Regularly eating foods containing omega-3 fatty acids has been shown to help protect against many different health conditions, such as cardiovascular diseases, type 2 diabetes, high blood pressure, arthritis, certain cancers, depression, and bipolar disorders, and chronic health problems of the skin, nervous system and immune and inflammatory systems.
Now researchers from the University of California at San Francisco (UCSF), including Australian Nobel prize-winner Dr. Elizabeth Blackburn, have discovered that omega-3s help slow down aging by protecting chromosomes from damage.
Chromosome Damage Leads to Ill-health
What the UCSF researchers found was that regularly eating foods containing omega-3s protected the chromosomes in people’s cells from damage as the cells aged.
The ends of chromosomes are protected by structures called telomeres, rather like the fasteners on the end of shoelaces to stop the laces unravelling. Cells in the human body divide to reproduce and die many times a month, and during cell division the telomeres can become shortened.
When the telomeres are too short to protect the ends of the chromosomes, the chromosomes are damaged, and this damage can lead to disease. In men, the loss or extreme shortness of telomeres in white blood cells has been linked with increased risk of coronary heart disease.
Regular Omega-3 Consumption Protects Chromosomes
Dr. Blackburn and her colleagues measured the length of telomeres in the white blood cells of 608 participants, outpatients from California hospitals who had stable coronary artery disease.
They measured the participants’ telomeres twice – once at the start of the study and again, five years later. At the same time, the blood levels of omega-3 fatty acids were measured in all participants.
The researchers discovered a positive link between omega-3 levels in the blood and the length of the telomeres on the chromosomes inside the white blood cells. Higher blood levels of omega-3s corresponded to longer telomeres, and lower blood levels meant a risk of telomeres becoming too short.
They reported that fairly small increases in the blood levels of omega-3s were associated with between 30-35 per cent reduced risk of shortened telomeres - a significant risk reduction.
Telomere Length Indicates Biological Age
The researchers said they designed the study because, although increased dietary intake of marine omega-3 fatty acids is associated with prolonged survival in patients with coronary heart disease, it was unclear how this actually worked.
However, as Dr. Blackburn’s work on telomeres had shown their valuable role in protecting chromosomes, and telomere length as a marker of biological age, they hypothesised that levels of omega-3 in the blood were associated with changes in telomere length.
Following the five-year study, the UCSF researchers concluded that “there was an inverse relationship between baseline blood levels of marine omega-3 fatty acids and the rate of telomere shortening”.
The study was published in the January 20, 2010 edition of the Journal of the American Medical Association (JAMA)
Fatty Fish Good Sources of Omega-3s
The specific omega-3 fatty acids measured in the participants’ blood were EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA and DHA are the main omega-3s found in fatty fish like salmon and halibut.
While Dr. Blackburn and colleagues did not mention a recommended intake of omega-3 fatty acids, other research has shown that eating a 250 gram (eight ounce) serving twice a week of omega-3-rich food over several months can more than double the amount of EPA and almost double the amount of DHA in the blood.
Fatty fish such as salmon, halibut, herrings and sardines are good marine sources of omega-3s. Vegetarian sources include flaxseeds, walnuts, soybeans and tofu.
You might also be interested to read Cardio-protective Benefits of Weekly Fatty Fish, Pan Fry Fish to Maximise Omega-3 Fatty Acid Benefits, and Omega-3 Lowers Risk of Alzheimers.
Sue Cartledge - I'm a science, health, nutrition and lifestyle journalist, fascinated by the way the physical world operates in all its forms, and how ...
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