Beliefs, Facts, and Truth
In their recent book, Jennifer Kavanagh and Michael Rich tell us that we’re suffering from truth decay. Public discourse now brings more disagreement about facts and their interpretation. They say the line separating facts from personal beliefs and opinions has become blurry. And thus, we have increasing difficulty with civil discourse and policymaking.
Certainly, we can think of subjects related to nutrition, obesity, and health where these trends are evident. Sugar and tax policies come to mind for one example.
Beliefs, Suppositions, and Objective Facts
Beliefs, suppostions, and objective facts come into play whenever we consider a challenging subject. But it’s well worth separating one from the other. Beliefs come from convictions about what is true, based on faith, trust, or personal conviction. Unlike beliefs, we can directly test our suppositions. Some will turn out to be true. Others will not. And from testing our suppostions, we build up a body of facts.
In policy discussions about taxing sugary drinks, we have facts that tell us a tax on these beverages leads to less consumption. So many people suppose that a drop in obesity prevalence will inevitably result. Some folks are so committed to this idea that it’s become a core belief. Others are waiting for evidence.
Secular Beliefs to Satisfy a Human Need for Deeper Truths
Much has been written about the declining influence of organized religious faith. Yet most adults say they believe in a higher power. At the same time, more people think that belief in God is not necessary for a person to have good, moral values.
Where people once turned to religion for their convictions, perhaps some are turning more to secular belief systems. All the while, distinctions between facts and beliefs are fading. Trust in some long established systems for judging facts continues to erode.
And thus we have an ongoing struggle with truth decay.
For more on this subject, we recommend you go to the source, freely available here.
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June 9, 2018
June 14, 2018 at 12:19 pm, David Brown said:
“I never know how much of what I say is true.” Bette Midler
A big problem, as I see it, is the failure to define concepts with precision. Truth is what is so. A fact is always true. A belief is whatever a person chooses to accept as true.
In nutrition science there exists a long-standing debate between nutritional epidemiologists and biochemists. “Some experts, notably ones affiliated with the American Heart Association, credit our current intake of omega-6s with lowering the incidence of cardiovascular disease. Others, which include biochemists, say the relatively high intake of omega-6 is a reason for a slew of chronic illnesses in the Western world, including asthma, various cancers, neurological disorders and cardiovascular disease itself.” http://www.asbmb.org/asbmbtoday/asbmbtoday_article.aspx?id=18365
Taken together, evidence from biochemistry and epidemiology suggest that intermediate intakes of linoleic acid are the most lethal.
Experimental biochemistry
Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century and is associated with greater prevalence of obesity. The endocannabinoid system is involved in regulation of energy balance and a sustained hyperactivity of the endocannabinoid system may contribute to obesity. Arachidonic acid (ARA, 20:4n-6) is the precursor for 2-AG and anandamide (AEA), and we sought to determine if low fat diets (LFD) could be made obesogenic by increasing the endocannabinoid precursor pool of ARA, causing excessive endocannabinoid signaling leading to weight gain and a metabolic profile associated with obesity.”
Results: We found that increasing dietary LNA from 1 to 8 en% in LFD and MFD significantly increased ARA in phospholipids (ARA–PL), elevated 2-AG and AEA in liver, elevated plasma leptin, and resulted in larger adipocytes and more macrophage infiltration in adipose tissue. In LFD, dietary LNA of 8 en% increased feed efficiency and caused greater weight gain than in an isocaloric reduction to 1 en% LNA. Increasing dietary LNA from 1 to 8 en% elevates liver endocannabinoid levels and increases the risk of developing obesity. Thus a high dietary content of LNA (8 en%) increases the adipogenic properties of a low fat diet. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889814/
Nutritional epidemiology
Swapping saturated fat and carbohydrates for linoleic acid – the main polyunsaturated fat found in vegetable oil, nuts, and seeds – lowers risk of coronary heart disease, according to a new study by Harvard School of Public Health researchers. https://www.hsph.harvard.edu/nutritionsource/2014/11/05/dietary-linoleic-acid-and-risk-of-coronary-heart-disease/
Unfortunately, nutritional epidemiology does not have data on subjects consuming low levels of linoleic acid (1% or less total energy) and the biochemists haven’t thought to test what higher than average levels of linoleic acid intake would do for the health of the mice. Consequently, the dispute continues thanks to incomplete data sets.