Tracking “telomeres” reveals cell age

To better understand the omega-3-healthy-heart connection, researchers studied telomere (teal-oh-meer) length. Telomeres cap the ends of DNA, the cells’ “instruction manual.” They are similar to the plastic tips on shoelaces that prevent them from unraveling.

Telomere length is a good marker of cellular age, because as cells age, telomeres get shorter. The shorter a cell’s telomeres, the older that cell is. Eventually telomeres get too short to protect DNA from damage. The cell goes into a quiet phase or dies and is replaced by other cells when this happens.

More omega-3s, younger cells

For the study, white blood cell telomere length of 608 people with stable heart disease was measured at the beginning of the study (baseline) and five years later. Baseline omega-3 blood levels were measured as well.

People with the highest omega-3 fat levels at baseline had the slowest rate of telomere shortening over the five years. The telomeres from people with low levels of omega-3 fats became shorter much more quickly.

The study suggests that omega-3 fats may protect cells from aging. This may be one reason why omega-3s lead to better heart health, both before and after heart disease sets in.

Optimizing your omegas

We don’t know if higher omega-3s in the body and longer telomere length cause better heart health. They may be an effect of being healthier to begin with. Despite this, there are few downsides to getting more omega-3s. These healthy fats also may lower risk of cancer and other chronic diseases.

To optimize your omega-3 intake:

• Eat fatty fish: Try salmon, sardines, or cod a couple of times per week. Opt for wild-caught fish instead of farmed. Wild fish typically have higher levels of omega-3s and lower levels of environmental contaminants.
• Experiment with other sources: The study focused on fish fats, but it’s worthwhile to eat omega-3-rich plants too. Plant sources of omega-3s include walnuts, flaxseeds, olive and canola oil, and other nuts and seeds.
• Try enriched eggs: Omega-3-enriched eggs are an additional way to get more of these healthy fats into your diet. A 2006 study found that eating enriched eggs for breakfast may improve blood triglyceride levels and help people reach their omega-3 recommended intakes.
• If you eat beef, stick to grass-fed: Grass-fed beef has more omega-3 than beef from grain-fed cows. Grass-fed beef is pricier, but your health is worth the investment. Eating better quality beef less often is a better choice than eating a lot of low-quality meat.
• Consider an omega-3 supplement: Many people don’t eat fish regularly because they feel they can’t afford it, or because they don’t like it. For these folks, an omega-3 supplement may be the best option.
• Ask your doctor: Most people can take an omega-3 supplement safely, but some medications don’t mix well with these fats. So ask your healthcare provider for advice on how much omega-3 fat and what type of supplement is right for you.

(JAMA 2010;303:250–57; Food Research International;39:910–6)