A Broken Generation (or two)

Healthy Aging

A C15:0-deficient world: How we got here

Well, it’s just over one week until Simon & Schuster’s March 25th release of The Longevity Nutrient. This book tracks our 20-year scientific journey – starting with an unexpected discovery of C15:0’s health benefits while helping dolphins – which has culminated in a movement to improve global health. And dare we say, humanity?

In this series of Science Says!, we provide a behind-the-scenes science peek relevant to each of the book’s chapters – from surprising dolphin discoveries to longevity molecule must-haves, from how essential fatty acids are discovered to the many ways C15:0 works, from how a newly found nutritional deficiency accelerates aging to how fixing and optimizing our C15:0 levels can slow aging to help us live healthier, longer.

In this issue, we talk about how we got here. Here, being a world in which as many as 1 in 3 of us has nutritional C15:0 deficiency.

It started with a scary rise of heart attacks in the 1950s.

Since the 1950s, as described by the American Heart Association, heart disease has been the #1 cause of death in the U.S. – and just about everywhere else. Page et al. showed that increased LDL cholesterol was associated with a higher risk of heart disease. Additionally, dietary saturated fats were linked to higher LDL cholesterol.

Which resulted in 1977 dietary guidelines for all Americans to decrease dietary saturated fats.

A Congressional committee of eight Senators developed nutritional guidelines to address the rise in heart disease among older men, as well as the rise in obesity and type 2 diabetes in the general population. At the time, obesity had risen to 14% of the U.S. population, and type 2 diabetes was affecting more than 3.7 million Americans.

They released the Dietary Guidelines for the United States, which focused on lowering cholesterol by lowering Americans’ dietary intake of saturated fats, specifically from whole fat cow’s milk and butter. Which you probably know well.

What most people don’t know is that there was massive push back from medical and scientific communities, who authored an 869-page report titled Dietary Guidelines for the United States – Supplemental Views. As a result, a second edition of Dietary Guidelines for the United States was released in 1977, in which three of the eight original Senators on the committee openly dissented the release of the recommendations to lower dietary milkfat. Leaving five Senators, who against the advice of leading health authorities, set the stage for a 50-year experiment of drastically decreasing our intake of whole milkfat.

While we have been successfully avoiding milkfat, our health has gotten worse.

These dietary recommendations worked, perhaps too well. Today, people have not only stopped drinking whole fat cow’s milk – according to the USDA (Stewart et al.), there has been a 50% decline in drinking any cow’s milk. Even more extreme, Fomon et al. showed that the percentage of 1-year olds who have received any cow’s milk has dramatically dropped from nearly 100% in 1971 to 10% by 1998. Since our primary source of C15:0 is milkfat, this explains why our C15:0 levels have been declining, too.

Meanwhile, since 1977:

• Heart disease has been on the rise, specifically among people 18 to 44 years old.
• Obesity has risen from 14% to 43% of Americans.
• Type 2 diabetes has increased from 3.7 to 24.4 million Americans.
• A new nonalcoholic fatty liver disease (now called MASLD) has emerged, now affecting 1 in 3 people globally, including 1 in 10 children.

So, lowering our intake of cow’s milk has certainly not driven down the health issues of concern during the 1970s. Instead, these health issues have worsened.

Another clue from dolphins.

Coincidentally, the fatty, high C15:0-containing fish (called eulachon) that Navy dolphins had been enjoying for decades disappeared during the late 1990s. This resulted in a change in their diets to a non-C15:0-containing fish species (called capelin).

Similar to us humans, some older dolphins started developing mild fatty liver disease, insulin resistance, elevated cholesterol, and liver iron overload (see last week’s Science Says! on iron overload and ferroptosis).

Over a series of studies described in our 2024 Metabolites paper, we were able to show that the primary driver of this accelerated aging was low C15:0. Better yet, when we restored dolphins’ C15:0 levels to greater than 5 µg/ml, they returned to a healthy aging state.

A chance to fix what’s broken.

Today, numerous studies across many species – from worms, to mice, to dolphins, to placebo-controlled clinical trials in humans from Robinson et al. –  have since shown that restoring C15:0 levels to greater than 5 µg/ml helps to reverse nutritional C15:0 deficiencies and its accompanying condition, Cellular Fragility Syndrome. In turn, this helps to stop ferroptosis, slow aging, and keep us healthy, longer.

We go deep into the fascinating story behind how milkfat and C15:0 fell out of our lives during the 1970s (and even more so in the 1990s) in The Longevity Nutrient. More importantly, we cover the mounting science showing how restoring C15:0 can help fix the health of our most recent generations.

We are working alongside leaders in nutrition, longevity, and medicine to help get C15:0 back into people’s lives. This includes revisiting dietary guidelines, helping to adapt agricultural practices that can replenish C15:0 content in milkfat, recommending reported C15:0 content in foods, and increasing access to C15:0 food fortification and supplementation.

Yes, the movement is on.