You Are What You Eat

In 1826, this famous saying was published in a treatise called The Physiology of Taste, or, Meditations on Transcendental Gastronomy, by French lawyer, politician, gastronome and bon vivant Anthelme Brillat-Savarin. PURE has taken the concept to a global level.  

Centuries later the concept has a new place at the health management table as published comprehensive and ground breaking international research has cast new meaning on this concept with some heart-felt views and advice.

Given its importance in keeping your body alive the relationship between diet and heart health has come to the fore. Not to mention that heart disease is New Zealand’s biggest ‘killer’.

There is no argument that cardiovascular disease (heart and blood vessels) is a global epidemic with 80% of the burden of disease in low-income and middle-income countries.

Similarly, consensus is that diet is one of the most important modifiable risk factors for cardiovascular disease in addition to other non-communicable (non-infectious) diseases.

Desperately seeking solutions

The search for the Holy Grail of creating the ultimate heart-health diet has produced a cornucopia of ideas, fads, recommendations, research and conclusions about what best suits the human physiology.

Along the way what has been considered as bona fide research conclusions have been debated, debunked or totally reconsidered.

In one of the world’s most comprehensive studies—with the matter of fact title of Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study—popular beliefs have been turned upside down.

The PURE in the title is an acronym referring to a Prospective Urban Rural Epidemiology. The last word in the mix refers to the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health.

By any standard the research is a massive undertaking providing a feast of information and findings. It involves studying 225,000 participants in detail, and 500,000 with simple information, from more than 1,000 urban and rural communities in 27 high, middle and low-income countries.

PURE is investigating the impact of diet, modernization, urbanization, and globalization on health behaviours, how risk factors develop and influence cardiovascular disease, diabetes, lung diseases, cancers, kidney disease, brain health, and injuries. Over a time frame of January 1st 2003 and March 31st 2030*. The focus is on the efficacy of existing knowledge as well as fresh information that might produce a change of perspective related to dietary contributions to better health. This includes documentation of the characteristics of the community, the household and individual lifestyles, health conditions, and anthropometrics which are inclusive of: blood pressure, lipids, glucose and lung function, drugs used and stored bloods and urine.

*In terms of updating the data there is a long-term and ongoing follow up(FU) current mean of 10 years with >95% FU for mortality and >90% for morbidity. Plus there are plans to extend the follow up for another 10 years to study the conditions of aging (dementia, frailty, arthritis & disability globally).

Excessive consumptions

PURE has added energy to the whole ‘fat’ debate. For decades, guidelines have focused on reducing total fat and saturated fatty acid intake. This was based on the presumption that replacing the latter with carbohydrate and unsaturated fats will lower LDL cholesterol (the so-called ‘bad’ cholesterol) and should therefore reduce cardiovascular disease events.

This perspective was predominantly based on selective emphasis on some observational and clinical data.

Most of which has stemmed from European and North American populations where nutrition excess is common.

Needless to say the applicability of these outcomes and conclusions to other populations has been open to speculation.
In conducting the research the targeted outcomes is two-fold.

The primary focus is on total mortality (death) and overarching major cardiovascular events; such as fatal cardiovascular disease, non-fatal myocardial infarction (heart attack), stroke, and heart failure.

The secondary focus looks at the specifics of myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality.

The associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality, are also assessed.

The Findings

The PURE study to date has found that high carbohydrate intake (more than about 60% of energy) was associated with an adverse impact on total mortality and non-cardiovascular disease mortality.

By contrast, higher fat intake was associated with lower risk of total mortality, non-cardiovascular disease mortality, and stroke.
Furthermore findings to date suggest higher intakes of individual types of fat are associated with lower total mortality, noncardiovascular disease mortality, and stroke risk; and are not associated with risks of major cardiovascular disease events, myocardial infarction, or cardiovascular disease mortality.
In short the findings to date do not support recommendations to limit total fat intake to less than 30% of energy, and saturated fat intake to less than 10% of energy.

Moreover the findings to date suggest that individuals with high carbohydrate intake might benefit from a reduction in carbohydrate intake, and increase in the consumption of fats; as this was associated with an adverse impact on total mortality. Whereas, in contrast the findings to date show fats (including saturated and unsaturated fatty acids) are associated with lower risk of total mortality and stroke.

Importantly there have been to date no observed detrimental effect of fat intakes on cardiovascular disease events.

Should global dietary guidelines be reconsidered in light of the consistency of findings from PURE? The researchers say ‘Yes’. Whatever the case there is clear food for thought in the debate about the impact of what you eat has on your health and wellbeing.

In Short:

• The PURE study refocuses on the relationship between a diet high in fat and an increased risk of cardiovascular disease.
• The PURE study has challenged current thinking to limit total fat intake to less than 30% of energy and saturated fat intake to less than 10% of energy.
• The new view is that individuals with high carbohydrate intake might benefit from a reduction in carbohydrate intake and increase the consumption of fats as this was associated with an adverse impact on total mortality.
• Whereas, in contrast, fats (including saturated and unsaturated fatty acids) seem to be associated with lower risk of total mortality and stroke.
• With heart disease reaching epidemic proportions it means this PURE approach will likely come to the fore as its data gathering is planned through until 2030.