Lung health and fruit/vegetable

consumption

Dariusz Nowak

Department of Clinical
Physiology, Medical
Uniwersity of Lodz
Mazowiecka 6/8 Poland

Respiratory unit (respiratory
lobule) = respiratory bronchiole,
alveolar ducts, atria, alveoli
( diameter ~ 0.2 mm, 300 x 10

6

in two lungs) Respiratory
membrane- 0.6 µm, Diffusion
area ~ 70 m

2

Cross-sectional view of alveolar walls and

their vascular supply.

• Lungs are exposed to

high concentration of oxygen (13.6% in

alveolar air)

air pollutions (e.g. ozone, NO

x

,SO

2

),

cigarette smoke

Pulmonary cells are able to produce

reactive oxygen species:

mitochondrial respiratory chain (leakage

of 2-4% of reduced oxygen as superoxide

radical, then it is converted to H

2

O

2

)

pulmonary phagocytes (alveolar

macrophages, neutrophils)

epithelial and endothelial cells

Antioxidants are the first line of

defense against ROS

Enzymatic (SOD, catalase, GSH-Px)
Non-enzymatic, food-derived
Antioxidant vitamins: C and E,
β-carotene, lycopene,other carotenoids
Ubiquinone, selenium
Flavonoids (e.g.

quercetin,hesperidin,kaempherol),
polyphenols (phloretin, chlorogenic acid,
catechin)

• Oxidative stress occurs in variety of

lung disorders:

• Bronchial asthma
• Emphysema
• Chronic obstructive pulmonary disease (COPD)
• Cystic fibrosis
• Pneumonia
• Idiopathic pulmonary fibrosis
• Adult respiratory distress syndrome
• Tuberculosis
• Lung cancer

Lung function decline with age

(FEV

1

- forced expiratory volume in the first second)

COPD and fruits/vegetables

consumption

• High fruit intake is inversely related to the COPD

risk (3 cross-sectional studies)

• Non-citrus fruits (apples, pears, grapes)

consumption is associated with reduced cough with
phlegm – cross-sectional study involved 49 140
men in Singapore

• Solid fruits (apples, pears) inversely associated with

prevalence of COPD symptoms (chronic cough,
breathlessness)- 13 651 adults in Netherlands
(aged 20-59 years). Fruits consumption> 180 g/day
lowered the prevalence of respiratory symptoms.

• Increased vegetable consumption associated with

reduced COPD risk (3 cross-sectional studies) . Two
large studies – no effect on respiratory symptoms

Soy consumption and COPD risk

•

Cross-sectional study: 278 patients with COPD (244 men)

aged 50-70 years and 340 controls (272 men)

•

Spirometry – lung function, demographic data, habitual

food consumption – structural questionnaire

•

Results : a) - significant reduction of COPD risk for highest

daily intake of total soybean products and:

•

b) – respiratory symptoms (breathlessness) were inversely

associated with high consumption of soy foods

•

Beneficial effect of isoflavones on lungs

•

Limitation of the study – low patient number - preliminary

results that should be confirmed in further studies

.

Lung function and fruits/vegetables

consumption

• Cross-sectional analysis:
• Individuals with high intake of

Vitamin C, A and E have higher lung
function (15 studies)

• Higher magnesium intake associated

with higher lung function and
reduced risk of asthma (4 studies)

Limitations of cross-sectional

studies:

• Numerous unrecognized confounding factors

may affect the results

• It is unclear whether obtained associations

represent causal effect on lung function

• Therefore longitudinal ( and intervention) studies

are necessary

• Phase I , 2512 subjects (aged 45-59 years) UK ,1979,

interventions: FEV1, demographic data, smoking, dietary data
by semi-quantitative food frequency questionnaire. Cross-
sectional analysis

•

↓

longitudinal analysis

• Phase II 1983 year 1827 subjects (in both phases)
• Cross-sectional results: Subjects consuming 5 or more apples

per week had FEV1 by 138 ml higher than non-consumers (for
vitamin E difference – 39 ml)

• Longitudinal analysis: Average apple consumption was

significantly associated with change in lung function over 4
year period. Consumers of ≥ 5 apples per week had lower FEV1
decline by 74.1 ml.

• Adjustment for confounders: by 47.7 ml and lost significance

(p= 0.098).

• No association with vitamins.
• Possible effect of flavonoids (Quercetin)

Butland BK et al. Thorax 2000,55,102-108

• Phase I , 2633 adults (aged 18-70 years) UK 1991

year, interventions: FEV1, respiratory symptoms,

demographic data, smoking, dietary intake semi-

quantitative food frequency questionnaire (Vit. C,A,E,

magnesium,) skin reactivity to common inhaled

allergens. Cross-sectional analysis

•

↓

(nine years) longitudinal analysis

• Phase II 2000 year, 1346 subjects, cross-sectional
• Cross-sectional results (1991 and 2000) higher intake

of Vit C and magnesium was associated with higher

FEV1 values.

• Longitudinal analysis: decline in FEV1 between 1991

and 2000 was lower in persons with higher vit. C

intake by 50.8 ml per 100 g vit C per day (no relation

with vit. A and E and magnesium)

• Diet rich in the foods that provide vit. C is likely to be

beneficial for lungs

• Mc Keever TM et al.. Am.J.Respir.Crit Care Med. 2002,165,1299-1303

Lung cancer and fruits/vegetables

consumption

• Epidemiological studies (prospective and

retrospective) : high consumption of fruits or
vegetables (or both) reduces the risk of lung cancer
by ~ 25%

• Flavonoids ? , β-carotene ?
• Prospective study , 29 133 heavy smoking men, aged

50-69 years (Finland); intervention – 50 mg α-
tocopherol or 20 mg β-carotene , both, or placebo

• After 5-8 years of supplementation with carotene

alone or with combination with tocopherol :

significant 18% increase in lung cancer and 8%

increase in overall mortality

Lung cancer and fruits/vegetables

consumption

• Another prospective study with β-carotene: 18 341

heavy smokers or asbestos workers (USA) ,
randomization : 30 mg β-carotene daily and 25 000 IU
retinyl palmitate (Vit A) for 4 years

• Results: supplementation group : 28% more lung

cancer and 17% more deaths than group
without supplementation

• Explanation: high doses of β-carotene can down

regulate tumor suppressor genes or up-regulate cell
proliferation genes especially in cigarette smokers

• Other studies: Dietary intake of β-carotene

reduces risk of lung cancer !!! – Other factors can
protect : fibers ?, polyphenols ?, ….?

•

Lung cancer and fruits/vegetables

consumption

• Aberrant promoter methylation of tumor suppressor genes

[(e.g. p16 (CDKN2A), O6-methylguanine-DNA

methyltransferase (MGMT), ras effector homologue 1] is

higher in patients with lung cancer – screening approach

(sputum samples) for early cancer detection (?)

• 1101 cigarette smokers , food questionnaire, sputum

analysis for promoter gene methylation

• Results – consumption of leafy green vegetables (and

usage of multivitamin) protected against methylation

•

Stidley CA et al. Cancer Res 2010,70,568

Apples consumption and lung cancer

risk

• Apples- significant source of flavonoids (phenolics)

in people’s diet in Europe and USA

• Nurses’ Health Study and Health Professionals’

Follow-up Study (72 000 women and 47 000 men) –
fruit and vegetable intake was associated with 21%
reduced risk in lung cancer in women (this was not
seen in men !)

• Apples as a one of individual fruits associated with

decreased risk of lung cancer – one apple per day
was protective

• Other 2 studies also revealed protective effect of

flavonoids intake against lung cancer

Apples and lung health

• Apples contain: quercetin-3-

galactoside, quercetin-3-
glucoside,quercetin-3-rhamnoside,
catechin, epicatechin, procyanidin,
cyanidin-3-galactoside, coumaric
acid, chlorogenic acid, gallic acid,
and phloridzin

Further longitudinal, with

randomized intervention studies are
necessary to establish the impact of
fruit/vegetables intake on the
incidence and evolution of lung
diseases