Dill, Red Onions, and Carrots

Take Your Vegetables by Prescription?

Are you ready for vegetables by prescription? That’s what nutrition policy wonks are pushing with a new publication in PLOS Medicine. Yujin Lee, a postdoctoral fellow and lead author, sums up their bold claims:

We found that encouraging people to eat healthy foods in Medicare and Medicaid – healthy food prescriptions – could be as or more cost-effective as other common interventions, such as preventative drug treatments for hypertension or high cholesterol.

A Modeling Exercise

Right up front you should know that this is a microsimulation model. As such, it’s a great tool for laying out a thought experiment. So the first step is making assumptions. How well do you think this would work? To their credit, these researchers have been very explicit about their critical assumptions. In fact, they summarize them in a table and also provide a detailed appendix with all the details. They even go so far as to say:

Our model cannot prove the health and cost effects of these food incentive programs through Medicare and Medicaid.

In other words, this model tells us that if these vegetable prescriptions worked as well as these folks think they might, they’d be very cost effective. Fair enough.

Do Vegetable Prescriptions Work?

This is the 25 million dollar question. These authors base their estimates on a randomized study of a SNAP incentive program to promote fruit and vegetable intake. So they’re not pulling numbers out of thin air.

But of course, this is just data from a short term pilot of a program with a different population. So we don’t really have a test of the outcomes for this program over time. We only have assumptions.

On one hand, this is a reasonable proposition. These investigators have a reasonable model to support testing it. And that’s exactly what comes next.

In fact, the 2018 Farm Bill includes funding for a $25 million Produce Prescription Program. So perhaps this money will pay for an actual, rigorous test. This program might work much better than expected. Or it might not work at all.

The only way to learn is through genuine curiosity and a passion for objectivity. Here’s hoping for some deep learning.

Click here for the analysis and here more perspective on it.

Dill, Red Onions, and Carrots; photograph © Samantha Durfee / flickr

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March 29, 2019

3 Responses to “Take Your Vegetables by Prescription?”

  1. March 29, 2019 at 7:36 am, Al Lewis said:

    The good news is that unlike just about everything else that has ever been tried, no one will get harmed.

  2. March 29, 2019 at 8:25 am, Mary-Jo said:

    On the one hand, I’m thinking, how did it come to this?, but, on the other hand, if it takes prescribing wholesome foods to give folks access to it, who could, otherwise, not afford it, then, I’m all ears to see results of whether it 1) increases intake of fruit, vegetables and other wholesome foods and 2) improves health, 3) saves health spending.

  3. March 29, 2019 at 9:41 am, David Brown said:

    I know from personal experience that eating lots of vegetables, though helpful, does not protect a person from excessive polyunsaturated fatty acid intake. Here’s the problem:

    “Combining reduction of the intake of AA with enhancement of the intake of oleic acid will, moreover, also be a better strategy for reducing the total extent of in vivo lipid peroxidation, rather than adding more EPA (with 5 double bonds) and DHA (with 6 double bonds) to a diet already over-abundant in arachidonic acid and linoleic acid. A reduction of the dietary ratio of total polyunsaturated fatty acids to oleic acid will not only make plasma lipoproteins less vulnerable to oxidation, but must also be expected to lead to reduction of the rate of formation of mutagenic aldehydes that arise as secondary products of lipid peroxidation, such as malondialdehyde, crotonaldehyde, acrolein and 4-hydroxynonenal. High rates of production of these mutagenic aldehydes must be expected simultaneously to lead to enhancement of the risk of various forms of cancer, and enhancement of the rate of mitochondrial DNA aging, which could lead to earlier onset of various age-associated degenerative diseases perhaps including type 2 diabetes. The degree of fatty acid unsaturation of mitochondrial membrane lipids has been found to be one of those biochemical parameters that are most strongly correlated with longevity, when different species of mammals and birds are compared, with a low degree of fatty unsaturation being correlated with less lipid peroxidation and a longer normal life-span. Oxidatively modified LDL is much more atherogenic than non-modified LDL. Oleic acid has, moreover, also been reported to have antiatherogenic protective effects on endothelial cells by reducing rates of intracellular generation of reactive oxygen species (ROS) and counteracting the activation of nuclear factor-kappaB.

    In other words, if accelerated aging is of no concern, don’t worry about reducing your omega-6 intake. Just eat fish and supplement with flax seeds or marine oils.