Slowing the aging process: How the Mediterranean diet preserves your chromosomal telomeres

| December 10, 2014
This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation.

The Mediterranean diet has been all the rage over in recent weeks because of a flurry of reports about new research suggesting that adherence to the diet slows the aging process.

The diet is not a fad and is really not anything new. Just think about Greek or Italian food and that’s the general idea of the Mediterranean diet. Whole grains, vegetables, fruits, nuts and olive oil are emphasized. Moderate fish consumption, some poultry, and very small amounts of lean beef are allowed as protein sources, as are small amounts of alcohol, such as a glass of wine with dinner, but fatty meats are avoided and sugars kept to a minimum.

Because the Mediterranean diet keeps saturated fats at a low and replaces them with monounsaturated fat (as in olive oil) and omega-3 polyunsaturated fats (as in fish), it is known to decrease risk for heart disease and strokes. Part of the reason is thought to involve special particles that carry cholesterol in the blood. Eating more monounsaturated fat and less saturated fat raises the levels of good blood cholesterol, known as HDL, while lowering the level of bad cholesterol, known as LDL. This helps keep arteries in the heart and brain from narrowing. Mild alcohol consumption also may help keep good cholesterol at a high, while low levels of sugar help to protect against diabetes.

But cholesterol and sugar in the blood do not completely explain the risk lowering effect of the diet against heart disease, strokes, and diabetes. Nor do they explain the fact that Mediterranean diet also reduces the risk of certain cancers. Thus, for many years, scientists have suspected that changes in dietary fats, sugars and other foods must do something at the level of cells and DNA, and that’s why the new research is so exciting. But excitement suggest that we should proceed with caution, since anything powerful to affect DNA in a good way also has the ability to do harm.

Some slack for your chromosomes

Most body cells do not live as long as the individual who carries them, but instead divide to produce daughter cells. When cells divide, chromosomes in the nucleus must replicate their DNA. The DNA of each chromosome is a long strand containing thousands of genes. Each time the chromosome replicates, the strand gets cut a little shorter on each end. Over many years, as old cells divide to make new cells, the DNA of each chromosome gets shorter at the ends of each chromosome. Known as telomeres, the ends of the DNA strand of each chromosome do not contain any genes, but are needed as a kind of slack, so they’re expendable as long as they don’t get too short.

Think of telomeres like the ends of shoelaces. You can keep snipping the ends and the laces work perfectly fine, but as you snip them too short they don’t work so well anymore. In the case of chromosomes, when the telomeres get too short, genes near the ends of the strand can get cut out the next time the chromosome replicates, and also chromosomes can start fusing together. These effects–the gene loss and chromosome fusing–are associated with aging, cancer and various medical conditions. In other words, long telomeres are a sign of youthfulness and good general health, while telomere shortening means that things are starting to go wrong.

Aging and disease

Although telomeres of chromosomes get shorter and shorter as cells reproduce throughout a person’s lifetime, science has revealed factors other than the passage of time that can affect telomere length. One major factor is stress. Because it’s fairly easy to take blood samples from people, most human research involving telomeres looks at the telomeres of white blood cells (leukocytes). Over the years, a range of stress types, including radiation exposure, spaceflight and domestic physical abuse in children have been show to shorten telomeres in white blood cells. We’ve always had an idea that physical and mental stress accelerate aging, but now we know why and apparently the Mediterranean diet can work against that effect.

Double-edged sword

As with anything involving chromosomes and genes, putting a discovery into practical use requires caution. Probably, the Mediterranean diet merely slows telomere shortening modestly, rather than adding length to telomeres. However, the connection between short telomeres and aging and disease underlies some drug development research aimed at increasing telomere length.

This may sound logical, because long telomeres are good for overall health, but last summer researchers at the University of California at San Francisco and the Mayo Clinic found that people with certain genes associated with long telomeres are at increased risk for gliomas–malignant brain tumors. Now, gliomas are very rare compared with heart disease, strokes, and diabetes, and of course aging, which affects everyone. However, the San Francisco/Mayo results suggest that we probably don’t want to go overboard in terms of preventive therapies to make telomeres very long.

“Though longer telomeres might be good for you as a whole person, reducing many health risks and slowing aging, they might also cause some cells to live longer than they’re supposed to,” says Kyle M. Walsh, a neurosurgeon and one of the researchers of the study.

In other words, short telomeres have their uses too, namely the help cancer cells and other cells that we want to eliminate meet their demise before they develop into disease. So let’s be careful as we consider going beyond dietary control to stronger therapies. We do need slack on our shoelaces, but not so much that we might trip over them.

David Warmflash is an astrobiologist, physician and science writer. Follow @CosmicEvolution to read what he is saying on Twitter.

The GLP featured this article to reflect the diversity of news, opinion and analysis. The viewpoint is the author’s own. The GLP’s goal is to stimulate constructive discourse on challenging science issues.

Outbreak Daily Digest

podcasts GLP Podcasts More...
Biotech Facts & Fallacies
Talking Biotech
Genetics Unzipped

video Videos More...
stat hospitalai ink st x mod x

Meet STACI: STAT’s fascinating interactive guide to AI in healthcare

The Covid-19 pandemic underscores the importance of the technology in medicine: In the last few months, hospitals have used AI ...

bees and pollinators Bees & Pollinators More...
mag insects image superjumbo v

Disaster interrupted: Which farming system better preserves insect populations: Organic or conventional?

A three-year run of fragmentary Armageddon-like studies had primed the journalism pumps and settled the media framing about the future ...
dead bee desolate city

Are we facing an ‘Insect Apocalypse’ caused by ‘intensive, industrial’ farming and agricultural chemicals? The media say yes; Science says ‘no’

The media call it the “Insect Apocalypse”. In the past three years, the phrase has become an accepted truth of ...

infographics Infographics More...
breastfeeding bed x facebook x

Infographic: We know breastfeeding helps children. Now we know it helps mothers too

When a woman becomes pregnant, her risk of type 2 diabetes increases for the rest of her life, perhaps because ...

biotechnology worker x

Can GMOs rescue threatened plants and crops?

Some scientists and ecologists argue that humans are in the midst of an "extinction crisis" — the sixth wave of ...
food globe x

Are GMOs necessary to feed the world?

Experts estimate that agricultural production needs to roughly double in the coming decades. How can that be achieved? ...
eating gmo corn on the cob x

Are GMOs safe?

In 2015, 15 scientists and activists issued a statement, "No Scientific consensus on GMO safety," in the journal Environmental Sciences ...
glp profiles GLP Profiles More...
Screen Shot at PM

Charles Benbrook: Agricultural economist and consultant for the organic industry and anti-biotechnology advocacy groups

Independent scientists rip Benbrook's co-authored commentary in New England Journal calling for reassessment of dangers of all GMO crops and herbicides ...
Screen Shot at PM

ETC Group: ‘Extreme’ biotechnology critic campaigns against synthetic biology and other forms of ‘extreme genetic engineering’

The ETC Group is an international environmental non-governmental organization (NGO) based in Canada whose stated purpose is to monitor "the impact of emerging technologies and ...
report this ad report this ad report this ad


News on human & agricultural genetics and biotechnology delivered to your inbox.
Optional. Mail on special occasions.
Send this to a friend