I read an interesting article the other day about how a man doubled his testosterone levels by natural methods. His dietary change was to add more fat and more cholesterol – more eggs, bacon, etc. By doing this and some other things, his testosterone levels went from 383 to 778.
So just load up on the fat and cholesterol, and your testosterone will rise, right? Ah, if only things were so simple in nutrition-land.
For some counter-evidence, take a look at this study that compares testosterone levels among vegetarians, vegans, and meat-eaters. Vegans actually had slightly higher testosterone levels, though the difference wasn’t significant. Here’s a table from the study:
And here’s a table that shows the hormone levels:
So how did the vegetarians and vegans consuming low levels of dietary cholesterol not have lower testosterone? Well, it appears that dietary cholesterol isn’t a primary factor then.
Even with regards to dietary fat, the vegans consumed the lowest percentage of dietary fat but had the highest testosterone.
So if it’s not cholesterol and fat driving testosterone levels, then what is?
One clue to this is that testosterone levels in men have been dropping over the last few decades, as has been reported by the media. Certainly, men are not consuming radically lower amounts of fat and cholesterol (in total amounts) then a few decades ago. And from the vegan/vegetarian data, that doesn’t appear to be a key anyway. So what’s changed?
My hypothesis is that the fall in testosterone levels has been driven by higher blood glucose levels. I believe this is due to two major dietary changes over time:
- The increased consumption of foods with a higher glycemic index
- Increased snacking
Both of these habits will push blood sugar levels up and keep them up.
As to the cause-and-effect, here’s one study that shows that high-normal glucose levels in non-diabetic and pre-diabetic men is associated with decreased testosterone levels.
From this perspective, the diet that doubled the person’s testosterone makes more sense. For breakfast, he had eggs and bacon – this would have minimal effect on blood sugar. For lunch, he had a salad with some meat – again, minimal effect on blood sugar. Dinner was varied, though he said he watched the carbs. So overall, this type of diet would lower blood sugar levels, and consequently raise testosterone levels in my view.
