What to Eat When the Air Is Polluted: Diet, Diwali Smog and the Evidence

Some of that advice has a thread of evidence behind it, and much of it has none. This page separates the two, explains what pollution does inside the body, and sets out what is worth eating, what is worth skipping, and what matters far more than anything on a plate.

Can food protect you from air pollution?

No food stops polluted air reaching your lungs, and none reverses the damage of breathing it. What diet may do is change how well the body copes with the oxidative stress and inflammation that pollution sets off. The human evidence is modest: small trials of particular nutrients under controlled exposure, and large observational studies in which people with healthier diets suffered less pollution-related heart disease. None of it justifies a run on a severe AQI morning because you ate amla at breakfast. Treat diet as a supporting layer beneath the measures that work better, which means cutting exposure first and eating well alongside.

What does polluted air do inside the body?

Fine particles, called PM2.5 because they measure 2.5 micrometres or less, travel deep into the lungs, and the smallest cross into the bloodstream. Their surfaces carry metals and organic chemicals that generate reactive oxygen species, unstable molecules that damage cell membranes, proteins and DNA. The thin fluid lining the airways holds antioxidants, including vitamin C, glutathione, uric acid and vitamin E, which absorb the first wave. When exposure outruns those defences, inflammation follows, first in the airways and then through the body, where it stiffens blood vessels and makes blood more likely to clot. Gases such as ozone and nitrogen dioxide add their own irritation to the airways.

How bad is the air in India, and who is most at risk?

Bad enough to rank among the largest health risks in the country. The Global Burden of Disease analysis for Indian states attributed 1.67 million deaths in 2019 to air pollution, 17.8 per cent of all deaths that year. The death rate from household smoke from solid cooking fuels fell by about 64 per cent between 1990 and 2019, while the rate linked to outdoor particulate pollution more than doubled. Risk is highest for children, whose lungs are still growing, older adults, pregnant women, and people with asthma, chronic obstructive pulmonary disease or heart disease. Traffic police, street vendors and other outdoor workers take the heaviest doses, usually with the least protection.

Which foods help the body cope when the AQI is high?

The strongest signal is for an overall eating pattern rather than a single food. In the NIH-AARP study of 548,845 American adults followed for 17 years, long-term exposure to fine particles and nitrogen dioxide raised the risk of dying from cardiovascular disease, but that added risk was smaller among people whose diets most resembled the Mediterranean pattern. An everyday Indian equivalent is easy to picture: plenty of vegetables and greens, seasonal fruit, dal and chana, whole grains such as millets and atta, a handful of nuts, mustard or groundnut oil in moderation, and fish where it is part of the diet. The same pattern serves most other health goals too.

Does vitamin C help against pollution?

Probably a little, for people whose intake was low, and food is the sensible route. Vitamin C is one of the main antioxidants in the fluid lining the lungs, and people exposed to smoke use it faster. In a trial of 158 children with asthma in Mexico City, those given a daily vitamin C and vitamin E supplement did not show the ozone-linked falls in lung function seen in the placebo group, where the effect was clearest in moderate and severe asthma. That was a supplement trial in one specific group, not proof for healthy adults. Amla, guava, oranges, sweet lime, capsicum and raw cabbage are generous sources, and vitamin C, food or tablets compares the options.

Should you take antioxidant supplements for smog?

Not routinely, and some people should actively avoid them. The clearest warning is the CARET trial, in which 18,314 smokers, former smokers and asbestos-exposed workers took beta-carotene and vitamin A pills or a placebo. Lung cancer was 28 per cent more common in the supplement group, and the trial was stopped early. A smoker's lungs are not a commuter's lungs, but the lesson travels: nutrients that look protective in food do not reliably behave the same way as concentrated pills, and a larger dose is not a safer one. Carrots, papaya, pumpkin and spinach supply carotenoids in amounts no trial has tied to harm.

Do cabbage, cauliflower and other cruciferous vegetables help?

The evidence is intriguing, though it stops short of proving a health benefit. Cruciferous vegetables contain glucoraphanin, which the body turns into sulforaphane, a compound that switches on enzymes used to process and excrete foreign chemicals. In a 12-week trial of 291 adults in a heavily polluted part of Qidong in China, a daily broccoli sprout drink raised excretion of benzene breakdown products by 61 per cent and of acrolein products by 23 per cent, both airborne pollutants. The drink was concentrated, and the trial measured excretion rather than illness. Cabbage, cauliflower, mustard greens, radish with its leaves and kohlrabi are the familiar Indian sources, and light cooking preserves more of the active enzyme.

Is fish oil useful on smoggy days?

The evidence is small and early. In a controlled study of 29 healthy middle-aged adults, four weeks of fish oil capsules, compared with olive oil capsules, appeared to soften the changes in heart rate variability and blood fats that followed two hours of breathing concentrated fine particles. That hints that omega-3 fats may blunt the heart's response to pollution, but it was one small trial at a dose researchers chose, not advice for the public. Eating fish such as rohu, katla, mackerel or sardines once or twice a week, or walnuts and flaxseed for vegetarians, is sensible for many reasons. Food sources and capsules are compared in omega-3 foods and capsules.

Can B vitamins undo pollution damage?

Not on current evidence, whatever the headlines suggest. A pilot crossover trial exposed 10 healthy adults to fine particles for two hours and found that high-dose B vitamin supplements prevented the changes in DNA methylation, a chemical tagging of genes, and the loss of mitochondrial DNA that the exposure otherwise caused. The result is biologically interesting and far too small to act on, so there is no case for high-dose B vitamin pills because of smog. Folate from dal, rajma and leafy greens, and vitamin B12 from milk, curd, eggs and fish, or a prescribed supplement for vegetarians who need one, keep ordinary supplies normal, which is all the evidence supports.

Does jaggery clean the lungs?

No. The belief is old and widespread, and workers in some dusty trades were traditionally handed gur to clear the chest, but no study has shown that jaggery removes particles from the lungs or protects them. The lungs clear what they inhale through mucus, the beating of tiny hairs called cilia, and scavenger cells that engulf debris, and none of these responds to sugar. Jaggery is mostly sucrose with traces of iron and other minerals, so eating more of it adds sugar with no benefit to the lungs, a real cost for anyone with diabetes. How it compares with white sugar and honey is set out in jaggery, honey or sugar.

Do haldi milk, tulsi and ginger help with pollution?

They may soothe an irritated throat, but none has been shown to protect people against pollution. Curcumin, the active compound in turmeric, is anti-inflammatory in laboratory work, yet it is poorly absorbed from food and human trials against air pollution are lacking. Tulsi and ginger teas are warm, pleasant and hydrating, and warm drinks do ease the scratchy throat and dry cough so many people notice on smoggy days. That comfort is real and worth having. What these drinks cannot do is replace a mask, an inhaler or medical care, and concentrated turmeric capsules carry their own rare risk of liver injury, so kitchen amounts are the sensible limit.

A day of eating when the air is bad

No special menu is required, but it helps to see the principles on a plate. Breakfast might be vegetable poha or a besan chilla with a guava or some amla on the side. Lunch can be dal, a cabbage or cauliflower sabzi, a mustard-greens dish such as sarson ka saag in North Indian homes, roti or rice, and a bowl of curd. An afternoon snack of a few walnuts or roasted chana with an orange brings vitamin C and useful fats together. Dinner can be a fish curry or rajma with vegetables. Warm water, tea or soup through the day keeps the throat comfortable.

What matters more than anything on your plate?

Reducing how much polluted air you breathe. Check the AQI each morning: on India's national scale, readings above 200 are poor, above 300 very poor and above 400 severe. On poor days and worse, move exercise indoors, and keep children and older relatives away from long outdoor exertion. A well-fitted N95 mask filters most fine particles, while cloth and loose surgical masks do far less. An air purifier with a true HEPA filter can clean the air of a closed bedroom. Skip firecrackers altogether, and ventilate the kitchen, since smoke from tadka, incense and mosquito coils adds to the particles you breathe indoors.

When should breathing trouble send you to a doctor?

Seek care promptly for breathlessness at rest, wheezing that does not settle with a prescribed reliever inhaler, chest pain or tightness, or a racing heartbeat, and get emergency help at once if lips or fingertips turn bluish. People with asthma or COPD should follow the action plan their doctor gave them, and ask before smog season whether their medicines need adjusting, rather than trying to eat their way through it. A cough lasting more than three weeks, or coughing up blood, needs examination whatever the air is like. Pregnant women, and parents of young children with any breathing difficulty, should not wait to see whether it passes.

Where food chemistry meets public health

Answering smog questions honestly takes two kinds of knowledge: how phytochemicals such as sulforaphane, carotenoids and flavonoids actually behave in the body, and how exposure, risk and evidence play out across a population. NNWA's Antioxidants and Phytochemicals course builds the first at intermediate level over three to four weeks, the grounding that lets a nutrition professional explain why broccoli sprouts are interesting and why beta-carotene pills became a warning. The fee is Rs 7,999 against a listed Rs 11,999, or Rs 667 a month on EMI. Classes are taught live by faculty such as Dr Induja Dixit, who holds a PhD in Nutrition and has 21 years of experience, and the NNWA team page lists every teacher's credentials.

Eating through smog season: the short version

Food cannot filter the air, so cut your exposure first with a fitted mask, a purifier, indoor exercise on bad days and no firecrackers. Then eat the pattern with the best support behind it: vegetables and greens, cruciferous vegetables such as cabbage and cauliflower, vitamin C fruit like amla and guava, dal, whole grains, nuts, and fish if you eat it. Skip high-dose antioxidant pills, beta-carotene above all if you smoke, and do not count on jaggery, haldi or tulsi for protection. Anyone with asthma, heart disease or new breathing symptoms needs a doctor's plan rather than a diet. Recovering from the rest of the festival is covered in detox after Diwali.

Research this article draws on

Pandey et al. (2021). Health and economic impact of air pollution in the states of India: the Global Burden of Disease Study 201930298-9). The Lancet Planetary Health. Air pollution was linked to 1.67 million deaths in India in 2019, 17.8 per cent of the total. Household air pollution death rates fell sharply since 1990 while ambient particulate rates more than doubled.

Lim et al. (2019). Mediterranean Diet and the Association Between Air Pollution and Cardiovascular Disease Mortality Risk. Circulation. In 548,845 adults followed for 17 years, fine particles and nitrogen dioxide raised cardiovascular mortality, but less so among those with higher Mediterranean diet scores. Observational, so diet may mark other protective factors.

Romieu et al. (2002). Antioxidant Supplementation and Lung Functions among Children with Asthma Exposed to High Levels of Air Pollutants. American Journal of Respiratory and Critical Care Medicine. Among 158 Mexico City children with asthma, daily vitamin C and E supplements appeared to blunt ozone-related declines in lung function, especially in moderate to severe asthma. The finding is specific to that group.

Omenn et al. (1996). Effects of a Combination of Beta Carotene and Vitamin A on Lung Cancer and Cardiovascular Disease. New England Journal of Medicine. In 18,314 smokers and asbestos-exposed workers, beta-carotene with vitamin A raised lung cancer risk by 28 per cent and the trial was halted early, a warning against high-dose antioxidant pills.

Egner et al. (2014). Rapid and Sustainable Detoxication of Airborne Pollutants by Broccoli Sprout Beverage: Results of a Randomized Clinical Trial in China. Cancer Prevention Research. In 291 adults in polluted Qidong, a daily broccoli sprout drink for 12 weeks increased excretion of benzene metabolites by 61 per cent and acrolein by 23 per cent. Illness outcomes were not measured.

Tong et al. (2012). Omega-3 Fatty Acid Supplementation Appears to Attenuate Particulate Air Pollution to Induced Cardiac Effects and Lipid Changes in Healthy Middle-Aged Adults. Environmental Health Perspectives. In 29 healthy middle-aged adults, four weeks of fish oil rather than olive oil appeared to lessen heart rate variability and blood lipid changes after two hours of concentrated particle exposure. A small, preliminary study.

Zhong et al. (2017). B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial. Proceedings of the National Academy of Sciences. In a pilot crossover trial of 10 healthy adults, high-dose B vitamin supplements prevented DNA methylation and mitochondrial DNA changes caused by two hours of fine particle exposure. Too small to guide practice.