Treating Asthma with Fruits and Vegetables

Treating Asthma with Fruits and Vegetables

September 11, 2019 27 By Ewald Bahringer


“Treating Asthma With Fruits and Vegetables” In the international study of asthma and
allergies in childhood of over a million kids, a consistent inverse relationship, meaning
a protective relationship, was seen, between prevalence rates of asthma, allergies, and eczema, and the intake of plants, starch, grains, and vegetables. If these findings could be generalized, and if the average daily consumption
of these foods increased, researchers speculated over a decade ago an important decrease in
symptoms prevalence may be achieved. No need to speculate any more, though;
plants were finally put to the test. Researchers had proposed that by eating
less and less fruits and vegetables, this had increased the susceptibility
of the population as a whole to potentially harmful inhaled substances by reducing the antioxidant defenses within our lungs. That makes sense. The thin lining
of fluid that forms the interface between our lung lining and the external environment is our first line of defense against oxidative damage, which plays an important role in asthma, contributing to airway constriction,
contraction, mucous, hypersensitivity. Antioxidants protect against oxidative stress, though, and so our lung lining contains a range
of antioxidants our body makes itself, as well as those obtained from our diet,
particularly from fruits and vegetables. In fact we can even quantify the level
of oxidative stress in people by measuring the level of oxidation
products in their exhaled breath, which drops as they start eating
more fruits and vegetables, then drops further when they combine
more plants with less animal foods. So do those with asthma really have lower levels
of antioxidants than people without asthma? Compared to healthy controls, subjects with asthma had lower whole blood levels of total carotenoids, and each of the individual plant
phytonutrients they measured, cryptoxanthin, lycopene, lutein,
alpha-carotene and beta-carotene, compared to healthy controls.
So the accumulating evidence does suggest that diet has an influence on modulating the response
of the lung to inhaled allergens and irritants. But wait second. It’s possible that the reduced
carotenoid levels in asthma are a result of increased utilization
in the presence of excess free radicals. So it’s like a chicken-or-the-egg phenomenon. Or in cholesterol-free vernacular,
which came first: the pea or the pod? We know antioxidant-rich diets have been
associated with reduced asthma prevalence. However, direct evidence that altering intake of antioxidant-rich foods actually
affects asthma was lacking, until now. There’s two ways to test the effects
of fruits and vegetables on asthma. Add fruits and vegetables to people’s
diets and see if their asthma improves, or, like they did here, take asthmatics and remove fruits and vegetables from
their diets and see if they get worse. This was the first research group to see if altering the intake of antioxidant-rich
foods directly affects asthma outcomes. Placing subjects with asthma on a low
antioxidant diet for just a matter of days led to a significant worsening of lung
function and asthma control. “This finding is highly significant
for subjects with asthma, as it indicates that omitting antioxidant-rich foods
from the diet, for even a short time frame, will have a detrimental effect on asthma symptoms.” Interestingly, ironically, the low
antioxidant diet consumed by the subjects, where they were restricted to one serving of fruit and only up to two servings of vegetables
per day, is typical of Western diets. In other words, the low antioxidant diet
they used to worsen people’s asthma, to cripple their lung function, was just
like the standard American diet. As about half the population usually consumes a diet with an intake of fruit and vegetables
equivalent to the study diet or less, it appears likely that this dietary pattern, which
must be considered suboptimal for lung health, may be having a significant impact on asthma management, indicating the potential for typical Western dietary patterns to contribute to a worsening
of lung function and asthma control. Within just days, cutting down fruit and
vegetable intake can impair lung function, but does adding fruits and vegetables
actually help with asthma? That was the second phase of the study. Asthmatics on the standard American diet
in this study had about a 40% chance of relapsing into an asthma
exacerbation within three months. But put them on seven servings of fruits
and vegetables instead of three and you can cut their exacerbation
rate in half, down to 20%. Just with a few fruits and vegetables.