Add to that, doing the right thing

when it comes to preventing

and treating a chronic disease,

fighting a virus, or losing weight,

and suddenly our nutrition choices

can seem almost overwhelming.

Well, I’m here to help.

Welcome to the Nutrition Facts Podcast.

I’m your host, Dr. Michael Greger.

It’s time for the Nutrition Facts Grab Bag

where we look at the science on a whole variety of topics.

Today, we start with an unusual finding.

Did you know that burning incense

has been found to generate about four times

the particulate matter as burning cigarettes?

Here’s the story.

Frankincense and myrrh date back to thousands of years

before the three wise men.

The burning of witch's incense

may have actually had a hygienic functions,

like maybe repelling mosquitoes, and when put to the test,

incense fumes were able to kill off

some bacteria and mold in the air

but may also carry health risks.

Although the adverse health effects of second-hand tobacco smoke

are well recognized, the impact of burning incense in the home

has received less attention, but burning incense has been found

to generate like four times the particulate matter as cigarettes;

so, incense may be even worse!

No wonder home incense use may have significant adverse

health effects, particularly on the heart and lungs,

including childhood asthma.

No wonder, since the incense smoke particle size

peaks down in the danger range, so ultrafine they can float

down into the deepest parts of the lungs.

It’s not just the little ash particles in the smoke though,

there’s carbon monoxide, nitric oxides, sulfur dioxide,

carcinogenic polycyclic aromatic hydrocarbons,

and volatile organic compounds like benzene and formaldehyde.

The World Health Organization suggests limiting indoor formaldehyde

to about 80 parts per billion, but even with a window open

during the hour or so incense is burning,

formaldehyde levels exceed the safety limit.

What does this all mean in terms of disease outcomes?

Studies on rats show incense can do all sorts of terrible things,

but what about people?

A study of thousands of children followed over time found

that exposure to household incense burning was associated

with impaired lung function, reduced lung function growth,

and increased risks of respiratory diseases and symptoms.

Daily exposure is associated with impaired lung function

in adolescents too, though interestingly those who had

pets at home appeared to have better lung function.

Something I noted previously, how having a dog or cat in the house

during early life may protect against childhood asthma and allergy.

What about the heart?

Long-term exposure to incense burning in the home environment

was associated with an increased risk of cardiovascular mortality.

Approximately 8 percent of heart disease deaths and

12 percent of stroke deaths could potentially be attributed

to incense use, though they were looking at long-term exposure,

so like incense burning at home on a daily basis for more than 20 years.

What about cancer?

Temple workers exposed to incense day in and day out were found

to have evidence of significantly more DNA damage,

including DNA strand breaks.

Does this translate into greater cancer risk?

One unsolved mystery has been why non-smoking Asian women

have such high lung cancer rates.

Might it be incense?

Probably not, since the association between incense use

and lung cancer remains inconclusive,

though incense use does appear to be linked to cancers

of the upper respiratory tract, as well as brain tumors

among children whose mother were exposed to incense.

Three times the odds, even more than that of second-hand smoke.

In fact, even more than the consumption of bologna sandwiches.

Processed meat consumption only appears to at most

double brain tumor risk among children.

Even without tumors, a study of 15,000 infants found that

household incense burning was associated with a delay

in brain development milestones such as when they start to walk.

And then on the other side of the life cycle,

incense exposure among older adults was associated with reduced

cognitive performance and adverse structural changes in the brain.

The researchers conclude that this calls for safer practices,

such as avoiding burning incense indoors

or using safer incense alternatives.

So-called environmentally friendly types of incense have been

put to the test, and…

they were found to contain even higher concentrations

of several potentially carcinogenic polycyclic aromatic hydrocarbons.

Despite being a recognized health hazard,

burning incense remains in widespread use.

In the very least, we may want to avoid burning incense in the home

when susceptible individuals are present,

such as the very young, the very old, or

people with a family history of allergy or pre-existing

cardiovascular or respiratory disease.

One innovative suggestion is electronic incense,

like the e-cigarette of the incense world,

so you can get the fragrance

without the combustion by-products of smoke.

Most of the concern about e-cigarette-related adverse events

traditionally have revolved around the nicotine,

which wouldn’t be a problem with e-incense,

the concern that e-cigarette use would lead to real cigarette use.

But now that there have been thousands of cases of lung injury

associated with vaping, and we’re still actually not sure

what’s causing the issue,

it seems to me we should figure that out

before we push for the electronic incense equivalent.

One option in the meantime is scented candles,

which, under normal conditions of use,

do not appear to pose known health risks to the consumer.

Next up, we look at specific foods

that have shown in randomized controlled trials

to improve symptoms like hot flashes.

There is a great variety of symptoms

suffered by women undergoing menopause.

There are the so-called vasomotor symptoms,

like night sweats and hot flashes, difficulty sleeping

or full-on insomnia, vaginal dryness, and pain during sex,

as well as adverse effects on mood including full-blown depression.

Might exercise help?

Exercise can certainly help with physical and psychological quality

of life in general, but unfortunately there was no evidence

for the effects of exercise on menopause-specific symptoms.

You know researchers are getting desperate when they try

to see if giving people pig placenta will help.

Spoiler alert: it doesn’t.

Well, we know oxidative stress, which is a consequence of

excessive free oxygen radicals or impaired antioxidant defense,

is linked not only to diseases

such as diabetes, obesity, and cardiovascular disease,

but also menopausal symptoms like hot flashes.

Low free oxygen radical defense is associated with

more menopausal symptoms, just like having a diet with more

antioxidants is associated with fewer menopausal symptoms.

In fact, a high intake of fruits and vegetables may delay

the onset of menopause in the first place,

thought to be because the presence of antioxidants

in fruits and vegetables may counteract the adverse effects

of free radicals on the number of functional eggs you still have

in your ovaries, whereas a reason high meat consumption

has been related to degenerative diseases

may not just be the saturated fat and cholesterol,

but the pro-oxidation products generated during their production,

storage, digestion, and metabolism of meat.

Similarly, since a pro- inflammatory diet has also been

associated with higher menopause- specific somatic symptoms,

meaning like hot flashes and sleep issues,

that would mean moving towards a more plant-based diet

packed with anti-inflammatory components like fiber

and away from pro-inflammatory foods containing

saturated fat and cholesterol.

No wonder whole plant foods intake has been

associated with fewer menopausal symptoms.

In terms of specific foods, poultry and skim dairy products

may be particularly bad, whereas soy milk seemed to help.

So, women may derive benefit from lower consumption

of poultry and skimmed dairy and a greater consumption

of vegetables and soy milk.

You don’t really know, though... until you put it to the test.

And indeed, women randomized to drink soy milk reduced

their menopausal symptoms by 20 percent within 12 weeks.

No wonder that those eating strictly plant-based diets

report less bothersome menopausal symptoms.

Among women undergoing menopause,

vegans reported less bothersome symptoms,

and within the diet groups more vegetables,

and in the meat-eating group, less flesh food was associated

with less bothersome symptoms as well.

So, eating a plant-based diet may be helpful for women