Khorasan Wheat-Based Diet and Acute Coronary Syndrome

Whittaker A, Sofi F, Luisi ML, et al. An organic khorasan wheat-based replacement diet improves risk profile of patients with acute coronary syndrome: a randomized crossover trial. Nutrients. 2015;7(5):3401-3415.

Randomized, double-blinded, crossover trial

Twenty-two participants: 13 men, 9 women. Median age 61 years(range: 47-75 years). Mean body mass index (BMI): 26.9 +/- 4.4.

 

All participants had a previous diagnosis of acute coronary syndrome (ACS). ACS refers to conditions that result from decreased blood flow through the coronary arteries—primarily either myocardial infarction or unstable angina. 

 

Diagnosis was based on: 

 

Patients had to meet criteria 1 plus criteria 2 or 3 to be enrolled in the study. Conditions for exclusion included renal, hepatic, gastrointestinal, or gallbladder disorders.

Subjects were randomly assigned to 2 groups. Each group was given products made either entirely of organic modern wheat (ie, kamut wheat) or organic khorasan wheat (Triticum turgidum subsp turanicum) and were instructed to consume these as their sole grain product for 8 weeks. This was followed by an 8-week washout period, and then a second 8-week round in which the grain consumed by each subject was switched. Each participant received weekly: 500 g of pasta, 1,000 g bread, 250 g crackers, and 250 g biscuits (ie, what Americans would call cookies). All products were delivered in unmarked packages and were produced by the same artisan bakery. Behavioral risk factors such as smoking and sedentary lifestyle, as well as medications, remained unchanged throughout the study.

At baseline and after each intervention period, the following data was collected from each subject:

Subjects consuming the khorasan wheat products were found to have a decrease in total cholesterol (6.8%), LDL cholesterol (8.1%), glucose (8%), and insulin (24.6%) and an increase in serum magnesium. ROS production and lipoperoxidation in circulating monocytes (but not granulocytes) decreased significantly. TNF-alpha also decreased significantly (34.5%); no other changes were reported for pro- or anti-inflammatory cytokines.

 

No significant changes were found for any of the parameters listed above for those on the wheat-only diet. 

On first glance, this study has a straightforward message: khorasan wheat improves cardiovascular health markers relative to modern wheat. A deeper look, however, yields more questions than answers: Is khorasan wheat itself better for cardiovascular health than other grains? Would any older variety of wheat have the same cardioprotective effects? Would the substitution of any type of grain be similarly health-promoting? And finally, is it simply the elimination of modern wheat from the diet rather than the addition of a different variety of wheat that is causing these improvements? 

 

Despite the fact that all participants were diagnosed with active coronary artery disease, this study was designed based on the assumption that participants were already eating a Mediterranean diet, which is good for cardiovascular health. (Note: a similar study was conducted earlier on healthy participants with similar results.¹) Researchers used a questionnaire to assess whether the participants followed a Mediterranean diet before and during the testing periods and found them to be generally compliant. The Mediterranean diet is widely researched and regarded as cardioprotective.^2,3,4 It emphasizes consumption of fruits, vegetables, healthy oils (mainly olive oil), nuts, and legumes, but also includes whole grains on the bottom tier of its pyramid. Generally, Mediterranean diet guidelines recommend 4 to 6 servings per day of grain products. 

 

In this study, participants received a fairly large amount of either khorasan or organic modern wheat, averaging 2.5 slices of bread, two-thirds cup pasta, 15 crackers, and 3 cookies per day, consisting of 202.5 g/day of flour. Assuming this is half whole/half white flour (as stated in the study), this averages around 700 calories per day coming from the flour, or around 35% of a 2,000-calorie diet. There has been a great emphasis recently on encouraging people to regularly consume whole-grain products, as studies have shown up to a 40% reduction in risk of cardiovascular events in comparison to those who eat refined or white flour.^5,6,7 It is important to note the positive results in the khorasan wheat group even when including a large dose of the semi-whole milled grain each day. 

      

Nutritionally speaking, what is the difference between these varieties of wheat? Khorasan wheat flour (though not semolina) was found to have higher antioxidant content. Another animal study comparing khorasan wheat and modern wheat bread also showed it caused lower oxidative status and greater activity of antioxidant enzymes in the liver.^8,9 Both the khorasan wheat flour and semolina contain greater amounts of selenium and vanadium. There is evidence to suggest that selenium protects against atherosclerosis and vanadium helps to regulate pancreatic function to help with glucose regulation.^10,11,12 Fiber and starch contents did not vary between the kamut and modern wheat varieties, but kamut had a little more protein than the wheat varieties. 

 

It is useful to look at the taxonomy of wheat to more fully understand the differences between the 2 grains.¹³ Khorasan wheat (Triticum turgidum, ssp turanicum) is genetically distinct from modern wheat (Triticum aestivum). The turgidum species is tetraploid (ie, it has 4 sets of genes) and emerged around 500,000 years ago. Durum wheat, the source of semolina flour, which is made into pasta, is another variety of this species. Modern bread flour comes from the Triticum aesticum species, which is hexaploid. This species was never wild, but emerged under cultivation around 8,000 to 10,000 years ago from the combination of a triticum species with a wild goat grass of the genus Aegilops. The ability to bring wheat under cultivation is widely regarded as the turning point that allowed people to transition from a nomadic to a more agrarian lifestyle and marked the birth of empires that fostered modern culture. Wheat has been hybridized continuously by farmers since that time, but more rigorous and intensive hybridization has been taking place since the 1960s. Hybridization has helped with disease resistance, cold hardiness, tolerance to changes in soil and water, ease of threshing, and yield, but not necessarily with nutritional content.^14,15

 

With this in mind, the vast majority of the wheat under cultivation today around the world is quite different from wheat grown even just 50 to 100 years ago. Studies on other, older varieties of wheat have shown similar reductions in oxidation due to higher amounts and different types of phenol and lignan compounds that have antioxidant capacity.^16,17 Similar effects on cholesterol and inflammatory markers were found in a study on healthy subjects when an older variety of modern wheat was used (Verna from Tuscany).¹⁸ So the question remains whether the hybridizing modifications made to wheat in the past 50 to 75 years to make it more viable for commercial production have also altered its effects on human health.

 

Extrapolating this question to the larger world of grains causes one to ask whether substituting any grain for modern wheat would yield similar results. In this study, substituting khorasan wheat resulted in a decrease in markers of inflammation. Inflammatory markers such as TNF-alpha are also associated with higher risk of recurrent coronary artery events.¹⁹ Similar results were found, however, with subjects consuming a whole-grain diet that included barley, oats, rice, and rye.^{20, 21} So while the comparison between khorasan wheat and modern wheat specifically shows a profound difference, could that difference be replicated by substituting with any grain? Even further, we can ask whether taking out wheat flour and not replacing it with another grain would yield similar results. Grain-free diets (such as the Paleo diet) have also shown similar types of changes in oxidative status and markers of cardiovascular and blood sugar health.²²

 

While the results of this study are compelling, they give rise to a wide variety of questions about the health effects of modern wheat. It would be easy to say that khorasan wheat should be substituted in our diets to improve cardiovascular health. However, khorasan wheat was virtually unknown in modern commerce until 20 years ago, and its ideal growing climate encompasses a small region of the northern United States and Saskatchewan.²³ It is challenging to find this grain even in health food stores in the United States, let alone throughout the world in areas where wheat flour is a staple. With this in mind, Kamut is unlikely to become a major substitute for modern wheat for purely practical reasons. This study, however, is a great starting place for a conversation about whether the modern cultivar subspecies of wheat are ideal for promoting human health and what might optimally replace it.