1. Introduction
Dietary pulses, including several varieties of dry beans, peas, chickpeas, and lentils, are the edible seeds of members of the legume family [
1]. Pulse crops have a long tradition of being part of human diets, with historical records dating as far back as 10,000 years before present [
2], and are rich sources of dietary fiber, protein, antioxidants, minerals (i.e., iron, zinc, magnesium and phosphorous), as well as folate and other B-vitamins [
3]. For this reason and for their actions in reducing risk or managing major diet-related chronic disorders, such as obesity, diabetes mellitus (DM), and cardiovascular disease (CVD) [
4,
5,
6,
7], consumption of dietary pulses is recommended by health authorities worldwide [
8,
9,
10,
11,
12,
13,
14,
15,
16].
Canada’s Food Guide [
4] encourages regular consumption of cooked pulses as part of the recommended 2–3 daily servings of foods from the “Meat and Alternatives” group for the adult population. Within Canada’s Food Guide, ¾ cup (175 mL) represents one serving of cooked pulses. Although Canada is a world leader in the production and sale of pulses [
17], and pulses are plentiful within the Canadian marketplace, their consumption remains low, with only 13% of the adult population reporting consumption of pulses (at an average of 113 g) on any given day [
18].
The economic burden of diet-related disorders is recognized worldwide. For instance, diabetes-related expenditures reached over US
$600 billion in 2014 and have been forecast to increase by 40%, from US
$500 billion to over US
$700 billion, between 2010 and 2030 [
19]. Similarly, it has been estimated that the global expenditures related to CVD will reach US
$20 trillion between 2010 and 2030 [
19]. Healthy dietary behaviors have been demonstrated to contribute to substantial savings on healthcare and related costs [
20,
21,
22,
23,
24]. In this regard, epidemiological, randomized controlled, and meta-analytic research support the beneficial effect of dietary pulse consumption on established risk factors for type 2 diabetes (T2D) [
25,
26,
27,
28,
29,
30] and CVD [
31,
32,
33,
34,
35]. As such, increasing consumption of pulses has the potential to be a powerful tool for policymakers to help manage healthcare resources associated with these illnesses. Data on the economic value of greater habitual or recommended pulse consumption are, however, lacking.
Given that dietary pulses are a readily available and affordable source of nutrition within the Canadian marketplace, the objective of this research was to assess the potential annual savings in healthcare and productivity costs that would arise from reduced incidence of CVD and management of T2D following increased pulse consumption, or adoption of low glycemic index (GI) or high fiber diets that include pulses in Canada, respectively.
3. Results
Potential healthcare and productivity cost savings associated the use of pulses to decrease with T2D complications and CVD incidence reductions among 5%, 15%, 25%, and 50% of Canadian adult population (≥18 years of age) (
n = 28,895,209 as of July 2015) [
40], are summarized in
Table 5 and
Table 6.
Under the very optimistic scenario, assuming a 50% success rate and potential benefit over the long term, our analysis predicted total annual healthcare and related cost savings equal to Can$62.4 (95% CI $26.0–$98.8) million for T2D and Can$315.5 (95% CI $110.6–$520.4) million for CVD. The optimistic scenario, assuming a 25% success rate and medium-to-long-term benefit, predicted savings of Can$31.2 (95% CI $13.0–$49.4) million in T2D costs and Can$157.7 (95% CI $55.3–$260.2) million in CVD costs annually. With a 15% success rate and a more practical short-to-medium-term benefit, the pessimistic scenario showed savings of Can$18.7 (95% CI $7.8–$29.6) million in costs of T2D and Can$94.6 (95% CI $33.2–$156.1) million in costs of CVD annually. Finally, the very pessimistic scenario of a 5% success rate suggested total annual savings of Can$6.2 (95% CI $2.6–$9.9) million for T2D and Can$31.6 (95% CI $11.1–$52.0) million for CVD costs.
Table 7 and
Table 8 summarize the potential financial savings in T2D and CVD total costs, respectively, by province/territory following the increased intakes of pulses. For T2D, total annual savings ranged from less than Can
$0.1 (95% CI <
$0.1–<
$0.1) million in each of The Northwest Territories, Nunavut, and Yukon, in very pessimistic through very optimistic scenarios, to Can
$2.4 (95% CI
$1.0–
$3.8) and Can
$23.9 (95% CI
$10.0–
$37.9) million in very pessimistic and very optimistic scenarios, respectively, in Ontario; with other provincial cost saving figures falling in between (
Table 7). Similarly, annual savings in CVD costs were estimated to range between less than Can
$0.1 (95% CI <
$0.1–<
$0.1) million (very pessimistic) to Can
$0.2 (95% CI
$0.1–
$0.4) million (very optimistic) in each of The Northwest Territories, Nunavut, and Yukon, and between Can
$11.1 (95% CI
$3.9–
$18.3) and Can
$111.3 (95% CI
$39–
$183.6) million in Ontario, given the very pessimistic through very optimistic scenarios (
Table 8). Detailed estimates of savings in the costs of the diseases of interest within each province/territory following a low GI or high fiber diet that includes pulses, for T2D management, or one serving of 100 g/day of dietary pulse, for CVD risk reduction, are provided in
Supplementary Tables S3–S15 for T2D and
Supplementary Tables S16–S28 for CVD. Adult populations (≥18 years of age) in Canadian provinces, as of July 2015, were as follows: Alberta (~3,271,000), British Columbia (~3,853,000), Manitoba (~1,003,000), New Brunswick (~620,000), Newfoundland and Labrador (~437,000), Northwest Territories (~33,000), Nova Scotia (~780,000), Nunavut (~23,000), Ontario (~11,117,000), Prince Edward Island (~119,000), Quebec (~6,734,000), Saskatchewan (~875,000), and Yukon (~30,000) [
40].
To account for time preference, the present values of adopting dietary paradigms of increasing success rates over a 20 year period are summarized in
Table 9. At an 8% real discount rate, adopting a low GI or high fiber dietary pattern that includes pulses to facilitate lower HbA1c concentrations decreased the potential total health costs (direct and indirect) associated with better management of T2D by Can
$228.9 (95% CI
$95.4–
$362.4) million. Over the same time frame, increasing the success rate of consuming 100 g/day pulses to facilitate concurrent reductions in LDL-C concentrations and SBP decreased the associated healthcare costs by Can
$1158 (95% CI
$406.1–
$1909) million.
4. Discussion
Using a cost-of-illness approach and conservative estimates of risk factor reduction, results of this research suggest opportunities for significant savings in T2D and CVD costs in Canada when a reasonable daily serving of dietary pulses is consumed. Specifically, if 50% of the Canadian adult population increased their intake of pulses, over Can
$370 (95% CI
$137–
$619) million could potentially be saved in T2D and CVD related healthcare and loss of productivity costs annually. Less optimistically, Can
$38 (95% CI
$14–
$62) to Can
$189 (95% CI
$68–
$310) million in annual cost savings in T2D and CVD could be realized if between 5% and 25% of Canadians used pulses to help manage T2D-related complications or prevent increases in LDL-C concentrations and SBP, respectively. Subgroup analyses of provincial and territorial expenditures demonstrated that the costs of T2D and CVD are substantial across Canada and each region stands to realize the relevant financial savings from enhanced consumption of pulses. Healthcare and related expenditures account for roughly 50% of provincial total spending. For example, the “Health, Healthy Living, and Seniors” portfolio accounted for Can
$5.5 million out of a total budget of Can
$11.9 million in the province of Manitoba in 2015 [
64].
Evidence highlights that consistent consumption of healthy foods, such as pulse crops, can decrease risk factors for chronic diseases, which are of enormous burden on health and the economy. It is thus logical that increasing intakes of pulses could result in financial benefits within the global healthcare sector. To our knowledge, to date, no studies have examined this association. Data from this study suggest that when the effects of healthy dietary constituents are applied to a financial model, Canada, and perhaps other jurisdictions, warrant the implementation of preventative strategies and policies from legislators that promote healthy dietary patterns, and ensure healthcare remains affordable and productively maximized.
Results of this study make a compelling case for increasing the use of pulses within the dietary patterns of Canadians. Provincial and federal governments would welcome any alterations in lifestyle that reduces financial pressure within the publicly funded healthcare system in Canada. In addition, positive lifestyle choices, which can include increasing consumption of pulses, could potentially reduce the level of monetary support required for the management of T2D and CVD in Canada, and allow for available funds to be reallocated to the treatment of ailments unrelated to these diseases, improvements in the healthcare system, or other priorities, such as education and infrastructure. Societal benefits from reduced disease prevalence could also extend beyond specific expenditures related to health, and can encourage economic growth by increasing productivity and the formation of human and financial capital [
65]. This is supported by the observed decrease in costs related to loss of productivity from T2D and CVD reported in this model as the rate of pulse consumption increases. At the same time, it cannot be overlooked that, over the long term, associated healthcare savings from increasing dietary intakes of pulses, or any other lifestyle related modifications, may not completely offset other possible healthcare and societal (i.e., pensions) expenditures that are linked to a longer lifespan. This has been demonstrated by van Baal et al. [
66], where lifetime health expenditures were greatest among healthy non-smokers, intermediate for obese individuals, and lowest for smokers. However, such evidence is still limited and in addition to healthcare expenditures, an increase in quality of life is also a compelling benefit for undertaking strategies that reduce disease risk factors related to lifestyle. Deficits in health have been linked to reductions in quality of life outcomes [
67] and serves as another driver for undertaking strategies, such as diet and exercise that promote longevity and prevent premature mortality. At >200 billion Canadian dollars per annum, healthcare will always represent a significant proportion of the Canadian government’s budgetary expenditures [
52]. Thus, the identification and implementation of lifestyle choices that help to decrease premature mortality by preventing or delaying the onset of associated diseases, such as T2D and CVD, are unlikely to relieve all of the financial pressures that Canada’s healthcare system faces. However, these preventative measures are one of many elements that can assist with resource reallocation, and improve efficiency and value of Canadian healthcare, as well as help to prolong quality of life for its population.
Keeping inflation rates constant, it is important to acknowledge that the money has greater value in the present day because the return on investment into healthcare is immediate. To account for time preference,
Table 9 demonstrated that, with an 8% real discount rate over a 20 year period, when success rates improve in five year increments, healthcare costs from the potential effects of pulses on CVD risk factors and low GI or high fiber diets on reduced T2D-related complications are higher compared to maintaining a constant success rate of 15% over the same time period. However, although an 8% discount rate aligns with Health Canada’s Cost-Benefit Analysis Guide [
61], its relatively high rate could predict a lower than expected reduction in healthcare expenditures for CVD and T2D from an increase in pulse consumption in Canada. In the US, regulatory impact analyses typically use 3% and 7% discount rates to inform regulatory decisions [
63]. That being said, given the uncertainty in increasing success rates around pulse consumption, 8% serves as a more conservative approach to considering time preference in this analysis.
Before such financial benefits from positive shifts in intakes of pulses can happen, challenges that impede pulse consumption within Canada should be addressed. Although pulses and other legumes are promoted as part of a healthy diet by Canada’s Food Guide, adequate pulse consumption in Canada is low [
18]. To increase consumption of pulses among Canadians, and perhaps other regions, initiatives such as government policies or programs that aggressively promote pulses as nutritious constituents of diets could be of assistance. For example, increased prominence and positive positioning of pulses in Canada’s dietary guidelines could help to enhance their familiarity and consumption among Canadians. In Canada’s Food Guide [
4], pulses are identified as an “alternative” source of protein, a description that could be perceived as a negative attribute. Moving forward, healthy foods, such pulses, should be promoted in dietary guidelines without descriptions that may overshadow their nutritional value as well as historical prominence in human diets. In addition, given their nutritional composition, pulses could be identified as foods that are part of both the protein and fruit and vegetable food groups, which accords with how pulses are positioned in other regions such as the US [
9] and Australia [
10]. Given their composition, pulses could be promoted in same fashion as whole grains and cereals, which have also been demonstrated in dietary guidelines for China [
68]. Interestingly, to help facilitate an increase in consumption, the French Agency for Food, Environmental and Occupational Health & Safety recently published the opinion that pulses should be an independent food group in the next iteration of France’s food-based dietary guidelines [
69]. Increased use of pulses in nutritional policies in schools could also help to familiarize Canadians with pulses from a young age. The abovementioned strategies could help to improve the nutritional quality of Canadian diets.
Education programs that target healthcare practitioners could encourage consumption of pulses to individuals already at risk of disease. In addition, there is a need for an increase in utilization of whole pulses and efficacious pulse-derived ingredients in the development of manufactured food products that will appeal to consumers. More fundamentally, consumer demand for such foods is necessary and will likely depend upon the success of educational initiatives. Approval of health claims and evidence-based messages around the healthful properties of pulses may help with manufacturers’ desire to incorporate and market the presence of new food products. It is hopeful that promotional efforts would increase the proportion of users beyond the levels assumed within the scenarios of this analysis.
In addition to promotional activities, increased use of whole pulses and pulse ingredients, such as flours and fiber fractions in familiar foods, can also enhance consumption of pulses and the nutrients that improve dietary quality and modulate disease risk factors of relevance. Research efforts continue to delineate improvements in protein quality of finished foods when cereals and pulses are used as complimentary amino acid profiles [
70]. In addition, approaches to optimize the functionality of pulse-based flours could increase utilization by the food industry to bolster the nutrient density of commonly consumed foods [
71,
72,
73,
74,
75].
While the potential effects of pulse consumption on incidence and cost reduction were separately analyzed for T2D and CVD, a decrease in endpoints associated with poor management of T2D could further reduce CVD-related expenditures. On its own, T2D is an independent risk factor for CVD [
76] and pulses have been shown to reduce CVD risk factors in individuals with T2D [
30]. Although T2D has been shown to increase the risk of CVD by two-to-four-fold [
77], appropriate literature that quantifies the reduced risk in CVD from a decrease in incidence of T2D
per se is, to our knowledge, lacking. At the same time, the use of cost estimates that are exclusive to CVD or T2D avoided double-counting and is a strength of this analysis. However, the widespread use of dietary patterns that include pulses to help drive financial benefits to Canada’s healthcare system could exceed the monetary savings reported in this analysis because of the possible benefits of pulses on other outcomes that affect healthcare resources, such as weight loss [
78], gastrointestinal function [
79], and nutrient deficiencies [
80].
This work is, to our knowledge, the first to examine the potential savings in costs attributed to lower rates of CVD and management of T2D from adopting dietary patterns that include pulses in Canada and each of its provinces/territories. The present cost and saving estimates are, as such, expected to attract interest at both the provincial and federal decision-making levels. However, limitations are worth noting. First, while recent literature and national databases were reviewed for identification of consumer trends and healthcare-related costs, as with previous cost-of-illness analyses [
54,
81,
82], isolating the effects of pulses from other elements of lifestyle is challenging.
Second, while rates of biomarker reduction were generated using the most recent aggregated effects on HbA1c, LDL-C, and SBP, a lack of dose response data examining the effects of pulses on CVD and T2D risk factors translated into a reliance on various assumptions that predicted effects per 100 g/day or low GI or high fiber diets that include pulses. This warrants deeper exploration of the association between pulse consumption and disease risk and complications. Furthermore, effects of pulses on costs associated with T2D were contingent on adopting a low GI or high fiber diet. Given, that pulses are an inherently low GI and high fiber food, it was reasonable that studies evaluating the effects of low GI and high fiber diets used pulses in establishing the corresponding dietary pattern. However, if a low GI or high fiber diet is a treatment or management strategy for T2D patients, other foods besides pulses with the same properties could be equally as effective in lowering HbA1c. On a related note, given that CVD is a broad category which includes diseases that may not be strongly associated with LDL-C or SBP changes, the reliance on the inherently higher costs of CVD than CHD in the present work, and, hence, estimations of the associated cost savings, may be perceived by some as a limitation. Alternatively, risks of conditions such as cerebrovascular disease, renal disease, and peripheral artery disease can also be linked to atherosclerosis due to higher LDL-C concentrations and/or SBP.
Third, substantial changes to Canadians’ dietary habits, especially among those who consume little to no pulses, would be needed to reach the 100 g/day benchmark used in this study to assess effects on CVD-related healthcare and societal costs. Although whole pulses have been shown to significantly decrease risk factors for CVD, for some, dosages of pulses required to impose a benefit could be substantial; even though 100 g/day of beans, peas, chickpeas, or lentils is well within the serving size guidance for pulses in many jurisdictions, including Canada [
8,
9,
10,
11,
12,
13,
14,
15,
16]. The perceived association between consumption of legumes and gastrointestinal discomfort, such as bloating and flatulence, could also be a deterrent -although studies demonstrate that perceived discomfort with ≥100 g cooked pulses was marginal when consumed more than or equal to three weeks [
83]. These challenges corresponding to adoption are further compounded by the fact that the diets of many Canadians encompass a variety of foods, making achievement of the recommended daily intake of pulses difficult. That being said, considering the results of this analysis that correspond to whole cooked pulses and the observation that daily servings of whole pulses already align with 100 g, increasing success rates among Canadians may rely more so on advocating for consumption, rather than dosage. Furthermore, recent consumer research showing increased awareness and desire for plant-based foods and meat alternatives [
84,
85] could help to drive increased intakes of pulses, especially over the long term. Given the low consumption rates in Canada, strategies that communicate an “eat as much as you can” approach may also be effective and could produce dietary benefits outside the scope T2D and CVD risk, such as improvements in dietary quality.
In addition, the incorporation of a variety of dietary adjustments could reduce risk factors for CVD and complications associated with T2D on an ongoing basis. Specifically, rather than taking a reductionist approach to dietary changes that focus on single exchanges of foods or nutrients, addressing overall quality of Canadian diets by promoting healthy and palatable dietary patterns is likely a more feasible strategy for long-term benefits to health and healthcare costs. These multifaceted dietary approaches may not necessarily require that efficacious foods be consumed on a daily basis. This has been demonstrated with the “portfolio diet” whereby the long term effectiveness of a dietary paradigm that incorporated almonds, viscous fibers, plant-based protein, and plant sterols substantially decreased LDL-C concentrations by 12% [
86,
87]. Under a dietary patterned approach, consumption of pulses a few times per week, alongside other risk factor-lowering foods, is likely a more appealing program.
In the end, it is important to emphasize that the current study is a modeling exercise to help elucidate the potential effects of diet on certain healthcare costs if pulses were consumed at increasing levels in Canada. We are mindful of the challenges for aligning Canadians to consuming pulses each day, no matter the amount. However, as previously discussed, this, and other studies that link diet to the financials associated with healthcare demonstrate the potentially favorable impact of positive lifestyle choices, beyond the individual, on societal healthcare resources. Future research including cost-benefit [
88] and cost-effectiveness [
89] analyses designed to assess the potential economic value of pulse intakes, compared to components of other dietary changes, is likely to draw further interest into this emerging arena of nutrition economics.