The nutrition world confuses many people because of all of the misinformation, conflicting information, and constantly changing information. One of the most controversial topics in nutrition is saturated fat. For years, saturated fat was demonized as the cause of high cholesterol and heart disease. In recent years, there has been a movement to dispel that argument.
So, which side is right? What is the truth about saturated fat? The purpose of today’s article is to shed some light on saturated fat with respect to cholesterol and testosterone. First, let’s understand what saturated fat actually is. Saturated fat is called “saturated” because it is fat that is full (“or saturated”) with hydrogens while monounsaturated and polyunsaturated fats have “open spaces” that aren’t filled by hydrogens.
If you look hard at the research, it is clear that consuming saturated fat is not actually detrimental to your health, but there is a dose-response relationship. Consuming too much saturated fat can be a bad thing. Increased saturated fat intake has been consistently shown to increase LDL cholesterol in certain people, but not all. In fact, the latest studies are showing that higher LDL is protective for seniors because cholesterol plays an important role in our immune systems.
As some of you may know, there are different types of LDL cholesterols and it appears that most of the increase happens with the larger, fluffy LDL, which is not dangerous. Nonetheless, for some individuals, it may impact your smaller, stickly LDL, which can be a problem. It really depends on your genetic sensitivity to saturated fat.
Saturated fat also increases HDL, and in fact, saturated fat has been shown to be a key component in maintaining elevated HDL levels, which is good for our health. The scientific evidence for this is quite extensive. Higher saturated fat intake equates to higher HDL cholesterol.
Additionally, studies show that eating more saturated fat will increase testosterone levels. Good news for guys who want to build muscle and/or remain healthy into old age. In fact, male vegetarians have been shown to have lower levels of plasma Testosterone compared to their meat eating counterparts(4).
Vegetarians consistently consume lower levels of fat (total and saturated fat) compared to omnivores. Dorgan et al(5) randomly assigned 45 men to either a high fat/low fiber or a low fat/high fiber diet. The subjects followed each diet for 10 weeks. The high fat/low fiber diet periods yielded 13% higher levels of total serum Testosterone compared to the low fat/high fiber diet period.
Another interesting study that was published in the International Journal of Sports Medicine compared 8 strength athletes and 10 active non-athletes(6). Upon comparison of the subject’s dietary analyses and blood tests, it was found that only the strength-training athletes had significant correlations between fat intake and Testosterone levels. That means, if you lift weights and eat a diet higher in fat, then you’ll receive the benefit of elevated Testosterone levels compared to if you were just “active” and ate a higher fat diet.
- After reviewing the literature and various studies, one can’t say that increased consumption of saturated fat definitively increases Testosterone levels, but it may, especially in strength training individuals. It’s evident, though, that a higher total intake of dietary fat (30-35% of calories) does increase Testosterone levels compared to a low fat diet.
- Eating more saturated fat will increase your HDL levels and eating a lot may impact your LDL levels, but this may or may not be harmful.
Above all else, use common sense. Everybody should consume a mix of healthy fats on a daily basis. Break up your fat consumption by eating some saturated, some monounsaturated, some omega-3’s and some omega-6’s. In other words, don’t eat 5 sticks of butter per day and think that it will end with a good health outcome.
- Grundy SSM. Influence of stearic acid on cholesterol metabolism relative to other long-chain fatty acids. The American journal of clinical nutrition 1994;60:986-90S.
- Nicholls SJSJ, Lundman PP, Harmer JAJA, Cutri BB, Griffiths KAKA, Rye KAK-A, Barter PJPJ, Celermajer DSDS. Consumption of saturated fat impairs the anti-inflammatory properties of high-density lipoproteins and endothelial function. Journal of the American College of Cardiology 2006;48:715-20.
- Volek JS, Forsythe CE. The case for not restricting saturated fat on a low carbohydrate diet. Nutr Metab (Lond) 2005;2:21.
- Howie BBJ, Shultz TTD. Dietary and hormonal interrelationships among vegetarian Seventh-Day Adventists and nonvegetarian men. The American journal of clinical nutrition 1985;42:127-34.
- Dorgan JJF, Judd JJT, Longcope CC, Brown CC, Schatzkin AA, Clevidence BBA, Campbell WWS, Nair PPP, Franz CC, Kahle LL, Taylor PPR. Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study. The American journal of clinical nutrition 1996;64:850-5.
- Sallinen JJ, Pakarinen AA, Ahtiainen JJ, Kraemer WWJ, Volek JJS, Häkkinen KK. Relationship between diet and serum anabolic hormone responses to heavy-resistance exercise in men. International journal of sports medicine 2004;25:627-33.