Post on 25-Dec-2015
Can changing the way we grow food make our diet more
nutritious?
Bruce TraillUniversity of Reading
Background
• Diet and health concerns:– Through energy imbalance leading to obesity and hence to
related NCDs• Recommendations: eat less and exercise more
– Through nutrient imbalance leading to NCDs • Recommendations: improve ‘diet quality’ including consume more
fruit and vegetables for their health-promoting phytochemicals; less saturated fatty acids; and more n-3 fatty acids.
• Government interest in a competitive agricultural sector comprising ‘healthy food chains’.
Possible diet quality responses
• Persuade/encourage/force people to consume more fruit and vegetables, less meat and dairy products– But the persuasion/encouragement route has not
been successful
• Make existing products healthier– Intensify phytochemical content of F&V– Improve fatty acid profile of meat and dairy products
Can the latter option work?
Depends on:• Is it scientifically feasible?• Would it raise the price of such products by less than
consumers are willing to pay?
(If the answer to these questions is ‘yes’, would the health benefits be significant; and would the outcome be desirable from the perspective of land use and the rural environment?)
Intensify phytochemical content
• Soft fruit – strawberry, raspberry, blueberry – • red lettuce
UK crops grown
in polytunnels –
uv light regime as
a potential
phytochemical intensifyer
0
100
200
300
400
500
Gra
ms
UV Block UV Standard
UV Window
0
500
1000
UV Block UVStandard
UVWindow
mg
Cy
/ g
FW
a
bc
Lettuce – UV Transmission improves quality but lowers yield
Increased anthocyanin content
Reduced yield
α-LNA
June September
Birdsfoot trefoil 2.3 2.3
Cats ear 1.1 2.7
Dandelion 2.8 4.4
Knapweed 0.8 2.6
Mouseear chickweed
0.3 0.4
Oxeye daisy 0.8 2.2
Plantain 1.5 2.6
Red clover 0.8 2.0
Rough hawkbit 1.5 2.7
Selfheal 1.7 1.7
Sorrel 0.9 3.2
White clover 1.6 1.9
Yarrow 1.5 1.9
α-LNA of 13 plants (g/100 g DM) collected from one site
at two different times of year for the RELU project
Effect of grazing lambs on biodiverse pastures on fatty acid composition of intramuscular fat (Lourenço et al., 2007)
Biodiverse Intensive ryegrass Significance
Total SFA 37.7 43.0 *
Total PUFA 21.6 11.9 **
PUFA:SFA 0.294 0.148 **
18:3 n-3 2.6 2.6 NS
Very long chain n-3 (EPA+DPA+DHA)
5.9 3.0
* 0.05>P>0.01; ** 0.01>P>0.001
Would these products cost more to produce?
Lettuce and strawberries: – compared to growth under normal plastic, yield
penalties are not significant and there are no additional production costs
Lamb:– For lowland fat lamb there is lost productivity and
additional costs that would reduce the margin by £0.69/kg (wholesale) or £0.11/kg if compensated under and ES HLS scheme.
Would consumers be willing to pay?
Lettuce
-2.00
-1.00
0.00
1.00
Open Pill Enhanced
£ p
er
lett
uc
e
Main
Over 18
Spend
Strawberries
-6.00
-4.00
-2.00
0.00
2.00
4.00
Open Pill Enhanced
£/k
g
Main
Over 18
Spend
Lamb
£0.00
£2.00
£4.00
£6.00
£8.00
£10.00
Enhanced Enh + Env.Sch.
MainOver 18SpendFemale
Conclusion
• People appear willing to pay enough to cover extra production costs, but– While science is promising it is not yet conclusive– Will supermarkets be able and willing to communicate
health benefits?– Will products come from UK or abroad?
• What about land use and environmental implications?
I think they look nice, personally. [male urban <50]
It gives me a happy feeling, because I think ‘oh something’s being done locally’. [female rural <50]
I bet you would get a bonus butterfly. [female urban 50+]
Once you let the lambs or the sheep loose on it, they’ll gnaw it down anyway. [male rural 50+]