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+]