observation – the patients cannot tell them what is wrong. According to M Pollen “Price identified no single ideal diet – he found populations that thrived on seafood diets, dairy diets, meat diets, and diets in which fruits, vegetables, and grain predominated” And on a personal note what has really fascinated me is that he found that seafaring groups in the Hebrides (where my ancestors resided) consumed no dairy at all, subsisting on a diet consisting largely of seafood and oats made into porridges and cakes. I have been lactose intolerant all my life and now eat a little goats or milk cheese and fear I might be addicted to sheep’s milk yogurt and my favorite meal would contain fish and nope I am not giving up my porridge which I had this morning with my usual nuts and seeds, sheep’s yogurt and fresh figs that are now in season here. We are just going to have to agree to differ on this one I think. On a serious note there is much to be done in the world before every child has as absolutely their birthright the kind of nutrition that will allow them to reach their full potential in life.

  25. dennis 13 July 2010 at 9:33 pm #

    Jill H
    I agree with what you 110% – and I wanted to add some final comments before this thread goes off the radar.
    I am an omnivore (age 63) eating a lot of sea fish and natural meats as well as eggs with loads of vegetables – also I eat lots of nuts, seeds, fruit and herbs and spices.
    However I do eat some grains as as follows :
    Organic oat porridge made with water with cinnamon and ground flax seeds and a couple of chopped unsulphured apricots (not too many !).
    Organic oats and mixed chopped nuts soaked overnight in diluted organic whole apple juice (too sugary to have it neat)
    Sourdough whole rye or spelt bread with home made chickpea houmus made with only a little extra virgin oil and tahini but also water and ground cumin seeds.
    A casserole containing some brown basmati rice and chick peas with aubergines, lemon slices, olives, veges and herbs and spices (modified Rose Eliot recipe)
    Millet bread (in local curry house !)
    I think this is the right way of using grains – I completely avoid eating wheat and use very little dairy or added oils/fats as the latter are not whole foods and have little nutritional value (you could live on grains as a core diet as most of the world have to do but you can’t live on oil/fat)
    I note that Dr John concludes (p130 of his book) that ‘vegetarian diets are not necessarily healthier than more omnivorous ones’ – but he does not say that ominivorous is categorically better. For most vegetarians, grains and legumes must be the core of their diet (and probably eaten in much larger quantities than we omnivores) so they can’t be all that bad !

  26. Chris 5 August 2010 at 11:42 pm #

    News just in ..

    Putin slaps ban on Russian Wheat Exports

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